The relationship between postoperative intravenous patient-controlled fentanyl analgesic requirements and severity of liver disease

Utility of Quadratus Lumborum Blocks in Patients Who Undergo Liver Transplant: A Single-Center Retrospective Study

BACKGROUND

Regional anesthesia is an alternative to opioids for pain in patients undergoing liver transplantation. Quadratus lumborum blocks may provide appropriate dermatomal coverage with an excellent safety profile.

METHODS

Data were collected retrospectively on adult patients who underwent liver transplant at an academic medical center from 2019 to 2022 (n = 207). The primary outcome was opioid administration during the 48 h after transplant.

RESULTS

Patient demographics did not differ between groups. No association was found between patients who received a block and postoperative opioid administration (p = 0.848). However, among patients extubated in the operating room, patients who received a block reported, on average, a 0.9-unit lower pain score than patients who received no block (p = 0.041). Patients who received a block were also more likely to be extubated in the operating room (87.8% block vs. 44.4% no block; p < 0.001).

CONCLUSION

Patients who underwent liver transplantation had similar postoperative opioid use whether or not they received a quadratus lumborum block. Yet, when evaluating additional factors, such as extubation, pain scores were lower in patients who received a quadratus lumborum block. This important finding supports the idea that quadratus lumborum blocks may be a safe and valuable technique for controlling postoperative pain in adult patients who undergo liver transplantation.

Future liver remnant volume is associated with postoperative fentanyl consumption following open donor hepatectomy: a retrospective multivariate analysis

PURPOSE

Liver resection has a risk of postoperative hepatic dysfunction, including drug metabolism. Since fentanyl is primarily metabolized in the liver, liver resection requires exercising caution against fentanyl overdose in postoperative analgesia. The rationale for dose adjustment of fentanyl in the preoperative prescription for patients undergoing liver resection remains unclear. We examined whether postoperative fentanyl consumption is associated with the future liver remnant after liver resection and investigated factors influencing fentanyl consumption.

METHODS

In this retrospective study, 89 living liver donors undergoing open liver resection received intravenous patient-controlled analgesia with fentanyl 2 mg with thoracic epidural analgesia. The primary outcome was postoperative hourly consumption of intravenous patient-controlled analgesia with fentanyl. Future liver remnant volume (ml) and the ratio of future liver remnant volume to whole liver volume (%) were estimated by computed tomography volumetry and compared to determine which correlated more strongly with fentanyl hourly consumption. Multivariable analysis identified independent factors affecting fentanyl consumption, with adjustments for patient characteristics and intravenous patient-controlled analgesia setting.

RESULTS

Future liver remnant volume (ml) was significantly correlated more strongly than the ratio of future liver remnant (%) with postoperative fentanyl consumption (r = 0.53 vs. 0.36, p < 0.001). Larger future liver remnant volume (β = 0.25, p = 0.006) and age < 45 years (β = 0.24, p = 0.009) were independently associated with higher fentanyl consumption, while sex and weight were not.

CONCLUSIONS

Future liver remnant volume was significantly associated with postoperative fentanyl consumption. Smaller remnant liver volume and older age (≥ 45 years) were independent factors reducing postoperative fentanyl consumption in patients undergoing open donor hepatectomy.

The Requirement of Isoflurane and Remifentanil During Liver Transplantation Using Bispectral Index and Surgical Pleth Index: An Observational Study

BACKGROUND

During liver transplantation (LT), patients and surgical factors potentially influence the pharmacokinetics of the anesthetic agents. The aim of this study was to investigate the requirement of isoflurane and remifentanil according to severity of liver disease during LT under balanced anesthesia.

METHODS

We enrolled 44 patients undergoing LT. Anesthetic depth was maintained within the bispectral index score of 40 to 60 and Surgical Pleth Index of 20 to 60. Patients were divided into 2 groups according to their median Model for End-Stage Liver Disease (MELD) score: low MELD group and high MELD group. We compared end-tidal inhaled anesthetics and remifentanil consumption.

RESULTS

Patients were divided into 2 groups according to median value of MELD score: MELD score <16 (low MELD group; n = 20) or MELD ≥16 (high MELD group; n = 20). There was no significant difference between the 2 groups in end-tidal concentration of isoflurane during 3 phases. However, the remifentanil requirement was lower in the high MELD group during the dissection and anhepatic phases (mean (SD), 0.105 (0.067) vs 0.064 (0.055) µg/kg/min; P = .037, and 0.167 (0.096) vs 0.108 (0.079) µg/kg/min; P = .039, respectively; low MELD group vs high MELD group) with no significant difference during the neohepatic phase.

CONCLUSIONS

The severity of liver dysfunction based on MELD score affected the intraoperative remifentanil requirement during LT. Patients with cirrhosis are required to use analgesics appropriate to their individual patient characteristics in clinical practice.

Comparison of Analgesic Efficacy of Erector Spinae Plane Block and Posterior Quadratus Lumborum Block in Laparoscopic Liver Resection: A Randomized Controlled Trial

Purpose

Ultrasound-guided fascial plane blocks, including the erector spinae plane (ESP) and quadratus lumborum (QL) blocks, provide effective postoperative abdominal analgesia. However, there is limited evidence on the analgesic efficacy of ESP and QL blocks after liver surgery. Therefore, we aimed to compare the cumulative opioid consumption between the ESP and QL blocks in patients with hepatocellular carcinoma undergoing laparoscopic liver resection.

Patients and Methods

Eighty-eight patients scheduled to undergo laparoscopic liver resection were randomized to receive bilateral single injection of ESP block at T8 (ESP group) or bilateral single injection of posterior QL block (QL group; 20 mL of 0.375% ropivacaine for each side, ie, total 150 mg of ropivacaine), in addition to intravenous (IV) fentanyl patient-controlled analgesia and multimodal analgesia. The primary outcome was cumulative opioid consumption over the first 24 h, expressed as IV morphine equivalents. Secondary outcomes included serial plasma ropivacaine concentrations, pain scores, time to first flatus, and Quality of Recovery-15 scores.

Results

Eighty-five patients were analyzed (ESP group, n = 42; QL group, n = 43). Cumulative 24-h opioid consumption was similar between the ESP and QL groups (41.4 ± 22.6 mg vs 44.2 ± 20.0 mg, mean difference (QL-ESP), 2.8 mg, 95% confidence interval, −6.4 to 12 mg, p > 0.99). There were no significant differences in resting pain scores at 24, 48 and 72 h postoperatively or recovery outcomes. The peak plasma ropivacaine concentration 30 min after injection was significantly higher in the ESP group (1.5 ± 0.3 µg/mL) than in the QL group (1.3 ± 0.5 µg/mL, p = 0.035); however, both were lower than the arterial threshold value of systemic toxicity (4.3 µg/mL).

Conclusion

ESP and QL blocks provided similar postoperative analgesia in patients undergoing laparoscopic liver resection.

Ultrasound-guided erector spinae plane block for postoperative analgesia in laparoscopic liver resection: A prospective, randomised controlled, patient and observer-blinded study

BACKGROUND

Erector spinae plane block (ESPB) has been reported to manage postoperative pain effectively after various types of surgery. However, there has been a lack of study on the effect of ESPB after liver resection.

OBJECTIVES

To investigate the analgesic effects of ESPB on pain control after laparoscopic liver resection compared with conventional pain management.

DESIGN

Prospective, randomised controlled study.

SETTING

A single tertiary care centre from February 2019 to February 2020.

PATIENTS

A total of 70 patients scheduled to undergo laparoscopic liver resection.

INTERVENTIONS

In the control group (n = 35), no procedure was performed. In the ESPB group (n = 35), ESPB was performed after induction of general anaesthesia. A total of 40 ml of ropivacaine 0.5% was injected at the T9 level bilaterally. After surgery, intravenous fentanyl patient-controlled analgesia was initiated. Fentanyl and hydromorphone were administered as rescue analgesics.

MAIN OUTCOME MEASURES

The primary outcome was the cumulative postoperative opioid consumption at 24 h (morphine equivalent). The secondary outcomes were rescue opioid (fentanyl) dose in the postanaesthesia care unit (PACU) and pain severity at 1, 6, 12, 24, 48 and 72 h, assessed using a numerical rating scale (NRS) score.

RESULTS

The median [IQR] postoperative opioid consumption during 24 hours following surgery was 48.2 [17.1] mg in the control group and 45.5 [35.8] mg in the ESPB group (median difference, 4.2 mg; 95% CI, -4.2 to 13.3 mg; P = 0.259). Conversely, rescue opioid in PACU was 5.3 [5.0] mg in the control group and 3.0 [1.5] mg in the ESPB group (median difference, 2.5 mg; 95% CI, 1.0 to 5.0 mg; P < 0.001). There was no significant difference in NRS scores point between the groups at any time.

CONCLUSION

ESPB does not provide analgesic effect within 24 h after laparoscopic liver resection.

TRIAL REGISTRATION

Clinical Trial Registry of Korea (https://cris.nih.go.kr.), identifier: KCT0003549).

Opioid Avoidance in Liver Transplant Recipients: Reduction in Postoperative Opioid Use Through a Multidisciplinary Multimodal Approach

The prevalence of substance use disorder in the liver transplantation (LT) population makes postoperative pain management challenging. We report our initial experience with a novel, comprehensive, multidisciplinary opioid avoidance pathway in 13 LT recipients between January 2018 and September 2019. Patients received comprehensive pre-LT education on postoperative opioid avoidance by the surgeon, pharmacist, and psychologist at the time of listing. Immediately after LT, patients received a continuous incisional ropivacaine infusion, ketamine, acetaminophen, and gabapentin as standard nonopioid medications; rescue opioids were used as needed. We compared outcomes with a historical cohort of 27 LT recipients transplanted between August 2016 and January 2018 managed primarily with opioids. On average, opioid avoidance patients used 92% fewer median (interquartile range [IQR]) morphine milligram equivalents (MMEs) versus the historical cohort (7 [1-11] versus 87 [60-130] MME; P < 0.001) per postoperative day over a similar length of stay (8 [7-10] versus 6 [6-10] days; P = 0.14). Fewer outpatient MMEs were prescribed within the first 60 days after LT in the opioid avoidance group versus the historical cohort: 125 (25-150) versus 270 (0-463) MME (P = 0.05). This proof-of-concept study outlines the potential to profoundly reduce opioid utilization in the LT population using a comprehensive multidisciplinary approach.

Effects of Pre-Existing Liver Disease on Acute Pain Management Using Patient-Controlled Analgesia Fentanyl With Parecoxib After Major Liver Resection: A Retrospective, Pragmatic Study

BACKGROUND

The aim of this study was to compare the outcomes of pain management with the use of patient-controlled analgesia (PCA) fentanyl with IV parecoxib between patients with healthy liver with patients with diseased liver undergoing major liver resection.

METHODS

Patients with healthy liver undergoing partial hepatectomy as liver donors for liver transplantation (group 1) and patients with liver cirrhosis (Child's criteria A) undergoing major liver resection for hepatoma (group 2) were identified retrospectively. Both groups routinely received post-operative IV PCA fentanyl and a single dose of parecoxib 40 mg. They were followed up for 3 days or until PCA fentanyl was discontinued post-operatively. Daily Visual Analog Scale, PCA fentanyl usage, rescue attempts, and common drug side effects were collected and analyzed with the use of SPSS version 20.

RESULTS

One hundred one patients were included in the study: 54 in group 1, and 47 in group 2. There were no statistical differences between the two groups in terms of the daily and total fentanyl usage, VAS resting, and incidence of itchiness. The rate of rescue analgesia on post-operative day (POD) 1 was lower in group 2, with a value of P = .045. VAS dynamics were better on POD 1 and 2 for group 2, with P = .05 and P = .012, respectively.

CONCLUSIONS

We found that combining a single dose of IV parecoxib 40 mg with PCA fentanyl is an easy and effective method of acute pain control after major liver resection. We propose the careful usage of post-operative fentanyl and parecoxib in patients with diseased liver, given the difference in effect as compared with healthy liver.

Opioid Drugs in Patients With Liver Disease: A Systematic Review

CONTEXT

The liver, one of the most important organs of the body, is known to be responsible for several functions. The functional contribution of the liver to the metabolism of carbohydrates, protein, drugs and toxins, fats and cholesterol and many other biological processes are still unknown. Liver disorders are classified into two types: acute and chronic. Different drugs are used in liver diseases to treat and control pain. Most pain relief medications such as opioids are metabolized via the liver; therefore, the adverse reactions of drugs are probably higher for patients with liver disease. The current study aimed to evaluate the effects of opioid drugs on patients with liver disease; therefore, it is necessary to select suitable opioids for such patients.

EVIDENCE ACQUISITION

This review was written by referring to research literature including 70 articles and four textbooks published from 1958 to 2015 on various reputable sites. Searches were carried out on the key phrases of narcotic pain relievers (opioids), acute and chronic hepatic failure, opioid adverse drug reactions, drug-induced liver injury (DILI) and other similar keywords. References included a variety of research papers (descriptive and analytical), intervention and review articles.

RESULTS

In patients with liver disease, administration of opioid analgesics should be observed, accurately. As a general rule, lower doses of drugs should be administered at regular intervals based on the signs of drug accumulation. Secondly, the interactions of opioid drugs with different levels of substrates of the P450 cytochrome enzyme should be considered.

CONCLUSIONS

Pain management in patients with liver dysfunction is always challenging to physicians because of the adverse reactions of drugs, especially opioids. Opioids should be used cautiously since they can cause sedation, constipation and sudden encephalopathy effects. Since the clearance of these drugs in patients with hepatic insufficiency is decreased, the initial dose must be decreased, the intervals between doses should be increased and some patients need to be continuously assessed.

Analgesia after liver transplantation

This article addresses postoperative analgesia in patients with end-stage liver disease who have undergone liver transplantation (LT). Postoperative analgesia determines how patients perceive LT. Although important, this topic is underrepresented in the current literature. With an increased frequency of fast tracking in LT, efficient intra- and postoperative analgesia are undergoing changes. We herein review the current literature, compare the benefits and disadvantages of the therapeutic options, and make recommendations based on the current literature and clinical experience.