The patient's vital signs on arrival to the emergency department were as follows: temperature, 97.8°F; BP, 60/40 mm Hg in both arms; pulse, 56 beats/min; respiration, 23 breaths/min; and arterial oxygen saturation, 98% on ambient air. The patient was lethargic but answered questions appropriately. His lungs were clear to auscultation bilaterally. A cardiovascular examination revealed bradycardia without murmurs, rub, or gallop. He had weak symmetric pulses in the upper and lower extremities. His abdomen was soft, nontender, and without bruit. On neurologic examination, cranial nerves 2 to 12 were intact, strength was grade 5/5 in the upper extremities and 0/5 in the lower extremities, with arreflexia in the bilateral lower extremities. There was loss of sensation to touch from the umbilicus down, and rectal tone was absent.