Definition
Failure to regain consciousness as expected within 20-30 min of the end of a surgical procedure - with all anesthetic off.
Causes
Anesthesic effect:
- Residual drug effects
- Absolute or relative overdose
 - Potentiation of agents by prior medications or intoxication.
 - Organ dysfunction (e.g. renal, liver) interfering with metabolism/excretion
 
 - Hypercapnia/hypoxemia
 - Hypothermia (<34 C)
 
Electrolytes:
- Hypo/hyperglycemia
 - Metabolic disturbances (Hyponatremia, hypo/hypercalcemia, hypomagnesemia)
 
Neuro:
- Neurologic insults (seizure/post ictal state or Increased ICP)
 - Perioperative stroke
- Risk Factors: A Fib, hypercoagulable state, intracardiac shunt
 - Incidence: 0.4% with low-risk procedures; 2.5-5% with high risk prcoedures.
 
 
Management
- 
Administer reversal agents:
- Naloxone 0.40mg - 2mg IV Q2-3 min (can dilute to give in 0.04mg increments). If no response after 10mg, reconsider narcoic overdose as cause for delayed emergence.
 - Flumazenil 0.2 mg IV bolus 45-60 seconds over 15 min. No more than 3mg total in one hour.
 - Physiostigmine 1-2 mg IV (for central cholinergic syndrome)
 - Neostigmine - maximum of 5 mg IV. Give with glycopyrolate.
 
 Ensure patient is normothermic (use bair hugger, warm the room).
- Check ABG for PaO2, PaCO2, glucose and electrolytes.
 - Consider neurological insults (seizures/strokes/increased ICP).