# Intraoperative Clonidine in Spine Surgery: A Randomised Controlled Trial

## TL;DR

A study found that using clonidine during spine surgery did not reduce post-surgery pain or opioid use, but increased the risk of low blood pressure.

## Contribution

This is the first randomized controlled trial evaluating intraoperative clonidine's effect on post-operative outcomes in spine surgery.

## Key findings

- Clonidine did not reduce opioid consumption within the first 3 hours after surgery.
- Pain intensity at rest was similar between clonidine and placebo groups.
- Clonidine increased the incidence of hypotension compared to placebo.

## Abstract

Patients undergoing spine surgery often experience post‐operative pain. In this context, clonidine, an alpha‐2 agonist, may be relevant due to its analgesic properties. We conducted a randomised, double‐blinded, placebo‐controlled trial to evaluate the effect of a single dose of intraoperative intravenous clonidine on post‐operative opioid consumption, pain intensity and side effects. Patients undergoing spine surgery at Aarhus University Hospital, Denmark, were randomised to receive intraoperative clonidine (3 μg/kg) or placebo. The primary outcome was opioid consumption within the first 3 h after surgery. Secondary outcomes included opioid consumption within the first 6 h, pain intensity at rest and during coughing, post‐operative nausea and vomiting (PONV), and sedation in the post‐anaesthesia care unit (PACU). Additional outcomes included time to discharge from the PACU, length of hospital stay and daily opioid consumption after 1 month. Data from 120 patients (49 females, 71 males, mean age 65 ± 14 years) were available for analysis; 61 received clonidine and 59 received placebo. Post‐operative intravenous morphine equivalents within 3 h were similar in the clonidine group 5 mg (0–15) and the placebo group 10 mg (0–15) (p = 0.58). Pain intensity at rest was 4 (0–5.5) in the clonidine group and 3 (0–5) in the placebo group upon arrival at the PACU (p = 0.20). No differences were observed between the clonidine and placebo groups regarding any secondary outcomes, except for hypotension, which was more frequent in the clonidine group (24 vs. 13 patients). A single dose of intraoperative clonidine did not reduce post‐operative opioid consumption or pain intensity in patients undergoing spine surgery.