Coma is classically defined as loss of mobility, sensation and consciousness
with preservation of autonomic functions.
Coma is caused by dysfunction of either or both the reticular
activating system and cerebral cortex. The most common cause of coma are
toxic metabolic de-arrangement, which are potentially treatable and
reverersible. The big three are toxic/metabolic causes,trauma and stroke.
1. Brain cancer
4. Drug abuse
6. Kidney failure
18.Vertebra basilar transient ischemic attack
Toxic-metabolic encephalopathy. This is an acute condition of brain
dysfunction with symptoms of confusion and/or delirium. The condition
is usually reversible. The causes of toxic-metabolic encephalopathy are
varied. They include systemic illness, infection, organ failure, and other
Anoxic brain injury. This is a brain condition caused by total lack of
oxygen to the brain. Lack of oxygen for a few minutes causes cell death
to brain tissues. Anoxic brain injury may result fromheart attack (cardiac
arrest), head injury or trauma, drowning, drug overdose, or poisoning.
Persistent vegetative state. This is a state of severe unconsciousness.
The person is unaware of his or her surroundings and incapable of
voluntary movement. With a persistent vegetative state, someone may
progress to wakefulness but with no higher brain function. With
persistent vegetative state, there is breathing, circulation, and sleep-wake
Locked-in syndrome. This is a rare neurological condition. The person is
totally paralyzed except for the eye muscles, but remains awake and alert
and with a normal mind.
Brain death. This is an irreversible cessation of all brain function. Brain
death may result from any lasting or widespread injury to the brain.
The signs and symptoms of coma commonly include:
Depressed brainstem reflexes, such as pupils not responding to light
No responses of limbs, except for reflex movements
No response to painful stimuli, except for reflex movements
Symptoms of a coma include the following:
No response to outside stimuli, such as:
Spontaneous body movements, such as:
Eyes opening and closing
• Diagnosis of coma is simple; however, diagnosing the cause of the
underlying disease process often proves to be challenging. The first
priority in treatment of a comatose patient is stabilization following the
basic ABCs (standing for airway, breathing, and circulation). Once a
person in a coma is stable, investigations are performed to assess the
underlying cause. Investigative methods are divided into physical
examination findings and imaging (such as CAT scan, MRI, etc.) and
special studies .
• When an unconscious patient enters a hospital, the hospital utilizes a
series of diagnostic steps to identify the coma
• Perform a general examination and medical history check
• Make sure patient is in an actual comatose state and is not mistaken for
locked-in state (patient will either be able to voluntarily move his eyes or
blink) or psychogenic unresponsiveness
• Find the site of the brain that may be causing coma (i.e. brain stem, back
of brain…) and assess the severity of the coma with the Glasgow coma
• Take blood work to see if drugs were involved or if it was a result of
• Check for levels of “serum glucose, calcium, sodium, potassium,
magnesium, phosphate, urea, and creatinine”
• Perform brain scans to observe any abnormal brain functioning using
either CT or MRI scans
• Continue to monitor brain waves and identify seizures of patient using
Initial assessment and evaluation
• In the initial assessment of coma, it is common to gauge the level of
consciousness by spontaneously exhibited actions, response to vocal
stimuli ("Can you hear me?"), and painful stimuli; this is known as the
AVPU (alert, vocal stimuli, painful stimuli, unresponsive) scale. More
elaborate scales, such as the Glasgow Coma Scale, quantify an
individual's reactions such as eye opening, movement and verbal
response on a scale; Glasgow Coma Scale (GCS) is an indication of the
extent of brain injury varying from 3 (indicating severe brain injury and
death) to a maximum of 15 (indicating mild or no brain injury).
• In those with deep unconsciousness, there is a risk of asphyxiation as the
control over the muscles in the face and throat is diminished. As a result,
those presenting to a hospital with coma are typically assessed for this
risk ("airway management"). If the risk of asphyxiation is deemed to be
high, doctors may use various devices (such as an oropharyngealairway,
nasopharyngeal airway or endotracheal tube) to safeguard the airway.
Imaging and special tests findings
• Imaging basically encompasses computed tomography scan of the brain,
or MRI for example, and is performed to identify specific causes of the
coma, such as haemorrhage in the brain or herniation of the brain
structures. Special tests such as an EEG can also show a lot about the
activity level of the cortex such as semantic processing,presence of
seizures, and are important available tools not only for the assessment
of the cortical activity but also for predicting the likelihood of the
patient's awakening. The autonomous responses such as the Skin
Conductance Response may also provide further insight on the patient's
• The prognosis for a coma varies with each situation. The chances of a
person's recovery depend on the cause of the coma, whether the
problem can be corrected, and the duration of the coma. If the problem
can be resolved, the person can often return to his or her original level
of functioning. Sometimes, though, if the brain damage is severe, a
person may be permanently disabled or never regain consciousness.
• Comas that result from drug poisonings have a high rate of recovery if
prompt medical attention is received. Comas that result from head
injuries tend to have a higher rate of recovery than comas related to lack
• It can be very difficult to predict recovery when a person is a coma.
Every person is different and it is best to consult with your doctor. As we
would expect, the longer a person is in a coma, the worse the prognosis.
Even so, many patients can wake up after many weeks in a coma.
However, they may have significant disabilities.
• Maintain ventilation oxygenation
• Maintain circulation
• Control seizure
• Reduce icp
• Maintain temperature
• Control hypoglycemia
• Insert oral airway
• Clean oropharyngeal secretion
Some medicines used are as follows:• inj. Lorazepam 4mg
• Inj diazepam 10-12mg
• Inj phenytoin 15-20mg
• Injmenintol 20% 1 gm/kg iv fast