Role of transversus abdominis plane block after caesarean delivery

The use of perineural dexamethasone and transverse abdominal plane block for postoperative analgesia in cesarean section operations under spinal anesthesia: an observational study

Background

During transverses abdominal plane block (TAP) procedure to provide analgesia in cesarean section (CS) operation, the use of perineural dexamethasone as an additive agent may improve pain relief and may cause a prolonged block duration. This study aims to investigate whether perineural dexamethasone, when added to bupivacaine local anesthetic agent during a TAP block, may provide adequate pain relief without adverse events.

Methods

This is a prospective cohort study of fifty-eight patients undergoing elective CS with spinal anesthesia. We hypothesized to perform bilateral TAP block using perineural dexamethasone as an additive agent. The patients were randomly divided into two groups using a systematic random sampling method. While one group of patients received perineural dexamethasone of 8 mg additive agent together with bupivacaine 0.25% 40 ml (Group TAPD), the other group received only bupivacaine 0.25% 40 ml in TAP block (Group TAPA). The primary outcomes are the period for the first request of postoperative pain relief medication and the numerical rating scale (NRS) pain intensity scores at 2, 6, 12, and 24 h after surgery. The secondary outcomes are comparing the 24-h tramadol and diclofenac analgesic requirements and the incidences of side effects on postoperative day one. A p-value of < 0.05 is statistically significant.

Results

The time to first analgesic request was 8.5 h (8.39–9.79) in the TAPD group versus 5.3 h (5.23–5.59) in the TAPA group, respectively. (p < 0.001) The median NRS scores were significantly reduced in the TAPD group compared to the TAPA group at 6, 12, and 24 h after surgery (p-values < 0.001). The total analgesics consumption over 24 h postoperatively was lower in Group TAPD compared to Group TAPA (p < 0.05).

Conclusion

An additive agent of perineural dexamethasone at a dose of 8 mg during bilateral TAP block for elective CS operation under spinal anesthesia provided better pain relief on postoperative day 1.

Anesthesia considerations and post-operative pain management in pregnant women with chronic opioid use

The prevalence of opioid use disorder in pregnancy has escalated markedly in recent years. Chronic opioid use during pregnancy poses several challenges for providing adequate analgesia and anesthesia in the peripartum period. These challenges include the potential for withdrawal, opioid tolerance and opioid-induced hyperalgesia. Here we discuss alterations in analgesic pharmacokinetics and pharmacodynamics that are associated with chronic opioid use. In addition, when treating pain in patients with opioid use disorder it is important to distinguish between different subgroups. In this review, we will discuss practical management strategies for parturients with (1) untreated opioid use disorder, (2) parturients on medication-assisted treatment (methadone, buprenorphine) and (3) patients recovering from opioid use disorder that are currently abstinent. Finally, we offer an overview of non-opioid strategies that may be utilized as part of a multimodal approach to providing optimal analgesia in this patient population.

Transversus Abdominis Plane Block Versus Wound Infiltration for Analgesia After Cesarean Delivery: A Randomized Controlled Trial

BACKGROUND

Transversus abdominis plane (TAP) block and local anesthetic wound infiltration provide analgesia after cesarean delivery. Studies comparing the 2 techniques are scarce, with conflicting results. This double-blind, randomized controlled trial aimed to compare bilateral ultrasound-guided TAP block with single-shot local anesthetic wound infiltration for analgesia after cesarean delivery performed under spinal anesthesia. We hypothesized that the TAP block would decrease postoperative cumulative fentanyl consumption at 24 hours.

METHODS

Eligible subjects were American Society of Anesthesiologists physical status II parturients with full-term singleton pregnancies undergoing elective cesarean delivery under spinal anesthesia. Exclusion criteria were: <19 years of age or >40 years of age; height <150 cm, weight <60 kg, body mass index ≥40 kg/m; contraindications to spinal anesthesia; history of recent opioid exposure; hypersensitivity to any of the drugs used in the study; significant cardiovascular, renal, or hepatic disease; and known fetal abnormalities. Eighty subjects were randomly allocated to 2 equal groups. In the infiltration group, participants received 15 mL of bupivacaine 0.25% in each side of the surgical wound (total 30 mL); and in the TAP group, participants received 20 mL of bupivacaine 0.25% bilaterally in the TAP block (total 40 mL). The TAP block and wound infiltration were performed by the primary investigator and the operating obstetrician, respectively. All participants received postoperative standard analgesia (ketorolac and paracetamol) and intravenous fentanyl via patient-controlled analgesia. Patients and outcome assessors were blinded to the study group. The primary outcome was the cumulative fentanyl consumption at 24 hours. Secondary outcomes were the time to the first postoperative fentanyl dose, cumulative fentanyl consumption at 2, 4, 6, and 12 hours, pain scores at rest and on movement at 2, 4, 6, 12, and 24 hours, the deepest level of sedation, the incidence of side effects (nausea and vomiting and pruritis), and patient satisfaction.

RESULTS

Data from 78 patients (39 patients in each group) were analyzed. The mean ± SD of cumulative fentanyl consumption at 24 hours was 157.4 ± 63.4 μg in the infiltration group and 153.3 ± 68.3 μg in the TAP group (difference in means [95% confidence interval] is 4.1 [-25.6 to 33.8] μg; P = .8). There were no significant differences between the 2 groups in the time to the first postoperative fentanyl dose, cumulative fentanyl consumption at 2, 4, 6, and 12 hours, pain scores at rest and on movement at 2, 4, 6, 12, and 24 hours, the deepest level of sedation, and patient satisfaction. The incidence of side effects (nausea and vomiting and pruritis) was low in the 2 groups.

CONCLUSIONS

TAP block and wound infiltration did not significantly differ regarding postoperative fentanyl consumption, pain scores, and patient satisfaction in parturients undergoing cesarean delivery under spinal anesthesia.

[Why and how to perform an ultrasound-guided transversus abdominis plane block: A step-by-step approach]

Used in clinical practice as part of a multimodal analgesic regimen, the transversus abdominis plane block (TAP block) is a relative novel procedure in which local anaesthetic agents are injected into the anatomic neurofascial space between the internal oblique and the transversus abdominis muscle. It allows a significantly prolonged duration of analgesia during the early postoperative stage in abdominal surgery. This regional anesthesia technique provides analgesia to the skin, muscles of the anterior abdominal wall and parietal peritoneum in order to decrease the incision-related pain. Thus, it reduces postoperative opiate requirements and opioids-related side effects (nausea, vomiting, delayed resumption of intestinal transit, drowsiness, respiratory depression, urine retention). Additionally, the TAP block appears particularly interesting when neuraxial techniques or opioids are contraindicated. Moreover, the ultrasound-guided procedure provides a significant success rate of this block and additionally avoids major complications. We describe our technique of ultrasound-guided TAP block and discuss its indications, contraindication and potential complications.

Transversus abdominis plane block vs. wound infiltration in Caesarean section: a randomised controlled trial

BACKGROUND

Multiple studies suggest that transversus abdominis plane (TAP) block (without intrathecal morphine) after Caesarean section (CS) reduces post-operative morphine consumption. In our study, we wanted to compare the analgesic effect of TAP block with infiltration of the wound after CS.

METHODS

We included 60 pregnant women scheduled for elective CS under spinal anaesthesia in a randomised, single-centre, double-blind study. Thirty patients received ultrasound-guided TAP block using 20 ml bupivacaine 0.25% with adrenaline 5 μg/ml bilaterally and 20 ml normal saline as wound infiltration (TAP group). The other 30 patients (the control group) received normal saline 20 ml bilaterally in the TAP, and 20 ml bupivacaine 0.25% with adrenaline 5 μg/ml as wound infiltration. The main outcome was cumulative morphine consumption at 48 h after surgery. In addition, continuous morphine consumption, pain scores and side effects were registered.

RESULTS

Fifty-seven patients completed the study. Cumulative morphine consumption at 48 h (mean±standard deviation) was 41±34 mg in the TAP group and 38±27 mg in the control group (P=0.7); a difference of 3 mg (95% confidence interval -13 to 19 mg). Morphine consumption at any time up to 48 h was virtually identical in both groups. Side effects were similar, except for a higher degree of sedation in the TAP group (P=0.04).

CONCLUSION

Compared with wound infiltration with local anaesthetics, TAP block did not reduce cumulative morphine consumption following CS. The TAP block was associated with more pronounced sedation.