Steps in assessing Brain Death.

PART 1

The physician determines that there is no motor response and the eyes do not open when a painful stimulus is applied to the supraorbital nerve or nail bed.

PART 2

A clinical assessment of brainstem reflexes is undertaken.

The tested cranial nerves are indicated by Roman numerals; the solid arrows represent afferent limbs, and the broken arrows efferent limbs. Depicted are the absence of grimacing or eye opening with deep pressure on both condyles at the level of the temporomandibular joint (afferent nerve V and efferent nerve VII), the absent corneal reflex elicited by touching the edge of the cornea (V and VII), the absent light reflex (II and III), the absent oculovestibular response toward the side of the cold stimulus provided by ice water (pen marks at the level of the pupils can be used as reference) (VIII and III and VI), and the absent cough reflex elicited through the introduction of a suction catheter deep in the trachea (IX and X).

PART 3

The apnea test is performed; the disconnection of the ventilator and the use of apneic diffusion oxygenation require precautionary measures. The core temperature should be ≥ 36˚C, the systolic blood pressure should be 90 mm Hg or higher, and the fluid balance should be positive for 6 hours. After preoxygenation (the fraction of inspired oxygen should be 1.0 for 10 minutes), the ventilation rate should be decreased. The ventilator should be disconnected if the partial pressure of arterial oxygen reaches 200 mm Hg or higher and if the partial pressure of arterial carbon dioxide reaches 40 mm Hg or higher.

PART 4

The oxygen catheter should be at the carina (delivering oxygen at a rate of 6 L/ min) shown here is the position of the oxygen catheter in an endotracheal tube. The physician should observe the chest and the abdominal wall for respiration for 8– 10 minutes and should monitor the patient for changes in vital functions. If there is a partial pressure of arterial carbon dioxide of 60 mm Hg or higher or an increase of more than 20 mm Hg from the normal baseline value, apnea is confirmed.