Intraoperative S-ketamine for the reduction of opioid consumption and pain one year after spine surgery: A randomized clinical trial of opioid-dependent patients.

BACKGROUND: We aimed to explore the effect of intraoperative S-ketamine on analgesic consumption and pain one year after spine surgery in chronic opioid-dependent patients undergoing spinal fusion surgery. METHODS: Single-centre, randomized, blinded trial of 147 patients. INTERVENTION: Perioperative S-ketamine bolus 0.5 mg/kg followed by S-ketamine 0.25 mg kg-1  hr-1 infusion or placebo. MAIN OUTCOMES: Analgesic use, pain (visual analogue scale 0-100 mm [VAS]) and labour market attachment one year after surgery assessed by written questionnaires. RESULTS: Response rate was 67%. One year after surgery, the daily use of oral morphine equivalents was lower in the ketamine group versus the placebo group: 0 (0-20) mg versus 20 (0-62) mg, (p = 0.02), and fewer patients had a daily use of any analgesics in the ketamine group versus placebo group, 42% (95% CI 23-61) versus 74% (95% CI 58-87), (p = 0.04). Mobilization pain was lower in the ketamine group compared to the placebo group: Median difference 17 mm (95% CI -30 to -3), (p = 0.02). Pain at rest was lower in the ketamine group compared to the placebo group with median difference: 13 mm (95% CI -23 to -3), (p = 0.01). Further, labour market attachment was better in the ketamine group, (p = 0.02). CONCLUSION: Intraoperative ketamine may reduce analgesic use, pain, and improve labour market attachment one year after spine surgery in a chronic opioid-dependent population. SIGNIFICANCE: This randomized clinical trial shows that intraoperative ketamine may reduce opioid use and pain and improve labour market attachment one year after spine surgery in an opioid-dependent population.

Intraoperative ketamine reduces immediate postoperative opioid consumption after spinal fusion surgery in chronic pain patients with opioid dependency: a randomized, blinded trial.

Perioperative handling of surgical patients with opioid dependency represents an important clinical problem. Animal studies suggest that ketamine attenuates central sensitization and hyperalgesia and thereby reduces postoperative opioid tolerance. We hypothesized that intraoperative ketamine would reduce immediate postoperative opioid consumption compared with placebo in chronic pain patients with opioid dependency undergoing lumbar spinal fusion surgery. Primary outcome was morphine consumption 0 to 24 hours postoperatively. Secondary outcomes were acute pain at rest and during mobilization 2 to 24 hours postoperatively (visual analogue scale), adverse events, and persistent pain 6 months postoperatively. One hundred fifty patients were randomly assigned to intraoperative S-ketamine bolus 0.5 mg/kg and infusion 0.25 mg·kg·h or placebo. Postoperatively, patients received their usual opioids, paracetamol and IV patient-controlled analgesia with morphine. In the final analyses, 147 patients were included. Patient-controlled analgesia IV morphine consumption 0 to 24 hours postoperatively was significantly reduced in the ketamine group compared with the placebo group: 79 (47) vs 121 (53) mg IV, mean difference 42 mg (95% confidence interval -59 to -25), P < 0.001. Sedation was significantly reduced in the ketamine group 6 and 24 hours postoperatively. There were no significant differences regarding acute pain, nausea, vomiting, hallucinations, or nightmares. Back pain at 6 months postoperatively compared with preoperative pain was significantly more improved in the ketamine group compared with the placebo group, P = 0.005. In conclusion, intraoperative ketamine significantly reduced morphine consumption 0 to 24 hours after lumbar fusion surgery in opioid-dependent patients. The trend regarding less persistent pain 6 months postoperatively needs further investigation.

Insufficient pain management after spine surgery.

INTRODUCTION: A prospective observational quality assurance study was performed at Glostrup Hospital, Denmark, to describe patients undergoing spine surgery with regard to perioperative analgesic management, post-operative pain, opioid consumption and side effects. MATERIAL AND METHODS: Patients eligible for the study were identified consecutively from the operation chart. The following data were registered: post-operative visual analogue (VAS) pain score at rest and during mobilisation, opioid consumption for the first 24 h, other analgesics administered and side effects. RESULTS: A total of 87 patients were included. For instrumented lumbar fusion patients (n = 24), the VAS pain scores at 1, 4 and 24 h after surgery were (median (interquartile range)) 5 (0-7), 2.5 (0-8) and 5.5 (0-9) at rest and 5 (0-8), 3 (0-9) and 7 (3-9) during mobilisation, respectively. The other surgical subgroups generally experienced VAS ≤ 3. For instrumented lumbar fusion, the total 0-24 h consumption of intravenous morphine equivalents was 39.1 (27.5-62.7) mg. Only eight of 87 patients received the entire scheduled standard post-operative pain treatment. Adverse events were rare. CONCLUSION: Most patients experienced acceptable pain levels, but instrumented lumbar fusion leads to moderate to severe pain levels and a relatively high opioid consumption. The scheduled standard pain management protocols were sparsely followed. Challenges exist in post-operative pain management as observed in previous surveys, especially for instrumented lumbar fusion surgery. Future work should focus on optimising treatment plans. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

Epidural blood patch for refractory low CSF pressure headache: a pilot study.

Once believed an exceedingly rare disorder, recent evidence suggests that low cerebrospinal fluid (CSF) pressure headache has to be considered an important cause of new daily persistent headaches, particularly among young and middle-aged individuals. Treatment of low CSF pressure headache consists of non-invasive/conservative measures and invasive measures with epidural blood patch providing the cornerstone of the invasive measures. In the present pilot study we therefore aimed to evaluate the treatment efficacy of epidural blood patch (EBP) in treatment-refractory low-pressure headache. Our primary effect parameter was total headache burden defined as area under the curve (AUC: intensity × duration) and as secondary effect parameters we identified: intensity (VAS 0-10), frequency (days per month), duration in hours (total hours/month) and also medication days (days on medication/month). In our primary effect parameter we found a significant reduction in AUC with more than 25% and this is considered to be clinically relevant. We found also a significant and relevant reduction at -22% in intensity. A trend towards reduction in duration was seen. We found no statistically significant reduction in frequency. An increase in days with use of medication was found. Increased awareness of low CSF pressure headache is emphasized and a controlled larger randomized study is needed to confirm the results. However the present results, allows us to conclude that EBP in treatment-refractory low CSF pressure headache can be considered as a treatment option.