Association between perioperative non-steroidal anti-inflammatory drug use and cardiovascular complications after non-cardiac surgery in older adult patients.

BACKGROUND: We investigated in older adult non-cardiac surgical patients whether receipt of perioperative non-steroidal anti-inflammatory drugs (NSAIDs) is associated with increased incidence of postoperative cardiovascular complications. METHODS: We retrospectively extracted the information for patients with age ≥  65 years who had inpatient non-cardiac surgery with a duration of ≥  1 h from the American College of Surgeons-National Surgical Quality Improvement Program registry data acquired at the University of Washington Medical Center. We compared patients who received NSAIDs perioperatively to those who did not receive NSAIDs, on the two composite outcomes: (1) the incidence of postoperative cardiovascular complications within 30 days of the surgery, and (2) the incidence of combined postoperative gastrointestinal and renal complications, and length of postoperative hospital stay. We used separate multivariable logistic regression models to analyze the two composite outcomes and a Poisson regression model for the length of hospital stay. RESULTS: The receipt of perioperative NSAIDs was not associated with postoperative cardiovascular complications (estimated odds ratio (OR), 1.78; 95% confidence interval (CI), 0.97 to 3.25; P =  0.06), combined renal and gastrointestinal complications (estimated OR, 1.30; 95% CI, 0.53 to 3.20; P =  0.57), and length of postoperative hospital stay in days (incidence rate ratio, 1.06; 95% CI, 0.93 to 1.21; P =  0.39). CONCLUSIONS: In older adult non-cardiac surgical patients, receipt of perioperative NSAIDs was not associated with increased incidences of postoperative cardiovascular complications, and renal and gastrointestinal complications within 30 days after surgery, or length of postoperative hospital stay.

Association Between Postoperative Methocarbamol and Postoperative Pain Opioid Dose Requirements: A Retrospective Cohort Study.

OBJECTIVES: We tested the hypothesis that patients who received methocarbamol postoperatively experience less severe pain and require smaller doses of opioids than those who did not receive methocarbamol. MATERIALS AND METHODS: This is a retrospective cohort study of patients undergoing surgery involving the musculoskeletal system. Of 9089 patients, 704 received methocarbamol during 48 hours postoperatively, while 8385 did not receive methocarbamol. The patients who received methocarbamol postoperatively and the patients who did not receive methocarbamol were compared on the time-weighted average (TWA) pain score and opioid dose requirements in morphine milligram equivalents (MME) during the first 48 hours postoperatively, using propensity score-weighted regression models to adjusting for preoperative and intraoperative covariates. RESULTS: Postoperative 48-hour TWA pain scores were 5.5±1.7 (mean±SD), and 4.3±2.1 for methocarbamol and non-methocarbamol patients. Postoperative 48-hour opioid dose requirements in MME were 276 [170-347] (median [interquartile range (IQR)]) mg, and 190 [60-248] mg for methocarbamol and non-methocarbamol patients. In propensity score-weighted regression models, receiving methocarbamol postoperatively was associated with 0.97-point higher postoperative TWA pain score (95% CI, 0.83-1.11; P <0.001), and 93.6-MME higher postoperative opioid dose requirements (95% CI, 79.9 to 107.4; P <0.001), compared with not receiving methocarbamol postoperatively. DISCUSSION: Postoperative methocarbamol was associated with significantly higher acute postoperative pain burden and opioid dose requirements. Although the results of the study are influenced by residual confounding, they suggest a limited-if any-benefit of methocarbamol as an adjunct of postoperative pain management.

Prediction of postoperative respiratory depression and respiratory complications in patients on preoperative methadone.

PURPOSE: We developed prediction models for postoperative respiratory depression and respiratory complications for 958 patients who were on methadone preoperatively. METHODS: The primary outcome was postoperative respiratory depression as defined by respiratory rate < 10/min, oxygen saturation (SpO2) < 90%, or requirement of naloxone for 48 h postoperatively. Secondary outcome was the composite of postoperative respiratory complications. Prediction models for postoperative respiratory depression and respiratory complications were constructed using multivariate logistic regression with preoperative and intraoperative characteristics as the predictors. RESULTS: For the multivariate logistic regression model for postoperative respiratory depression, surgery duration (P = 0.005), body mass index (BMI) (P = 0.008), surgery involving digestive system (P = 0.031), and American Society of Anesthesiologists (ASA) physical status ≥ 4 (P = 0.038) were statistically significant predictors. The area under the receiver operating characteristic curve (AUROC) of the model was 0.581 (0.558-0.601) [median (95% confidence interval (CI))] with fivefold cross-validation. For the model for postoperative respiratory complications, surgery duration (P = 0.001), history of hypertension (P = 0.028), surgery involving musculoskeletal system (P < 0.001), surgery involving integumental system (P = 0.034), surgery categorized to miscellaneous therapeutic procedures (P = 0.028), combined general and regional anesthesia (P = 0.033), ASA physical status 3 (P < 0.001), and ASA physical status ≥ 4 (P < 0.001) were statistically significant predictors, and AUROC of the model was 0.726 (0.712-0.737). CONCLUSIONS: Multivariate logistic regression models including preoperative, and intraoperative characteristics as the predictors performed poorly to predict postoperative respiratory depression, and moderately for postoperative respiratory complications. Neither model is accurate enough to be subject to clinical use.

Postoperative respiratory depression in patients on sublingual buprenorphine: a retrospective cohort study for comparison between postoperative continuation and discontinuation of buprenorphine.

BACKGROUND: We tested the hypothesis that patients who continued buprenorphine postoperatively experience postoperative respiratory depression less frequently than those who discontinued buprenorphine. METHODS: This is a retrospective cohort study of patients who were on buprenorphine preoperatively. The primary outcome was postoperative respiratory depression as defined by respiratory rate < 10/minute, oxygen saturation (SpO2) < 90%, or requirement of naloxone for 48 h postoperatively. The secondary outcome was the composite of postoperative respiratory complications. The associations between postoperative buprenorphine continuation and respiratory depression and respiratory complications were estimated using separate multivariable logistic regression models, including demographic, intraoperative characteristics, and preoperative buprenorphine dose as covariates. RESULTS: Postoperative buprenorphine continuation was not associated with postoperative respiratory depression (adjusted odds ratio (OR), 1.11, 95% confidence interval (CI), 0.61 to 1.99, P=0.72). In subanalysis stratified by the preoperative buprenorphine dose, buprenorphine continuation was not associated with postoperative respiratory depression either when preoperative buprenorphine dose was high (≥16 mg daily) or low (<16 mg daily). Postoperative buprenorphine continuation was associated with lower incidence of postoperative respiratory complications (adjusted OR, 0.43, 95% CI, 0.21 to 0.86, P=0.02). CONCLUSIONS: Continuing buprenorphine was not associated with respiratory depression, but it was associated with a lower incidence of respiratory complications.

Comparison Between Preoperative Methadone and Buprenorphine Use on Postoperative Opioid Requirement: A Retrospective Cohort Study.

OBJECTIVES: Buprenorphine is a partial agonist at mu-opioid receptors and competes for these receptors with other opioids in vitro. Whether patients on buprenorphine maintenance require high doses of opioid analgesics to attain adequate postoperative pain control has not been determined. We evaluated differences in acute postoperative opioid consumption and pain burden between patients taking buprenorphine and those taking methadone preoperatively. MATERIALS AND METHODS: A retrospective review of medical records of 928 patients, of whom 195 were on buprenorphine and 733 were on methadone preoperatively, was performed. Among methadone and buprenorphine patients, 615 and 89, respectively, continued to receive the medications postoperatively. Buprenorphine patients were compared with methadone patients for the first 48 hours postoperatively with regard to acute opioid dose requirements (morphine milligram equivalents [MME] above their baseline buprenorphine and methadone doses) and time-weighted average (TWA) pain scores (using targeted maximum likelihood estimation). RESULTS: Opioid dose requirements for 48 hours postoperatively were 150 (22 to 297) (median [interquartile range]) and 220 [90 to 360] MME for buprenorphine and methadone patients, respectively. Preoperative buprenorphine was associated with a 59.9% lower postoperative MME (95% confidence interval: 46.6%-69.8%, P<0.0001) compared with methadone. Postoperative TWA pain scores for the first 48 hours were 5.0±2.7 (mean±SD), and 5.4±2.3 for buprenorphine and methadone patients, respectively. Preoperative buprenorphine was associated with a 0.37-point lower TWA pain score (95% confidence interval: 0.14-0.61, P=0.002) compared with methadone. DISCUSSION: Preoperative buprenorphine use was associated with >50% reduction in postoperative opioid dose requirement and a statistically significant, though clinically unimportant, reduction in acute pain burden in comparison to methadone. The study is limited by several important factors such as the exclusion of patients requiring intravenous patient-controlled analgesia, small number of patients were on higher dose of buprenorphine, and a large percentage of methadone patients were not on a stable dose of methadone yet.

Postoperative Pain and Opioid Dose Requirements in Patients on Sublingual Buprenorphine: A Retrospective Cohort Study for Comparison Between Postoperative Continuation and Discontinuation of Buprenorphine.

OBJECTIVE: To test the hypothesis that patients who continued buprenorphine postoperatively experience less severe pain and require a smaller dose of opioids than those who discontinued buprenorphine. MATERIALS AND METHODS: This is a retrospective cohort study of surgical patients who were on buprenorphine preoperatively. Using our previous study's data as pilot data, we selected the covariates to be included in 2 regression models with postoperative time-weighted average pain score and opioid dose requirements in morphine milligram equivalents during 48 hours after surgery as the outcomes. Both contained preoperative daily buprenorphine dose, whether buprenorphine was continued postoperatively, and the preoperative daily dose-by-postoperative continuation interaction as predictors. Precision variables were identified by exhaustive search of perioperative parameters with the exposure variables (preoperative daily dose, postoperative continuation, and their interaction) included in the regression model. The model selected by using the pilot data was estimated again using the new data extracted for this study to make inference about the effect of the 2 exposures (postoperative buprenorphine continuation and preoperative daily buprenorphine dose) and their interaction on the outcomes. RESULTS: Continuing buprenorphine was associated with a 1.3-point lower time-weighted average pain score than discontinuing (95% confidence interval, 0.39-2.21; P=0.005) but was not associated with a difference in opioid dose requirements (P=0.48). DISCUSSION: Continuing buprenorphine was associated with lower postoperative pain levels than discontinuing. Our results were primarily driven by patients on lower buprenorphine dose as only 22% of patients were on daily doses of 24 mg or above.

Acute Pain Burden and Opioid Dose Requirements after Cesarean Delivery in Parturients with Preexisting Chronic Back Pain and Migraine.

INTRODUCTION: Preexisting chronic pain has been reported to be a consistent risk factor for severe acute postoperative pain. However, each specific chronic pain condition has unique pathophysiology, and it is possible that the effect of each condition on postoperative pain is different. METHODS: This is a retrospective cohort study of pregnant women with preexisting chronic pain conditions (i.e., migraine, chronic back pain, and the combination of migraine + chronic back pain), who underwent cesarean delivery. The effects of the three chronic pain conditions on time-weighted average (TWA) pain score (primary outcome) and opioid dose requirements in morphine milligram equivalents (MME) during postoperative 48 hours were compared. RESULTS: The TWA pain score was similar in preexisting migraine and chronic back pain. Chronic back pain was associated with significantly greater opioid dose requirements than migraine (12.92 MME, 95% CI: 0.41 to 25.43, P=0.041). Preoperative opioid use (P < 0.001) was associated with a greater TWA pain score. Preoperative opioid use (P < 0.001), smoking (P=0.004), and lower postoperative ibuprofen dose (P=0.002) were associated with greater opioid dose requirements. CONCLUSIONS: Findings suggest women with chronic back pain and migraine do not report different postpartum pain intensities; however, women with preexisting chronic back pain required 13 MME greater opioid dose than those with migraine during 48 hours after cesarean delivery.