0071643192.pdf

CAUSES

Causes are myriad and include:

■ Encephalopathy—metabolic, hypertensive, hypoxic, Wernicke’s

■ Toxins (see Table 15.9)

■ Drug reaction

■ Infection

■ Hyper-/hypothermia

■ Seizure

■ Psychiatric

■ CNS lesion or event (less common)

■ Sepsis

SYMPTOMS/EXAM

■ Eyes-closed state with inappropriate response to environmental stimuli

■ Other findings vary depending on depth of coma and underlying etiology

(see Table 15.10).

■ Look for asymmetric findings that suggest focal or regional CNS dysfunction.

DIAGNOSIS

■ Diagnosis is made based on clinical findings.

■ Evaluation should focus on identifying underlying cause.

■ Obtain head CT, glucose, electrolytes, renal, and liver function tests.

■ Consider EEG to evaluate for nonconvulsive status epilepticus in all.

TREATMENT

■ Supportive care

■ Coma “protocol” (intravenous) for the undifferentiated patient

■ Thiamine

■ Glucose

■ Naloxone

■ Treat underlying cause once identified.

■ Empiric antibiotic coverage for meningitis if cause not readily apparent

NEUROLOGY

Causes of coma—

TIPS AEIOU

Trauma, temperature

Infection

Psychiatric, poisonings

Space occupying lesion,

subarachnoid

Alcohol

Epilepsy, electrolytes,

enceophalopathy

Insulin

Opioids/overdose,

oxygen (hypoxia, CO 2

narcosis)

Uremia (metabolic)

Oculovestibular reflex:

Direction of fast

component of

nystagmus, with

irrigation of cold

versus warm water in

patient with intact

brainstem—

COWS

Cold

Opposite

Warm

Same

TABLE 15.9. Common Toxicologic Causes of Coma

Alcohols

Antipsychotics

Antiseizure medications

Carbon monoxide

Muscle relaxants

Opiates

Sedative/hypnotics