Comparison of bupivacaine, ropivacaine, and levobupivacaine in an equal dose and concentration for sympathetic block in dogs

Use of Caudal Quadratus Lumborum Block with Ropivacaine as Part of an Opioid-Free Analgesic Protocol in Dogs Undergoing Orchiectomy: A Randomized Trial

In veterinary medicine, the use of loco-regional anesthesia techniques is increasing. The Quadratus Lumborum block (QL) is an interfascial loco-regional technique that involves the release of local anesthetic (LA) between the Quadratus Lumborum and the Small Psoas (Pm) muscle. The study aims to evaluate the effect of the QL block on reducing the total amount of opioids in dogs undergoing pre-scrotal orchiectomy. A group of 36 dogs was enrolled in a randomized blinded study. The animals were divided into two groups: 18 in the experimental group (QL) and 18 in the control group (C). The QL group received 0.4 mL kg-1 of ropivacaine 0.5% for each hemiabdomen (total amount of 3 mg kg-1 of ropivacaine, 1.5 mg kg-1 per side). The C group was brought into the operating room (OR) after receiving the same clipping as the QL group. In the intraoperative period, opioid consumption in the QL group was significantly lower than in the C group. No differences were found in the post-operative phase. No side effects were reported when performing the QL technique. The QL block performed at the level of L6 appears to be a valid approach to reducing opioid use in dogs undergoing orchidectomy with a pre-scrotal surgical approach.

Beyond repeated-measures analysis of variance: advanced statistical methods for the analysis of longitudinal data in anesthesia research

BACKGROUND AND OBJECTIVES

Research in the field of anesthesiology relies heavily on longitudinal designs for answering questions about long-term efficacy and safety of various anesthetic and pain regimens. Yet, anesthesiology research is lagging in the use of advanced statistical methods for analyzing longitudinal data. The goal of this article was to increase awareness of the advantages of modern statistical methods and promote their use in anesthesia research.

METHODS

Here we introduce 2 modern and advanced statistical methods for analyzing longitudinal data: the generalized estimating equations (GEE) and mixed-effects models (MEM). These methods were compared with the conventional repeated-measures analysis of variance (RM-ANOVA) through a clinical example with 2 types of end points (continuous and binary). In addition, we compared GEE and MEM to RM-ANOVA through a simulation study with varying sample sizes, varying number of repeated measures, and scenarios with and without missing data.

RESULTS

In the clinical study, the 3 methods are found to be similar in terms of statistical estimation, whereas the parameter interpretations are somewhat different. The simulation study shows that the methods of GEE and MEM are more efficient in that they are able to achieve higher power with smaller sample size or lower number of repeated measurements in both complete and missing data scenarios.

CONCLUSIONS

Based on their advantages over RM-ANOVA, GEE and MEM should be strongly considered for the analysis of longitudinal data. In particular, GEE should be used to explore overall average effects, and MEM should be used when subject-specific effects (in addition to overall average effects) are of primary interest.