What is coma? A coma ( from the Greek Koma, meaning deep sleep) is a profound state of unconsciousness, in which a person is unresponsive and unarousable. Reflex movements and posturing maybe present
Biology of consciousness Two components of conscious behavior content- the sum of cognitive and affective function arousal- appearance of wakefulness Content depends on arousal but normal arousal does not guarantee normal content
Clues from History Onset of symptoms sudden onset fluctuations Associated neurologic symptoms Medications
Physical examination General examination. A thorough general examination, including vital signs, helps to establish and rule out potential causes of coma. Look for evidence of head trauma or metabolic encephalopathy.
Breathing . Cheyne-Stokes respiration: cerebral hemispheric or diencephalic injury or an encephalopathy (hypoxic or metabolic). Central hyperventilation: brainstem injury. Ataxic or Biot’s respiration, which can progress to apnea: injury to the reticular formation in the medulla and pons.
Eye examinationPupils (size, shape, position, PERLA)- Unilateral horner syndrome= hypothalamic lesion- Ipsilaterl pupil dilation= 3rd nerve palsy due to uncal herniation- Smaller than normal but reactive= metabolic encephalopathy- Fixed, dilated= overdose of atropine- Pinpoint, responsive= opiates
TREATMENT Appropriate treatment must be commenced concomitantly with routine measures Treat according to the cause The "Coma Cocktail" Its a mixture of thiamine 50mg , dextrose 50 % (25g) , and naloxene 0.4-1.2 mg given intravenously.
Other treatments Antibiotics Anticonvulsants Warm the pt if hypothermic Correct any electrolyte or metabolic imbalance Reduce raised ICP with diuretics or surgery Ventilation/ cardiovascular support
Long term treatment preventing infections such as pneumonia maintaining the patients physical state (preventing bed sores, for example) providing adequate nutrition.
PROGNOSIS The prognosis in comatose patients is typically poor except for those that are drug- related or result from traumas. In general, the longer the coma lasts, the poorer the prognosis. Coma rarely lasts longer than 4 weeks, after which, transition into a vegetative state or recovery occurs