Regional anaesthesia for postoperative pain management following laparoscopic, visceral, non-oncological surgery a systematic review and meta-analysis

BACKGROUND

Postoperative pain management following laparoscopic, non-oncological visceral surgery in adults is challenging. Regional anaesthesia could be a promising component in multimodal pain management.

METHODS

We performed a systematic review and meta-analysis with GRADE assessment. Primary outcomes were postoperative acute pain intensity at rest/during movement after 24 h, the number of patients with block-related adverse events and the number of patients with postoperative paralytic ileus.

RESULTS

82 trials were included. Peripheral regional anaesthesia combined with general anaesthesia versus general anaesthesia may result in a slight reduction of pain intensity at rest at 24 h (mean difference (MD) - 0.72 points; 95% confidence interval (CI) - 0.91 to - 0.54; I2 = 97%; low-certainty evidence), which was not clinically relevant. The evidence is very uncertain regarding the effect on pain intensity during activity at 24 h (MD -0.8 points; 95%CI - 1.17 to - 0.42; I2 = 99%; very low-certainty evidence) and on the incidence of block-related adverse events. In contrast, neuraxial regional analgesia combined with general anaesthesia (versus general anaesthesia) may reduce postoperative pain intensity at rest in a clinical relevant matter (MD - 1.19 points; 95%CI - 1.99 to - 0.39; I2 = 97%; low-certainty evidence), but the effect is uncertain during activity (MD - 1.13 points; 95%CI - 2.31 to 0.06; I2 = 95%; very low-certainty evidence). There is uncertain evidence, that neuraxial regional analgesia combined with general anaesthesia (versus general anaesthesia) increases the risk for block-related adverse events (relative risk (RR) 5.11; 95%CI 1.13 to 23.03; I2 = 0%; very low-certainty evidence).

CONCLUSION

This meta-analysis confirms that regional anaesthesia might be an important part of multimodal postoperative analgesia in laparoscopic visceral surgery, e.g. in patients at risk for severe postoperative pain, and with large differences between surgical procedures and settings. Further research is required to evaluate the use of adjuvants and the additional benefit of regional anaesthesia in ERAS programmes.

PROTOCOL REGISTRATION

PROSPERO CRD42021258281.

Efficacy and safety of perioperative ketamine for the prevention of chronic postsurgical pain: A meta-analysis

STUDY OBJECTIVE

Assessment of the efficacy and safety of perioperative intravenous ketamine in reducing incidence and severity of chronic postsurgical pain.

STUDY DESIGN

A systematic review and meta-analysis of randomized controlled trials (RCTs).

DATA SOURCES

The following data sources were systematically searched: MEDLINE, CENTRAL, and EMBASE (till 02/2021).

PATIENTS

Adult patients undergoing any surgery.

INTERVENTIONS

Perioperative use of intravenous ketamine as an additive analgesic drug compared to placebo, no active control treatment, and other additive drugs.

MEASUREMENTS

Primary outcomes were number of patients with chronic postsurgical pain after 6 months and ketamine related adverse effects. Secondary outcomes were chronic postsurgical pain incidence after 3 and 12 months, chronic postsurgical neuropathic pain incidence, chronic postsurgical moderate to severe pain incidence, intensity of chronic postsurgical pain at rest, and during movement, oral morphine consumption after 3, 6, and 12 months and incidence of opioid-related adverse effects.

MAIN RESULTS

Thirty-six RCTs were included with a total of 3572 patients. Ketamine compared to placebo may result in no difference in the number of patients with chronic postsurgical pain after 6 months (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.71-1.05; I2  = 34%; 16 studies; low-certainty evidence). Ketamine may reduce the incidence of chronic postsurgical neuropathic pain after 3 months in comparison to placebo (RR 0.78, 95% CI 0.62-0.99, I2  = 31%, seven trials, low-certainty evidence). Ketamine compared to placebo may increase the risk for postoperative nystagmus (RR 9.04, 95% CI 1.15-70.90, I2 30%, two trials, low-certainty evidence) and postoperative visual disturbances (RR 2.29, 95% CI 1.05-4.99, I2 10%, seven trials, low-certainty evidence).

CONCLUSIONS

There is low-certainty evidence that perioperative ketamine has no effect on chronic postsurgical pain in adult patients. Low-certainty evidence suggests that ketamine compared to placebo may reduce incidence of chronic postsurgical neuropathic pain after 3 months. Questions like ideal dosing, treatment duration and more patient-related outcome measures remain unanswered, which warrants further studies.

PROTOCOL REGISTRATION

Prospero CRD42021223625, 07.01.2021.

Erector spinae plane block for postoperative pain

BACKGROUND

Acute and chronic postoperative pain are important healthcare problems, which can be treated with a combination of opioids and regional anaesthesia. The erector spinae plane block (ESPB) is a new regional anaesthesia technique, which might be able to reduce opioid consumption and related side effects.

OBJECTIVES

To compare the analgesic effects and side effect profile of ESPB against no block, placebo block or other regional anaesthetic techniques.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Web of Science on 4 January 2021 and updated the search on 3 January 2022.

SELECTION CRITERIA

Randomised controlled trials (RCTs) investigating adults undergoing surgery with general anaesthesia were included. We included ESPB in comparison with no block, placebo blocks or other regional anaesthesia techniques irrespective of language, publication year, publication status or technique of regional anaesthesia used (ultrasound, landmarks or peripheral nerve stimulator). Quasi-RCTs, cluster-RCTs, cross-over trials and studies investigating co-interventions in either arm were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all trials for inclusion and exclusion criteria, and risk of bias (RoB), and extracted data. We assessed risk of bias using the Cochrane RoB 2 tool, and we used GRADE to rate the certainty of evidence for the primary outcomes. The primary outcomes were postoperative pain at rest at 24 hours and block-related adverse events. Secondary outcomes were postoperative pain at rest (2, 48 hours) and during activity (2, 24 and 48 hours after surgery), chronic pain after three and six months, as well as cumulative oral morphine requirements at 2, 24 and 48 hours after surgery and rates of opioid-related side effects.

MAIN RESULTS

We identified 69 RCTs in the first search and included these in the systematic review. We included 64 RCTs (3973 participants) in the meta-analysis. The outcome postoperative pain was reported in 38 out of 64 studies; block-related adverse events were reported in 40 out of 64 studies. We assessed RoB as low in 44 (56%), some concerns in 24 (31%) and high in 10 (13%) of the study results. Overall, 57 studies reported one or both primary outcomes. Only one study reported results on chronic pain after surgery. In the updated literature search on 3 January 2022 we found 37 new studies and categorised these as awaiting classification. ESPB compared to no block There is probably a slight but not clinically relevant reduction in pain intensity at rest 24 hours after surgery in patients treated with ESPB compared to no block (visual analogue scale (VAS), 0 to 10 points) (mean difference (MD) -0.77 points, 95% confidence interval (CI) -1.08 to -0.46; 17 trials, 958 participants; moderate-certainty evidence). There may be no difference in block-related adverse events between the groups treated with ESPB and those receiving no block (no events in 18 trials reported, 1045 participants, low-certainty evidence). ESPB compared to placebo block ESPB probably has no effect on postoperative pain intensity at rest 24 hours after surgery compared to placebo block (MD -0.14 points, 95% CI -0.29 to 0.00; 8 trials, 499 participants; moderate-certainty evidence). There may be no difference in block-related adverse events between ESPB and placebo blocks (no events in 10 trials reported; 592 participants; low-certainty evidence). ESPB compared to other regional anaesthetic techniques Paravertebral block (PVB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to PVB (MD 0.23 points, 95% CI -0.06 to 0.52; 7 trials, 478 participants; low-certainty evidence). There is probably no difference in block-related adverse events (risk ratio (RR) 0.27, 95% CI 0.08 to 0.95; 7 trials, 522 participants; moderate-certainty evidence). Transversus abdominis plane block (TAPB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to TAPB (MD -0.16 points, 95% CI -0.46 to 0.14; 3 trials, 160 participants; low-certainty evidence). There may be no difference in block-related adverse events (RR 1.00, 95% CI 0.21 to 4.83; 4 trials, 202 participants; low-certainty evidence). Serratus anterior plane block (SAPB) The effect on postoperative pain could not be assessed because no studies reported this outcome. There may be no difference in block-related adverse events (RR 1.00, 95% CI 0.06 to 15.59; 2 trials, 110 participants; low-certainty evidence). Pectoralis plane block (PECSB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to PECSB (MD 0.24 points, 95% CI -0.11 to 0.58; 2 trials, 98 participants; low-certainty evidence). The effect on block-related adverse events could not be assessed. Quadratus lumborum block (QLB) Only one study reported on each of the primary outcomes. Intercostal nerve block (ICNB) ESPB may not have any additional effect on postoperative pain intensity at rest 24 hours after surgery compared to ICNB, but this is uncertain (MD -0.33 points, 95% CI -3.02 to 2.35; 2 trials, 131 participants; very low-certainty evidence). There may be no difference in block-related adverse events, but this is uncertain (RR 0.09, 95% CI 0.04 to 2.28; 3 trials, 181 participants; very low-certainty evidence). Epidural analgesia (EA) We are uncertain whether ESPB has an effect on postoperative pain intensity at rest 24 hours after surgery compared to EA (MD 1.20 points, 95% CI -2.52 to 4.93; 2 trials, 81 participants; very low-certainty evidence). A risk ratio for block-related adverse events was not estimable because only one study reported this outcome.

AUTHORS' CONCLUSIONS

ESPB in addition to standard care probably does not improve postoperative pain intensity 24 hours after surgery compared to no block. The number of block-related adverse events following ESPB was low. Further research is required to study the possibility of extending the duration of analgesia. We identified 37 new studies in the updated search and there are three ongoing studies, suggesting possible changes to the effect estimates and the certainty of the evidence in the future.