Effectiveness of continuous hypertonic saline infusion with an automated infusion pump for decompressive neuroplasty: a randomized clinical trial

Background: Hypertonic saline (HS) injections for decompressive neuroplasty (DN) can cause pain. We assessed whether a continuous infusion of HS through an infusion pump would reduce injection-related pain compared with repeated bolus administrations. Methods: Fifty patients scheduled for DN were randomized to either the bolus injection or the continuous infusion group. After appropriately placing the epidural catheter, 4 mL of 5% NaCl was injected as four boluses of 1 mL each at 15-minute intervals or infused over 1 hour using an infusion pump. The severity of pain induced by HS injection, as measured by the 11-point numerical rating scale (NRS), was the primary outcome. The severity of low back or lower extremity pain, as measured by the 11-point NRS and Oswestry Disability Index (ODI), 3 months following the procedure, was the secondary outcome. Results: Data from 21 patients in the bolus group and 23 in the continuous infusion group were analyzed. No statistically significant difference in injection-related pain was identified between the two groups during the initial HS administration (P = 0.846). However, there was a statistically significant reduction in injection-related pain in the continuous infusion group compared to the bolus injection group from the second assessment onwards (P = 0.001, < 0.001, and < 0.001, respectively). No significant between-group differences in the NRS and ODI scores 3 months post-procedure were noted (P = 0.614 and 0.949, respectively). Conclusions: Our study suggests that administering HS through a continuous infusion is a useful modality for reducing HS injection-related pain during DN.