Transversus abdominis plane block in robotic gynecologic oncology: A randomized, placebo-controlled trial

• Published in: Gynecologic oncology 2015-03, Vol.136 (3), p.460-465
• Main Authors: Hotujec, B.T, Spencer, R.J, Donnelly, M.J, Bruggink, S.M, Rose, S.L, Al-Niaimi, A, Chappell, R, Stewart, S.L, Kushner, D.M
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Analgesics, Opioid - therapeutic use; Anesthetics, Local - therapeutic use; Bupivacaine - therapeutic use; Double-Blind Method; Female; Follow-Up Studies; Genital Neoplasms, Female - surgery; Hematology, Oncology and Palliative Medicine; Humans; Laparoscopy; Linear Models; Middle Aged; Morphine - therapeutic use; Nerve Block - methods; Nomograms; Obstetrics and Gynecology; Pain Measurement; Pain, Postoperative - drug therapy; Pain, Postoperative - prevention & control; Postoperative analgesia; Robotic surgery; Robotics; Transversus abdominis plane block; Treatment Outcome; Young Adult
• ISSN: 0090-8258; 1095-6859
• DOI: 10.1016/j.ygyno.2014.11.013

Abstract Objective Although robotic surgery decreases pain compared to laparotomy, postoperative pain can be a concern near the site of a larger assistant trocar site. The aim of this study was to determine the efficacy of transversus abdominis plane (TAP) block on 24-hour postoperative opiate use after robotic surgery for gynecologic cancer. Methods Sixty-four subjects with gynecologic malignancies who were scheduled to undergo robotic surgery were enrolled into the study. They were randomized to receive a unilateral TAP block to the side of the assistant port via ultrasound guidance. The block was comprised of 30 cc of 0.25% bupivacaine with 3 mcg/mL epinephrine or saline. Opiate use was measured and converted into IV morphine equivalents. Patient-reported pain was measured using the Brief Pain Inventory (BPI) and Visual Analog Scale (VAS). Results The treatment group used a mean of 64.9 mg morphine in the first 24 h compared to 69.3 mg for controls (primary outcome, p = 0.52). After age-adjustment, the treatment group used a mean of 11.1 mg morphine less than controls ( p = 0.09). Postoperative pain scores assessed by the BPI (6.44 vs. 6.97, p = 0.37) and the VAS (3.12 vs. 3.61, p = 0.30) were equivalent. Block placement was uncomplicated in 98.4% of participants with mean BMI of 35.3 kg/m2 . Linear regression revealed an approximate 8.1 mg decrease in morphine equivalents used per additional decade of life ( p = 0.0008). There was a positive correlation between the amount of opiates and BMI with an additional 8.8 mg of morphine per 10 kg/m2 increase in BMI ( p = 0.0012). Conclusions TAP block is safe and feasible in this patient population with a large proportion of morbid obesity. Preoperative TAP block does not significantly decrease opiate use. However; based on these data, a clinically useful nomogram has been created to aid clinicians in postoperative opiate-dosing for patients based on age and BMI.