Effects of different doses of tramadol added to levobupivacaine in continuous wound infusion for postoperative pain treatment following cesarean section

Efficacy and safety of wound infiltration modalities for postoperative pain management after cesarean section: a systematic review and network meta-analysis protocol

BACKGROUND

Postoperative pain after a cesarean section has negative consequences for the mother during the postoperative period. Over the years, various postoperative pain management strategies have been used following cesarean section. Opioid-based analgesics and landmark approaches have negative side effects, while ultrasound-based regional analgesia necessitates resources and experience, but various wound infiltration adjuvants are innovative with few side effects and are simple to use. The efficacy and safety of each adjuvant, however, are unknown and require further investigation.

OBJECTIVE

This network meta-analysis is intended to provide the most effective wound infiltration drugs for postoperative management after cesarean section.

METHOD

A comprehensive search will be conducted in PubMed/MEDLINE, Cochrane Library, Science Direct, CINHAL, and LILACS without date and language restrictions. All randomized trials comparing the effectiveness of wound infiltration drugs for postoperative pain management after cesarean section will be included. Data extraction will be conducted independently by two authors. The quality of studies will be evaluated using the Cochrane risk of bias tool, and the overall quality of the evidence will be determined by GRADEpro software.

DISCUSSION

The rate of postoperative acute and chronic pain is very high which has a huge impact on the mother, family, healthcare practitioners, and healthcare delivery. It is a basic human right to give every patient with postoperative pain treatment that is realistic in terms of resources, technique, cost, and adverse event profile.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021268774.

Postoperative Analgesic Effectiveness of Peripheral Nerve Blocks in Cesarean Delivery: A Systematic Review and Network Meta-Analysis

The purpose of this systematic review and network meta-analysis was to determine the analgesic effectiveness of peripheral nerve blocks (PNBs), including each anatomical approach, with or without intrathecal morphine (ITMP) in cesarean delivery (CD). All relevant randomized controlled trials comparing the analgesic effectiveness of PNBs with or without ITMP after CD until July 2021. The two co-primary outcomes were designated as (1) pain at rest 6 h after surgery and (2) postoperative cumulative 24-h morphine equivalent consumption. Secondary outcomes were the time to first analgesic request, pain at rest 24 h, and dynamic pain 6 and 24 h after surgery. Seventy-six studies (6278 women) were analyzed. The combined ilioinguinal nerve and anterior transversus abdominis plane (II-aTAP) block in conjunction with ITMP had the highest SUCRA (surface under the cumulative ranking curve) values for postoperative rest pain at 6 h (88.4%) and 24-h morphine consumption (99.4%). Additionally, ITMP, ilioinguinal-iliohypogastric nerve block in conjunction with ITMP, lateral TAP block, and wound infiltration (WI) or continuous infusion (WC) below the fascia also showed a significant reduction in two co-primary outcomes. Only the II-aTAP block had a statistically significant additional analgesic effect compared to ITMP alone on rest pain at 6 h after surgery (−7.60 (−12.49, −2.70)). In conclusion, combined II-aTAP block in conjunction with ITMP is the most effective post-cesarean analgesic strategy with lower rest pain at 6 h and cumulative 24-h morphine consumption. Using the six described analgesic strategies for postoperative pain management after CD is considered reasonable. Lateral TAP block, WI, and WC below the fascia may be useful alternatives in patients with a history of sensitivity or severe adverse effects to opioids or when the CD is conducted under general anesthesia.

Adjuncts to local anesthetic wound infiltration for postoperative analgesia: a systematic review

Local anesthetics (LAs) are commonly infiltrated into surgical wounds for postsurgical analgesia. While many adjuncts to LA agents have been studied, it is unclear which adjuncts are most effective for co-infiltration to improve and prolong analgesia. We performed a systematic review on adjuncts (excluding epinephrine) to local infiltrative anesthesia to determine their analgesic efficacy and opioid-sparing properties. Multiple databases were searched up to December 2019 for randomized controlled trials (RCTs) and two reviewers independently performed title/abstract screening and full-text review. Inclusion criteria were (1) adult surgical patients and (2) adjunct and LA agents infiltration into the surgical wound or subcutaneous tissue for postoperative analgesia. To focus on wound infiltration, studies on intra-articular, peri-tonsillar, or fascial plane infiltration were excluded. The primary outcome was reduction in postoperative opioid requirement. Secondary outcomes were time-to-first analgesic use, postoperative pain score, and any reported adverse effects. We screened 6670 citations, reviewed 126 full-text articles, and included 89 RCTs. Adjuncts included opioids, non-steroidal anti-inflammatory drugs, steroids, alpha-2 agonists, ketamine, magnesium, neosaxitoxin, and methylene blue. Alpha-2 agonists have the most evidence to support their use as adjuncts to LA infiltration. Fentanyl, ketorolac, dexamethasone, magnesium and several other agents show potential as adjuncts but require more evidence. Most studies support the safety of these agents. Our findings suggest benefits of several adjuncts to local infiltrative anesthesia for postoperative analgesia. Further well-powered RCTs are needed to compare various infiltration regimens and agents.

Protocol registration

PROSPERO (CRD42018103851) (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=103851)

A single dose of tramadol in continuous wound analgesia with levobupivacaine does not reduce post-sternotomy pain: a randomized controlled trial

Background

Medial sternotomy is commonly used in cardiac surgery, although it results in intense post-operative pain. The placement of a sternal wound catheter for the administration of local anesthetic represents an effective technique. An initial bolus of tramadol in the sternal wound catheter could potentiate the effect of the local anesthetic and decrease both the post-operative pain and the morphine consumption.

Patients and methods

We conducted a prospective, randomized, double-blind study at the University Hospital Center, Dijon, France. Patients requiring scheduled or non-extreme emergency surgery for valve disease, aorta disease, atrial myxoma, or coronary artery bypass graft via sternotomy were included. A sternal wound catheter was inserted at the end of the surgery. The patients were randomized to receive either a 2 mg/kg bolus of tramadol (n=80) or a placebo (n=80) in the wound catheter. The bolus administration was followed by a continuous infusion of 1.25% levobupivacaine for the first 48 hrs following surgery. The patients’ morphine consumption during the first 48 hrs after extubation was recorded. The other investigated variables were the patients’ rescue analgesia, arterial blood gasses, and length of stay in the intensive care unit and in hospital, as well as the incidence of chronic pain at the four-month follow-up point.

Results

The morphine consumption was found to be comparable in the two groups (38 mg vs 32 mg, p=0.102). No effect was found in terms of the arterial blood gasses, lengths of stay, or incidence of chronic pain.

Conclusion

The addition of tramadol to the local anesthetic delivered via a wound catheter following sternotomy did not reduce the patients’ post-operative morphine consumption.

Trial registration

Clinicaltrials.gov identifier: NCT02851394.