Patients suffering from coma will commonly present with the following signs and symptoms:

• Diminished brainstem reflexes (i.e. pupillary response)
• Closed eyes
• Extremities does not respond to movement
• Unresponsive to painful stimuli
• Intact reflexes in the extremities
• Irregular patterns of breathing

• Pain

  […] sounds 2 No response No response 1 Motor response† Moves spontaneously and purposefully Obeys commands 6 Withdraws to touch Localizes painful stimulus 5 Withdraws in response to pain Withdraws in response to pain 4 Responds to pain with decorticate posturing [merckmanuals.com]

  D4: Absence of any response to pain 9. Autonomic reactivity provides an assessment of the autonomous nervous system response to painful stimuli. Response to pain causes a period of apnea followed by tachypnea. Heart rate may increase or decrease. [doi.org]

• Fatigue

  Abstract A 48-year-old man was admitted to department of emergency medicine at a tertiary referral hospital due to dizziness and fatigue. [ncbi.nlm.nih.gov]

  Word origin ModL < Gr kōma (gen. kōmatos), deep sleep < IE base *keme-, to grow tired > Sans śamītē, to work, prepare, Gr kamatos, fatigue, effort coma in American English 2 (ˈkoʊmə ) nounWord forms: plural ˈcomae (ˈkoʊmi ) 1. [collinsdictionary.com]

  Diarrhea or constipation A feeling that your bowel does not empty completely Blood (either bright red or very dark) in your stool Stools that are narrower than usual Frequent gas pains or cramps, or feeling full or bloated Weight loss with no known reason Fatigue [medlineplus.gov]

  to work, prepare, Classical Greek kamatos, fatigue, effort noun pl. [yourdictionary.com]

  Common side effects of chemotherapy include: hair loss nausea fatigue vomiting Combination therapies often use multiple types of chemotherapy or combine chemotherapy with other treatments. [medicalnewstoday.com]

• Collapse

  We’ve once again been reminded of this after boxer Maxim Dadashev collapsed outside the ring after a bad 12 round beating at the hands of Subriel Matias. [mmamania.com]

  Still, analysts don't expect house prices to collapse in London. Inflation has moderated in recent months, employment remains strong and the British economy is growing. Lu said this should be considered "good news" for the stagnant market. [money.cnn.com]

  For example, any clinical process that causes circulatory collapse or profound hypoxemia may manifest as a coma. As little as fifteen seconds of circulatory collapse will result in loss of consciousness. [ncbi.nlm.nih.gov]

  “On 9 February, Tafida collapsed at home and suffered a cardiac and respiratory attack,” the petition continues. [independent.co.uk]

  ‘In one plot a taxi driver, who doesn't realise that he has diabetes despite having the classic symptoms, collapses into a coma in his car.’ ‘A large pulse through his brain sent him into a deep coma in which he slept for days.’ [en.oxforddictionaries.com]

• Myxedema

  […] coma scale C Coma blister Coma cocktail Coma scale D Diabetic coma Diffuse axonal injury G Glasgow Coma Scale H Hepatic encephalopathy I Induced coma Insulin shock therapy Intracranial injury with prolonged coma L List of people who awoke from a coma M Myxedema [en.wikipedia.org]

  […] coma Approximate Synonyms Acute ischemic stroke with coma Intracerebral hemorrhage with brain compression and coma Intracerebral hemorrhage, coma Intracerebral hemorrhage, w coma and brain compression Ischemic stroke w coma Ischemic stroke with coma Myxedema [icd9data.com]

  Anemia (low red blood cell count) Toxins Poisons External poisons are those that are ingested or inhaled Internal poisons are by-products of the body's normal metabolism that for some reason cannot be excreted properly Endocrine disorders Myxedema coma [emedicinehealth.com]

  Hormonal disorders: Patients having physiologic decompensation with hypothyroidism will result into a myxedema coma. Diabetes: Severe hyperglycemic states or hypoglycemic states may cause a stroke or a diabetic coma. [symptoma.com]

  Called also brain death. myxedema coma the mental stupor caused by severe hypothyroidism; seen most often in Doberman pinchers, it is associated with hypoventilation, hypothermia, hypotension and bradycardia. Death may occur. [medical-dictionary.thefreedictionary.com]

• Surgical Procedure

  Note that by this definition, doctors frequently put people into coma intentionally every time they use general anesthesia for a surgical procedure. [verywellhealth.com]

  One of the best reviews of experimental coma is Theodore Kocher's book on cerebral concussion, cerebral pressure and surgical procedures in cerebral disease (Kocher, 1901 ). [doi.org]

• Abnormal Breathing

  […] heart rate and blood pressure, as well as abnormal breathing and sweating, may also indirectly harm the functioning of the ARAS and lead to a coma. [en.wikipedia.org]

  Autonomic dysfunction: Patients may have abnormal breathing patterns (Cheyne-Stokes or Biot respirations), sometimes with hypertension and bradycardia (Cushing reflex). Abrupt respiratory and cardiac arrest may occur. [merckmanuals.com]

• Snoring

  In apoplexy, respiration is accompanied by snoring and the patient sleeps very deeply, can hardly be aroused, and all limbs are flaccid. [doi.org]

• Cheyne-Stokes Respiration

  Long-cycle, Cheyne-Stokes respiration - damage at the diencephalon. Short-cycle, Cheyne-Stokes respiration - damage at the medulla. Central neurogenic hyperventilation - lesions in the low midbrain and upper pons. [patient.info]

• Blister

  Immunohistochemical staining for CD45RO, CK-L, and M30 might be useful to observe sweat gland degeneration in the coma blister. Therefore, the apoptosis might be related to coma blisters and sweat gland degenerations. [ncbi.nlm.nih.gov]

  Coma B Blantyre coma scale C Coma blister Coma cocktail Coma scale D Diabetic coma Diffuse axonal injury G Glasgow Coma Scale H Hepatic encephalopathy I Induced coma Insulin shock therapy Intracranial injury with prolonged coma L List of people who awoke [en.wikipedia.org]

  […] word "coma" itself emerged from the Greek for "deep sleep" ( koma ) in around the 17th century, and methods throughout history for helping those in comas have included bloodletting from the head, emptying the stomach, cooling the body dramatically, blistering [bustle.com]

  […] for external bleeding or bone crepitation, snoring Cullen 1789 Coma, carus, cataphora, lethargy Trauma, tumor, intoxication, cerebral hemorrhage Loss of sense & voluntary motion, sometimes more on one side with convulsions on the other Bloodletting, blistering [doi.org]

• Anisocoria

  He was managed nonoperatively and discharged with a Glasgow Coma Scale score of 15, only to return 3 days later with obtundation, fixed downward gaze, anisocoria, and absent cranial nerve reflexes. [ncbi.nlm.nih.gov]

  ABG arterial blood gas, CSF cerebrospinal fluid, CT computed tomography, CTA computed tomography angiography, EEG electroencephalogram, SAH Subarachnoid hemorrhage The Coma Neuro Exam Carefully examine the eyes (Vertical Skew, Anisocoria, Eye Movements [emcrit.org]

  If one pupil is dilated, other causes of anisocoria should be considered; they include past ocular trauma, certain headaches, and use of a scopolamine patch (if the drug comes in contact with the eyes). [merckmanuals.com]

  Similar to Gowers Much in common with Gower's description Dana (in Dercum) 1895 Coma (transient) Hemorrhage Pupils contracted and immobile, anisocoria (more contracted on the sound side), eyes partly closed, slow heart beat, pulse hard and full. [doi.org]

• Suggestibility

  Other clues that can be gained from the examination: Clubbing suggests respiratory disease. Tracheal deviation, chest fluid or lung collapse suggest respiratory cause. [patient.info]

  Score < 8 suggests need for intubation and ventilation. Score ≤ 6 suggests need for intracranial pressure monitoring. † If the patient is intubated, unconscious, or preverbal, the most important part of this scale is motor response. [merckmanuals.com]

• Confusion

  Posterior reversible leukoencephalopathy syndrome (PRES) is a syndrome characterized by headache, hypertension, confusion, visual disturbance, and seizures accompanied by subcortical vasogenic edema, predominantly involving the parietal and occipital [ncbi.nlm.nih.gov]

  Untreated hypothyroidism may cause mental confusion and slowed thinking. The confusion may progress to stupor and coma. [msdmanuals.com]

• Stupor

  It's not considered stupor if you're just tired and sleepy from having been awake too long. Coma is when you're unconscious and can't be woken up, no matter what people try. [merckmanuals.com]

  The exception is in patients with catatonic stupor or catatonia. 3 Caloric testing in organic stupor will usually reveal tonic deviation, whereas in psychiatric stupor ocular nystagmus will be present. [jnnp.bmj.com]

  Stupor and Coma at the Merck Manuals Consumer version. What Is a Medically Induced Coma and Why Is It Used? at Scientific American. The Glasgow Coma Scale at the Institute of Neurological Sciences, Glasgow. [ilpi.com]

  KEYWORDS: catatonia; coma; conversion disorder; factitious; functional neurologic disorder; psychogenic; stupor; unconsciousness [ncbi.nlm.nih.gov]

• Lethargy

  Bacterial overgrowth can cause hyperammonemia that makes lethargy and loss of conscious and finally admitting in ICU. [ncbi.nlm.nih.gov]

  With respect to lethargy, Boerhaave taught: ‘Lethargy … is a brain disease accompanied by loss of motion and sense, with an irrepressible need to sleep, caused by cold, humid phlegm that moistens the brain, finally leading to putrefaction, slow fever [doi.org]

  Sometimes, the word coma is used humorously as a non-literal description of a state of extreme lethargy or sleepiness. For this meaning of coma as a literal or figurative unconscious state, the plural form is comas. [grammarist.com]

• Nystagmus

  The exception is in patients with catatonic stupor or catatonia. 3 Caloric testing in organic stupor will usually reveal tonic deviation, whereas in psychiatric stupor ocular nystagmus will be present. [jnnp.bmj.com]

  Oculovestibular testing (instil 20 ml ice-cold water into the external auditory meatus): Psychogenic coma - nystagmus with quick movement away from water (shows active pons and intact corticopontine connections). [patient.info]

  Except for the well-known phenomena on observation and examination described above, he mentioned the absence of nystagmus, emphasized the examination of brainstem reflexes, including the vestibulo-ocular reflexes and caloric stimulation tests (Biemond [doi.org]

• Dizziness

  Abstract A 48-year-old man was admitted to department of emergency medicine at a tertiary referral hospital due to dizziness and fatigue. [ncbi.nlm.nih.gov]

  These can include dyspnea, stupor, vertigo/dizziness, malaise, lethargy etc. Read the SDS for information about symptoms that may indicate exposure to the chemicals you are working with so you can address any issues before they grow more serious. [ilpi.com]

  Medical history Doctors may ask friends, family, police, and witnesses, if appropriate, the following: whether the coma or the preceding symptoms started slowly or suddenly if the person had or appeared to have any vision problems, dizziness, stupor, [medicalnewstoday.com]

A detailed clinical history is usually gathered from a reliable informant or a close family member in the case of a comatose patient. History regarding the events that surround the onset or the development of the coma is usually collected and chronologically assessed to determine the causative factor of the unconscious state. An extensive neurologic examination is done in all patients presenting with coma to determine the extent of the damage. Laboratory tests are also done to determine the exact causative factor of the disorder. The following laboratory tests are implored among patients with coma:

• Complete blood count (CBC)
• Blood pH levels [8]
• Electrolytes (Sodium and Calcium)
• Serum and intracranial glucose levels
• Thyroid function tests
• Liver enzymes 
• Alcohol levels in the serum
• Drug assays

Imaging techniques may elucidate the exact location of the pathology of the coma especially among patients with traumatic injuries:

• Computerized tomography (CT): A CT scan shows a detailed image of the brain demonstrating hemorrhage, tumors, and cerebrovascular ischemia.
• Magnetic resonance imaging (MRI): MRI renders a more enhanced view of the brain tissues damaged by ischemia, stroke, and hemorrhage.
• Electroencephalogram (EEG): This measures the electrical impulses of the brain and determine the presence of seizures as causative factor of the coma.

• Atelectasis

  Moving patients through the use of physical therapy also aids in preventing atelectasis, contractures or other orthopedic deformities which would interfere with a coma patient's recovery.[26] Pneumonia is also common in coma patients due to their inability [en.wikipedia.org]

• Burst Suppression

  The EEG showed then the appearance of burst suppression, which was compatible with a very severe pattern of post-anoxic coma. [ncbi.nlm.nih.gov]

  Burst-suppression In cases of very extensive anoxic damage there will be signs of combined metabolic failure and cortical disinhibition (26). This is called «burst-suppression» pattern. [tidsskriftet.no]

• Burst Suppression on EEG

  Burst-suppression In cases of very extensive anoxic damage there will be signs of combined metabolic failure and cortical disinhibition (26). This is called «burst-suppression» pattern. [tidsskriftet.no]

• Triphasic Waves

  This may cause epileptiform changes, varying in type and extent, such as spiked triphasic waves or periodic or persistent epileptic activity (24). [tidsskriftet.no]

All patients that present as coma in the hospital are always treated as a medical emergency. The airways and breathing of the patient are initially secured. Fluid resuscitation or blood transfusion may be immediately indicated in the case of coma with shock. In cases of hypoglycemic shock, patients are given a glucose bolus to reverse the metabolic state [9]. Intravenous antibiotics are sometimes given in case of severe brain and systemic infections. Medications to decrease brain pressure may alleviate the symptoms of brain edema in the case of brain trauma and ketoacidosis [10]. Anti-seizure medications are also given to patients with seizure disorders that precipitated the coma.

The general outlook for patients in coma greatly depend on the location, cause, size, and extent of the neurologic damage. Coma that renders the patient in vegetative state for more than 5 weeks usually carries a poor prognosis. Some patients may emerge from coma with learning, physical, and psychological difficulties that fails to improve in time. The prompt identification and intervention of these problems will increase the chances for a full recovery. The time duration of the coma is currently revered as the best predictor of partial and full recovery among affected patients [7].

There are a number of medical conditions that can precipitate into a coma. The following conditions are common causes of coma:

• Cerebrovascular disease or stroke: This medical condition is characterized by the sudden cessation of blood flow in the brain or a ruptured brain vessel that can lead to coma.
• Brain tumors: Tumors located within the brain and the brainstem may result into coma.
• Traumatic brain injuries: Any direct trauma to the brain can initiate a comatose state.
• Hormonal disorders: Patients having physiologic decompensation with hypothyroidism will result into a myxedema coma [1].
• Diabetes: Severe hyperglycemic states or hypoglycemic states may cause a stroke or a diabetic coma [2].
• Seizures: Persistent and uncontrolled seizures can result in a vegetative state of consciousness.
• Toxins: Extrinsic toxins from the environment like lead and carbon monoxide can damage the brain and lead to coma.
• Drugs and alcohol: The elicit abuse of certain drugs like alcohol may lead to coma.
• Cerebral infections: Brain swelling due to meningitis or encephalitis can precipitate permanent brain damage and coma.
• Hypoxic states: Patients who has been resuscitated from a heart attack or rescued from drowning will experience low levels of oxygen to the brain and cause coma.

Coma is a result of a primary metabolic condition or a direct head trauma. Because coma is treated as a complication of a disease rather than a primary disorder, there are no available epidemiologic studies and statistics on the actual incidence and prevalence of coma. However, there are prospective studies conducted in the United Kingdom based on population about the general incidence of non-traumatic coma among children reaching an average rate of 30.8 cases per 100,000 children [3]. In Europe, non-traumatic coma has been an important source of pediatric mortality and morbidity [4].

Coma induced by drugs accounts for 40% of the total cases seen in the clinics. Drugs damage or retard the synaptic function in the ascending reticular activating system (ARAS) which makes it hard for the brain to arouse from unconsciousness or from a vegetative state [5]. Other drugs that cause hallucinations, seizures and poisoning have been found to adversely affect the ARAS in the same way. Coma from brain hypoxia tallies to about 25% of the total coma cases seen in the hospitals. The progressive oxygen deprivation of the brain causes a decrease in the neuronal intracellular calcium and sodium which significantly hampers interneuron communications within the cerebrum [6]. Patients who sustain a stroke will have some form of blockage or thrombosis that prevents blood, oxygen, and nutrients from reaching certain areas of the brain resulting to cell death.

The best way to prevent the occurrence of coma is to actively prevent the events that may incite coma. The prudent practice of wearing helmet while driving motorcycles and bicycles can effectively prevent brain trauma significantly. Using of alcohol in moderation and abstinence from dangerous recreational drugs can prevent undue coma and death. Diabetics must achieve good glycemic control to avoid ketoacidotic coma and hypoglycemic coma. Mild seizures must be brought to proper medical care in soonest possible time to avoid coma as one of its serious complication.

Coma is a neurologic state of prolonged unconsciousness that results from various medical conditions like brain tumors, alcohol intoxication, diabetes mellitus, and cerebral infections. Coma is considered as a medical emergency, where all efforts are made to preserve life and brain functions as soon as the patient is brought to the emergency room. A number of tests are immediately done to determine its etiologic cause for the proper and prompt treatment of the medical condition. Coma usually last for several weeks, patients who stay comatose for more than a year will most likely stay in a persistent vegetative state.

Definition

Coma is a state of prolonged unconsciousness that may result from various medical factors like brain tumors, alcoholic intoxication, diabetes mellitus, trauma, and cerebral infections.

Cause

Majority of cases of coma is brought about by the intake drugs. Brain hypoxia and stroke are among the more common factors that triggers the clinical state. Sometimes seizures, diabetes, and hormonal imbalance may directly cause coma.

Symptoms

Patients are typically brought to the emergency room unconscious and eyes closed. They are usually not responsive to external stimuli like sound and pain but they maintain their deep tendon reflexes.

Diagnosis

A detailed clinical history is taken from the companion or witness. A complete physical examination and neurologic examination is also done on the patient. Blood tests for pH, CBC, thyroid and liver function test will be most helpful in the diagnostic process. Imaging modalities like CT and MRI may demonstrate bleeding and tumors within the brain.

Treatment and follow-up

The primary goal of treatment is to reverse the effects of the primary inciting factor that produces the coma. Glucose bolus with insulin for diabetic coma and fluid resuscitation for those with dehydration and electrolyte imbalance.

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