Ketamine infusion for 96 hr after thoracotomy: Effects on acute and persistent pain

Abstract

Introduction Pain which persists after thoracotomy is well recognized, and activation of the N‐methyl‐d‐aspartate (NMDA) receptor could be a contributing factor. This study sought to establish whether ketamine given peri‐operatively could reduce persistent post‐surgical pain. Trial design Double‐blind, randomized, placebo‐controlled trial comparing low‐dose intravenous ketamine and saline placebo. Methods Seventy patients undergoing thoracotomy were randomized to receive either intravenous ketamine (0.1 mg kg−1 hr−1) or saline placebo for 96 hr, starting 10 min prior to surgery. A bolus dose of 0.1 mg/kg of ketamine/placebo was given prior to starting the infusion. Post‐operative analgesia consisted of either an epidural infusion or patient‐controlled analgesia (PCA), +/− a paravertebral infusion of local anaesthetic. Pain scores and opioid consumption were collected at 24 and 48 hr after surgery. Patients completed numeric pain scores (NPS), modified Brief Pain Inventory (BPI), the short form Leeds Assessment of Neuropathic Symptoms and Signs (S‐Lanss) at baseline, 6 weeks, 3, 6 and 12 months after surgery. Results There were no significant differences in post‐operative pain, except the ketamine group reported less pain at rest 48 hr after surgery (p = 0.03). The ketamine group requested significantly less morphine via PCA in the first 24 hr (p = 0.03). There were no differences in pain measures or opioid consumption at 6 weeks, 3, 6 or 12 months. Patients in the ketamine group were more lightheaded (p = 0.02) and experienced more vivid dreams (p = 0.001). Conclusions Ketamine reduced opioid consumption compared to placebo after surgery, but we were unable to detect any differences in persistent post‐surgical pain between the groups. Significance This study adds to the growing body of evidence advocating the use of ketamine to reduce opioid consumption. No previous studies of peri‐operative ketamine have followed patients for a year after thoracotomy. This study found no reduction in persistent post‐surgical pain.

Low dose intraoperative ketamine infusion with multilevel paravertebral block for pain after video-assisted thoracic surgery: a randomized-controlled study

“…Several studies have investigated the efficacy of intravenous ketamine on acute postoperative thoracotomy pain (12,19,(21)(22)(23)(24)(25). There is no consensus in standard dose, timing and route of administration of ketamine among studies (12).…”

Impact of Ketamine on Opioid Use and Persistent Pain After Cytoreductive Surgery with Hyperthermic Chemotherapy

“… 28 Similarly, a randomized controlled trial conducted by Chumbley et al showed that ketamine did not cause a reduction in opioid use six and 12 months after thoracic surgery. 29 …”

Persistent postoperative opioid use in Europe

“…Comparing the reported user rates at 3 and 12 months after surgery, shows a decrease in every area. In 5 of 7 scenarios (6 studies), that give information about use during the follow up year, the absolute reduction of opioid users was smaller than 10 percentage points (Simoni et al 10 : -5.6%; Dengler et al ( 8): -2 %; Blågestad et al 16 : -0.6 %; Fenten et al 14 : FNB -2.5%; Chumbley et al 12 : -8.19 %). Just Grosu et al 18 and Fenten et al 14 (LIA group) reported a higher reduction of user rated from the third to the twelfth month after surgery (Grosu et al 18 : -20%; Fenten et al 14 : LIA -10.6%).…”

“…2019) analysed 70 thoracotomy patients in the UK, that were not using strong opioids preoperatively. 12 The patients were randomised to receive either intravenous ketamine or saline placebo for 96 hours, starting 10 minutes prior surgery. 34 patients were randomised in the "saline placebo" group and were relevant for us.…”