Multimodal Analgesic Regimen for Spine Surgery: A Randomized Placebo-controlled Trial.

Implications of Practice Variability: Comment.

Background: Trigeminal neuralgia (TN) is considered one of the most debilitating disorders. Several medications such as anticonvulsants are available to provide relief from pain. In this study we used either ketamine which acts as an antagonist to N-methyl-d-aspartate receptors, or lidocaine which can block sodium channels in controlling of refractory trigeminal neuralgia. Aim: The primary outcome of the study was the pain score (The NRS) for pain assessment during the 12-week study period. The secondary outcomes were (1) Amount of analgesic medications (2) Frequency of pain (3) descriptors of pain. Methods: This study was conducted on 100 adult patients (aged 20-70 years) with refractory trigeminal neuralgia. Patients were enrolled into two groups each group contain 50 patients. In group I (ketamine group), patients underwent ketamine infusion protocol which consisted of 3 sessions of ketamine infusion in a dose of 0.4 mg/Kg over 30-45 minutes in 250 mL of 5% dextrose solution, and each session was performed consecutively every 4 days. In group II (lidocaine group), patients underwent lidocaine infusion protocol which consisted of 3 sessions of lidocaine infusion in a dose of 5 mg/kg over 30-45 minutes in 250 mL of 5% dextrose solution, and each session was performed consecutively every 4 days. Results: Our results showed that both groups were comparable regarding age, gender and site of pain. A significantly longer duration of pain relief was noticed in group I when compared to group II at 2 weeks, 1 month, 2 months and 3 months (3.11 ± 2.01, 3.15 ± 1.23, 4.23 ± 1.12, 4.50 ± 1.02) p<0.001. Immediately after infusion, 12 h and at 24 h pain relief was highly significant decreased in lidocaine group when compared to ketamine group (1.27 ± 1.11, 1.67 ± 1.48, 2.35 ± 1.25) p<0.001. At 48 h there was decrease in pain scores in both groups when compared to pre infusion values but without any statistical significance (3.25 ± 1.24, 3.56 ± 1.25) p=0.216. The analgesic consumption was significantly decreased in ketamine group. Complications were minor and self-controlled. Conclusion: The infusion of either ketamine or lidocaine controls pain in refractory trigeminal neuralgia and decreases anticonvulsant consumption with minimal post- infusion complications but with the upper hand to ketamine.

Background: Most patients suffer from moderate to severe pain after elective laparotomy. They often require opioids to alleviate their pain. Opiates invariably induce certain side effects and, occasionally, dependence. Intraoperative infusion of lidocaine and low-dose ketamine reduces postoperative pain and analgesic requirements. This study aims to evaluate the effects of simultaneous infusion of lidocaine and ketamine during open abdominal surgery on the postoperative pain severity and analgesic consumption. Methods: In this randomized, double-blinded, single-center study that was performed in Iran, 80 patients scheduled for elective open abdominal surgery under general anesthesia were enrolled in two LK and P groups. Group LK (n=40) received lidocaine-ketamine infusion, and group P (n=40) received placebo (normal saline). Both infusions were started thirty minutes after initiation of surgery and were terminated once the surgery was completed. For postoperative pain management, patient-controlled analgesia (PCA), including fentanyl and paracetamol, was administered for both groups. All patients were evaluated for pain visual analogue scale (VAS) and total adjunctive analgesic (diclofenac suppository) consumption within the first 24 hours after the surgery. The data were analyzed using SPSS. P values <0.05 were considered significant. Results: Intraoperative infusion of Lidocaine and Ketamine resulted in desirable postoperative pain control. Patients of LK group demonstrated a significant reduction in the pain score at 1, 6, 12, 18, and 24 hours after termination of surgery (p<0.001). It also resulted in a decreased requirement for postoperative analgesics, as cumulative analgesic consumption was decreased meaningfully in the patients of LK group (p<0.001). Conclusion: Intravenous infusion of lidocaine and ketamine during elective open abdominal surgery reduces pain intensity and analgesic requirements in the first 24 hours postoperatively, without major additional side effects.

A Randomized, Double-Blind, Placebo-Controlled Study of Odanacatib (MK-822) In The Treatment of Postmenopausal Women With Low BMD: 18-Month Results

Hip arthroscopy is an increasingly common outpatient surgical procedure where postoperative pain can be severe. Peripheral nerve blocks have been evaluated for analgesia following hip arthroscopy; however, there is no consensus on an optimal technique that provides effective local anesthetic-based postoperative analgesia without motor blockade. We hypothesized that the pericapsular nerve group (PENG) block would provide effective motor-sparing analgesia following ambulatory hip arthroscopy. We conducted a randomized placebo-controlled double-blind trial comparing an ultrasound-guided PENG block with 20 mL of 0.5% ropivacaine to a control with a sham injection. Our primary outcomes were cumulative opioid consumption (oral morphine equivalent) and quality of recovery (QoR-15) scores at 24 hours postoperatively. Secondary outcomes included pain, postoperative opioid consumption, time to first analgesic request, postanesthesia care unit (PACU) length of stay, and opioid and block-related side effects. 94 patients were included (47 per group). QoR was similar between groups at 24 hours as measured by the QoR-15 (range 0-150, higher scores indicate better recovery): mean SD 96.8±20.9 in the PENG group versus 101.0±20.9 in the control group (mean difference -4.2; adjusted p=0.414). Opioid consumption at 24 hours was also similar between groups. In adjusted analyses, the PENG group required less opioid analgesia in the PACU (mean difference -9.5 MME; p=0.039) and had a shorter PACU stay (mean difference -20.5 min; p=0.027). Pain scores at rest and on movement decreased over time in both groups, with no consistent differences in overall pain trajectories. Opioid consumption at 48 hours, opioid-related adverse effects and block-related complications were similar between groups. When administered preoperatively, the PENG block provides only modest early perioperative benefits without improving overall postoperative analgesia or QoR in patients undergoing ambulatory hip arthroscopy. Based on these findings, routine preoperative use of the PENG block for ambulatory hip arthroscopy cannot be recommended beyond standard multimodal analgesia, although it may be considered selectively to facilitate early PACU recovery in carefully chosen patients. The potential role of postoperative PENG block as a rescue intervention warrants further investigation. NCT03449680; https://clinicaltrials.gov/study/NCT03449680.

Efficacy of prolonged intravenous lidocaine infusion for postoperative movement-evoked pain following hepatectomy: a double-blinded, randomised, placebo-controlled trial

ObjectiveTo compare efficacy of oral versus intravenous (IV) methadone on postoperative pain and opioid requirements after spine surgery.MethodsThis was a retrospective, single-academic center cohort study evaluating 1010 patients who underwent >3 level spine surgery from January 2017 to May 2020 and received a one-time dose of oral or intravenous methadone prior to surgery. The primary outcome measured was postoperative opioid use in oral morphine equivalents (ME) and verbal response scale (VRS) pain scores up to postoperative day (POD) three. Secondary outcomes were time to first bowel movement and adverse effects (reintubation, myocardial infarction, and QTc prolongation) up to POD 3.ResultsA total of 687 patients received oral and 317 received IV methadone, six patients were excluded. The IV group received a significantly greater methadone morphine equivalent (ME) dose preoperatively (112.4 ± 83.0 mg ME versus 59.3 ± 60.9 mg ME, p < 0.001) and greater total (methadone and non-methadone) opioid dose (119.1 ± 81.4 mg ME versus 63.9 ± 62.5 mg ME, p < 0.001), intraoperatively. Although pain scores for the oral group were non-inferior to the IV group for all postoperative days (POD), non-inferiority for postoperative opioid requirements was demonstrated only on POD 3. Based on the joint hypothesis for the co-primary outcomes, oral methadone was non-inferior to IV methadone on POD 3 only. No differences in secondary outcomes, including QTc prolongation and arrhythmias, were noted between the groups.ConclusionsOral methadone is a feasible alternative to IV methadone for patients undergoing spine surgery regarding both pain scores and postoperative opioid consumption.

P59. Chronic preoperative opioid use is associated with higher perioperative resource utilization and adverse outcomes in adult spinal deformity patients

Risk factors for postoperative urinary retention following elective spine surgery: a meta-analysis

Registration number: NTR4943 (http://www.trialregister.nl).

Gabapentin and postoperative pain and opioid consumption: A double-blind randomized controlled trial of perioperative pain management for sinus surgery

IntroductionThe effects of deep neuromuscular block (DNMB) on chronic postsurgical pain (CPSP) have not been conclusively determined. Moreover, a limited number of studies have examined the impact of DNMB on long-term recovery quality after spinal surgery. We investigated the impact of DNMB on CPSP and the quality of long-term recovery in patients who had been subjected to spinal surgery.MethodsThis was a randomized, controlled, double-blind, single-center study performed from May 2022 to November 2022. A total of 220 patients who underwent spinal surgery under general anesthesia were randomly assigned to receive either DNMB (post-tetanic count at 1–2) (the D group) or moderate NMB (MNMB) (train-of-four at 1–3) (the M group). The primary endpoint was the incidence of CPSP. The secondary endpoints included the visual analogue scale (VAS) score in the post-anesthesia recovery unit (PACU), at 12, 24, 48 h and 3 months after surgery; postoperative opioid consumption; quality of recovery-15 (QoR-15) scores on the second postoperative day, before discharge, and 3 months after surgery.ResultsThe incidence of CPSP was significantly lower in the D group (30/104, 28.85%) than in the M group (45/105, 42.86%) (p = 0.035). Besides, VAS scores were significantly reduced at the third month in the D group (p = 0.016). In the PACU and 12 h after surgery, VAS scores were also significantly lower in the D group than in the M group (p < 0.001, p = 0.004, respectively). The total amount of postoperative opioid consumption (expressed in total oral morphine equivalents) was significantly less in D group than M group (p = 0.027). At 3 months after surgery, QoR-15 scores were significantly higher in D group than M group (p = 0.003).ConclusionsCompared with MNMB, DNMB significantly reduced CPSP and postoperative opioid consumption in spinal surgery patients. Moreover, DNMB improved the long-term recovery of patients.Trial RegistrationChinese Clinical Trial Registry (ChiCTR2200058454).

Study DesignRetrospective cohort study.ObjectiveDespite increasing cannabis use, its prevalence in specific surgical groups is unclear, and its impact on perioperative care and outcomes is understudied. This study estimates cannabis use incidence in patients undergoing lumbar spine surgery and explores associations between preoperative use and anxiety, pain scores, and postoperative opioid consumption. We hypothesized a correlation between cannabis use and decreased reliance on opioids for postoperative pain relief.MethodsThis single-center retrospective cohort study included 204 patients undergoing single or multilevel spinal fusion surgery between July 2022 and August 2023. Self-reported cannabis use, demographics, surgical characteristics, numeric rating scale (NRS) pain scores, anxiety, inpatient opioid consumption, and discharge prescribing (total morphine equivalent dose) were extracted from electronic medical records (EMR). Patients were categorized into cannabis users or non-cannabis users, and group differences were analyzed using bivariable and multivariable regression.ResultsOf 204 patients, 27 (13.2%) were cannabis users and 177 (86.8%) were non-users. Cannabis users were younger (P = 0.007), more likely male (P = 0.028), and Caucasian (P = 0.032) than non-users. Preoperative cannabis use correlated significantly with anxiety disorder (P = 0.023) and higher preoperative (P = 0.016) and postoperative (P = 0.002) NRS pain scores. Multivariable analysis showed cannabis use associated with higher preoperative (P = 0.015) but not postoperative (P = 0.073) pain scores. No significant differences were found in preoperative, discharge opioid prescribing or postoperative opioid consumption.ConclusionThe incidence of cannabis use was low, but positively associated with anxiety and higher preoperative NRS pain scores. Large, well-powered trials are needed to understand cannabis’s impact on spine surgery outcomes.

Background: Ketamine might be effective in blocking central sensitization of pain transmission neurons through its effect on NMDA receptors in refractory Complex Regional Pain Syndrome (CRPS) patients. At higher doses, ketamine infusions can be associated with significant risks; outpatient therapy requires return visits for a 10-day period with variable efficacy and duration. Objective: This study determined the efficacy of a 5-day moderate dose, continuous racemic ketamine infusion. The pharmacodynamic responses to racemic ketamine and norketamine were examined. Design: Observational study Methods: In this study, ketamine was titrated from 10-40 mg/hour in 16 CRPS patients, and maintained for 5 days. Pain was assessed daily. Ketamine and norketamine concentrations were obtained on Day 1 before starting the infusion; at 60 to 90 minutes, 120 to 150 minutes, 180 to 210 minutes, and 240 to 300 minutes after the initiation of the infusion on Days 2, 3, 4, and 5; and on Day 5 at 60 minutes after the conclusion of the infusion. The plasma concentrations of (R)-ketamine, (S)-ketamine, (R)-norketamine and (S)-norketamine were determined using an enantioselective liquid chromatography – mass spectrometry method. Results: Ketamine and norketamine infusion rates stabilized 5 hours after the start of the infusion. The subjects showed no evidence of significant tachycardia, arterial oxygen desaturation, or hallucinatory responses. Subjects generally experienced minimal pain relief on day one followed by significant relief by day 3. Mean pain scores decreased from the 8-9 to 3-5 ranges; however, the analgesic response to ketamine infusion was not uniform. On day 5, there was little or no change in the pain measure assessed as the worst pain experienced over the last 24 hours in 37% of the subjects. (R)- and (S)-ketamine concentrations peaked at 240-300 min. (R)- and (S)-norketamine concentrations were lower and peaked on Day 2 of the infusion, as opposed to Day 1 for (R)- and (S)-ketamine. Significant pain relief was achieved by the second day of infusion and correlated with the maximum plasma levels of ketamine and norketamine. Pain relief continued to significantly improve over the 5 day infusion at concentrations of 200-225 ng/mL for (R)- and (S)-ketamine, and 90-120 ng/mL for(R)- and (S)-norketamine. Conclusions: A 5-day ketamine infusion for the treatment of severe CRPS provided significant (P &lt;0.05) pain relief by Day 3 compared to baseline. The pain relief experienced on Day 2 of the infusion continued to improve over the 5-day infusion period and correlated with the maximum plasma levels of ketamine and norketamine. We speculate that downstream metabolites of ketamine and norketamine might be playing a role in its therapeutic efficacy. Key words: ketamine, norketamine, CRPS, pharmacodynamics, chronic pain, enantiomers

Perioperative Medicine: Managing for Outcome, 2nd Edition