The use of four-point transversus abdominis plane block for liver resection

Local anesthetic dosing and toxicity of adult truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Anesthesiologists frequently use truncal catheters for postoperative pain control but with limited characterization of dosing and toxicity.

OBJECTIVE

We reviewed the published literature to characterize local anesthetic dosing and toxicity of paravertebral and transversus abdominis plane catheters in adults.

EVIDENCE REVIEW

We searched the literature for bupivacaine or ropivacaine infusions in the paravertebral or transversus abdominis space in humans dosed for 24 hours. We evaluated bolus dosing, infusion dosing and cumulative 24-hour dosing in adults. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 121 and 108 papers for ropivacaine and bupivacaine respectively with a total of 6802 patients. For ropivacaine and bupivacaine, respectively, bolus dose was 1.4 mg/kg (95% CI 0.4 to 3.0, n=2978) and 1.0 mg/kg (95% CI 0.18 to 2.1, n=2724); infusion dose was 0.26 mg/kg/hour (95% CI 0.06 to 0.63, n=3579) and 0.2 mg/kg/hour (95% CI 0.06 to 0.5, n=3199); 24-hour dose was 7.75 mg/kg (95% CI 2.1 to 15.7, n=3579) and 6.0 mg/kg (95% CI 2.1 to 13.6, n=3223). Twenty-four hour doses exceeded the package insert recommended upper limit in 28% (range: 17%-40% based on maximum and minimum patient weights) of ropivacaine infusions and 51% (range: 45%-71%) of bupivacaine infusions. Toxicity occurred in 30 patients and was associated with high 24-hour dose, bilateral catheters, cardiac surgery, cytochrome P-450 inhibitors and hypoalbuminemia.

CONCLUSION

Practitioners frequently administer ropivacaine and bupivacaine above the package insert limits, at doses associated with toxicity. Patient safety would benefit from more specific recommendations to limit excessive dose and risk of toxicity.

Dexmedetomidine in a surgically inserted catheter for transversus abdominis plane block in donor hepatectomy: A prospective randomized controlled study

BACKGROUND

Transversus abdominis plane (TAP) block is a promising technique for analgesia after abdominal surgery. This prospective, randomized controlled trial assessed the effect of adding dexmedetomidine to bupivacaine in TAP block for donor hepatectomy. We hypothesized that this would improve postoperative morphine consumption and reduce analgesia related complication and inflammation.

METHODS

A total of 50 donor hepatectomy were enrolled in this study. Patients divided into two equal groups according to drugs used for TAP block. Group (B) received 20 ml of bupivacaine hydrochloride 0.25%, Group (BD) received 20 ml of bupivacaine hydrochloride 0.25% and 0.3 μg/kg dexmedetomidine, on both sides at the end of surgery and every 8 h for 48 h at right side only through inserted catheter. Primary outcome objective was morphine consumption at first 72 h. Secondary outcome objectives were morphine requirement, numbers of intake, time to first intake, pain score numerical analog scale (NAS), postoperative analgesia related complications, recovery of intestinal motility, and inflammatory markers.

RESULTS

Data were analyzed, rescue morphine analgesia was significantly lower in (BD) group compared with (B) groups as considering total morphine consumption (B 4 ± 1.9, BD 1.5 ± 0.5, P = 0.03), numbers of morphine intake (P = 0.04), morphine requirement (P = 0.03), and first time of analgesia intake (P = 0.04). NAS was significantly lower in group (BD) compared with group (B) group in the first 12 h (NAS 0 - P = 0.001, NAS 1 - P = 0.03). Adding dexmedetomidine improved gut motility, first oral intake without detectable anti-inflammatory effect.

CONCLUSION

Adding dexmedetomidine to bupivacine in a surgically inserted catheter for TAP block in donor hepatectomy reduced morphine consumption without detectable anti-inflammatory effect.