Clinical recommendations for use of lidocaine lubricant during bowel care after spinal cord injury prolong care routines and worsen autonomic dysreflexia: results from a randomised clinical trial.

STUDY DESIGN: Clinical trial. OBJECTIVE: Spinal cord injury (SCI) impacts autonomic function and bowel management. Bowel care is a potential trigger for autonomic dysreflexia (AD; paroxysmal hypertension elicited by sensory stimuli below the level of lesion). AD can be life threatening so strategies to minimise AD are prioritised after SCI. Lidocaine lubricant is recommended during bowel care with the rationale to minimise the sensory stimulus, reducing AD. The objective of this study was to assess whether lidocaine lubricant (Xylocaine 2%) ameliorates AD during at-home bowel care compared with standard lubricant (placebo). SETTING: Community. METHOD: Participants (n = 13; age 44.0 ± 3.3 years) with high-level SCI (C3-T4) performed their normal at-home bowel care on two days, each time using a different lubricant, with continuous non-invasive cardiovascular monitoring. Injury to spinal autonomic (sympathetic) nerves was determined from low-frequency systolic arterial pressure (LF SAP) variability. RESULTS: Participants displayed reduced autonomic function (LF SAP 3.02 ± 0.84 mmHg2), suggesting impaired autonomic control. Bowel care duration was increased with lidocaine (79.1 ± 10.0 min) compared to placebo (57.7 ± 6.3 min; p = 0.018). All participants experienced AD on both days, but maximum SAP was higher with lidocaine (214.3 ± 10.5 mmHg) than placebo (196.7 ± 10.0 mmHg; p = 0.046). Overall, SAP was higher for longer with lidocaine (6.5 × 105 ± 0.9 × 105 mmHg • beat) than placebo (4.4 × 105 ± 0.6 × 105 mmHg • beat; p = 0.018) indicating a higher burden of AD. Heart rate and rhythm disturbances were increased during AD, particularly with lidocaine use. CONCLUSIONS: At-home bowel care was a potent trigger for AD. Our findings contradict recommendations for lidocaine use during bowel care, suggesting that anaesthetic lubricants impair reflex bowel emptying, resulting in longer care routines with an increased burden of AD.