Saturday, May 14, 2016

Diabetic Coma

What is a Coma?
In medicine, a coma (from the Greek κῶμα koma, meaning deep sleep) is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as comatose. According to the Glasgow Coma Scale though, a person with confusion is considered to be in the mildest coma.

Coma may result from a variety of conditions, including intoxication (such as illicit drug abuse, overdose or misuse of over the counter medications, prescribed medication, or controlled substances), metabolic abnormalities, central nervous system diseases, acute neurologic injuries such as strokes or herniations, hypoxia, hypothermia, hypoglycemia or traumatic injuries such as head trauma caused by falls or vehicle collisions. It may also be deliberately induced by pharmaceutical agents in order to preserve higher brain functions following brain trauma, or to save the patient from extreme pain during healing of injuries or diseases.

In order for a patient to maintain consciousness, two important neurological components must function impeccably. The first is the cerebral cortex which is the gray matter covering the outer layer of the brain, and the other is a structure located in the brainstem, called reticular activating system (RAS or ARAS). Injury to either or both of these components is sufficient to cause a patient to experience a coma.

The human cortex is a group of tight, dense, "gray matter" composed of the nucleus of the neurons whose axons then form the "white matter", and is responsible for the perception of the universe, relay of the sensory input (sensation) via the thalamic pathway, and most importantly directly or indirectly in charge of all the neurological functions, from simple reflexes to complex thinking.

Reticular activating system (RAS), on the other hand, is a more primitive structure in the brainstem that is tightly in connection with reticular formation (RF), a critical anatomical structure needed for maintenance of arousal and sleep-wake transitions. Reticular activating system (RAS) takes its name from the effect it has on the reticular formation, which is via its stimulation. It is therefore necessary to investigate the integrity of the bilateral cerebral cortices, as well as that of the reticular activating system (RAS) in a comatose patient.

Outcomes from a coma range from recovery to death. Comas can last from several days to several weeks. In more severe cases a coma may last for over 5 weeks, while some have lasted as long as several years. After this time, some patients gradually come out of the coma, some progress to a vegetative state, and others die. Some patients who have entered a vegetative state go on to regain a degree of awareness. Others remain in a vegetative state for years or even decades (the longest recorded period being 37 years).

The outcome for coma and vegetative state depends on the cause, location, severity and extent of neurological damage. A deeper coma alone does not necessarily mean a slimmer chance of recovery, because some people in deep coma recover well while others in a so-called milder coma sometimes fail to improve.

People may emerge from a coma with a combination of physical, intellectual and psychological difficulties that need special attention. Recovery usually occurs gradually—patients acquire more and more ability to respond. Some patients never progress beyond very basic responses, but many recover full awareness.

Regaining consciousness is not instant: in the first days, patients are only awake for a few minutes, and duration of time awake gradually increases. This is unlike the situation in many movies where people who awake from comas are instantly able to continue their normal lives. In reality, the coma patient awakes sometimes in a profound state of confusion, not knowing how they got there and sometimes suffering from dysarthria, the inability to articulate any speech, and with many other disabilities.

Predicted chances of recovery are variable owing to different techniques used to measure the extent of neurological damage. All the predictions are based on statistical rates with some level of chance for recovery present: a person with a low chance of recovery may still awaken. Time is the best general predictor of a chance of recovery: after 4 months of coma caused by brain damage, the chance of partial recovery is less than 15%, and the chance of full recovery is very low.

The most common cause of death for a person in a vegetative state is secondary infection such as pneumonia which can occur in patients who lie still for extended periods.

Occasionally people come out of coma after long periods of time. After 19 years in a minimally conscious state, Terry Wallis spontaneously began speaking and regained awareness of his surroundings. Similarly, Polish railroad worker Jan Grzebski woke up from a 19-year coma in 2007.

A brain-damaged man, trapped in a coma-like state for six years, was brought back to consciousness in 2003 by doctors who planted electrodes deep inside his brain. The method, called deep brain stimulation (DBS) successfully roused communication, complex movement and eating ability in the 38-year-old American man who suffered a traumatic brain injury. His injuries left him in a minimally conscious state (MCS), a condition akin to a coma but characterized by occasional, but brief, evidence of environmental and self-awareness that coma patients lack.

Coma lasting seconds to minutes results in post-traumatic amnesia (PTA) that lasts hours to days; recovery plateau occurs over days to weeks. Coma that lasts hours to days results in PTA lasting days to weeks; recovery plateau occurs over months. Coma lasting weeks results in PTA that lasts months; recovery plateau occurs over months to years.

What is a Diabetic Coma?
A diabetic coma is a reversible form of coma found in people with diabetes mellitus. It is a medical emergency.

There are 3 major types of diabetic coma:
  1. Severe diabetic hypoglycemia
  2. Diabetic ketoacidosis advanced enough to result in unconsciousness from a combination of severe hyperglycemia, dehydration and shock, and exhaustion
  3. Hyperosmolar nonketotic coma in which extreme hyperglycemia and dehydration alone are sufficient to cause unconsciousness.
In most medical contexts, the term diabetic coma refers to the diagnostical dilemma posed when a physician is confronted with an unconscious patient about whom nothing is known except that he has diabetes. An example might be a physician working in an emergency department who receives an unconscious patient wearing a medical identification tag saying DIABETIC. Paramedics may be called to rescue an unconscious person by friends who identify him as diabetic. Brief descriptions of the three major conditions are followed by a discussion of the diagnostic process used to distinguish among them, as well as a few other conditions which must be considered.

An estimated 2 to 15 percent of diabetics will suffer from at least one episode of diabetic coma in their lifetimes as a result of severe hypoglycemia.

Severe hypoglycemia. People with type 1 diabetes mellitus who must take insulin in full replacement doses are most vulnerable to episodes of hypoglycemia. It is usually mild enough to reverse by eating or drinking carbohydrates, but blood glucose occasionally can fall fast enough and low enough to produce unconsciousness before hypoglycemia can be recognized and reversed. Hypoglycemia can be severe enough to cause unconsciousness during sleep. Predisposing factors can include eating less than usual, prolonged exercise earlier in the day, Some people with diabetes can lose their ability to recognize the symptoms of early hypoglycemia.

Unconsciousness due to hypoglycemia can occur within 20 minutes to an hour after early symptoms and is not usually preceded by other illness or symptoms. Twitching or convulsions may occur. A person unconscious from hypoglycemia is usually pale, has a rapid heart beat, and is soaked in sweat: all signs of the adrenaline response to hypoglycemia. The individual is not usually dehydrated and breathing is normal or shallow. A meter or laboratory glucose measurement at the time of discovery is usually low, but not always severely, and in some cases may have already risen from the nadir that triggered the unconsciousness.

Unconsciousness due to hypoglycemia is treated by raising the blood glucose with intravenous glucose or injected glucagon.

Advanced diabetic ketoacidosis. Diabetic ketoacidosis (DKA), if it progresses and worsens without treatment, can eventually cause unconsciousness, from a combination of severe hyperglycemia, dehydration and shock, and exhaustion. Coma only occurs at an advanced stage, usually after 36 hours or more of worsening vomiting and hyperventilation.

In the early to middle stages of ketoacidosis, patients are typically flushed and breathing rapidly and deeply, but visible dehydration, pallor from diminished perfusion, shallower breathing, and rapid heart rate are often present when coma is reached. However these features are variable and not always as described.

If the patient is known to have diabetes, the diagnosis of DKA is usually suspected from the appearance and a history of 1–2 days of vomiting. The diagnosis is confirmed when the usual blood chemistries in the emergency department reveal hyperglycemia and severe metabolic acidosis.

Treatment of DKA consists of isotonic fluids to rapidly stabilize the circulation, continued intravenous saline with potassium and other electrolytes to replace deficits, insulin to reverse the ketoacidosis, and careful monitoring for complications.

Nonketotic hyperosmolar coma. Nonketotic hyperosmolar coma usually develops more insidiously than DKA because the principal symptom is lethargy progressing to obtundation, rather than vomiting and an obvious illness. Extreme hyperglycemia is accompanied by dehydration due to inadequate fluid intake. Coma from NKHC occurs most often in patients who develop type 2 or steroid diabetes and have an impaired ability to recognize thirst and drink. It is classically a nursing home condition but can occur in all ages.

The diagnosis is usually discovered when a chemistry screen performed because of obtundation reveals extreme hyperglycemia (often above 1800 mg/dl (100 mM)) and dehydration. The treatment consists of insulin and gradual rehydration with intravenous fluids.

Can You Help a Person in a Coma?                               
When a patient is in an intensive care unit (ICU), family members and friends will all want to help. As a concerned family member or friend, here are some suggestions of things that you can do to help.

Ask the medical staff. Find a caring nurse to discuss ways that you can be involved in the daily care of the patient in the coma.

Be respectful. This is an emotional time, but don't get overly emotional, i.e. don't holler, argue, scream, etc. in front of the patient. Loving care from family members is important to the recovery process. It is also a positive way to spend time with the patient as well as a learning process for family members.

Keep a journal or notebook. This is VERY IMPORTANT. Have a notebook strictly for taking notes when the doctors tell you things about the patient's condition, etc. Otherwise, you will never remember what was said to relay to other family members. When a large family is involved it gets tiring to keep repeating the same information -- so they can read your notebook.

Also, write down all the pertinent phone numbers of people who would need to be called when changes in condition occur. There are a lot of people who want this information and not everyone can be called.

This is also a good way to keep busy. Also, you may capture something that could be important to the medical staff. A journal may not only serve as a method for coping with grief, it may also be helpful for the patient when they come out of the coma -- to realize what happened to them.

Keep a calendar or photo album. Keep a calendar or photo album next to the patient's bed. Make sure the calendar has pictures the patient might like. On each appropriate date, write significant dates, such as birthdays and anniversaries of people who are special to the patient.

Music and Laughter. If the hospital allows it, bring a small CD player or tape player and play some of the patient's music softly in the background. Bring up funny stories about the patient and encourage others to do the same -- this will create an environment of happiness. Make an audio or video recording of these happy times.

Phone helpers. Designated phone helpers can help to communicate status to others. For example, a friend who works at the patient's place of employment can get the latest news from you, and then send it to his distribution list on e-mail -- this will save you a lot of work!

Another notebook. If you have a lot of visitors, have a notebook available for everyone to sign-in. You may also want to keep a basket handy for all the cards. This information will be invaluable to the patient during his/her recovery.

Gift baskets. This is an excellent to help. Some ideas of gift baskets include donations of telephone cards, containers of quarters, mouthwash, nice soaps, shower bag, fruit, paid parking, a night's stay at a hotel just across from the hospital, bringing meals (hospital food gets really tiring), instant tea, notebooks for taking notes, people acting as a laundry service (i.e. picking up clothes).

Volunteers. There are so many things that your friends can do to help. For example, a volunteer can mow your lawn or shovel your driveway if you're spending most of your time in the hospital with your loved one.

After the crisis. You can still help even after the crisis is over. The road ahead is a long one. They will need you even more as others fade away, thinking the crisis is over. Rides to therapy or doctor visits, a day out away from home, visits from friends just because, invitations to dinner. Don't forget them or think you are intruding.

Invaluable! You may think this is a waste of your time, but all together, these activities comprise the chronicle of the patient's recovery, or at least his/her stay in the hospital. It reflects your emotions as a family, including your fears, frustration, anger, and joyful moments. It shows how you bickered and strained under the stress, but ultimately pulled together and worked to support one another and to assist in the patient's recovery. It shows what the patient's friends and co-workers said and felt. It chronicles the patient's progress from bed-ridden and unconscious, with tubes and monitors, to his final trip home, and onward.

Educate yourself.  Use this time to learn about brain injury. Families are encouraged to learn about brain injuries so they will be able to help the brain-injured person recover to the fullest extent possible.

Use your energy wisely. During the first few hours and days, most people are running on adrenaline. This may be the best time for you to deal with some of the issues surrounding the condition of your family member. There is not much you can do for the person in a coma at this point, most decisions are being made by the medical team, and taking action may help you to cope with the stress you are feeling at this difficult time.

Buy a book to put phone numbers in. You will need to call employers, insurance carriers, friends, family, an attorney, etc. It is easier if you make this a separate book that you can check each day to remind you of phone calls to make. When you are exhausted with status reports, this book can serve as a guide that someone else may use to take over the task of informing family members and friends of the progress of the patient. It can be very exhausting to keep everyone updated in the first weeks.

Be sure and jot down notes during your calls. As you continue through the process of waiting, you may forget what you were told, or how you were supposed to follow up on the information you received.

Be positive when visiting the person in a coma. Every brain injury is unique. No one knows how much the person in a coma is aware of his/her surroundings. Some people remember very vividly what was going on around them while they were in a coma. Other people do not. Most people do not remember physical sensations while they were comatose.

Although most medical doctors don't agree with this, it is generally accepted that speaking positively while in the presence of someone who is in a coma is beneficial. Talking to them, telling them about your day as you normally would, reading cards that have been sent...these things help with recovery.

Always begin your visits with your name. "Hi, its me,____."

Occasionally the comatose patient can become agitated by too much stimulation; that's when its a good time to just sit and hold a hand.

When discussing the patient in their presence, always be aware that what you say may be heard. Never speak as if they weren't there.

A person emerging from a coma is disoriented. As soon as the ICU staff allows: Every day write the date in large letters on a large piece of paper. Tape this where the patient can see it. This helps to orient the patient.

Remember the recovery of consciousness is a gradual process and is not just a matter of "waking up" as people often imagine.

Take care of yourself. You will not be helping the patient by becoming ill yourself. Your loved one is in the care of a trained medical team. No one can predict the rate of recovery, so it is important that you try to return to a routine that is as normal as possible.

Accept help from friends and neighbors. Often people in your situation feel uncomfortable about accepting help from others. By accepting help from those who offer, you are allowing them to take some action; to do SOMETHING. If someone asks what they can do to help, don't be afraid to ask for simple things like babysitting one day or bringing a meal. Your life at home may feel slightly overwhelming at this time, so allow friends and neighbors to help.

Remember: You are not alone.

Medical Personnel
The following is a list of the medical personnel and their roles in providing care.

Anesthesiologist: A physician who administers anesthesia for surgery and other medical procedures. This physician may meet with family members before surgery.

Attending Physician: The physician primarily responsible for the care of the patient, often a neurosurgeon.

Consulting Physicians: Physicians who are specialists in fields other than neurology and neurosurgery. They may be called upon by the attending physician for their expertise on other facets of medicine, especially in the event of other injuries.

Intern: A physician who has finished medical training and is usually in the first year of training in a specialty. Interns work under the supervision of attending physicians and residents.

Internist: A physician who specializes in internal medicine. They are experts in problems of the heart, digestive tract and other internal organs, and are often consulted after a brain injury.

Neurologist: Physician specialist concerned with treating disorders of the brain, spinal cord, nerves and muscles.

Neuropsychologist: A psychologist who specializes in evaluating brain/behavior relationships.They use a variety of techniques, including testing. Groups of tests, called batteries, can establish the location of the brain injury. Neuropsychologists plan training programs and recommend alternative cognitive (thinking) and behavioral strategies to help brain-injured people think and behave as close to their pre-injury status as possible. They also get involved in helping families to understand what is happening to their family member. In addition, they help families try to come to grips with the fact that this injury effects not only the person who is injured but all members of the family. Neuropsychologists typically have more time to talk to patients and their families than other members of the medical team. You should feel free to ask to speak to the neuropsychologist.

Neurosurgeon: Physician specialist trained to care for all varieties of nervous system problems and perform brain and spinal cord surgery as needed. This person is primarily concerned with coordinating the medical treatment of the brain injured, and deciding whether or not there is a need for surgical treatment.

Nutritionist: An expert in the nutritional requirements of patients. Nutritionists are also adept at various methods of feeding, for those unable to take in food and fluid by mouth.

Occupational Therapist: OTs work to improve function in the patient's hands and upper body. They become involved in the acute rehabilitation phase.The occupational therapist uses self-care, work and play activities to increase independent function, enhance development and prevent disability. This may include the adaptation of a task or the environment to achieve maximum independence and to enhance the quality of life.

Orthopedist: Physician specialist concerned with the study and treatment of the skeletal system, its joints, muscles and associated structures.

Physiatrist: A physician who specializes in physical medicine and rehabilitation. Some physiatrists are experts in neurologic rehabilitation. The physiatrist examines the patient to assure that medical issues are addressed; provides appropriate medical information and oversees the patient's rehabilitation program.

Physical Therapist: The physical therapist evaluates components of movement, including: muscle strength, muscle tone, and general mobility. This is done initially by moving the arms and legs (called Range of Motion) and thereby exercising unused muscles in order to prevent further deterioration of physical function in the unconscious patient. The physical therapist also evaluates the potential for functional movement, such as the ability to move in the bed, transfers and walking and then proceeds to establish an individualized treatment program to help the patient achieve functional independence.

Primary Care Nurse: The nurse principally responsible for the nursing care of a given patient. The primary care nurse develops and implements a care plan, participates in conferences, collaborates with the patient, the rehabilitation team, and the family, as well as evaluating the outcome of care.

Psychologist: A professional specializing in counseling, including adjustment to disability. Psychologists use tests to identify personality and cognitive functioning. This information is shared with team members to assure consistency in approaches. The psychologist may provide individual or group psychotherapy for the purpose of cognitive retraining, management of behavior and the development of coping skills by the patient and members of the family.

Rehabilitation Nurses: Nurses especially trained in rehabilitation techniques as well as basic nursing care. Nurses assist the patient and family in acquiring new information, developing skills, and achieving competence. They provide and coordinate all patient care, liaison to other team members and are often a patient advocate.

Resident: A physician who has completed medical training and is taking additional training in a specialty, such as neurosurgery. Residents work under the supervision of attending physicians.

Respiratory Therapist: Concerned with helping the patient breathe adequately as a means of preventing further complications and/or infections. If the patient is on a respirator, the respiratory therapist is responsible for maintaining the equipment. If the patient is unable to cough up secretions, the respiratory therapist may assist by lowering the head, tapping the back, and suctioning the patient.

Speech Therapist: Assists patients in their recovery of all aspects of communication skills and swallowing ability.

How to get information from doctors and other medical professionals.
When a patient is in an ICU, family members and friends will all want and need information. However the medical team caring for the patient must spend their time providing the best treatment for the patient.

It is important that the family select a spokesman to liason with the medical team.

The family spokesman should write down all questions and concerns of the family. In turn, the spokesman should also take notes on the answers he/she receives in order to pass them on to family members. It is important to remember the recovery process involves a number of specialists who work as a team and information should be sought from all team members in order to understand the patient's situation.

The neuropsychologist is an excellent source of information. Feel free to ask to speak with the neuropsychologist. They typically have more time to speak with the family than members of the team dealing with the medical issues. Part of their job is helping the family to understand the effects brain injury on the patient, and the family members as well.

There should be preparation for some unpleasant information.
Every brain injury is unique. No one can predict the outcome of a brain injury. In general terms, it is believed that the longer the coma lasts, the less likely the individual is to recover fully. However, the location of the damage in the brain may be a more significant indicator. The full effect of the brain injury may not be known for months or years.

There may be no answers to your specific questions.
Your questions may be answered with "wait and see." Although this may be the most accurate answer to your questions, there is more you can do.

Use this time to learn about brain injury.
Your loved one has suffered a brain injury. The extent of recovery is unpredictable. Brain injury is now a part of your life and understanding is the first step in coping with the grief. Many hospitals have libraries with information on brain injury, and the staff will help you to locate any information available. There is a national Brain Injury Association (BIA). Most states have brain injury associations. We attempt to answer some of your questions here, and provide resources on our resources page.

Don't give up! Don't ever give up!
The first few days/weeks are the toughest, because there's so much waiting and wondering.

Continue to talk to and comfort your loved one and assume that he/she can hear you. Look for telltale responses, such as eye/hand movements.

Find any and all information you can about comas, because you're going to have medical people throwing strange terminology at you that you don't understand.

Ignore any doctor who says there is no chance of recovery - there is always a chance for recovery to some degree.

Above all, don't give up HOPE!

Equipment Used in an ICU
There is a lot of medical equipment that may be used for a patient in a coma. The following is a list of the various equipment. Of course, not all patients will have all of this equipment available to them -- it depends on the specific health of the patient, the hospital's facilities, and, possibly the patient's insurance.

Arterial Line: A very thin tube (catheter) is inserted into one of the patient's arteries (usually in the arm) to allow direct measurement of the blood pressure and to measure the concentration of oxygen and carbon dioxide in the blood. Arteries carry oxygen and nutrient-rich blood from the heart to tissues and organs throughout the body. Veins carry blood that is higher in waste products and carbon dioxide back to the heart and lungs. The arterial line allows nurses and doctors to monitor these levels at regular intervals. The arterial line is attached to a monitor.

Brain Stem Evoked Response Equipment: Auditory brain stem responses evoked by stimulating the brain stem with painless sound waves using headphones. These sound waves are received by the brain, and a machine is used to test whether the brain stem has received the signals.

The quality of the brain stem's functioning in a comatose patient is thought to be an important indicator of the degree and location of brain injury. This highly specialized equipment is not available in all hospitals.

Catheter: A flexible plastic tube of varying sizes for withdrawing fluids from, or introducing fluids into, a cavity of the body. Frequently used to drain the urinary bladder.

Central Venous (CVP) Line: A very thin tube which is inserted into a vein to measure the venous blood pressure (the pressure of the blood as it returns to the heart). CVP lines are inserted into veins in either the arm or the chest just below the shoulder, or occasionally on the side of the neck. The CVP line is connected to a monitor.

Chest Tubes: Tubes inserted into the chest between the lung and ribs to allow fluid and air to drain from the area surrounding the lungs. Removing this fluid and air from around the lungs allows them to more fully expand. An accumulation of fluid and air in the lung cavity can cause the lung to collapse. Chest tubes drain into a large plastic container near the foot of the patient's bed. The patient may have one or more of these tubes in place. Nurses will monitor the comatose patient for non-verbal signs of pain.

Electrocardiogram (ECG/EKG): The recording made by small, round electrode pads located on the patient's chest to monitor heart rate and rhythm. These are connected to a monitor and uses routinely in the intensive care unit.

Endotracheal Tube (E.T. Tube): A tube that serves as an artificial airway inserted through the patient's nose or mouth. It passes down the throat and into the air passages to help breathing. To do this, it must also pass through the vocal chords. The patient will be unable to speak as long as the endotracheal tube is in place. It is this tube that connects the respirator to the patient.

Eye Tape: Tape used to close the patient's eyes. It is important that the eyes be kept moist. We do this naturally when we blink our eyes. This reflex is lost in the patient who is unresponsive but has open eyes. To protect the eyes and to prevent them from drying out, eye drops may be put into the eyes and eye tapes may be used to close them.

Foley Catheter: This is a tube (catheter) inserted into the urinary bladder for drainage of urine. This helps to monitor the patient's fluid status and kidney function. The urine drains through the tube into a plastic bag hanging low by the foot of the bed.

GI Tube: A tube inserted through a surgical opening into the stomach. It is used to introduce liquids, food, or medication into the stomach when the patient is unable to take these substances by mouth.

Intracranial Pressure (ICP) Monitor: A monitoring device to determine the pressure within the brain. It consists of a small tube (catheter) attached to the patient's skull by either a ventriculostomy, subarachnoid bolt or screw and is then connected to a transducer, which registers the pressure.

Ventriculostomy is a procedure for measuring intracranial pressure by placing an ICP monitor within one of the fluid-filled, hollow chambers of the brain, called ventricles. These four natural cavities are filled with cerebrospinal fluid (CSF), which also surrounds the brain and spinal chord.

Intravenous (IV): Tubing inserted into a vein through which fluids and medications can be given.

Intravenous Board: A simple wooden or plastic board usually attached with tape to the patient's forearm. It prevents bending and dislocation of the intravenous (IV), arterial or CVP lines.

Jejunostomy Tube (J Tube): A type of feeding tube surgically inserted into the small intestine.

Leg Bag: A small, thick plastic bag that can be tied to the leg and collects urine. It is connected by tubing to a catheter inserted into the urinary bladder.

Monitor, Intensive Care: A TV-like screen with a continuous display of different wave forms representing different pressures and activities in the body such as blood pressure, intracranial pressure, and EKG. It may also show a corresponding number for them (digital readout).

Nasogastric Tube (NG Tube): A tube that passes through the patient's nose and throat and ends in the patient's stomach. This tube allows for direct "tube feeding" to maintain the nutritional status of the patient or removal of stomach acids.

Posey Vest/Houdini Jacket: A vest worn to keep the patient stationary. This is for the patient's safety.

Respirator/Ventilator: A machine that does the breathing work for the unresponsive patient. It serves to deliver air in the appropriate percentage of oxygen and at the appropriate rate. The air is also humidified by the respirator.

Shunt: A procedure to draw off excessive fluid in the brain. A surgically-placed tube running from the ventricles which deposits fluids into either the abdominal cavity, heart or large veins of the neck.

"Space Boots" (Spenco Boots): Padded support devices made of lamb's wool used to position the feet and ankles of the patient. Without this support and alignment, patients who are unconscious for long periods may develop deformities limiting future movement.

Subarachnoid Screw: Also Subarachnoid Bolt. A device for measuring intracranial pressure which is screwed through a hole in the skull and rests on the surface of the brain.

Support Hose/TEDS: Anti-embolic stockings. Tight knee or thigh-high stockings that support the leg muscles and thus help prevent pooling of blood in veins of legs.

Swan-Ganz Monitor: A catheter (tube) similar to the Central Venous Pressure (CVP) Line. It is used to measure blood pressure and blood gas concentrations in the right side of the heart, in vessels of the lungs and in the left side of the heart.

Tracheostomy Tube: A tube inserted into a temporary surgical opening at the front of the throat providing access to the trachea and windpipe to assist in breathing. Click Here To Return To List

Traction: A weighted traction setup composed of pulleys and lines used in the care of the patient with broken leg or spine. After repair of the fractures and application of the appropriate casts, weights are used to keep the bones in alignment.

Transducer: A sensitive electronic device which detects bodily functions, such as heart rate and blood pressure, and transmits signals representing those functions to a monitor so that the can be observed.

Life Support
Life support, in medicine is a broad term that applies to any therapy used to sustain a patient's life while they are critically ill or injured. There are many therapies and techniques that may be used by clinicians to achieve the goal of sustaining life. Some examples include:

    Feeding tubes
    Total parenteral nutrition
    Mechanical ventilation
    Heart/Lung bypass
    Urinary catheterization
    Cardiopulmonary resuscitation
    Artificial pacemaker

These techniques are applied most commonly in the Emergency Department, Intensive Care Unit and, Operating Rooms. As various life support technologies have improved and evolved they are used increasingly outside of the hospital environment. For example a patient who requires a ventilator for survival are commonly discharged home with these devices. Another example includes the now ubiquitous presence of Automated external defibrillator in public venues which allow lay people to deliver life support in a prehospital environment.

The ultimate goals of life support depend on the specific patient situation. Typically life support is used to sustain life while the underlying injury or illness is being treated or evaluated for prognosis. Life support techniques may also be used indefinitely if the underlying medical condition cannot be corrected but a reasonable quality of life can still be expected.

Life Support Decisions
You hear about it on the news, you probably know someone who’s had to face it, or you might be facing it yourself. The decision of when to withdraw life support or whether to begin it at all is a sticky one, muddled with confusing terms and strong emotions. A notable case in the media was that of Terry Schiavo in 2005. Her case dealt with whether her husband could decide to discontinue her artificial nutrition. It sparked a national debate. Although her case was very prominent in the news, it’s not the only case like it in the U.S. People are faced with the decision to withhold or withdraw life support every day.

Life sustaining treatment, also known as life support, is any treatment intended to prolong life without curing or reversing the underlying medical condition. This can include mechanical ventilation, artificial nutrition or hydration, kidney dialysis, chemotherapy and antibiotics.

Quality vs Quantity of Life
Advances in medicine and technology are helping people live longer. Life expectancy has increased from 68.2 years in 1950 to 77.8 years in 2004. These advances in medical technology are not only helping people live longer, but they help prolong the lives of people who couldn’t sustain life on their own. This raises the debate over quality vs. quantity of life.

Ethical questions include:
  • Are we helping people live longer at the expense of their comfort and dignity?
  • If we don’t use artificial means to support life, are we denying them the chance to live longer or recover fully?
  • What if a miracle happens while they are on life support and they are cured?
  • What if we take them off life support and they find a cure shortly after they die?
Who Can Make Life Support Decisions?
The American Medical Association’s Code of Medical Ethics states that "a competent, adult patient, may, in advance, formulate and provide a valid consent to the withholding and withdrawing of life-support systems in the event that injury or illness renders that individual incompetent to make such a decision." This decision is usually made in the form of an Advanced Healthcare Directive or a Living Will. In the same document, a patient may designate a surrogate to make the decision for them if they are unable. If an advanced directive isn’t made and a surrogate isn’t designated, the choice whether to withhold or withdraw life support falls to the next of kin, according to state law.

How to Make the Decision
If you find yourself or someone you love faced with this decision, the most important thing you can do is evaluate your own goals and the known wishes, if any, of the patient. Gather all the information you can about the types of life sustaining measures the patient requires, including the benefits and risks of each one. Review the patient’s Advanced Healthcare Directive, Living Will, or Preferred Intensity of Care form if they are in a nursing home. If you are the designated healthcare surrogate, you hopefully have had a conversation about the patient’s wishes.

If there is no legal document to refer to and you have not had conversations about life sustaining treatments with the patient, the decision can be more difficult to make. I usually recommend to gather all close relatives and perhaps very close friends to discuss what the patient would have wanted. Each person will have their own unique experiences with the patient to draw on and the picture gained collectively will always be more complete that individually.

It is best when all the patient's loved ones can agree on whether to withhold or withdraw life support. If a unanimous decision can’t be made, it may be helpful to try mediation. A social worker or chaplain can often help mediate difficult situations like these. The decision will ultimately fall to the designated or default surrogate but if all the patient’s loved ones can participate in the decision making process, it can help foster closer relationships and prevent resentment (and lawsuits).

After the Decision Is Made
The choice whether to withhold or withdraw life support is a difficult one to make. Get some emotional support during and especially after making the decision. Making an informed decision, taking into consideration the benefits, risks, and what you feel the patient would have wanted for him/herself, can still cause feelings of guilt and uncertainty. Talk with a professional counselor, a member of clergy, or even a good friend to get those feelings out in the open and begin to deal with them. Check with your local hospice agency to find support groups of people who have gone or are going through the same thing.

And lastly, give yourself a break. You are merely human and not divinely all-knowing. You can only make the decision you feel is best at the time.
Questions for Your Doctor about Treatment Options
When considering any treatment options, whether they're considered curative or palliative, there are some essential questions you will want to ask your doctor.
  1. What treatments are available for my illness?Your doctor should tell you what treatments are standard for your illness. Your doctor will not always share the option of palliative care or hospice without being asked directly. If you are interested in finding out how palliative care or hospice can help you, be sure to ask.
  2. What are the chances that a particular treatment will be effective?Some treatments are standard and very effective. If you have tried treatments before that have lost their effectiveness or haven’t worked at all, ask your doctor about less standard and experimental treatments. Knowing what the chances are that a treatment will provide relief will help you determine if the benefits of the treatment are worth any risks.
  3. Will this treatment prolong my life?Some treatments will target symptoms of an illness without extending life. You will want to know whether the treatment you're considering will extend your life and based on your goals of care, you can decide if that indeed what you want.
  4. What are the risks of a particular treatment?This may the most important question to ask. Just about every treatment has some sort of undesired consequence or side effect. Depending on your goals of care, a particular risk may not be worth the potential benefit. For example, if the treatment will likely make you feel sick, weak, and tired but not cure your illness, you might decide to forgo it to focus on quality of life.
  5. How will this treatment affect my other medical conditions and treatments?Some treatments have unintended effects on other medical conditions or treatments. For example, a patient with lung disease, heart disease, and kidney disease may take steroids to control lung disease, which can lead to increased water retention making their heart disease worse. Then, taking diuretics to control water retention and swelling can lead to worsening kidney failure. Finding out how potential side effects will affect any other illnesses will help you decide if the treatment is worth it.
  6. If this treatment doesn’t work, what is our next step?You will want to know where your heading if things don’t go as hoped. Having a plan in place will make any new decision easier to make.
Identifying the Cause of a Coma
Diabetic coma was a more significant diagnostic problem before the late 1970s, when glucose meters and rapid blood chemistry analyzers became universally available in hospitals. In modern medical practice, it rarely takes more than a few questions, a quick look, and a glucose meter to determine the cause of unconsciousness in a patient with diabetes.

Laboratory confirmation can usually be obtained in half an hour or less. Also, the astute physician remembers that other conditions can cause unconsciousness in a person with diabetes: stroke, uremic encephalopathy, alcohol, drug overdose, head injury, or seizure.
Fortunately, most episodes of diabetic hypoglycemia, DKA, and extreme hyperosmolarity do not reach unconsciousness before a family member or caretaker seeks medical help.

Treatment for Comas
Treatment depends upon the underlying cause:
  • Ketoacidotic diabetic coma: intravenous fluids, insulin and administration of potassium and sodium.
  • Hyperosmolar diabetic coma: plenty of intravenous fluids, insulin, potassium and sodium given as soon as possible.
  • Hypoglycaemic diabetic coma: administration of the hormone glucagon  to reverse the effects of insulin, or glucose given intravenously.

Medical Treatments for Coma Patients
There is no one treatment that can cause someone to come out of a coma. Treatments can prevent further physical and neurological damage, however.

First, doctors ensure that the patient isn't in immediate danger of dying. This may require placing a tube in the patient's windpipe through the mouth, and hooking up the patient to a breathing machine, or ventilator.

If there are other serious or life-threatening injuries to the rest of the body they will be dealt with in order of decreasing severity. If excess pressure in the brain caused the coma, doctors can relieve it by surgically placing a tube inside the skull and draining the fluid.

A procedure called hyperventilation, which increases the rate of breathing to constrict blood vessels in the brain, can also relieve pressure.

The doctor may also give the patient medication to prevent seizures. If a drug overdose or condition such as very low blood sugar is responsible for the coma, doctors attempt to correct this as soon as possible. Patients with acute ischemic strokes may undergo procedures or receive special clot-busting medication in an effort to restore blood flow to the brain.

Doctors may use imaging studies, such as magnetic resonance imaging (MRI), or computed tomography (CT) scans, to look inside the brain and identify a tumor, pressure, and any signs of damage to the brain tissue.

Electroencephalography (EEG) is a test used to detect any abnormalities in the brain's electrical activity. This can also show brain tumors, infections, and other conditions that might have caused the coma. If the doctor suspects an infection such as meningitis, he may perform a spinal tap to make the diagnosis. To perform this test, a doctor inserts a needle into the patient's spine and removes a sample of cerebrospinal fluid for testing.

Once the patient is stable, doctors will concentrate on keeping him or her as healthy as possible. Coma patients are susceptible to pneumonia and other infections. Many comatose patients stay in the hospital's intensive care unit(ICU), where doctors and nurses can continually monitor them. People who are in a coma for a long time may receive physical therapy to prevent long-term muscle damage. Nurses will also move them periodically to preventbedsores -- painful skin wounds caused by lying in one position for too long.

Because patients who are in a coma can't eat or drink on their own, they receive nutrients and liquids through a vein or feeding tube so that they don't starve or dehydrate. Coma patients may also receive electrolytes -- salt and other substances that help regulate body processes.

If a coma patient continues to be dependent on a ventilator to breathe, they may receive a special tube that goes directly into their windpipe through the front of the throat (a tracheotomy). The tracheotomy tube can be left in place for extended periods of time because it requires less maintenance and does not injure the soft tissues of the oral cavity and upper throat. Because patients who are in a coma can't urinate on their own, they will have a rubber tube called a catheter inserted directly into their bladder to remove the urine.

Difficult Decisions

Watching a spouse or family member in a coma or vegetative state is difficult enough, but when the condition persists for a long time, the family may have to make some very difficult decisions. In cases where people do not recover quickly, the families must decide whether to keep their loved one on a ventilator and feeding tube indefinitely, or to remove these aids and allow the person to die.

If the person in question has written up an advanced medical directive (also known as a "living will") that decision is much easier, because family members can simply follow his or her wishes. In the absence of a living will, the family must carefully consult with doctors to determine what's best for the patient.

In several cases, that decision has been contentious enough to wind up in court -- and in the headlines. In 1975, 21-year-old Karen Ann Quinlan suffered severe brain damage and ended up in a persistent vegetative state after ingesting a dangerous combination of sedatives and alcohol. Her family went to court to have Karen's feeding tube and respirator removed. In 1976, a court in New Jersey assented. However, Karen began to breathe on her own after doctors removed her respirator. She lived until 1985, when she died of pneumonia.

A recent case spawned an even bigger court battle that reached all the way to the highest executive office. In 1990, Terri Schiavo's heart temporarily stopped beating due to complications from bulimia. She suffered severe brain damage and fell into a persistent vegetative state. Her husband and parents went to court to fight over whether to have her feeding tube removed. Their dispute made its way to Congress, and even drew the attention of President George W. Bush. Eventually, the feeding tube was removed. Terri died in March 2005.

How Do People "Come Out" of Comas?
How fast a person comes out of a coma depends on what caused it and the severity of the damage to the brain. If the cause was a metabolic problem such as diabetes, and doctors treat it with medication, he can come out of the coma relatively quickly. Many patients who overdose on drugs or alcohol also can recover once the substance clears their system. A massive brain injury or brain tumor can be more difficult to treat, and can lead to a much longer or irreversible coma.

Most comas don't last more than two to 4 weeks. Recovery is usually gradual, with patients becoming more and more aware over time. They may be awake and alert for only a few minutes the first day, but gradually stay awake for longer and longer periods. Research shows that a comatose patient's outcome relates very closely to his or her Glasgow Coma Scale score. The majority of people (87 percent) who score a three or a four on the scale within the first 24 hours of going into a coma are likely to either die or remain in a vegetative state. On the other end of the scale, about 87 percent of those who score between 11 and 15 are likely to make a good recovery.

Some people come out of a coma without any mental or physical disability, but most require at least some type of therapy to regain mental and physical skills. They may need to relearn how to speak, walk, and even eat. Others are never able to recover completely. They may regain some functions (such as breathing and digestion) and transition into a vegetative state, but will never respond to stimuli.

  1. a b c d Weyhenmyeye, James A.; Eve A. Gallman (2007). Rapid Review Neuroscience 1st Ed. Mosby Elsevier. pp. 177–9. ISBN 0-323-02261-8.
  2. a b c d e f Hannaman, Robert A. (2005). MedStudy Internal Medicine Review Core Curriculum: Neurology 11th Ed. MedStudy. pp. (11–1)-(11–2). ISBN 1-932703-01-2.
  3. ^ Russ Rowlett. "Glasgow Coma Scale". University of North Carolina at Chapel Hill.
  4. ^ Daltrozzo, J., Wioland, N., Mutschler, V., Lutun, P., Jaeger, A., Calon, B., Meyer, A., Pottecher, T., Lang, S., Kotchoubey, B. (2009c). Cortical Information Processing in Coma, Cognitive & Behavioral Neurology, 22(1), 53-62.[1]
  5. ^ Daltrozzo, J., Wioland, N., Mutschler, V., Kotchoubey, B. (2007). Predicting Coma and other Low Responsive Patients Outcome using Event-Related Brain Potentials: A Meta-analysis. Clinical Neurophysiology, 118, 606-614.[2]
  6. ^ Daltrozzo, J., Wioland, N., Mutschler, V., Lutun, P., Calon, B., Meyer, A., Jaeger, A., Pottecher, T., Kotchoubey, B. (2010a). Electrodermal Response in Coma and Other Low Responsive Patients. Neuroscience Letters, 475(1), 44-47.[3]
  7. ^ According to the Guinness Book of Records, the longest period spent in coma was by Elaine Esposito. She did not wake up after being anaesthetized for an appendectomy on August 6, 1941, at age 6. She died on November 25, 1978 at age 43 years 357 days, having been in a coma for 37 years 111 days.
  8. ^ NINDS (October 29, 2010). "Coma Information Page: National Institute of Neurological Disorders and Stroke (NINDS)". Retrieved 2010-12-08.
  9. ^ Formisano R, Carlesimo GA, Sabbadini M, et al. (May 2004). "Clinical predictors and neuropleropsychological outcome in severe traumatic brain injury patients". Acta Neurochir (Wien) 146 (5): 457–62. doi:10.1007/s00701-004-0225-4PMID 15118882.
  10. ^ brain injury .com | Coma traumatic brain injury - Brain Injury Coma
  11. ^ "Mother stunned by coma victim's unexpected words"The Sydney Morning Herald. 2003-07-12.
  12. ^ "Electrodes stir man from six-year coma-like state"Cosmos Magazine. 2 August 2007.
  13. a b "Coma". Retrieved 2010-12-08.
  14. ^ Coma Care (2010-03-30). "Caring for Care Giver and Family". Retrieved 2010-12-08.
  15. ^ Eelco F.M. Wijdicks, MD and Coen A. Wijdicks, BS (2006). "The portrayal of coma in contemporary motion pictures"Neurology 66 (9): 1300–1303.doi:10.1212/01.wnl.0000210497.62202.e9PMID 16682658. Retrieved 2009-11-25.
More Information About Comas                                    
Causes of Coma

There are hundreds of causes of coma as listed below, so the following is an over-simplification that most comas are caused by 2 major conditions:

#1. Trauma, or physical injury -- this can be determined with MRI, etc.

#2. Biochemical, drug, toxin-related due to imbalances of chemicals in the body -- this can be determined with blood/hormone tests.

For #1, if coma persists, there may be internal bleeding that the MRI is not picking up. If so, you'll need to push for more MRI-type tests. But they may resist doing the extra tests because of the cost.

For #2, if coma persists, they may be missing something in the blood/hormone tests. If so, you'll need to push for more blood/hormone-type tests. But they may resist doing the extra tests because of the cost.

Constant falls and mini-strokes can lead to some kind of damage to the brain even though the MRI may not be showing it. A mini-stroke is a stroke although not as dangerous -- but a series of mini-strokes can be just as dangerous if ignored over time.

A type of stroke, called an ischemic stroke, can also lead to a coma. This stroke occurs when an artery that supplies the brain with blood is blocked. The blockage starves the brain of blood and oxygen. If it is very large, the person can fall into a coma.

In people with diabetes, the body does not produce enough of the hormone insulin. Because insulin helps cells use glucose for energy, a lack of the hormone causes blood glucose levels to rise (hyperglycemia). Conversely, when insulin isn't in the right proportion, blood sugar can drop too low (hypoglycemia). If the blood sugar is either extremely high or low, it can cause a person to fall into a diabetic coma.

Comas can also be caused by brain tumors, alcohol or drug overdoses,seizure disorders, lack of oxygen to the brain (such as from drowning) or extremely high blood pressure.

A person can become comatose immediately or gradually. If an infection or other illness causes the coma, for example, the person might run a high fever, feel dizzy or seem lethargic before falling into a coma. If the cause is a stroke or severe head trauma, they can become comatose almost immediately.   

If a person suffers severe head trauma (i.e. from a fall), the impact can cause the brain to move back and forth inside the skull. The movement of the brain inside the skull can tear blood vessels and nerve fibers, which causes swelling in the brain (but the swelling may be undetectable or overlooked). This swelling presses down on blood vessels, blocking the flow of blood (and with it, oxygen) to the brain. The oxygen- and blood-starved parts of the brain begin to die.

Some infections of the brain and spinal cord (such as encephalitis or meningitis) can also cause swelling in the brain. Conditions that cause an excess of blood inside the brain or skull, such a skull fracture or a burst aneurysm, can also lead to swelling and further brain injury.

Please Note: In reality, coma survival rates are 50 percent or less, and less than 10 percent of people who come out of a coma completely recover from it. Comas as seen on TV can lead to unrealistic expectations by the families and loved ones of people who are in a real-life coma.

Bottom line: You need to ask the doctors what is your mother's current diagnosis, and what is the plan of treatment. Then, ask them what is her prognosis or outlook for the future state of her health.

Also, you need to find a health advocate in the hospital to help you (i.e. a nurse), or someone not affiliated with the hospital (to get an honest answer) -- maybe another doctor to give you a second opinion.

Here are some questions that you should be able to answer. If you can't answer them, seek the answers as soon as possible from the doctors and hospital staff.

How is the patient being treated by the doctors and the hospital? What kind of care is she receiving?

What doctors are treating the patient? cardiologist? neurologist? endocrinologist?  other specialty doctor?

Do they all agree on her diagnosis? If not, you need to find out why.

Is the patient totally unresponsive to external stimuli?

Does the patient respond to stimuli, with reactions such as movement or increased heart rate?

Can the patient see, hear, touch, and taste, but cannot respond? 

Does the patient have a tube in the windpipe through the mouth, and hooked up to a breathing machine, or ventilator?

Does the patient have any other tubes or connections? If excess pressure in the brain caused the coma, doctors can relieve it by surgically placing a tube inside the skull and draining the fluid. A procedure called hyperventilation, which increases the rate of breathing to constrict blood vessels in the brain, can also relieve pressure. The doctor may also give the patient medication to prevent seizures.

If a drug overdose or condition such as very low blood sugar is responsible for the coma, doctors attempt to correct this as soon as possible. Patients with acute ischemic strokes may undergo procedures or receive special clot-busting medication in an effort to restore blood flow to the brain.

Have they given her imaging scans, such as magnetic resonance imaging (MRI), or computed tomography (CT) scans, to look inside the brain and identify a tumor, pressure, and any signs of damage to the brain tissue?

Have they used an Electroencephalography (EEG) is a test used to detect any abnormalities in the brain's electrical activity. This can also show brain tumors, infections, and other conditions that might have caused the coma.

If the doctor suspects an infection such as meningitis, he may perform a spinal tap to make the diagnosis. To perform this test, a doctor inserts a needle into the patient's spine and removes a sample of cerebrospinal fluid for testing.

Coma patients are susceptible to pneumonia and other infections. Many comatose patients stay in the hospital's intensive care unit (ICU), where doctors and nurses can continually monitor them. People who are in a coma for a long time may receive physical therapy to prevent long-term muscle damage. Nurses will also move them periodically to prevent bedsores -- painful skin wounds caused by lying in one position for too long.

Coma patients receive nutrients and liquids through a vein or feeding tube so that they don't starve or dehydrate. Coma patients may also receive electrolytes  -- salt and other substances that help regulate body processes.

If a coma patient continues to be dependent on a ventilator to breathe, they may receive a special tube that goes directly into their windpipe through the front of the throat (a tracheotomy). The tracheotomy tube can be left in place for extended periods of time because it requires less maintenance and does not injure the soft tissues of the oral cavity and upper throat. Because patients who are in a coma can't urinate on their own, they will have a rubber tube called a catheter inserted directly into their bladder to remove the urine.   

The above list are some of the key ways that a coma patient is treated in a hospital. Check to ensure the patient is receiving maximum care in these areas.

And, don't forget to review the highlighted areas below in bold yellow -- these are areas that you and/or the doctors may want to review.


The following information consists of the following sub-sections:
  • Causes of Coma
  • Pairs of Symptoms, i.e. Coma & Confusion; Coma & Shortness of Breadth, Coma & Diabetes
  • Drugs That Cause Coma
  • Questions to Ask Doctor

Causes of a Coma

The following medical conditions (from are some of the possible causes of Coma. There are likely to be other possible causes, so ask your doctor about your symptoms.

Coma: 709 causes

Causes of Coma listed in Disease Database:

Other medical conditions listed in the Disease Database as possible causes of Coma as a symptom include:
- (Source - Diseases Database)

What are the Causes of Coma?

The 2 major causes of a coma are trauma and metabolic/biochemical.Generally, coma is commonly a result of traumableeding and/or swelling affecting the brain. Inadequate oxygen or blood sugar (glucose) and various poisons (including drugs) can also directly injure the brain to cause coma. Coma can also occur as with Mr. McCulley when there is an imbalance or heightened levels of electrolytes, biochemicaland hormonal levels in the body.


Minor head injuries can cause brief loss of consciousness, but the brain is able to turn itself back on. Similarly, patients with seizures become unconscious - but gradually waken relatively quickly. Those people who cannot respond after head injury usually have had significant force applied to their head and brain.

The skull is a rigid box that protects the brain. Unfortunately, if the brain is injured and begins to swell (edema), there is no room for the additional fluid. This causes the brain to push up against the sides of the skull and it then compresses. Unless the pressure is relieved, the brain will continue to swell until it pushes down onto the brain steam, which then damages the RAS, which subsequently affects blood pressure and breathing control centers.

The affect of trauma on the brain is not predictable. It may or may not cause significant injury. If the brain is shaken, shear injury may occur, where the nerve connections within the brain are damaged. Coma may occur even with a normal CT scan in this situation. Similarly, head trauma may cause swelling of the brain without any bleeding, and coma may be the result.

Head trauma can cause different types of brain injury. The injury can occur to the brain tissue itself or may cause bleeding to occur between the brain and the skull. Computerized Tomography (CT) of the head can identify most bleeding from trauma.

Bleeding (Hemorrhage)

Intracerebral hemorrhage (intra= within + cerebral=brain + hemorrhage=bleeding) may be small, but it is associated swelling that may cause damage.

Epidural, subdural, and subarachnoid hemorrhages

The lining of the brain has multiple layers, and these layers can act as potential spaces where bleeding can occur. Epidural (epi= outside the dura= an outer layer of brain lining) and subdural (sub=below the dura) may not cause coma immediately, but as the bleeding continues, it compresses the injured side of the brain and shifts it to the unaffected side. Now both cerebral hemispheres are affected and loss of consciousness or coma may occur; the more swelling, the deeper the coma.

Subarachnoid hemorrhage (below the arachnoid layer) is in the layer of the brain lining where cerebrospinal fluid (CSF) is. CSF is the nutrient fluid that bathes the brain and spinal cord. Bleeding here may be without symptoms or it may cause significant problems, such as paralysis.

Bleeding can occur within the skull or brain without trauma. Blood accumulating in areas it should not b,e result with the same problem. Some medical causes include:
  • Hypertension (high blood pressure): when blood pressure is too high, and not controlled, blood vessels in the brain may not be able to tolerate the high pressure and may leak blood.
  • Cerebral aneurysm, or an area in a blood vessel that is congenitally weak and ruptures. Some people are born with blood vessels that have a weak wall and it gradually balloons, like a weak spot in an inner tube. At some time in their life, or perhaps never, the weak spot gives way and blood is spilled into the brain.
  • Arteriovenous malformations (AVMs) are abnormal blood vessels where arteries connect to veins and cause potential weak spots that can leak blood. Normally, arteries branch into smaller and smaller vessels until they form the smallest set of vessels called capillaries. Capillaries form meshes where chemicals, nutrients, oxygen and carbon dioxide are exchanged from the blood stream to individual cells. The capillaries then merge to form larger blood vessels, the veins. In AVMs, this relationship of artery to capillary to vein is abnormal.
  • Tumors, either benign or malignant, can be very vascular (composed of many veins and capillaries) and have significant bleeding potential.


While trauma can make the brain swell, other types of injury or insult can cause cerebral edema (cerebral=brain + edema=swelling due to increased fluid). Whether the insult is lack of oxygen, abnormal electrolytes, or hormones, it may ultimately result in edema of the brain tissue. As with bleeding, the skull limits the space available for brain swelling to occur; thus the brain tissue is damaged and its function decreases the more it is compressed against the bones of the skull.

Lack of oxygen

The brain requires oxygen to function; and without it the brain shuts down. There is a very short time to get oxygen back to brain tissue before there is permanent damage. Most research suggests that the time window is four to six minutes.

The body provides oxygen to the brain through the lungs. The lungs extract oxygen from the air, hemoglobin in red blood cells pick up the oxygen, and the heart pumps blood through normal blood vessels to cells in the body. If any part of the system fails, the oxygen supply to the brain can be interrupted.

The most common failure occurs with heart rhythm disturbances. The coordinated electrical beat of the heart is lost and the heart muscle doesn't squeeze blood adequately; no blood is pumped to the brain and it stops functioning almost immediately.

Lungs can also fail; examples include pneumoniaemphysema, or asthma. In each case, inflammation in the lung tubes (bronchi or bronchioles) or lung tissue makes it difficult for oxygen to get into the lungs and transferred into the blood stream.

Hemoglobin, a molecule in the red blood cell, attaches oxygen from the lungs and delivers it to cells for use in metabolism. Anemia, or low red blood cell count, can cause the brain to fail directly, or more likely it causes other organs like the heart to fail. The heart, like any other muscle requires oxygen to function. Anemia can occur chronically or it can be due to an acute blood loss (examples include trauma, bleeding from the stomach). If the blood loss is slow, the body is better able to adapt and tolerate low hemoglobin levels; if the bleeding occurs quickly, the body may be unable to compensate, the result being inadequate oxygen supply to tissues such as the brain.

Hypoglycemic coma

All cells in the body need glucose and oxygen to perform their functions by aerobic metabolism (aerobic= with oxygen). While other parts of the body can continue for short periods of time anaerobically (an=without + aerobic+oxygen), the brain cannot. Without glucose, the brain stops.

Hypoglycemia (hypo=low + glyc=glucose + emia= blood) most often occurs in people with diabetes who have given themselves too much insulin or have not taken in enough food.

In normal physiology, the pancreas makes insulin and balances the amount it produces with the amount of glucose in the blood stream. Diabetics need to inject insulin into their body, or take medication to stimulate the pancreas to make insulin. Monitoring blood sugars is critical to avoid hypoglycemic coma.

Poisons (incl. Medications)

There are two sources of poisons that can affect the brain, those that we take in (through ingestion or inhaling) and those that the body generates and cannot dispose of in some way.

If the body can be considered a factory, it needs to have the ability to get rid of the waste products that are made when the body generates energy. These waste products can cause different organs in the body to fail, including the brain.

The liver performs many functions including glucose and protein manufacturing. It also breaks down and metabolizes chemicals in the body. When the liver fails different chemicals like ammonia can accumulate and can cause brain cells to stop functioning. Hepatic encephalopathy (hepatic=liver + encephalo=brain + pathy=disease) or hepatic coma occurs when the liver fails because of an acute or chronic injury. The most common is cirrhosis due to alcoholism.

The kidneys filter blood to rid the body of waste products. When the kidneys fail, a variety of waste products can accumulate in the bloodstream and cause direct or indirect damage to the brain. An example of indirect causes would be an elevated potassium level affecting heart electrical activity. Direct causes include uremia, where blood urea levels rise and are directly toxic to brain cells. Common causes of kidney failure include poorly controlled diabetes andhigh blood pressure.

The thyroid acts as the thermostat for the body and regulates the speed at which the body functions. If thyroid levels drop too low, gradually, over a period of time myxedema coma can occur because of profoundhypothyroidism.

Ingestions can cause the brain to slow down, speed up or alter its perception of the world. Some ingestions may cause coma in an indirect way.Acetaminophen is a prime example, an overdose may cause the liver to failand few days later subsequent hepatic coma occurs.

Alcohol is probably the most common cause of ingested poison or toxin, leading to altered mental status and coma. In acute alcohol intoxication, the brain is directly poisoned. Blood alcohol levels fall when metabolized by the liver, but depth of intoxication can be so great it shuts off many of the involuntary brain activities that control breathing and maintain muscle function. Opiates like pain pills or heroin can cause similar slowing of brain function.

Cocaine and amphetamines are the common "uppers" or brain stimulants. These brain stimulants cause an adrenaline-like body response, thus blood pressure and heart rate spiral out of control and the risk of heart attack, heart rhythm disturbances, or bleeding in the brain occur.

Coma: Check Pairs of Symptoms

The list below shows all pairs of co-occurring symptoms for Coma which have cause information in the database. Each symptom link shows a list of diseases or conditions that have both symptoms. You can also select additional symptoms for more specificity.


Conditions listing medical symptoms: Coma:

The following list of conditions have 'Coma' or similar listed as a symptom in our database. This computer-generated list may be inaccurate or incomplete. Always seek prompt professional medical advice about the cause of any symptom. 


























Conditions listing medical complications: Coma:

The following list of medical conditions have 'Coma' or similar listed as a medical complication in our database. This computer-generated list of complications may be inaccurate or incomplete. Always seek prompt professional medical advice about the cause of any symptom.

Drug side effect causes of Coma

The following drugs, medications, substances or toxins may possibly cause Coma as a side effect. 

Drug interaction causes of Coma:

Drug interactions may be a possible cause of Coma.
  • Phenelzine and tricyclic antidepressant interaction
  • Nardil and tricyclic antidepressant interaction
  • Parnate and tricyclic antidepressant interaction
  • Meperidine and monoamine oxidase inhibitor antidepressant interaction
  • Demerol and monoamine oxidase inhibitor antidepressant interaction

Medications or substances causing Coma

The following drugs, medications, substances or toxins are some of the possible causes of Coma as a symptom.

This list is incomplete and various other drugs or substances may cause your symptoms (see Coma). Always advise your doctor of any medications or treatments you are using, including prescription, over-the-counter, supplements, herbal or alternative treatments.

Diagnosis Checklist for Coma 

Questions Your Doctor May Ask - and Why!

During a consultation, your doctor will use various techniques in his assesment of the symptomComa. These may include a physical examination or other medical tests. Your doctor may ask several questions when assessing your condition. It is important to remember that your consultation is a two-way process and any extra information you can share with your doctor may help them with their diagnosis.
Some of the questions your doctor may ask are listed below:
  1. A history can be obtained from relatives, friends, witnesses and ambulance officers
  2. When did the comatose state start?
    Why: to determine if acute or chronic.
  3. What was the setting in which the person was found?
  4. Recent head injury?
    Why: e.g. car accident - may suggest subdural or extradural haematoma or intracerebral hemorrhage.
  5. Past medical history?
    Why: e.g. diabetes, hypothyroidism, hepatic failure, renal failure, heart arrhythmias, epilepsy, Addison's disease, high blood pressure, lung disease.
  6. If patient is diabetic
    Why: do they have insulin injections, have they had a recent infection, have they been eating properly? - may indicate risk of hypoglycemia or hyperglycemic ketoacidotic coma or hyperglycemic hyperosmolar non- ketotic coma.
  7. Past psychiatric illness?
    Why: e.g. depression, schizophrenia, bipolar disorder - may indicate increased risk of suicide attempt by overdose, carbon monoxide poisoning or other poisoning.
  8. Recent stress or personal problems?
    Why: may suggest increased risk of suicide attempt.
  9. Medications?
    Why: overdose of prescribed medication may be the cause e.g. tranquilizers, antidepressants, pain relief medications such as morphine.
  10. Illegal drug history?
    Why: may suggest drug overdose as cause of collapse e.g. heroin, amphetamines; may also be drug withdrawal e.g. benzodiazepines.
  11. Alcohol history?
    Why: may suggest acute alcohol intoxication, alcohol withdrawal or hepatic failure as cause.

Questions your doctor may ask about related symptoms:

Sometimes, other symptoms may be present and may help your doctor analyse your condition. These may include:
  1. Fever?
    Why: suggests severe infection and shock as cause of coma e.g. meningitis, encephalitis, septicemia, pelvic inflammatory disease, aspiration pneumonia, urinary tract infection, peritonitis, pancreatitis.
  2. Shortness of breath?
    Why: may suggest pulmonary embolism, pneumonia or tension pneumothorax.
  3. Seizure activity?
    Why: e.g. twitching of limbs, incontinence of urine or feces - may suggest epilepsy, brain cancer, meningitis, stroke, hypoglycemia, hyperglycemia.
  4. Headache?
    Why: may suggest subarachnoid hemorrhage (sudden severe headache), brain tumor, meningitis, encephalitis.
  5. Palpitations?
    Why: may suggest complete heart block, sick sinus syndrome, ventricular tachycardia or ventricular fibrillation all which may cause collapse.
  6. Symptoms of stroke?
    Why: e.g. weakness of limbs, problems with speech or swallowing.
Causes of Coma and Fever

Causes of Coma AND High fever

Results: 766 causes of Coma OR High fever

    1. 2-Methylbutyric Aciduria
     A very rare genetic disorder where an enzyme deficiency prevents the break down of certain proteins into energy and results in a harmful accumulation of acids in the blood and body tissues. More specifically, there is a deficiency of an enzyme (2-methylbu...more »
    2. 2-methylbutyryl-coenzyme A dehydrogenase deficiency
     A very rare genetic disorder where an enzyme deficiency prevents the break down of certain proteins into energy and results in a harmful accumulation of acids in the blood and body tissues. More specifically, there is a deficiency of an enzyme (2-methylbu...more »
    3. 3 alpha methylcrotonyl-Coa carboxylase 1 deficiency
     A rare inherited disorder where lack of a certain enzyme (3-methylcrotonyl-Coa carboxylase) stops proteins with the amino acid leucine being metabolized normally by the body. The leucine builds up in the body and causes damage to the brain and nervous sys...more »
    4. 3 alpha methylcrotonyl-coa carboxylase 2 deficiency
     A rare inherited disorder where lack of a certain enzyme (3-methylcrotonyl-Coa carboxylase) stops proteins with the amino acid leucine being metabolized normally by the body. The leucine builds up in the body and causes damage to the brain and nervous sys...more »
    5. 3-alpha-Hydroxyacyl-CoA Dehydrogenase Deficiency
     A rare inherited form of biochemical disorder characterized by the deficiency of a particular enzyme (3-Hydroxyacyl-CoA Dehydrogenase). The enzyme deficiency only affects certain body tissues, in particular the skeletal muscles. The lack of enzyme activit...more »
    6. 3-alpha-hydroxyacyl-coenzyme A dehydrogenase deficiency
     A rare inherited form of biochemical disorder characterized by the deficiency of a particular enzyme (3-Hydroxyacyl-CoA Dehydrogenase). The enzyme deficiency only affects certain body tissues, in particular the skeletal muscles. The lack of enzyme activit...more »
    7. 3-methylcrotonyl-CoA carboxylase deficiency
     A rare inherited disorder where lack of a certain enzyme (3-methylcrotonyl-Coa carboxylase) stops proteins with the amino acid leucine being metabolized normally by the body. The leucine builds up in the body and causes damage to the brain and nervous sys...more »
    8. Accelerated hypertension
     Accelerated hypertension is a condition characterized by a rapid increase in blood pressure. The condition is a medical emergency which can cause organ damage if not treated promptly....more »
    9. Acid-Base Imbalance
     A disruption to the normal acid-base equilibrium in the body. There are four main groups of disorder involving an acid-base imbalance: respiratory acidosis or alkalosis and metabolic acidosis or alkalosis. Obviously the severity of symptoms is determined ...more »
    10. Acidemia, isovaleric
     A rare genetic condition where the body can't process proteins adequately. More specifically, there are insufficient levels of the enzyme needed to break down an amino acid called leucine. This results in a build up of isovaleric acid which can harm the b...more »

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