Optimized efficacy of transversus abdominis plane block combined with oxycodone in patients undergoing kidney transplantation

Abstract

Objective To evaluate the optimized efficacy of transversus abdominis plane (TAP) block combined with oxycodone in patients undergoing kidney transplantation. Methods Ninety patients of both sexes, aged 22-45 yr, weighing 45-75 kg, of American Society of Anesthesiologists physical status Ⅲ, scheduled for elective living donor kidney transplantation, were divided into 3 groups (n=30 each) using a random number table: blank control group (group C), TAP block group (group TAP) and TAP block combined with oxycodone group (group TAP+ O). Ultrasound-guided lateral approach to TAP block was performed on the operated side with the mixture (20 ml) of 0.375% ropivacaine and 5 mg dexamethasone at 30 min before induction of anesthesia in TAP and TAP+ O groups.Anesthesia was induced by injecting midazolam, target-controlled infusion of remifentanil and propofol and injecting cisatracurium.The patients were mechanically ventilated after placement of the laryngeal mask airway, and the end-tidal pressure of carbon dioxide was maintained at 35-45 mmHg.Propofol and remifentanil were intravenously injected and sevoflurane was inhaled to maintain anesthesia, and cis-atracurium was intermittently injected to maintain muscle relaxation.Narcotrend value was maintained at 37-46 during operation.Oxycodone 0.1 mg/kg was intravenously injected at 20 min before the end of surgery in group TAP+ O.Patient-controlled intravenous analgesia (PCIA) was performed with sufentanil 1.5 μg/kg in 100 ml of normal saline at the end of surgery, the PCIA pump was set up to deliver a 2 ml bolus dose, a 20 min lockout interval and background infusion at a rate of 1.5 ml/h, and visual analog scale score was maintained ≤4.The consumption of intraoperative remifentanil and effective pressing times of PCIA within 24 h after surgery were recorded.Blood samples were collected at 1 day before surgery and 2 and 5 days after surgery from the median cubital vein for determination of blood urea nitrogen and creatinine (Cr) concentrations in serum.The occurrence of nausea and vomiting, dizziness and headache, respiratory depression and TAP block-related complications (hematoma at puncture site, injury to abdominal organs, local anesthetic intoxication) was recorded within 24 h after surgery. Results Compared with group C, the consumption of intraoperative remifentanil was significantly reduced, the effective pressing times of PCIA within 24 h after surgery were decreased, and the concentrations of creatinine and blood urea nitrogen in serum were decreased at 2 days after surgery in TAP and TAP+ O groups(P 0.05). TAP block-related complications were not found in TAP and TAP+ O groups (P>0.05). There was no significant difference in the incidence of nausea and vomiting or dizziness and headache among three groups (P>0.05). Conclusion TAP block combined with oxycodone can reduce the intraoperative consumption of opioids, inhibit postoperative hyperalgesia and be helpful for early recovery of transplanted kidney function in patients undergoing kidney transplantation. Key words: Nerve block; Abdominal muscles; Qxycodone; Renal transplantation