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

Could epidural analgesia be safely used for acute postoperative pain in older adults to enhance recovery?

Epidural analgesia is often considered cornerstone in multimodal analgesia when used in major surgeries. However, its role in managing acute postoperative pain in elderly patients is debatable because of its known potential complications. Furthermore, postoperative pain in elderly patients is under-treated because of complex comorbidities, and they are more prone to adverse events related to pain therapies. All systemic analgesic drugs have pharmacological limitations and precautions in elderly people. Recent meta-analyses showed that epidural analgesia provided better postoperative pain control compared to intravenous opioids. Interestingly, peripheral nerve blocks had no superior control of pain over epidural analgesia. In addition, epidural analgesia has shown to positively affect perioperative morbidities and mortalities, and reduce opioid-related side effects because of its non-analgesic effects on each organ system. When tailored in a specific multimodal approach, it shortens the intensive care and hospital stays. In conclusion, if complications are identified and treated early, and contraindications are ruled out, epidural analgesia can achieve sufficient postoperative pain management with insignificant adverse events in this population.

Comparative efficacy and safety of non-neuraxial analgesic techniques for midline laparotomy: a systematic review and frequentist network meta-analysis of randomised controlled trials

BACKGROUND

Fascial plane blocks provide effective analgesia after midline laparotomy; however, the most efficacious technique has not been determined. We conducted a systematic review and network meta-analysis of randomised controlled trials to synthesise the evidence with respect to pain, opioid consumption, and adverse events.

METHODS

We searched Ovid MEDLINE, Embase, Cochrane Central, and Scopus databases for studies comparing commonly used non-neuraxial analgesic techniques for midline laparotomy in adult patients. The co-primary outcomes of the study were 24-h cumulative opioid consumption and 24-h resting pain score, reported as i.v. morphine equivalents and 11-point numerical rating scale, respectively. We performed a frequentist meta-analysis using a random-effects model and a cluster-rank analysis of the co-primary outcomes.

RESULTS

Of 6115 studies screened, 67 eligible studies were included (n=4410). Interventions with the greatest reduction in 24-h cumulative opioid consumption compared with placebo/no intervention were single-injection quadratus lumborum block (sQLB; mean difference [MD] -16.1 mg, 95% confidence interval [CI] -29.9 to -2.3, very low certainty), continuous transversus abdominis plane block (cTAP; MD -14.0 mg, 95% CI -21.6 to -6.4, low certainty), single-injection transversus abdominis plane block (sTAP; MD -13.7 mg, 95% CI -17.4 to -10.0, low certainty), and continuous rectus sheath block (cRSB; MD -13.2 mg, 95% CI -20.3 to -6.1, low certainty). Interventions with the greatest reduction in 24-h resting pain score were cRSB (MD -1.2, 95% CI -1.8 to -0.6, low certainty), cTAP (MD -1.0, 95% CI -1.7 to -0.2, low certainty), and continuous wound infusion (cWI; MD -0.7, 95% CI -1.1 to -0.4, low certainty). Clustered-rank analysis including the co-primary outcomes showed cRSB and cTAP blocks to be the most efficacious interventions.

CONCLUSIONS

Based on current evidence, continuous rectus sheath block and continuous transversus abdominis plane block were the most efficacious non-neuraxial techniques at reducing 24-h cumulative opioid consumption and 24-h resting pain scores after midline laparotomy (low certainty). Future studies should compare techniques for upper vs lower midline laparotomy and other non-midline abdominal incisions.

CLINICAL TRIAL REGISTRATION

PROSPERO Registration Number: CRD42021269044.

Comparison of postoperative back pain between paramedian and midline approach for thoracic epidural anesthesia

Background: The development of back pain following epidural analgesia is one reason for patient refusal of neuraxial analgesia. The primary endpoint of this study was to compare the incidence and severity of back pain following midline and paramedian epidural technique. The secondary endpoint was to identify the risk factors associated with the occurrence of back pain.Methods: This prospective randomized study included 114 patients receiving thoracic epidural catheterization for pain management following upper abdominal or thoracic surgery. Patients were allocated to either the midline or the paramedian group by computer-generated randomization. An investigator who was blinded to the patient group interviewed patients at 24, and 48 h, and 3–5 days after surgery about the existence of back pain and its severity.Results: The total incidence of back pain following epidural anesthesia was 23.8% in the midline group and 7.8% in the paramedian group. The numerical rating scale of back pain was not different between the two groups at 24 h and 4 days after surgery. The paramdian technique was associated with a lower incidence of back pain than the midline technique (95% confidence interval 0.05–0.74, odds ratio 0.2, P < 0.01). However, the number of attempts, surgical position, body mass index, and duration of surgery were not associated with back pain.Conclusions: This study showed that the midline group of thoracic epidural analgesia demonstrated higher incidence of back pain than the paramedian group. However, the pain was mild in intensity and decreased with time in both groups.

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.

Trial Sequential Analysis explained using a post-hoc analysis of meta-analyses published in Korean Journal of Anesthesiology

Background

Trial sequential analysis (TSA) is a recent cumulative meta-analysis method used to weigh type I and II errors and to estimate when the effect is large enough to be unaffected by further studies. The aim of this study was to illustrate possible TSA scenarios and their significance using meta-analyses published in the Korean Journal of Anesthesiology (KJA) as working material.

Methods

We performed a systematic medical literature search for meta-analyses published in the KJA. TSA was performed on each main outcome, estimating the required sample size on the calculated effect size for the intervention, considering a type I error of 5% and a power of 90% or 99%.

Results

Six meta-analyses with a total of ten main outcomes were included in the analysis. Seven TSAs confirmed the results of the meta-analyses. However, only three of them reached the required sample size. In the two TSAs, the cumulative z-lines were not statistically significant. One TSA boundary for effect was reached with the 90% analysis, but not with the 99% analysis.

Conclusions

In TSA, a meta-analysis pooled effect may be established to assess if the cumulative sample size is large enough. TSA can be used to add strength to the conclusions of meta-analyses; however, pre-registration of the TSA protocol is of paramount importance. This study could be useful to better understand the use of TSA as an additional statistical tool to improve meta-analysis quality.