Search

Study Objective: To identify whether adding intrathecal ketamine to intrathecal bupivacaine prolongs the time to first analgesic request in adult humans., Design: A meta-analysis of randomized controlled trials in humans., Setting: The majority of data was obtained in an operating room and postoperative recovery area., Patients: A total of 750 ASA physical status I and II patients were included in the study. Procedures performed include: cesarean section, lower abdominal surgery, lower limb surgery, and urologic surgery., Interventions: Databases including PubMed, Embase, Web of Science, and Cochrane were searched. Google Scholar was also queried. Multiple reviewers screened the papers for inclusion., Measurements: The primary outcome assessed was time to first analgesic request. Secondary outcomes included onset of sensory blockade, onset of motor blockade, duration of sensory blockade, and duration of motor blockade. Data were extracted to include means, 95% confidence intervals, tests for heterogeneity, and use of the Cochrane Collaboration guidelines to assess for publication bias., Main Results: Eleven randomized controlled trials met inclusion criteria. When comparing intrathecal bupivacaine plus ketamine to intrathecal bupivacaine alone, the time to first analgesic request was prolonged (effect size = 58.23 min (95% CI 37.36 to 79.10) p < 0.0001). Secondary outcomes showed the onset time of sensory blockade was shortened (effect size = -0.87 min (95% CI -1.361 to 0.378) p = 0.0005), the onset time of motor blockade was reduced (effect size = -0.88 min (95% CI -1.77 to 0.013) p = 0.05), the duration of sensory blockade was prolonged (effect size = 39.73 min (95% CI 15.97 to 63.50) p = 0.001), and the duration of motor blockade was prolonged (effect size = 4.02 min (95% CI 3.27 to 4.78) p < 0.0001). Studies were shown to have high heterogeneity. Egger tests for all outcomes were non-significant and funnel plots assessing publication bias were all asymmetrical., Conclusions: The studies analyzed suggest there may be a benefit to using intrathecal ketamine as an adjunct to bupivacaine. Additional studies are warranted to optimize dosing, clarify the safety and efficacy of this intrathecal drug combination, and examine the various ketamine formulations as intrathecal bupivacaine adjuvants., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Local periarticular infiltration (PAI) analgesia has emerged as an important component of multimodal approaches to treat total knee arthroplasty postoperative pain. Liposomal bupivacaine may provide prolonged analgesic duration when injected into the surrounding tissues. The purpose of this study was to compare the analgesic efficacy and serum bupivacaine levels of a continuous femoral nerve block (CFNB) with bupivacaine to PAI with liposomal bupivacaine., Methods: Sixty-five patients undergoing primary unilateral total knee arthroplasty were randomized into 2 groups: (1) CFNB and PAI with bupivacaine (CFNB group) or (2) PAI with bupivacaine:liposomal bupivacaine mixture at the end of surgery (LB group). The primary outcome was pain intensity at maximum knee flexion 24 hours following surgery. Secondary outcomes included pain intensities at rest and movement at timed intervals and serum bupivacaine levels., Results: Patients in the CFNB group experienced lower pain scores at maximum knee flexion at 24 hours (7.91; 95% confidence interval, 7.19-8.61) compared to the LB group (8.95; 95% confidence interval, 8.42-9.48; P = .02). The mean peak serum bupivacaine level in the LB group up to 72 hours was 0.55 μg/mL versus 1.4 μg/mL for CFNB group (P = .0008) with one patient in the CFNB group exceeding the reported minimum serum bupivacaine threshold for toxicity., Conclusion: While similar pain control was observed on the day of surgery for both groups, patients with a CFNB experienced lower pain intensities during maximum knee flexion at 24 hours. Total serum concentrations in LB group remained below the toxicity threshold over the study period., (Copyright © 2018 Elsevier Inc. All rights reserved.)