Critical Care Medicine-Neurologic Disorders>>>>>Encephalopathy and Delirium
Question 5#

A 72-year-old man has survived a witnessed cardiac arrest with return of spontaneous circulation after 32 minutes of cardiopulmonary resuscitation. There was a delay with securing advanced airway—an emergency tracheostomy was performed 15 minutes after onset of chest compressions. He is now in the ICU 72 hours after the arrest, intubated, showing no signs of discomfort off of sedative or analgesic medications.

Which of the following is MOST likely to predict an adverse clinical outcome in this patient?

A. Plasma lactate 7 mmol/L
B. K 6.0 mEq/L
C. Segmental pulmonary embolus on computed tomography
D. Urine output 0.1 mL/kg/hr
E. Extensor response to pain

Correct Answer is E

Comment:

Correct Answer: E

This patient has likely suffered hypoxic-ischemic brain injury in the setting of cardiac arrest with significant duration of cerebral hypoperfusion. Despite clinical and laboratory evidence of multiorgan failure, his neurologic injury due to global cerebral ischemia is a critical predictor of severe long-term disability. The Quality Standards Subcommittee of the American Academy of Neurology has reported the following level A markers of poor prognosis when assessed 3 days after cardiopulmonary resuscitation:

1. Absent pupillary light response or corneal reflexes
2. Extensor or no motor response to pain

The duration of cardiopulmonary resuscitation >30 minutes and anoxia >10 minutes (due to delay with advanced airway) are other risk factors for unfavorable prognosis in this patient.

This patient is suffering from severe tissue hypoxia (Answer A), has signs of organ failure (Answer D) with metabolic abnormalities (Answer B). Both shock and acute renal failure decrease the accuracy of clinical examination-based prognostication in hypoxic-ischemic encephalopathy. Segmental pulmonary embolus is a less reliable predictor of adverse clinical outcome than extensor response to pain, a sign of likely severe neurologic disability.

References:

1. Wijdicks EF, Hijdra A, Young GB, et al. Practice parameter: Prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review): report of the quality standards subcommittee of the American Academy of Neurology. Neurology. 2006;67:203-210.
2. Booth CM, Boone RH, Tomlinson G, et al. Is this patient dead, vegetative, or severely neurologically impaired? assessing outcome for comatose survivors of cardiac arrest. JAMA. 2004;291:870-879.
3. Golan E, Barrett K, Alali AS, et al. Predicting neurologic outcome after targeted temperature management for cardiac arrest: Systematic review and meta-analysis. Crit Care Med. 2014;42:1919-1930.
4. Berek K, Jeschow M, Aichner F. The prognostication of cerebral hypoxia after out-of-hospital cardiac arrest in adults. Eur Neurol. 1997;37:135- 145.