Coma

A profound state of unconsciousness

Consciousness

A measurement of arousability and responsiveness to environmental

stimuliA vital sign

Levels of consciousness Conscious- normal attention & wakefulness Confused- disoriented, slow thinking & response Delirious- disoriented, restless, marked attention

deficit Somnolent- sleepy, excessive drowsiness Obtunded- decreased alertness, slowed psychomotor

responses Stuporous- deep sleep, no spontaneous activity,

respond by grimacing/withdrawl Coma- no arousal, no response to stimuli

Impaired consciousness- causes Hypoxia Shock Uremia/HE Hyper/hypoglycemia Hypo/hypernatremia Dehydration Acidosis/alkalosis

Hyper/hypothermia Drugs/alcohol CNS Stroke Trauma Infection Ictal/post-ictal Raised ICP

Pathophysiology of Coma

Bilaterally impairedascending reticular activating system

(receives all sensory input)

Coma- causes

~64% metabolic~33% brain

(2/3rd supratent., 1/3rd infratent.)~1% psychiatric

Coma- classification No focal signs, normal CSF cytology- Metabolic, poisoning, sepsis, shock,

hypo/hyperthermia, epilepsy, eclampsia, concussion

No focal signs, abnormal CSF- SAH, meningitis, encephalitis Focal signs, abnormal CT scan- CVA, head injury, abscess, tumor

Coma- evaluation History Examination- temperature, color, PR,

BP, breath odour, breathing Neurological examination- Observe- posture, spontaneous movement, breathing State of responsiveness- GCS Pupil & eye examination Retinal examination, papilledema Plantar reflex Other reflexes- corneal, Doll’s eye, gag

Glasgow coma scale Eye opening response 1- none 2- to painful stimuli 3- to verbal stimuli 4- spontaneously

Verbal response 1- no sound 2- incomprehensible sounds 3- inappropriate words 4- coherent, disoriented 5- oriented, converses normally

Motor response 1- no movement 2- extension to painful stimuli 3- abnormal flexion to pain 4- withdrawl to pain 5- localizes pain 6- obeys command

Score- Minimum- 3- deep coma Maximum- 15- fully awake Severe- ≤8, Minor- ≥13

Glasgow Coma Scale Best eye, verbal, motor response

Expressed as ExVxMx, total score

Used for initial assessment and subsequent monitoring of altered sensorium

Breathing pattern Cheyne-Stokes- cerebral Central hyperventilation- upper pontine Apneustic- lower pontine Ataxic- medullary

Kussmaul- acidotic hyperventilation

Coma- investigation CT scan

CSF examination

Gastric lavage, in suspected poisoning

Urine & blood examination, as needed

Management Airway.Breathing.Circulation (ABC)-

basic life support Oxygen, glucose, thiamine Naloxone, Flumazenil Mannitol & steroids for raised ICT Seizure control Catheterization, IV fluids, feeding Good nursing care

Treat underlying cause Surgery, if required for a hemorrhage or SOL

Coma- prognosis Depends on cause, duration & depth No pupillary or eye response within 6

hours- 95% mortality After trauma, GCS- 3-5 indicates fatal

brain damage Early return of verbal response,

spontaneous eye movements or ability to follow commands is good sign

Locked-in syndrome

Mute, quadriparesisAwareness with responsiveness

by partial eye movementsAcute ventral pontine lesion

Persistent vegetative state

No responsiveness or awareness with preserved autonomic & motor reflexes and

sleep-wake cyclesSevere global cerebral dysfunction

sparing brainstem

Brain death Absence of cerebral function- No movement, spontaneous or stimulated Absence of brainstem function- Apnea/no spontaneous respiration over 10 minutes No spontaneous eye movement Absent Doll’s eye movement & corneal reflex Dilated fixed pupils Irreversibility- over at least 6 hours No hypothermia or residual intoxication

Brain death

Equivalent to deathImportant when considering

organ transplantation