We determined whether the cardiovascular responses to endotracheal intubation change as a function of the time elapsed after injury and the level of injury in patients with spinal cord injury.

One-hundred-eighty six patients with complete cord injury were grouped into 3 according to the level of injury: high- (T1-T4, n = 34), mid- (T5-T10, n = 47) and low paraplegics (< T10, n = 105). They were further divided into 5 according to the time elapsed since injury: < 4 wks, 4 wks-1 yr, 1-5 yrs, 5-10 yrs, and > 10 yrs. Twenty-five patients with no cord injury served as controls. Systolic arterial blood pressure (SAP), heart rate (HR), and plasma catecholamine concentrations were measured.

The intubation caused an increase of SAP and norepinephrine concentrations in every group. However, the magnitude of their peak increases was less in high paraplegics compared with all other groups (P < 0.05). HR was similarly increased in all groups (P < 0.01). Pressure but not either HR or norepinephrine response was enhanced in mid- and low-paraplegics whose injury elapsed more than 10 yrs compared with controls (P < 0.05). The incidence of arrhythmias did not differ among the groups.

The pressure and plasma catecholamine changes associated with endotracheal intubation may be attenuated in high-paraplegics, and the pressure changes may be enhanced over time in mid- and low-paraplegics.