ORIGINAL CONTRIBUTION

The Effect of Transversus Abdominis Plane Blocks on Postoperative Pain in Laparoscopic Colorectal Surgery: A Prospective, Randomized, Double-Blind Trial Deborah S. Keller, M.S., M.D.1 • Bridget O. Ermlich, R.N., M.S.N.2 Nicholas Schiltz, Ph.D.3 Bradley J. Champagne, M.D.1 • Harry L. Reynolds, Jr., M.D.1 Sharon L. Stein, M.D.1 Conor P. Delaney, M.D., M.Ch., Ph.D., F.R.C.S.I.1 1Division of Colorectal Surgery, Department of Surgery, University Hospitals-Case Medical Center, Cleveland, Ohio 2Department of Surgery, University Hospitals-Case Medical Center, Cleveland, Ohio 3Department of Statistics, Case Western Reserve University, Cleveland, Ohio

BACKGROUND:  Superior early pain control has been suggested with transversus abdominis plane blocks, but evidence-based recommendations for transversus abdominis plane blocks and their effects on patient outcomes are lacking. OBJECTIVE:  The aim of this study was to determine whether transversus abdominis plane blocks improve early postoperative outcomes in patients undergoing laparoscopic colorectal resection already on an optimized enhanced recovery pathway. DESIGN:  This study is based on a prospective, randomized, double-blind controlled trial. SETTINGS:  The trial was conducted at a tertiary referral

center. PATIENTS:  Patients undergoing elective laparoscopic colorectal resection were selected. Financial Disclosures: Dr Delaney has a licensed patent from Ethicon, serves as a consultant for Cubist, Tranzyme, and Ferring, is on the advisory board for Pacira, and has ownership in Socrates Analytics. Drs Champagne and Stein serve as consultants for Covidien. The remaining authors reported no disclosures. Podium presentation at the meeting of The American Society of Colon and Rectal Surgeons, Hollywood, FL, May 17 to 21, 2014. Correspondence: Conor P. Delaney, M.D., M.Ch. Ph.D., F.R.C.S.I., Chief, Division of Colorectal Surgery, Vice-Chair, Department of Surgery, University Hospitals Case Medical Center, Case Western Reserve University, 11100 Euclid Ave, Cleveland, OH 44106-5047. E-mail: [email protected] Dis Colon Rectum 2014; 57: 1290–1297 DOI: 10.1097/DCR.0000000000000211 © The ASCRS 2014

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INTERVENTIONS(S):  Patients were randomly assigned to receive either a transversus abdominis plane block or a placebo placed intraoperatively under laparoscopic guidance. All followed a standardized enhanced recovery pathway. Patient demographics, perioperative procedures, and postoperative outcomes were collected. MAIN OUTCOME MEASURES:  Postoperative pain and

nausea/vomiting scores in the postanesthesia care unit and department, opioid use, length of stay, and 30-day readmission rates were measured. RESULTS:  The trial randomly assigned 41 patients to the transversus abdominis plane block group and 38 patients to the control group. Demographic, clinical, and procedural data were not significantly different. In the postanesthesia care unit, the transversus abdominis plane block group had significantly lower pain scores (p < 0.01) and used fewer opioids (p < 0.01) than the control group; postoperative nausea/vomiting scores were comparable (p = 0.99). The transversus abdominis plane group had significantly lower pain scores on postoperative day 1 (p = 0.04) and throughout the study period (p < 0.01). There was no significant difference between groups in postoperative opioid use (p = 0.65) or nausea/ vomiting (p = 0.79). The length of stay (median, 2 days experimental, 3 days control; p = 0.50) and readmission rate (7% experimental, 5% control, p = 0.99) was similar across cohorts. LIMITATIONS:  This study was conducted a single center. CONCLUSIONS:  Transversus abdominis plane blocks improved immediate short-term opioid use and pain outcomes. Pain improvement was durable throughout the hospital stay. However, the blocks did not translate into Diseases of the Colon & Rectum Volume 57: 11 (2014)

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Diseases of the Colon & Rectum Volume 57: 11 (2014)

less overall narcotic use, shorter length of stay, or lower readmission rates. KEY WORDS:  Transversus abdominis plane block; Laparoscopic colorectal surgery; Health care outcomes; Enhanced recovery pathways.

P

ostoperative length of stay (LOS) is being increasingly recognized as a quality measure for health care resource consumption.1 Reducing LOS has become a health-care priority for the surgical community, with interventions having great implications for reducing costs and improving the delivery of care.2 The expanding use of laparoscopic colorectal surgery and enhanced recovery pathways (ERPs) have significantly reduced postoperative LOS without increasing readmission rates.3–13 Prolonged hospital stay still persists, driven primarily by postoperative pain, nausea, and vomiting (PONV), and ileus.14 Reducing pain, PONV, and ileus may reduce the physiological response to stress, patient morbidity, use of resources, overall health-care costs, and LOS.15–18 Transversus abdominis plane (TAP) blocks are a potentially valuable pain management tool introduced to address these issues. The TAP block, first described in 2001 by Rafi,19 places local anesthetic into the neurovascular plane between the internal oblique and transversus abdominis muscle. This directly blocks the sensory nerves of the anterior abdominal wall from T9 to L1, reducing pain from abdominal incisions.20 To date, the reported outcomes of TAP block studies have focused on open abdominal and gynecological surgery.21–25 Results have been mainly positive, with all but 1 trial showing improved postoperative pain and reduced opioid consumption.25 Although published trials suggest superior early pain control with TAP blocks, evidence-based recommendations for optimal analgesia with TAP blocks are lacking.26 Recommendations based on laparoscopic abdominal surgery are also lacking. A recently completed retrospective cohort analysis of TAP blocks during laparoscopic colorectal surgeries suggested that the addition of TAP blocks to an established ERP resulted in a significantly shorter LOS (mean, 3.2 vs 2.1 days, p < 0.01).27 However, the retrospective nature of this study precluded definitive conclusions to support its use in colorectal surgery. The objective of this study was to evaluate the effectiveness of local anesthetic given via a TAP block on postoperative pain, opioid use, PONV, and short-term patient outcomes in laparoscopic colorectal surgery. Our hypothesis was that patients who receive a TAP block would have significantly less postoperative pain, lower rates of postoperative opioid use, and shorter hospital LOS compared with a control group.

METHODS This prospective, double-blind, randomized controlled trial was performed by the Department of Colorectal Surgery at University Hospitals Case Medical Center, Cleveland, Ohio. The Institutional Review Board approved the study protocol, and the trial was registered with the National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov Identifier: NCT01731782). Enrollment began in August 2012 and continued to August 2013, after more than appropriate power was reached. All patients older than 18 years scheduled for an elective laparoscopic colorectal resection via an abdominal approach for benign or malignant disease were invited to participate in the study. Patients less than 18 years of age, patients on chronic preoperative opiate analgesics, those with existing pain syndromes, allergy, or other contraindications to the use of bupivacaine, or inability to give informed consent were excluded preoperatively. Subjects who underwent conversion from laparoscopic to an open approach were excluded from the analysis intraoperatively. Patients who underwent an unplanned reoperation during the same hospital stay were excluded postoperatively; their exclusion details were recorded in the Adverse Event Log. Based on appropriate power calculations, patients were recruited until a goal of 75 participants were enrolled. Informed Consent

Study informed consent was obtained at the time of enrollment into the study, either during the preoperative surgical visit or in the presurgical area on the day of surgery. All patients underwent routine preoperative assessment, including surgical informed consent, collection of demographic information, medical/surgical history, physical examination, and routine laboratory testing. Randomization

Randomization was performed in the operating room after consent had been obtained. A numbered, sealed envelope, corresponding to the patient’s assigned study number, was opened, and the research coordinator alerted the operating room nurse to prepare bupivacaine hydrochloride (Marcaine; Sanofi Pharmaceuticals, Bridgewater, NJ) or placebo (normal saline). Patient and surgeon were blinded to which group the patient was assigned. Study Protocol

All procedures were performed by straight laparoscopic or hand-assisted laparoscopic (HAL) technique using standard surgical procedures according to standard of care. Four experienced laparoscopic surgeons performed all procedures. At the completion of the procedure, and under laparoscopic visualization, patients had a TAP block placed by the attending surgeon. Based on the randomization, patients received one of the following solutions:

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1. Control: 0.5 mL/kg of 0.9% normal saline for a maximum of 30 mL 2. Experimental: 0.5 mL/kg of 0.50% Marcaine (bupivacaine) for a maximum of 30 mL

The block was administered between the costal margin and iliac crest in the anterior axillary line. A Braun Stimuplex A (B. Braun Medical Inc, Bethlehem, PA) insulated needle (80 mm 21 gauge) with 0.5 mL/kg solution (maximum of 30 mL) was passed through the skin, and then continued until 2 distinct “pops” were felt, indicating the needle pierced each of the 2 fascial layers. The needle was then deemed to be in the intermuscular plane between the internal oblique and transversus abdominis muscles, targeting the spinal nerves in this plane. The laparoscope was used to depict the needle tip to ensure it did not penetrate the peritoneum or inject into the preperitoneal space. The local anesthetic was infiltrated in 2 separate injections into the same plane on each side. Two-thirds of the solution was injected, then the needle was withdrawn 5 mm, and the remaining solution was injected. After injecting in the correct plane, a smooth raised area of fluid, covered by transversus, was seen via the laparoscope. This procedure was repeated on the patient’s other side to complete a bilateral block. The total cost of the block was $14.37 (needle, $11.00; syringe, $0.07; vial of 0.5% bupivacaine, $3.00). Perioperative Care

All patients were managed with a standardized ERP and discharge criteria. Our standardized ERP includes preand postoperative patient information, preservation of GI function, the avoidance of organ dysfunction, active pain control, and the promotion of patient autonomy. The well-implemented ERP has been developed, modified, and refined since 1999, and benefits have previously been described in the literature.4,5,8,28 As part of the ERP, all patients were administered diclofenac sodium (Voltaren; Novartis, Parsippany, NJ) 100 mg on the evening before surgery and gabapentin 300 mg 1 to 2 hours before surgery in the preoperative holding area. In the postoperative holding area, a morphine patient-controlled analgesia (PCA) was initiated for all patients. All opioids in the postanesthesia care unit (PACU) were self-administered via the PCA. On the nursing floor, patients receive gabapentin 300 mg orally twice a day for 72 hours (or while in the hospital), Toradol 15 mg intravenously every 6 hours for 48 hours, and Tylenol 1 g every 6 hours. On postoperative day 1, the morphine PCA is discontinued, Tylenol is transitioned from intravenous to oral, and pain management is initiated with Oxycodone 10 mg orally every 6 hours as needed. Data Collection

Postoperative pain scores were assessed in a standardized fashion. All assessments were made by 1 of 2 research

Keller et al: RCT of TAP Blocks in LAP CRS

c­ oordinators. Patients were assigned a unique number for data collection; the coordinators referenced the unique identifier on all data, not the patient’s assigned group. On postoperative day (POD) 0, the patients were assessed in the PACU 1 hour after leaving the operating suite and on the floor after administration of evening medications. The daily assessment was made at the same approximate time each morning after breakfast, when patients were awake and had already moved out of bed. A standardized script and validated visual analogue pain score was used.29 Medication usage was retrospectively collected from intraoperative anesthesia records, PCA, and nursing logs. Outcomes

Patient demographic, perioperative, and short-term outcomes were evaluated. Data analyzed included age, sex, BMI, ASA score, indication for operation, procedure performed, operative procedure time, estimated blood loss, ostomy creation, opiate use in the operating suite, opiate use in the PACU (morphine equivalents), daily use of antiemetics and analgesics (PCA and oral) in morphine equivalents, daily pain scores and postoperative nausea/ vomiting scores while in the hospital, postoperative complications, including ileus (defined as reduction in diet and placement of a nasogastric tube), LOS, discharge disposition, opiate use at discharge, and whether opioids are used at home, day of return of normal function, and 30-day readmission rates. The “day of return of normal function” was a subjective, patient-reported measure of the postoperative day they were able to resume all normal activities of daily living. Patients converted intraoperatively to open surgery were excluded from the analysis. Statistical Analysis

Demographic and outcome data were analyzed by using the Student t test for continuous variables and the Fisher exact test for categorical variables, as appropriate. Normally distributed data were presented as means (SD), nonnormally distributed data were presented as medians (range), and categorical data were presented as frequencies (percent). Postoperative pain, nausea, and vomiting were analyzed as a binary outcome (yes/no). A p value of