Autonomic dysreflexia during urodynamic examinations in patients with suprasacral spinal cord injury

Abstract

Objective: To investigate blood pressure (BP) and pulse rate (PR) changes during urodynamic (UD) examinations in patients with suprasacral spinal cord injury (SCI).

Design: A case control study.

Setting: Tertiary hospital affiliated with a medical university.

Patients: Control subjects (n=22) and patients with suprasacral SCI (n=120).

Interventions: Not applicable.

Main outcome measures: Systolic (SBP) and diastolic BP (DBP) and PR before and during UD studies.

Result: Healthy subjects had an average SBP change of 9.7 ± 10.6 mm Hg and a maximal SBP increase of 21 mm Hg. Autonomic dysreflexia (AD) was defined as an SBP increase of 20mm Hg or more, and incidence rates were 36.7% overall, 42.6% in patients with injury level at or above T6, and 15.4% in patients with lesions below T6. Both SBP and DBP changes in patients with SCI showed significant negative correlations with injury levels (r=-.383 and -.315; P<.05). The BP increase was more significant in patients with SCI who had detrusor sphincter dyssynergia (DSD), especially the continuous type, or severely impaired bladder compliance than in those who did not. Most patients (75%) had no significant PR changes (within 10 beats/min) during AD responses and only 22.7% had a decrease of 10 beats/min or more. Patients younger than 50 years had a greater PR decrease than those 50 years or older (-7.1 ± 9.0 vs 0.7 ± 11.4 beats/min; P<.05).

Conclusions: AD occurred not only in patients with lesions above T6, but also in those with lower lesion levels. Patients with higher injury level, continuous DSD, or a poorly compliant bladder had greater SBP changes during UD studies. During AD reactions, younger patients tended to have a greater PR decrease than older patients.