Serial Analgesic Consumptions and Predictors of Intravenous Patient-controlled Analgesia with Cluster Analysis

Impact of Genetic Variants on Postoperative Pain and Fentanyl Dose Requirement in Patients Undergoing Major Breast Surgery: A Candidate Gene Association Study

BACKGROUND

Postoperative analgesia is crucial for the early and effective recovery of patients undergoing surgery. Although postoperative multimodal analgesia is widely practiced, opioids such as fentanyl are still one of the best analgesics. The analgesic response of fentanyl varies widely among individuals, probably due to genetic and nongenetic factors. Among genetic factors, single nucleotide polymorphisms (SNPs) may influence its analgesic response by altering the structure or function of genes involved in nociceptive, fentanyl pharmacodynamic, and pharmacokinetic pathways. Thus, it is necessary to comprehensively ascertain if the SNPs present in the aforementioned pathways are associated with interindividual differences in fentanyl requirement. In this study, we evaluated the association between 10 candidate SNPs in 9 genes and 24-hour postoperative fentanyl dose (primary outcome) and also with postoperative pain scores and time for first analgesia (secondary outcomes).

METHODS

A total of 257 South Indian women, aged 18-70 years, with American Society of Anesthesiologists (ASA) physical status I-III, undergoing major breast surgery under general anesthesia, were included in the study. Patients were genotyped for candidate SNPs using real-time polymerase chain reaction. All patients received a standardized intravenous fentanyl infusion through a patient-controlled analgesic (PCA) pump, and the 24-hour postoperative fentanyl dose requirement was measured using PCA.

RESULTS

The median 24-hour postoperative fentanyl requirement was higher in rs1799971 carriers (G/G versus A/A + A/G-620 μg [500-700] vs 460 μg [400-580]) with a geometric mean (GM) ratio of 1.91 (95% confidence interval [CI], 1.071-1.327). The median 24-hour pain scores were higher in rs4680 carriers (A/G + A/A versus G/G-34 [30-38] vs 31 [30-38]) with a GM ratio of 1.059 (95% CI, 1.018-1.101) and were lower in rs1045642 carriers (A/A + A/G versus G/G-34 [30-38] vs 30 [30-34]) with a GM ratio of 0.936 (95% CI, 0.889-0.987). The median time for first analgesic was lower in rs734784 carriers [C/C versus T/T + C/T-240 minutes (180-270) vs 240 minutes (210-270)] with a GM ratio of 0.902 (95% CI, 0.837-0.972). Five of 9 clinical factors, namely, history of diabetes, hypertension, hypothyroidism, anesthesia duration, and intraoperative fentanyl requirement were associated with different outcomes individually ( P < .05) and were used to adjust the respective associations.

CONCLUSIONS

The SNP opioid receptor mu-1 ( OPRM1 ) (rs1799971) was associated with higher postoperative fentanyl requirement in South Indian patients undergoing major breast surgery. Twenty-four hour postoperative pain scores were higher in catechol-O-methyl transferase ( COMT ) (rs4680) carriers and lower in ATP binding cassette subfamily B member 1 ( ABCB1 ) (rs1045642) carriers, whereas time for first analgesic was lower in potassium channel subunit 1 ( KCNS1 ) (rs734784) carriers. However, these exploratory findings must be confirmed in a larger study.

Predictive models for fentanyl dose requirement and postoperative pain using clinical and genetic factors in patients undergoing major breast surgery

ABSTRACT

Fentanyl exhibits interindividual variability in its dose requirement due to various nongenetic and genetic factors such as single nucleotide polymorphisms (SNPs). This study aims to develop and cross-validate robust predictive models for postoperative fentanyl analgesic requirement and other related outcomes in patients undergoing major breast surgery. Data regarding genotypes of 10 candidate SNPs, cold pain test (CPT) scores, pupillary response to fentanyl (PRF), and other common clinical characteristics were recorded from 257 patients undergoing major breast surgery. Predictive models for 24-hour fentanyl requirement, 24-hour pain scores, and time for first analgesic (TFA) in the postoperative period were developed using 4 different algorithms: generalised linear regression model, linear support vector machine learning (SVM-Linear), random forest (RF), and Bayesian regularised neural network. The variant genotype of OPRM1 (rs1799971) and higher CPT scores were associated with higher 24-hour postoperative fentanyl consumption, whereas higher PRF and history of hypertension were associated with lower fentanyl requirement. The variant allele of COMT (rs4680) and higher CPT scores were associated with 24-hour postoperative pain scores. The variant genotype of CTSG (rs2070697), higher intraoperative fentanyl use, and higher CPT scores were associated with significantly lower TFA. The predictive models for 24-hour postoperative fentanyl requirement, pain scores, and TFA had R-squared values of 0.313 (SVM-Linear), 0.434 (SVM-Linear), and 0.532 (RF), respectively. We have developed and cross-validated predictive models for 24-hour postoperative fentanyl requirement, 24-hour postoperative pain scores, and TFA with satisfactory performance characteristics and incorporated them in a novel web application.

Factors affecting sufentanil consumption for intravenous controlled analgesia after hepatectomy: retrospective analysis

Background

Pain control after hepatectomy is usually achieved by opioids. There are significant individual differences in the amount of opioids used after hepatectomy, and the metabolism of opioids is liver-dependent. The purpose of our study was to explore the possible risk factors for opioid consumption during the first 48 h after surgery.

Methods

In a retrospective study design involving 562 patients undergoing open or laparoscopic hepatectomy, all patients were treated with intravenous patient-controlled analgesia (IV-PCA) along with continuous and bolus doses of sufentanil for a duration of 48 h after surgery during the time period of August 2015 and February 2019. The primary endpoint was high sufentanil consumption 48 h after hepatectomy, and patients were divided into two groups: those with or without a high PCA sufentanil dosage depending on the third quartile (Q3). The secondary endpoint was the effect of a high PCA sufentanil dosage on various possible clinical risk factors. The relevant parameters were collected, and correlation and multivariate regression analyses were performed.

Results

The median operation time was 185 min (range, 115–250 min), and the median consumption of sufentanil 48 h after the operation was 91 μg (IQR, 64.00, 133.00). Factors related to the consumption of sufentanil at 48 h after hepatectomy included age, operation time, blood loss, intraoperative infusion (red blood cells and fresh-frozen plasma), pain during movement after surgery (day 1 and day 2), preoperative albumin, and postoperative blood urea nitrogen. Age (≤ 60 and > 60 years), extent of resection (minor hepatic resection and major hepatic resection), surgical approach (laparoscope and open) and operation time (min) were independent risk factors for sufentanil consumption at 48 h postoperatively.

Conclusion

Age younger than 60 years, major hepatic resection, an open approach and a longer operation are factors more likely to cause patients to require higher doses of sufentanil after hepatectomy, and the early identification of such patients can increase the efficacy of perioperative pain management.

Factors Related to the Consumption of Patient-Controlled Postoperative Analgesics in Korea: A Retrospective Study

BACKGROUND

Pain is the most common symptom among inpatients, and patient-controlled analgesia (PCA) is one of the effective pain management methods for postoperative patients.

AIMS

This study aimed to identify the predictors of analgesic consumption in patients using postoperative PCA.

DESIGN

As part of a descriptive and retrospective study, data were collected from the nursing records of 662 patients who underwent postoperative intravenous PCA for three days after surgery at one medical institution. Stepwise multiple regression analyses were conducted to select significant variables that could predict total analgesic consumption.

RESULTS

The results demonstrated that surgical sites, physical characteristics, donation surgery, and postoperative pain significantly influenced total analgesic consumption (POD 3, R² = 53%, p < .001).

CONCLUSION

The present findings provide valuable information for the effective postoperative administration of intravenous PCA and may contribute to the development of customized patient-centered pain management intervention by nurses through more accurate predictions of analgesic consumption based on individual characteristics, the surgical site, and the type of surgery-especially organ donation surgery. This study could contribute to improving preventive interventions by general nurses as well as pain control nurses by enabling more accurate predictions of patients' pain and consumption of self-controlled analgesic agents based on personal characteristics and surgical characteristics.