Coma. The patient must exhibit complete loss of consciousness, vocalization and volitional activity.

• Patients must lack all evidence of responsiveness. Eye opening or eye movement to noxious stimuli is absent.

• Noxious stimuli should not produce a motor response other than spinally mediated reflexes. The clinical differentiation of spinal responses from retained motor responses associated with brain activity requires expertise.

Loss of all brain stem reflexes including:

Midposition or fully dilated pupils which do not respond to light.

Absence of pupillary response to a bright light is documented in both eyes. Usually the pupils are fixed in a midsize or dilated position (4–9 mm). When uncertainty exists, a magnifying glass should be used.

Absence of movement of bulbar musculature including facial and oropharyngeal muscles.

Deep pressure on the condyles at the level of the temporomandibular joints and deep pressure at the supraorbital ridge should produce no grimacing or facial muscle movement.

Absent gag, cough, sucking, and rooting reflex

The pharyngeal or gag reflex is tested after stimulation of the posterior pharynx with a tongue blade or suction device. The tracheal reflex is most reliably tested by examining the cough response to tracheal suctioning. The catheter should be inserted into the trachea and advanced to the level of the carina followed by 1 or 2 suctioning passes.

Absent corneal reflexes

Absent corneal reflex is demonstrated by touching the cornea with a piece of tissue paper, a cotton swab, or squirts of water. No eyelid movement should be seen. Care should be taken not to damage the cornea during testing.

Absent oculovestibular reflexes

The oculovestibular reflex is tested by irrigating each ear with ice water (caloric testing) after the patency of the external auditory canal is confirmed. The head is elevated to 30 degrees. Each external auditory canal is irrigated (1 ear at a time) with ∼10 to 50 mL of ice water. Movement of the eyes should be absent during 1 minute of observation. Both sides are tested, with an interval of several minutes.

Apnea. The patient must have the complete absence of documented respiratory effort (if feasible) by formal apnea testing demonstrating a Paco₂ ≥ 60 mm Hg and ≥ 20 mm Hg increase above baseline.

• Normalization of the pH and Paco₂, measured by arterial blood gas analysis, maintenance of core temperature > 35°C, normalization of blood pressure appropriate for the age of the child, and correcting for factors that could affect respiratory effort are a prerequisite to testing.

• The patient should be preoxygenated using 100% oxygen for 5–10 minutes prior to initiating this test.

• Intermittent mandatory mechanical ventilation should be discontinued once the patient is well oxygenated and a normal Paco₂ has been achieved.

• The patient's heart rate, blood pressure, and oxygen saturation should be continuously monitored while observing for spontaneous respiratory effort throughout the entire procedure.

• Follow up blood gases should be obtained to monitor the rise in Paco₂ while the patient remains disconnected from mechanical ventilation.

• If no respiratory effort is observed from the initiation of the apnea test to the time the measured Paco₂ ≥ 60 mm Hg and ≥ 20 mm Hg above the baseline level, the apnea test is consistent with brain death.

• The patient should be placed back on mechanical ventilator support and medical management should continue until the second neurologic examination and apnea test confirming brain death is completed.

• If oxygen saturations fall below 85%, hemodynamic instability limits completion of apnea testing, or a Paco₂ level of ≥ 60 mm Hg cannot be achieved, the infant or child should be placed back on ventilator support with appropriate treatment to restore normal oxygen saturations, normocarbia, and hemodynamic parameters. Another attempt to test for apnea may be performed at a later time or an ancillary study may be pursued to assist with determination of brain death.

• Evidence of any respiratory effort is inconsistent with brain death and the apnea test should be terminated.

Flaccid tone and absence of spontaneous or induced movements, excluding spinal cord events such as reflex withdrawal or spinal myoclonus.

• The patient's extremities should be examined to evaluate tone by passive range of motion assuming that there are no limitations to performing such an examination (eg, previous trauma, etc) and the patient observed for any spontaneous or induced movements.

• If abnormal movements are present, clinical assessment to determine whether or not these are spinal cord reflexes should be done.