Group-based trajectory analysis of postoperative pain and outcomes after liver cancer surgery

Pain Predictors in Patients in the Postanesthesia Care Unit

PURPOSE

To analyze the effects of pain-predicting factors on patients in the postanesthesia care unit (PACU).

DESIGN

This is an observational and prospective study.

METHODS

This study was conducted at a University Hospital in the state of Minas Gerais (Brazil). To collect data on demographic, clinical, and surgical factors, a collection instrument was devised. The verbal numerical scale was employed to measure pain levels before and after surgery in the PACU. A path analysis was used to assess a predictive model.

FINDINGS

A total of 226 patients were included in this study. The incidence of pain in the PACU was 31.9%. A model with demographic, clinical, and surgical variables was tested. The final model, after including modification indices, obtained results that indicated an acceptable data fit (comparative fit index = 0.996; root mean square error of approximation = 0.08). Age (being young), sex (being a woman), oncological diagnosis as an indication for the surgical procedure, type of surgery (surgery of the digestive system), duration of surgery (longer surgeries), and high intraoperative doses of opioids were predictive variables for pain in the PACU.

CONCLUSIONS

This study's findings provide support for pain management in the PACU. Furthermore, the results of this research can be used to anticipate the occurrence of acute postoperative pain and personalized perioperative analgesia needs.

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

BACKGROUND

The analgesic effect of intravenous lidocaine varies with the duration of lidocaine infusion and surgery type. We tested the hypothesis that prolonged lidocaine infusion alleviates postoperative pain in patients recovering from hepatectomy over the first 3 postoperative days.

METHODS

Patients undergoing elective hepatectomy were randomly assigned to receive prolonged i.v. lidocaine treatment or placebo. The primary outcome was incidence of moderate-to-severe movement-evoked pain at 24 h postoperatively. The secondary outcomes included incidence of moderate-to-severe pain during movement and at rest throughout the first 3 postoperative days, postoperative opioid consumption, and pulmonary complications. Plasma lidocaine concentration was also monitored.

RESULTS

We enrolled 260 subjects. Intravenous lidocaine lowered the incidence of moderate-to-severe movement-evoked pain at 24 h and 48 h postoperatively (47.7% vs 67.7%, P=0.001; 38.5% vs 58.5%, P=0.001) and reduced movement-evoked pain scores (3.7 [1.7] vs 4.2 [1.6]; mean difference 0.5 [95% confidence interval {CI}: 0.1-0.9]; P=0.018) and morphine equivalent consumption (47.2 [16.7] mg vs 52.6 [19.2] mg; mean difference 5.4 mg [95% CI: 1.0-9.8]; P=0.016) at 24 h postoperatively. Lidocaine also lowered the incidence of postoperative pulmonary complications (23.1% vs 38.5%; P=0.007). Median plasma lidocaine concentrations were 1.5, 1.9, and 1.1 μg ml^-1 (inter-quartile ranges: 1.1-2.1, 1.4-2.6, and 0.8-1.6, respectively) after bolus injection, at the end of the surgery, and 24 h postoperatively.

CONCLUSIONS

Prolonged intravenous lidocaine infusion reduced the incidence of moderate-to-severe movement-evoked pain for 48 h after hepatectomy. However, the reduction in pain scores and opioid consumption by lidocaine was below the minimal clinically important difference.

CLINICAL TRIAL REGISTRATION

NCT04295330.

Dose-response relationship between epidural bupivacaine dose and mortality risk after surgical resection of nonsmall-cell lung cancer

BACKGROUND

Preclinical studies have shown that local anesthetics may modify the growth and invasion of cancer cells. However, few clinical studies have evaluated their impact on cancer outcomes after tumor resection.

METHODS

In this single-center cohort study, patients who underwent surgical resection of stage IA through IIIB nonsmall-cell lung cancer and used patient-controlled epidural analgesia from 2005 to 2015 were recruited and followed until May 2017. Data of the epidural bupivacaine dose for each patient were obtained from infusion pump machines. Proportional hazards regression models were used to analyze the associations between bupivacaine dose with postoperative cancer recurrence and all-cause mortality.

RESULTS

A total of 464 patients were analyzed. Among these patients, the mean bupivacaine dose was 352 mg (± standard deviation 74 mg). After adjusting for important clinical and pathological covariates, a significant dose-response relationship was observed between epidural bupivacaine dose and all-cause mortality (adjusted hazard ratio: 1.008, 95% confidence interval: 1.001-1.016, p = 0.029). The association between bupivacaine dose and cancer recurrence were not significant (adjusted hazard ratio: 1.000, 95% confidence interval: 0.997-1.002, p = 0.771). Age, sex, body mass index, mean daily maximum pain score, and pathological perineural infiltration were independently associated with bupivacaine dose.

CONCLUSION

A dose-dependent association was found between epidural bupivacaine dose and long-term mortality among patients following surgical resection of nonsmall-cell lung cancer. Our findings do not support the hypothetical anticancer benefits of local anesthetics. More studies are needed to elucidate the role of local anesthetics in cancer treatment.

Group-based trajectory analysis of acute pain after spine surgery and risk factors for rebound pain

Background

This retrospective study was designed to explore the types of postoperative pain trajectories and their associated factors after spine surgery.

Materials and methods

This study was conducted in a single medical center, and patients undergoing spine surgery with intravenous patient-controlled analgesia (IVPCA) for postoperative pain control between 2016 and 2018 were included in the analysis. Maximal pain scores were recorded daily in the first postoperative week, and group-based trajectory analysis was used to classify the variations in pain intensity over time and investigate predictors of rebound pain after the end of IVPCA. The relationships between the postoperative pain trajectories and the amount of morphine consumption or length of hospital stay (LOS) after surgery were also evaluated.

Results

A total of 3761 pain scores among 547 patients were included in the analyses and two major patterns of postoperative pain trajectories were identified: Group 1 with mild pain trajectory (87.39%) and Group 2 with rebound pain trajectory (12.61%). The identified risk factors of the rebound pain trajectory were age less than 65 years (odds ratio [OR]: 1.89; 95% CI: 1.12–3.20), female sex (OR: 2.28; 95% CI: 1.24–4.19), and moderate to severe pain noted immediately after surgery (OR: 3.44; 95% CI: 1.65–7.15). Group 2 also tended to have more morphine consumption (p < 0.001) and a longer length of hospital stay (p < 0.001) than Group 1.

Conclusion

The group-based trajectory analysis of postoperative pain provides insight into the patterns of pain resolution and helps to identify unusual courses. More aggressive pain management should be considered in patients with a higher risk for rebound pain after the end of IVPCA for spine surgery.

Group-based trajectory analysis of postoperative pain in epidural analgesia for video-assisted thoracoscopic surgery and risk factors of rebound pain

BACKGROUND

The current study aimed to investigate the patterns of postoperative pain trajectories over time and their associated risk factors in patients receiving video-assisted thoracoscopic surgery (VATS) and epidural analgesia (EA) for non-small cell lung cancer (NSCLC).

METHODS

This retrospective study was conducted at a tertiary medical center and included patients undergoing VATS for stage I NSCLC between 2011 and 2015. Maximal pain intensity was recorded daily during the first postoperative week. Group-based trajectory analysis was performed to categorize variations in pain scores over time. Associations between pain trajectory classification and amount of EA administered and length of hospital stay (LOS) after surgery were also evaluated.

RESULTS

A total of 635 patients with 4647 pain scores were included in the analysis, and 2 postoperative pain trajectory groups were identified: group 1, mild pain trajectory (78%); and group 2, rebound pain trajectory (22%). Risk factors for rebound pain trajectory were a surgical time longer than 3 hours (odds ratio [OR], 1.97; 95% CI, 1.27-3.07), female sex (OR, 1.62; 95% CI, 1.04-2.53), and higher pain score on postoperative day 0 (OR, 1.21; 95% CI, 1.08-1.36; linear effect). Although group 2 had a longer LOS (p < 0.001), they did not receive more EA than group 1 (p = 0.805).

CONCLUSION

Surgical time, sex, and pain intensity after surgery were major determinants of rebound pain trajectory, and more aggressive pain control strategies should be considered in high-risk patients.