A 65-year-old man was admitted to the intensive care unit after going into cardiac arrest when alone at home. Cardiopulmonary resuscitation and advanced cardiac life support were performed extensively in the field, and return of spontaneous circulation was eventually achieved. Two days later, he remains intubated and is on full ventilator support. The patient is unresponsive to verbal and tactile stimuli. His temperature is 37.2 C (99 F), blood pressure is 110/70 mm Hg, and pulse is 70/min. The treating physician discusses with the patient's family the possibility of brain death.
Which of the following is most consistent with the criteria for brain death?

Question

A 65-year-old man was admitted to the intensive care unit after going into cardiac arrest when alone at home.  Cardiopulmonary resuscitation and advanced cardiac life support were performed extensively in the field, and return of spontaneous circulation was eventually achieved.  Two days later, he remains intubated and is on full ventilator support.  The patient is unresponsive to verbal and tactile stimuli.  His temperature is 37.2 C (99 F), blood pressure is 110/70 mm Hg, and pulse is 70/min.  The treating physician discusses with the patient's family the possibility of brain death. 
Which of the following is most consistent with the criteria for brain death?

Quizplus · Accepted Answer

Explanation: Brain death is the irreversible absence of cerebral and brain stem function. Clinical criteria suggesting brain death include clinical and brain imaging evidence of a devastating cause, absence of confounding factors (eg, major endocrine or electrolyte disturbances, drug intoxication), and hemodynamic stability (core body temperature >36 C [96.8 F], systolic blood pressure >100 mm Hg). Neurologic examination typically shows irreversible absence of cerebral and brainstem reflexes including pupillary, oculocephalic, oculovestibular (caloric), corneal, gag, sucking, swallowing, and extensor posturing. (Choice A) A positive apnea test can confirm brain death by documenting an absent respiratory response off the ventilator for 8-10 minutes with a PaCO₂ >60 mm Hg (or >20 mm Hg from baseline) and a final arterial pH <7.28. (Choice B) Hypothermia can confound brain testing, and a patient with hypothermia requires a warming blanket to increase body temperature to >36 C (96.8 F). (Choices C and E) Other ancillary testing includes electroencephalography (electrocerebral silence or absence of somatosensory or brainstem evoked potentials) or brain imaging (eg, transcranial Doppler) showing the absence of intracranial blood flow. There also may be local laws listing further criteria (eg, >24 hours of observation) needed for the diagnosis of brain death. Educational objective: Brain death is the irreversible absence of all cerebral and brainstem reflexes. There are no spontaneous breaths, regardless of hypercarbia or hypoxemia. A brain death diagnosis requires a central nervous system catastrophe of known etiology with an absence of confounding factors (eg, endocrine or electrolyte disturbances, drug intoxication) and hypothermia. References: Diagnosis of brain death. (http://www.ncbi.nlm.nih.gov/pubmed/21577338)

A 65-Year-Old Man Was Admitted to the Intensive Care Unit