Quadratus lumborum block (transmuscular approach) versus transversus abdominis plane block (unilateral subcostal approach) for perioperative analgesia in patients undergoing open nephrectomy: a randomized, double-blinded, controlled trial

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

Peripheral nerve block technology is important to balanced anesthesia technology. It can effectively reduce opioid usage. It is the key to enhance clinical rehabilitation as an important part of the multimodal analgesia scheme. The emergence of ultrasound technology has accelerated peripheral nerve block technology development. It can directly observe the nerve shape, surrounding tissue, and diffusion path of drugs. It can also reduce the dosage of local anesthetics by improving positioning accuracy while enhancing the block's efficacy. Dexmedetomidine is a highly selective drug α₂-adrenergic receptor agonist. Dexmedetomidine has the characteristics of sedation, analgesia, anti-anxiety, inhibition of sympathetic activity, mild respiratory inhibition, and stable hemodynamics. Numerous studies have revealed that dexmedetomidine in peripheral nerve blocks can shorten the onset time of anesthesia and prolong the time of sensory and motor nerve blocks. Although dexmedetomidine was approved by the European Drug Administration for sedation and analgesia in 2017, it has not yet been approved by the US Food and Drug Administration (FDA). It is used as a non-label drug as an adjuvant. Therefore, the risk-benefit ratio must be evaluated when using these drugs as adjuvants. This review explains the pharmacology and mechanism of dexmedetomidine, the effect of dexmedetomidine on various peripheral nerve block as an adjuvant, and compare it with other types of adjuvants. We summarized and reviewed the application progress of dexmedetomidine as an adjuvant in nerve block and look forward to its future research direction.

Quadratus Lumborum Blockade for Postoperative Analgesia in Infants and Children Following Colorectal Surgery

Background

Adult studies have indicated that the quadratus lumborum block (QLB) may provide superior analgesia compared to single-shot neuraxial and other truncal peripheral nerve blocks. The technique is being increasingly used for postoperative analgesia in children undergoing lower abdominal surgery. To date, these pediatric reports have been limited by small sample sizes, which may hinder the interpretation of results and assessment of safety. In this study, we retrospectively examined QLBs performed at a large tertiary care hospital for evidence of effectiveness and safety in the pediatric colorectal surgery population.

Methods

Patients less than 21 years of age who underwent abdominal surgery and received a unilateral or bilateral QLB over a 4-year period were identified in the electronic medical record. Patient demographics, surgery type, and QLB characteristics were retrospectively examined. Pain scores and opioid consumption were tabulated over the first 72-h postoperative period. QLB procedural complications or adverse events attributable to the regional anesthetic were obtained.

Results

The study cohort included 204 QLBs in 163 pediatric-aged patients (2 days to 19 years of age, median age of 2.4 years). The most common indication was unilateral blockade for ostomy creation or reversal. The majority of QLBs were performed using ropivacaine 0.2% with a median volume of 0.6 mL/kg. The median opioid requirement in oral morphine milligram equivalents (MMEs) was 0.7, 0.5, and 0.3 MME/kg on the first, second, and third postoperative days, respectively. Median pain scores were less than 2 over each time period. Aside from block failure (incidence 1.2%), there were no complications or postoperative adverse events related to the QLBs.

Conclusion

This retrospective review in a large cohort of pediatric patients demonstrates that the QLB can be performed safely and efficiently in children undergoing colorectal surgery. The QLB provides adequate postoperative analgesia, has a high success rate, may limit postoperative opioid consumption, and is associated with a limited adverse effect profile.