A patient unexpectedly does not “wake up” at the end of an anesthetic and is taken to the PACU

Dr. Falk discusses what needs to be done when a patient unexpectedly does not “wake up” at the end of a general anesthetic: An unresponsive patient in the recovery suite should be approached as if they have a life threatening condition.  Immediate evaluation and survey should include the basics of resuscitation.  Can the patient maintain an airway? Are they respiring effectively?  Are hemodynamic parameters adequate?  If this initial survey is satisfactory further investigation to determine the cause of unconsciousness should be performed.  Oxygenation should be immediately assessed with a pulse oximeter.  A blood gas should be sent to determine ventilatory adequacy and for a quick determination of metabolic abnormalities (pH, PaCO2, glucose, hyper/hyponatremia, hypo/hypercalcemia).  Other labwork should include a chemistry panel and a CBC.  A thorough neurologic exam should be performed checking basic reflexes (pupil response and size, corneal, cough/gag reflex).  In the absence of protective airway reflexes the patient should be intubated.  If there is no suspicion of metabolic abnormalities or residual anesthetic drug, neurologic imaging and testing should be the next diagnostic step including CT scan and EEG.

A Quick Differential Diagnosis includes:

Hypoxemia

Hypercarbia

Hypotension

Hypoglycemia

Narcotic Excess

Residual Neuromuscular Blocking Drug

Residual Volatile Anesthetic

Residual intravenous sedative drugs (midazolam, propofol, etomidate, ketamine, et al)

Central Cholinergic Syndrome (atropine, scopolamine, etc.)

Stroke
Seizure (non-convulsive status epilepticus)

Hypernatremia

Hyponatremia

Hypophosphatemia

Hypo/Hypercalcemia

Severe Anemia

Scott A Falk, M.D., is Assistant Professor of Anesthesiology and Critical Care, Department of Anesthesiology and Critical Care University of Pennsylvania, Philadelphia.  He is also Medical Director of the Post Anesthesia Care Unit at the Hospital of the University of Pennsylvania

Comments

[Rex Russell]

Very nice quick reference. I would also like to include another possibility; Central anticholinergic syndrome. This etiology of delayed emergence may not be as uncommon as we thought. I believe I took care of a patient who represented an extreme case of this years ago as a new attending at Johns Hopkins. Unfortunately, I did not recognize it as such and she went to the ICU for a FULL work up(all negative) and woke up on POD 0 late in the evening with no sequelae. Had we tried a small dose of physostigmine it may have solved the mystery. I recently posted on my blog about this case.

[David Smith]

Thank you for your comment.
I have updated the entry
I was particularly embarrassed by the omission since one of my first published case reports as a resident was on the subject of delayed emergence after atropine (Smith DS, Gardner SM, Orkin FK: Prolonged Sedation After Intraoperative Atro¬pine in Two Elderly Patients. Anesthesiology 51:348-349, 1979).

[gclub]

Great idea...you have some of my favorite people contributing to your blog. I enjoy it a great deal. I'm still working out how to do links neatly but in the meantime will keep it as a post...up now.