Postoperative Analgesia after Open Liver Surgery: Systematic Review of Clinical Evidence

Analgesic efficacy of an opioid-free postoperative pain management strategy versus a conventional opioid-based strategy following open major hepatectomy: an open-label, randomised, controlled, non-inferiority trial

Background

Convincing clinical evidence regarding completely opioid-free postoperative pain management using erector spinae plane block (ESPB) in patients undergoing open major hepatectomy (OMH) is lacking. Herein, we aimed to compare the postoperative analgesic efficacy of the visualised continuous opioid-free ESPB (VC-ESPB) and conventional intravenous opioid-based postoperative pain management in hepatocellular carcinoma (HCC) patients undergoing OMH.

Methods

This open-label, randomised, controlled, non-inferiority trial enrolled patients with HCC undergone open major hepatectomy in Fujian Provincial Hospital and compared the postoperative analgesic efficacy of VC-ESPB (VC-ESPB group) and conventional intravenous opioid-based pain management regimen (conventional group). Patients were randomly assigned (1:1) to VC-ESPB group and conventional group. Patients were not masked to treatment allocation. The VC-ESPB group was treated with intermittent injections of 0.25% ropivacaine (bilateral, 30 mL each side) given every 12 h through catheters placed in the space of erector spinae and an opioid-free intravenous pump (10-mg tropisetron diluted to 100 mL with 0.9% normal saline [NS]) for postoperative pain management. The conventional group did not receive ESPB and was treated with a conventional intravenous opioid-based pump (2.5-μg/kg sufentanil and 10-mg tropisetron diluted to 100 mL with 0.9% NS). Patients in the VC-ESPB group underwent magnetic resonance imaging (MRI) to identify local anaesthetic diffusion after ESPB was performed under ultrasound guidance. The primary outcome was postoperative analgesic efficacy, which was indicated by the cumulative area under the curve (AUC) of the pain visual analogue scale scores (range, 0-10; a higher score indicates more pain) obtained at rest and at movement until 48 h postoperatively after leaving the post-anaesthesia care unit (PACU). Herein, an AUC of 26.5 was set as the noninferiority margin, which needed to be satisfied for both cumulative AUCPACU-48 h at rest and cumulative AUCPACU-48 h at movement. Per protocol participants were included in primary and safety analyses. This trial was registered with ChiCTR.org.cn (ChiCTR1900026583).

Findings

Between October 30, 2019, and May 1, 2023, 106 patients were enrolled and randomly assigned to the VC-ESPB group (n = 53) and the conventional group (n = 53). After the dropout (n = 5), a total of 101 patients (VC-ESPB group, n = 50; conventional group, n = 51) were analysed. Both the level of cumulative AUCPACU-48 h (at rest: 160.08 ± 38.00 vs. 164.94 ± 31.00; difference [90% CI], -4.861 [-16.308, 6.585]) and cumulative AUCPACU-48 h (at movement: 209.64 ± 28.98 vs. 212.59 ± 33.11; difference [90% CI], -2.948 [-13.236, 7.339]) were similar between the VC-ESPB and control groups within the first postoperative 48 h. The upper limit of the 90% CIs for the difference in cumulative ACUPACU-48 h at rest and at movement did not reach the upper inferiority margin (26.5). During the first postoperative 48 h, the rate of nonsteroidal anti-inflammatory drug rescue analgesia was similar between the VC-ESPB group and conventional group (n = 16, 32.0% vs. n = 11, 21.6%; P = 0.236). Treatment-related death was not observed in the VC-ESPB group (n = 0, 0%) and conventional group (n = 0, 0%). In VC-ESPB group, local site paralysis (n = 1, 2.0%) was observed in one patient and rash (n = 1, 2.0%) was observed in another patient. One patient in the conventional group was observed with rash preoperatively (n = 1, 2.0%). The VC-ESPB group had significantly lower rates of postoperative nausea (n = 2, 4.0%, vs. n = 9, 17.6%, P = 0.028), vomiting (n = 1, 2.0% vs. n = 8, 15.7%, P = 0.031) and lower incidence of major complications (n = 4, 8.0% vs. n = 6, 11.8%; P = 0.033).

Interpretation

This study demonstrates the noninferiority of VC-ESPB when compared with the conventional opioid-based approach for postoperative pain management after OMH, suggesting that it is feasible to achieve opioid-free postoperative pain management for OMH.

Funding

The Joint Funds for the Innovation of Science and Technology, Fujian Province, China; the Youth Scientific Research Project of Fujian Provincial Health Commission; the Fujian Research and Training Grants for Young and Middle-aged Leaders in Healthcare; and the Key Clinical Specialty Discipline Construction Program of Fujian, China.

Assessment of Ultrasound-Guided Continuous Low Serratus Anterior Plane Block for Pain Management After Hepatectomy: A Randomized Controlled Trial

Purpose

Adequate postoperative analgesia is a key to earlier recovery from open surgery. This work investigated the pain control and quality of patient recovery after hepatectomy to evaluate the modified continuous serratus anterior plane block (called low SAPB) for postoperative analgesia.

Patients and Methods

This single-center, blinded, randomized, controlled study included 136 patients who underwent hepatectomy under general anesthesia. For postoperative analgesia, the patients in the SAPB group were given a continuous low SAPB at the 7th intercostal space in the right mid-axillary line, and the patients in the control group were given continuous intravenous opioid analgesia. The numeric pain rating scale (NPRS) was used for pain assessment. The postoperative assessment focused on the remedial drug consumption, the occurrence of adverse postoperative analgesic reactions, and the quality of patient recovery evaluated with the QoR-15 questionnaire.

Results

Compared to the controls, the SAPB patients had significantly lower NPRS scores at 12 h and 24 h at rest and 6 h, 12 h, and 24 h in motion, and a longer time to first use of remedial analgesics at 24 h, and higher overall QoR-15 scores at 24 h [124 (121, 126) vs 121 (120, 124)] and 48 h [129 (126, 147) vs 126 (125, 128)], after surgery. There was no significant difference in the incidence of analgesia-related adverse reactions between the two groups.

Conclusion

The continuous low SAPB could achieve superior pain control, especially for motor pain, to intravenous opioid analgesia during the first 24 h post-surgery. Even with no significant difference in the incidence of postoperative adverse reactions, patients with continuous low SAPB appeared to have a higher quality of recovery in the first two days post-surgery than patients with continuous intravenous analgesia.

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.

A Retrospective Comparison of Three Patient-Controlled Analgesic Strategies: Intravenous Opioid Analgesia Plus Abdominal Wall Nerve Blocks versus Epidural Analgesia versus Intravenous Opioid Analgesia Alone in Open Liver Surgery

Background: Adequate pain control is of crucial importance to patient recovery and satisfaction following abdominal surgeries. The optimal analgesia regimen remains controversial in liver resections. Methods: Three groups of patients undergoing open hepatectomies were retrospectively analyzed, reviewing intravenous patient-controlled analgesia (IV-PCA) versus IV-PCA in addition to bilateral rectus sheath and subcostal transversus abdominis plane nerve blocks (IV-PCA + NBs) versus patient-controlled thoracic epidural analgesia (TEA). Patient-reported pain scores and clinical data were extracted and correlated with the method of analgesia. Outcomes included total morphine consumption and numerical rating scale (NRS) at rest and on movement over the first three postoperative days, time to remove the nasogastric tube and urinary catheter, time to commence on fluid and soft diet, and length of hospital stay. Results: The TEA group required less morphine over the first three postoperative days than IV-PCA and IV-PCA + NBs groups (9.21 ± 4.91 mg, 83.53 ± 49.51 mg, and 64.17 ± 31.96 mg, respectively, p < 0.001). Even though no statistical difference was demonstrated in NRS scores on the first three postoperative days at rest and on movement, the IV-PCA group showed delayed removal of urinary catheter (removal on postoperative day 4.93 ± 5.08, 3.87 ± 1.31, and 3.70 ± 1.30, respectively) and prolonged length of hospital stay (discharged on postoperative day 12.71 ± 7.26, 11.79 ± 5.71, and 10.02 ± 4.52, respectively) as compared to IV-PCA + NBs and TEA groups. Conclusions: For postoperative pain management, it is expected that the TEA group required the least amount of opioid; however, IV-PCA + NBs and TEA demonstrated comparable postoperative outcomes, namely, the time to remove nasogastric tube/urinary catheter, to start the diet, and the length of hospital stay. IV-PCA with NBs could thus be a reliable analgesic modality for patients undergoing open liver resections.

Pain Management After Open Liver Resection: Epidural Analgesia Versus Ultrasound-Guided Erector Spinae Plane Block

Background: Multimodal analgesia techniques, including regional analgesia, have been shown to provide effective analgesia and minimize opioid consumption after liver resection surgery. While thoracic epidural analgesia (TEA) is considered the gold standard, its role in the current era of enhanced recovery after surgery (ERAS) has been questioned. Erector spinae plane blocks (ESPBs) have the potential to provide effective postoperative analgesia without the risks associated with epidural analgesia. The primary aim of this quality improvement project was to evaluate the analgesic efficacy of ultrasound-guided ESPB in comparison with TEA in patients undergoing open liver resection.

Methods: Fifty patients who underwent open liver resection and received TEA (n=25) or ESPB (n=25) as part of an ERAS pathway were retrospectively identified. The primary outcome measure was cumulative postoperative opioid consumption at 24 hours. Secondary outcomes included opioid consumption, pain scores, the incidence of nausea and vomiting requiring antiemetics, lower extremity muscle weakness, and occurrence of hypotension requiring treatment on arrival to the post-anesthesia care unit and at 2, 6, 12, 24 hours, and daily through postoperative day 7. 

Results: Opioid requirements were significantly lower in the TEA group compared to the ESPB group. Postoperative pain scores at rest and with deep inspiration were significantly lower in the TEA group through postoperative day 5. There were no differences in other outcome measures.

Conclusions: These findings suggest that compared with ESPB, TEA provides superior pain relief after open liver resection.

Race, ethnicity, and the use of regional anesthesia in cancer patients undergoing open abdominal surgery: A single-center retrospective cohort study

Background

Where applicable, regional anesthesia has been shown to be superior to opioid or non-opioid analgesic modalities alone. However, some studies have shown ethnic-based disparities in the use of regional anesthesia in patients undergoing surgical procedures. In this study of patients who had undergone major oncologic surgery, our main objective was to compare the use of regional anesthesia between patients of different ethnicities.

Methods

A retrospective review of adults who had undergone major open abdominal surgical procedures between 2016 and 2021 was performed. Logistic regression models were used to assess the association between baseline patient characteristics and the use of regional anesthesia.

Results

A total of 4,791 patients were included in the analysis. The median age was 60.5 years [interquartile range, 49, 69], the majority were female (65%), and of American Society of Anesthesiologists Physical Status Class (ASA) 3 (94.7%). Regional anesthesia was used in 2,652 patients (55.4%) and was not associated with race or ethnicity (p = 0.287). Compared to White patients, the odds of regional anesthesia use in other racial/ethnic groups were: Asian {odds ratio (OR) 0.851 [95% confidence interval (CI), 0.660–1.097]; p = 0.2125}, Black/African American [OR 0.807 (95% CI, 0.651–1.001); p = 0.0508], Hispanic/Latino [OR 0.957 (95% CI, 0.824–1.154); p = 0.7676], Other race [OR 0.957 (95% CI, 0.627–1.461); p = 0.8376]. In the multivariable analysis, age [OR 0.995 (95% CI, 0.991–1.000); p = 0.0309] and female gender [OR 1.231 (95% CI, 1.090–1.390); p = 0.0008] were associated with the use of regional anesthesia.

Conclusion

In this single-institution retrospective study of adults who had undergone major open abdominal surgery, the use of regional anesthesia was not associated with race or ethnicity. In the multivariable analysis, age and female gender were associated with the use of regional anesthesia.