A prospective, randomized, open label, controlled study investigating the efficiency and safety of 3 different methods of rectus sheath block analgesia following midline laparotomy

Investigation into the clinical performance of rectus sheath block in reducing postoperative pain following surgical intervention: A systematic review and meta-analysis of randomised controlled trials

Background and Aims

Rectus sheath block (RSB) is an effective postoperative pain control technique in abdominal surgical procedures. This systematic review evaluated the efficacy and outcome data of patients undergoing RSB compared to the standard of care in both laparoscopic and open surgical procedures.

Methods

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO ID: CRD42022372596). The search was restricted to randomised controlled trials (RCTs) comparing RSB effectiveness on postoperative pain to any standard general anaesthesia technique (control). We systematically explored PubMed, Medline, Central, Scopus and Web of Science for RCTs from inception to September 2023. The primary outcome was the evaluation of pain scores at rest 0-2, 10-12 and 12-24 h postoperatively. The secondary outcome was the analysis of postoperative intravenous (IV) morphine equivalent consumption at 24-h. A risk-of-bias tool for randomised trials (ROB 2.0, Cochrane, Copenhagen, Denmark) assessment and Grades of Recommendation, Assessment, Development and Evaluation (GRADE, Cochrane, Copenhagen, Denmark) analysis was conducted to evaluate the quality of the RCTs.

Results

Twenty RCTs involving 708 participants who received RSB intervention and 713 who received alternative analgesic care were included. RSB pain scores were significantly lower than control at 0-2 h (P < 0.001) and 10-12 h (P < 0.001) postoperatively. No significant effect was observed at 24 h (P = 0.11). RSB performance compared to control in 24-h IV morphine equivalency in milligrams was significantly lower (P < 0.001).

Conclusion

RSB implementation was associated with reduced postoperative pain scores and decreased opioid consumption in IV morphine equivalency up to 24 h following surgical intervention.

Rectus sheath catheters reduce opiate use in pancreaticoduodenectomy: a pre- and postintervention cohort study

BACKGROUND

Pancreaticoduodenectomy is the only curative option for patients with pancreatic cancer; however, pain remains a considerable problem postoperatively. With many centres moving away from using epidural analgesia, there is the need to evaluate alternative opiate sparing techniques for postoperative analgesia. We sought to determine if rectus sheath catheters (RSCs) had an opiate sparing and analgesic effect compared with standard care alone (opiate analgesia).

METHODS

We conducted a retrospective pre- and postintervention cohort study of patients undergoing pancreaticoduodenectomy at a single tertiary academic hospital in Toronto, Canada, between April 2018 and December 2019. All patients undergoing a pancreaticoduodenectomy were eligible for inclusion. Among the 101 patients identified, 84 (61 control, 23 RSCs) were analyzed after exclusion criteria were applied (epidural analgesia, admission to intensive care intubated or reintubated within the first 96 hours). The pre-intervention group received a semi-standardized course of analgesics, including intravenous hydromorphone, acetaminophen, ketamine, with or without nonsteroidal anti-inflammatory, and with or without intravenous lidocaine; the latter 2 drugs were at the individual anesthesiologist and surgeon's preference. For the postintervention group, the same course of analgesics were used, with the addition of RSCs. These were inserted at the end of the operation, with a loading dose of ropivacaine administered and followed by a programmed intermittent bolus regime for 72-96 hours. The primary outcome measure was total postoperative opiate consumption (oral morphine equivalents). Secondary outcomes included pain scores (numeric rating scale) and treatment-related adverse effects.

RESULTS

Opiate consumption (oral morphine equivalents) at 96 hours was significantly lower (median 188 mg, interquartile range [IQR] 112-228 v. 242.4 mg, IQR 166.8-352) with and without RSC, respectively (p = 0.01). The RSC group used significantly less opiates at each time point from 24 hours postoperatively, with no significant difference in pain scores between the groups and no significant catheter-related complications.

CONCLUSION

The use of RSCs was associated with significant reductions in postoperative opiate consumption. Given the ease of placement and management, with minimal complications, RSCs should be incorporated into a course of postoperative multimodal analgesia. A large scale randomized controlled trial should be conducted to further investigate these findings.

A retrospective cohort study of three wound catheter infusion analgesia regimes after midline laparotomy

Background

Local anesthetic wound infusion catheters are increasingly used postmidline laparotomy to reduce pain and opioid use, however there is little evidence to support any particular infusion regime.

Methods

A retrospective cohort study was undertaken of patients after midline laparotomy who had bilateral local anesthetic wound infusion catheters surgically placed. Patients were recruited into 3 cohorts: ropivacaine 0.2% 5–8 mL/hour continuous wound infusion, 10 mL programmed intermittent bolus 2 hourly, 20 mL programmed intermittent bolus 4 hourly. The primary outcome was the maximum daily Numerical Rating Pain Score with movement (dynamic pain score) recorded during first 96 hours postprocedure. Secondary outcomes included the maximum daily resting pain score and opioid utilization.

Results

In three cohorts of 70 patients (n=210), the maximum daily dynamic pain score in the intermittent bolus 2-hourly and 4-hourly cohorts was lower when compared with the continuous infusion group over the first 4 postoperative days. The mean difference in maximum daily pain score with respect to the continuous infusion regime was 0.8 (95% CI 0.2 to 1.4) for the intermittent bolus 2-hourly group and 0.6 (95% CI 0.0 to 1.2) for the 4-hourly group. Generalized estimating equation modeling indicates the reduction in dynamic pain score is greatest with the intermittent bolus 2-hourly regime over the first 72 hours postprocedure. The 2-hourly intermittent bolus regime was also associated with lower opioid utilization and local anesthetic exposure.

Conclusions

Intermittent wound infusion catheter infusion regimes were associated with lower maximum daily dynamic pain scores, although the magnitude of this change may be of limited clinical significance.

Comparison of analgesic modalities for patients undergoing midline laparotomy: a systematic review and network meta-analysis

BACKGROUND

Midline laparotomy is associated with severe pain. Epidural analgesia has been the established standard, but multiple alternative regional anesthesia modalities are now available. We aimed to compare continuous and single-shot regional anesthesia techniques in this systematic review and network meta-analysis.

METHODS

We included randomized controlled trials on adults who were scheduled for laparotomy with solely a midline incision under general anesthesia and received neuraxial or regional anesthesia for pain. Network meta-analysis was performed with a frequentist method, and continuous and dichotomous outcomes were presented as mean differences and odds ratios, respectively, with 95% confidence intervals. The quality of evidence was rated with the  grading of recommendations, assessment, development, and evaluation system.

RESULTS

Overall, 36 trials with 2,056 patients were included. None of the trials assessed erector spinae plane or quadratus lumborum block, and rectus sheath blocks and transversus abdominis plane blocks were combined into abdominal wall blocks (AWB). For the co-primary outcome of pain score at rest at 24 hr, with a minimal clinically important difference (MCID) of 1, epidural was clinically superior to control and single-shot AWB; epidural was statistically but not clinically superior to continuous wound infiltration (WI); and no statistical or clinical difference was found between control and single-shot AWB. For the co-primary outcome of cumulative morphine consumption at 24 hr, with a MCID of 10 mg, epidural and continuous AWB were clinically superior to control; epidural was clinically superior to continuous WI, single-shot AWB, single-shot WI, and spinal; and continuous AWB was clinically superior to single-shot AWB. The quality of evidence was low in view of serious limitations and imprecision. Other results of importance included: single-shot AWB did not provide clinically relevant analgesic benefit beyond two hr; continuous WI was clinically superior to single-shot WI by 8-12 hr; and clinical equivalence was found between epidural, continuous AWB, and continuous WI for the pain score at rest, and epidural and continuous WI for the cumulative morphine consumption at 48 hr.

CONCLUSIONS

Single-shot AWB were only clinically effective for analgesia in the early postoperative period. Continuous regional anesthesia modalities increased the duration of analgesia relative to their single-shot counterparts. Epidural analgesia remained clinically superior to alternative continuous regional anesthesia techniques for the first 24 hr, but reached equivalence, at least with respect to static pain, with continuous AWB and WI by 48 hr.

TRIAL REGISTRATION

PROSPERO (CRD42021238916); registered 25 February 2021.

Rectus sheath block and emergency midline laparotomy at a hospital in Ethiopia: A prospective observational study

BACKGROUND

Midline laparotomy is associated with severe postoperative pain. Literature showed controversial results regarding the efficacy of the rectus sheath block.

METHODS

This is a prospective cohort study that recruits 30 patients in the rectus sheath block (RSB) group and 30 patients in the multimodal analgesia (MMA) group who underwent emergency midline laparotomy. The RSB was performed by an experienced anesthetist using a land-mark technique. Independent t-test and Mann-Whitney-U test were used for numeric data while Chi-Square or Fisher exact test was used for categorical variables. P-values < 0.05 were considered as statistically significant.

RESULTS

The numeric rating scale score at the recovery was significantly reduced in an RSB group with a p-value of 0.039. Postoperative numeric rating scale scores at 3rd, 6th, 12th, and 24th hours were statistically significantly lower in the RSB group. Postoperative tramadol consumption in 24 h was significantly lower with a p-value of 0.0001 for the rectus sheath group.

CONCLUSIONS

For midline laparotomy, adding a bilateral rectus sheath block at the end of the operation might be an effective postoperative analgesia option.

Invasive placebos in research on peripheral nerve blocks: a follow-up study

INTRODUCTION

The Serious Harm and Morbidity "SHAM" grading system has previously been proposed to categorize the risks associated with the use of invasive placebos in peripheral nerve block research. SHAM grades range from 0 (no potential complications, eg, using standard analgesia techniques as a comparator) through to 4 (risk of major complications, eg, performing a sub-Tenon's block and injecting normal saline). A study in 2011 found that 52% of studies of peripheral nerve blocks had SHAM grades of 3 or more.

METHODS

We repeated the original study by allocating SHAM grades to randomized controlled studies of peripheral nerve blocks published in English over a 22-month period. Documentation was made of the number of study participants, age, number of controls, body region, adverse events due to invasive placebos and any discussion regarding the ethics of using invasive placebos. We compared the proportion of studies with SHAM grades of 3 or more with the original study.

RESULTS

In this current study, 114 studies fulfilled the inclusion criteria, 5 pediatric and 109 adult. The SHAM grade was ≥3 in 38 studies (33.3%), with 1494 patients in these control groups collectively. Several studies discussed their reasons for choosing a non-invasive placebo. No pediatric studies had a SHAM grade of ≥3.

CONCLUSIONS

The use of invasive placebos that may be associated with serious risks in peripheral nerve block research has decreased in contemporary peripheral nerve block research.

Intranasal Fentanyl for Intervention-Associated Breakthrough Pain After Cardiac Surgery

Background

Cardiac bypass surgery patients have early postoperative interventions that elicit breakthrough pain. We evaluated the use of intranasal fentanyl for breakthrough pain management in these patients.

Methods

Multimodal analgesia (paracetamol 1 g three times a day, oxycodone 2–3 mg boluses with a patient-controlled intravenous pump) was used in 16 patients (age 49–70 years, weight 59–129 kg) after cardiac bypass surgery. Intranasal fentanyl 100 µg or 200 µg was used to manage breakthrough pain on the first and third postoperative mornings in a randomised order. Blood samples were collected for up to 3 h after fentanyl administration, pain was assessed with a numeric rating scale of 0–10. Plasma fentanyl concentration was assayed using liquid chromatography-mass spectrometry. Body composition was measured with a bioelectrical impedance device.

Results

Bioavailability of intranasal fentanyl was high (77%), absorption half-time short (< 2 min) and an analgesic plasma concentration ≥ 0.5 ng/mL was achieved in 31 of 32 administrations. Fentanyl exposure correlated inversely with skeletal muscle mass and total body water. Fentanyl analgesia was effective both on the first postoperative morning with chest pleural tube removal and during physiotherapy on the third postoperative morning. The median time of subsequent oxycodone administration was 1.1 h after intranasal fentanyl 100 µg and 2.1 h after intranasal fentanyl 200 µg, despite similar oxycodone concentrations (median 13.8, range 5.2–35 ng/mL) in both fentanyl dose groups.

Conclusions

Intranasal fentanyl 100 µg provided rapid-onset analgesia within 10 min and is an appropriate starting dose for incidental breakthrough pain in the first 3 postoperative days after cardiac bypass surgery.

Clinical Trial Registration

EudraCT Number: 2018-001280-22.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-021-01002-4.

Continuous peripheral nerve blocks compared to thoracic epidurals or multimodal analgesia for midline laparotomy: a systematic review and meta-analysis

BACKGROUND

Continuous peripheral nerve blocks (CPNBs) have been investigated to control pain for abdominal surgery via midline laparotomy while avoiding the adverse events of opioid or epidural analgesia. The review compiles the evidence comparing CPNBs to multimodal and epidural analgesia.

METHODS

We conducted a systematic review using broad search terms in MEDLINE, EMBASE, Cochrane. Primary outcomes were pain scores and cumulative opioid consumption at 48 hours. Secondary outcomes were length of stay and postoperative nausea and vomiting (PONV). We rated the quality of the evidence using Cochrane and GRADE recommendations. The results were synthesized by meta-analysis using Revman.

RESULTS

Our final selection included 26 studies (1,646 patients). There was no statistically significant difference in pain control comparing CPNBs to either multimodal or epidural analgesia (low quality evidence). Less opioids were consumed when receiving epidural analgesia than CPNBs (mean difference [MD]: -16.13, 95% CI [-32.36, 0.10]), low quality evidence) and less when receiving CPNBs than multimodal analgesia (MD: -31.52, 95% CI [-42.81, -20.22], low quality evidence). The length of hospital stay was shorter when receiving epidural analgesia than CPNBs (MD: -0.78 days, 95% CI [-1.29, -0.27], low quality evidence) and shorter when receiving CPNBs than multimodal analgesia (MD: -1.41 days, 95% CI [-2.45, -0.36], low quality evidence). There was no statistically significant difference in PONV comparing CPNBs to multimodal (high quality evidence) or epidural analgesia (moderate quality evidence).

CONCLUSIONS

CPNBs should be considered a viable alternative to epidural analgesia when contraindications to epidural placement exist for patients undergoing midline laparotomies.

Analgesic effectiveness of rectus sheath block during open gastrectomy: A prospective double-blinded randomized controlled clinical trial

BACKGROUND

Despite recent advances in gastric cancer surgery, open gastrectomy is often needed to treat gastric cancer. Due to the large incision in the abdomen, the amount of opioid required during surgery increases and postoperative pain becomes worse. It is well known that postoperative pain has a negative impact on the patient's immune system. Herein, we performed an ultrasound-guided bilateral rectus sheath block (RSB) in patients undergoing open gastrectomy under general anesthesia and analyzed the analgesic effectiveness of RSB in open gastrectomy.

METHODS

A total of 46 patients scheduled for open gastrectomy were randomly divided into 2 groups: Group A (n = 21) consisted of patients who received an RSB using 40 mL of 0.375% ropivacaine under ultrasound guidance and Group B (n = 20) consisted of patients who received an RSB using 40 mL of normal saline. An electronic injection pump was connected to each patient for patient-controlled analgesia (PCA) immediately after the skin closure. The amount of remifentanil required during the surgery was analyzed. After using PCA, data on the use of PCA bolus dose were extracted and analyzed using Excel.

RESULTS

Group A used significantly less remifentanil (1021.4 ± 172.0 μg) than group B (1415.0 ± 330.6 μg; P = .03). The number of PCA bolus dose provided to the patients after surgery was significantly lower in group A (1 h: 1.14 ± 0.9, 2 h: 0.85 ± 0.7) than in group B (1 h: 1.85 ± 0.7, 2 h: 1.45 ± 1.0) until 2 hours after the surgery (1 h, P = .008; 2 h, P = .03), but after 3 hours, there were no significant differences between the 2 groups.

CONCLUSIONS

If ultrasound-guided bilateral RSB with 40 mL of 0.35% ropivacaine is performed precisely in patients undergoing open gastrectomy, the requirement for remifentanil during surgery can be reduced. In addition, it significantly reduces the use of PCA bolus dose for acute postoperative pain within 2 hours after surgery.