Application of ultrasound-guided anterior quadratus lumborum block approach at the lateral supra-arcuate ligament in elderly patients undergoing colorectal cancer surgery.

Objective: To investigate the anesthetic and analgesic effects of combining general anesthesia with an anterior quadratus lumborum block at the lateral supra-arcuate ligament (SA-AQLB) in elderly patients undergoing laparoscopic radical resection for colorectal cancer (CRC).

Methods: In this prospective study, 92 elderly patients scheduled for radical CRC resection were randomly divided into three groups: ultrasound-guided SA-AQLB group (SA group, n=31), ultrasound-guided subcostal AQLB (SC-AQLB) group (SC group, n=31), and a general anesthesia-only group (GA group, n=30). Measurements included mean arterial pressure (MAP) and heart rate (HR) at predefined time points, ranging from pre-operation to the end of surgery. Visual analog scale (VAS) pain scores were recorded at multiple postoperative time points up to 48 hours. Additional data collected included intraoperative drug dosages, anesthetic recovery times, patient-controlled intravenous analgesia (PCIA) usage, Lovett muscle strength scores, and early postoperative recovery indicators.

Results: The SA group consistently showed lower MAP and HR compared to the SC group, which in turn was lower than the GA group during the monitored time points (all P<0.05). Sensory block levels were significantly higher in the SA group than that in the SC group (P<0.05). Postoperative VAS scores were also significantly lower in the SA group compared to the other groups at all recorded times (all P<0.05). The SA group required lower doses of propofol, remifentanil, and sufentanil, but higher doses of ephedrine compared to the SC and GA groups (all P<0.05). Anesthesia recovery time was shorter in the SA group, and the total number of PCIA pump presses was least in the SA group (P<0.05). Early ambulation was achieved sooner in the SA and SC groups (P<0.05), and the incidence of nausea and vomiting was reduced in these groups compared to the GA group (P<0.05).

Conclusion: General anesthesia combined with ultrasound-guided SA-AQLB provides superior outcomes to general anesthesia alone in elderly patients undergoing laparoscopic CRC surgery. This approach significantly reduces general anesthesia drug dosage, decreases postoperative pain, minimizes perioperative adverse events, and accelerates patient recovery.