Efficacy of Transversus Abdominis Plane Block versus Epidural Analgesia in Pain Management Following Lower Abdominal Surgery

Transcription

1 Med. J. Cairo Univ., Vol. 85, No. 6, September: , Efficacy of Transversus Abdominis Plane Block versus Epidural Analgesia in Pain Management Following Lower Abdominal Surgery TAMER M. KHEIR, M.D. The Department of Anesthesiology, Faculty of Medicine, Cairo University Abstract Background and Objectives: Transversus Abdominis Plane (TAP) block is a new, rapidly expanding technique. And this study was designed to evaluate the efficacy of transversus abdominis plane block in comparison to epidural analgesia in pain management following lower abdominal surgery. Methods: This present work conducted on 60 patient, with their ages ranging between 20 to 75 years. These patients were admitted at Kasr El-Aini Hospital from February 2013 to March 2014, this patients were allocated to either Group I (TAP) (30 cases) or Group II (epidural block) (30 cases) using a randomized central computer; generated sequence held by an investigator not involved with the clinical management or data collection. Results: The primary outcome was the proportion of subjects who used more than 200µg/kg of morphine in the first 24h from arrival in the recovery ward. Secondary outcomes included: Morphine consumption from 0 to 8 and >8 to 24h after operation; pain measured by 0-10 self-assessment Visual Analogue Score (VAS) in the recovery ward and at 2, 6, 10, 14, 18 and 24h after operation, post-operative Nausea and Vomiting (PONV) measured by the total number of vomits during the first 24h, the main result in this study TAP block provides highly effective post-operative analgesia in the first 24 hours, especially in neurofascial plane in the muscles and the skin but not more the visceral pain, the TAP block reduced mean IV morphine requirements by more than 70%, this reduction in opioid requirement resulted in fewer opioidmediated side effects. In the present study, there is no significant difference between the studied groups as regard ASA classification, gender distribution and age. In addition, there was no significant difference between groups as regard time at recovery room, need for paracetamol in the first 8 hours after surgical intervention, Post-Operative Nausea and Vomiting (PONV) and duration of hospital stay. On the other hand, there was significant decrease of total morphine in first 8 hours in Group I in comparison to Group II; and there was significant increase of time when first morphine or first paracetamol needed in Group I (TAP) when compared to Group II. Finally, there was significant decrease of cases needed morphine more than 200 µg in the first 24 hours in TAP group when compared to Group II. Correspondence to: Dr. Tamer M. Kheir, The Department of Anesthesiology, Faculty of Medicine, Cairo University Conclusion: TAP represent an effective alternative for providing post-operative analgesia after lower abdominal surgery in comparison to epidural analgesia. Key Words: Transversus abdominis plane block Epidural analgesia. Introduction AS a regional anesthetic technique, Transversus Abdominis Plane (TAP) block is a new, rapidly expanding technique. It is relatively simple and efficacious. It had been reported to significantly reduce pain associated with lower abdominal surgery, regardless of whether it is used as the primary anesthetic or for pain control after general or spinal anesthesia [1]. TAP block has been described with promises of better localization and deposition of the local anaesthetic with improved accuracy [2]. The aim of a TAP block is to deposit local anaesthetic in the plane between the internal oblique and transversus abdominis muscles targeting the spinal nerves in this plane [3]. It had been used for adults undergoing colonic resection surgery, caesarean delivery and total abdominal hysterectomy [4]. In addition, TAP had been demonstrated to provide excellent analgesia to the skin and musculature of the anterior abdominal wall following appendectomy, inguinal hernia repair and radical prostatectomy [5]. A few complications have been reported with blind TAP block, the most significant of which was a case report of intrahepatic injection [6]. Other complications include: Intraperitoneal injection, bowel hematoma and transient femoral nerve palsy. Local anaesthetic toxicity could also occur due to the large volumes required to perform this block especially if it was done bilaterally [3]. 2231

2 2232 Efficacy of TAP Block versus Epidural Analgesia Epidural analgesia had been reported to be a popular analgesic technique for abdominal surgery with high efficacy and safety. However, the debate whether epidural analgesia improves outcome has not been settled. It had no effect on hospital stay in colorectal surgery, although it decreased postoperative pain and ileus rate [7]. Over TAP block, epidural analgesia has the advantage of providing analgesia for visceral and somatic pain [8] ; and to the best of researcher knowledge, clinical trials comparing different aspects of efficacy and safety between TAP and epidural analgesia are scarce. Thus, the present study was designed to investigate both efficacy and safety of TAP versus epidural analgesia in lower abdominal surgery. Patients and Methods After approval from the Hospital Ethics Committee, this present work was conducted on 60 patient with their ages ranging between 20 to 75 years, those patients were admitted to Kasr El- Aini Hospital from February 2013 to March 2014, patients were allocated to either Group I (TAP) (30 cases) or Group II (epidural block) (30 cases) using a randomized central computer-generated sequence held by an investigator not involved with the clinical management or data collection, all cases received a standard general anesthetic involving rapid sequence induction with propofol (2 mg/kg) and succinylcholine (1.5-2mg/kg) and continued paralysis with atracurium, anesthesia was maintained with sevofluran, all cases received i.v. fentanyl (1mg/kg) at the commencement of surgery and towards the end of the surgical procedure, standard monitoring maintained throughout the procedure included electrocardiography, noninvasive arterial blood pressure, oxygen saturation and capnometry. Exclusion criteria included: Age less than 18 years of age, absolute contraindications to TAP blocks include patient refusal, soft tissue infection of the abdominal wall and skin, or abnormality at the needle insertion site, patient need for acute surgery, or those for surgery requiring postoperative mechanical ventilation; and communicative or cognitive limitations interfering with pain measurements, patient suffering from coagulopathy. Technique for TAP block: After complete disinfection and sterilization of the entry site which located in the midaxillary line midway between the costal margin and the iliac crest, 150mm Stimuplex needle (B-Braun Medical, Bethlehem, PA, USA) was advanced in the neurofascial plane between the internal oblique muscle and transversus abdominis muscle using plane technique. Once the needle was introduced in the correct place 20ml of the LA solution was injected. Visualization of hypoechoic layer between the two muscles on injection of the local anesthetic solution was considered as the end point of success of the block. This procedure was repeated on the other side. After the end of the TAP block anesthesia was terminated and neuromuscular block was antagonized by 2.5mg neostigmine plus 1mg atropine, then extubation was done when airway reflexes returned. Parturients considered awake when they could open their eyes on command. Parturients were transferred to the Post Anesthesia Care Unit (PACU) where they were observed by nursing staff blinded with the concentration of LA used. Parturients received analgesic regimen of 1gm of intravenous paracetamol/24h, and diclofenac 75mg I.V infusion/8h starting from the time of admission to PACU to overcome the visceral component of postoperative pain. Parturients were advised that they could ask for a rescue analgesic dose if the VAS was >4 at any time. The rescue analgesic dose was bolus dose of 0.5mg/kg of tramadol hydrochloride though intravenous route. Epidural technique: Unless contraindicated, epidural analgesia was offered during the pre-operative assessment as an adjunct to general anesthesia to all patients undergoing open abdominal surgery, patients with epidural analgesia received bupivacaine 0.125% 4 to 8ml/hour, in case of inadequate pain reduction (visual analogue score >4), the epidural catheter was tested with a bolus dose of 5mL lidocaine 1% and the maintenance dose was increased by 2mL/ hour, in case of catheter dislocation or ongoing malfunctioning, the catheter was removed, in general, the epidural catheter was removed on the second postoperative day but if required, the treatment was continued. Concentration of sevoflurane was adjusted based on intraoperative hemodynamics to maintain an end-tidal concentration of 1.5-2%, all patients had a urethral Foley catheter inserted before the incision, the lactated Ringer's solution was used as the maintenance fluid and intraoperative losses were adequately replaced.

3 Tamer M. Kheir 2233 Outcome measurements: The primary outcome was the proportion of subjects who used more than 200µg/kg of morphine in the first 24h from arrival in the recovery ward, secondary outcomes included: Morphine consumption from 0 to 8 and >8 to 24h after operation: Pain measured by 0-10 self-assessment Visual Analogue Score (VAS) in the recovery ward and at 2, 6, 10, 14, 18 and 24h after operation (if the subject was asleep, the VAS was recorded as zero), Post-Operative Nausea and Vomiting (PONV) measured by the total number of vomits during the first 24h, and time to hospital discharge, adverse effects of TAP blocks including bleeding, swelling, or bruising at the injection site were recorded. Statistical analysis of data: The data of the present work were coded, tabulated and statistically analyzed using a personal computer with IBM-SPSS statistics computer package, Version 18 (IBM Corp., Armonk, NY), normally distributed numerical data are presented as mean and standard deviation, qualitative data are presented as relative frequency and percentage distribution, for normally distributed numerical data, the independent samples Student ( t) test was used to compare the difference in the means between the two studied groups, the Pearson Chi square test was used for comparison of the two groups as regards differences in categorical data, Fisher's exact test was applied in place of the Chi square test if [20% of the cells in any contingency table had an expected count of <5. All p-values are two-sided, and p 0.05 is considered statistically significant. Results In the present study, there is no significant difference between the studied groups as regard ASA classification (76.7% of Group I were ASA I compared to 73.3% of Group II), gender distribution (males represent 76.7% and 60.0% of groups I and II respectively) and age (the mean ± SD age was ± 1.43 and 42.16±4.29 of Groups I and II respectively), in addition, there was no significant difference between groups as regard time at recovery room, need for paracetamol in the first 8 hours after surgical intervention, Post-Operative Nausea and Vomiting (PONV) and duration of hospital stay (2.13 ±0.57 days in Group I and 2.06±0.44 days in Group II). On the other hand, there was significant increase of intervention duration in Group I in comparison to Group II ( ± vs 93.43±6.22 minutes respectively). In addition, there was significant decrease of total morphine in first 8 hours in Group I in comparison to Group II (69.0± vs 80.0± respectively), and there was significant increase of time when first morphine or first paracetamol needed in Group I (TAP) when compared to Group II. Finally, there was significant decrease of cases needed morphine more than 200µg in the first 24 hours in TAP group when compared to epidural group (43.3% vs 73.3% respectively) (Table 1). Regarding visual analogue scale, it was found that, there was statistically significant decrease of VAS in Group I in comparison to Group II at 2, 6, 10, 14 and 18 hours post-operatively. At 24 hours: There was no significant difference between both groups as regard to VAS (Table 2). Table (1): Comparison between Group I (TAP) and Group II (epidural group) as regard different variables. Variable Group I Group II Test p-value ASA I (n,%) 23 (76.7%) 22 (73.3%) (NS) Male gender (n,%) 23 (76.7%) 18(60.0%) (NS) Age (y) (mean ± SD) ± ± (NS) Procedure duration (min) ± ± <0.001 * Recovery room time (min) ± ± (NS) PONV 11 (36.7%) 12 (40.0%) (NS) Morphine in 1 st 8h 69.0± ± * Paracetamol in 1 st 8h 13.50± ± (NS) First morphine (min) ± ± * First paracetamol (h) 6.53± ± <0.001 * Hospital stay 2.13± ± (NS) Primary outcome (Morphine >200µg) 13 (43.3%) 22 (73.3%) *

4 2234 Efficacy of TAP Block versus Epidural Analgesia Table (2): Comparison between Group I (TAP) and Group II (epidural group) as regard visual analogue score at different post-operative time. VAS Group I Group II (t) Mean SD Mean SD Test p - value At 2 hours <0.001* At 6 hours <0.001* At 10 hours * At 14 hours * At 18 hours <0.001* At 24 hours (NS) Discussion Poorly controlled acute pain after abdominal surgery is associated with a variety of unwanted post-operative consequences, including patient suffering from distress, respiratory complications, delirium, myocardial ischemia, prolonged hospital stay and an increased likelihood of chronic pain. A major contributor to the pain experienced after abdominal surgery is pain from the incision made in the abdominal wall, with the remainder resulting from internal visceral trauma, traditionally, analgesia for abdominal surgery is provided either by systemic drugs such as opioids, ketamine, Nonsteroidal Anti-Inflammatories (NSAIDs), alpha-2 agonists and paracetamol, or by epidural anaesthesia. Peripheral nerve blockade is an alternative means of providing analgesia, by anaesthetizing the sensory nerves conveying pain impulses from the incision site to the spinal cord and brain [9]. The Transversus Abdominis Plane (TAP) block is a peripheral nerve block that anaesthetizes the abdominal wall, although this technique was first specifically described in 2004, variations have been used by anesthetists for decades without becoming widely adopted [10]. Supporters of this technique suggest that analgesia provided by the TAP block is equal or superior to that provided by systemic opioids such as morphine, it is also claimed that post-operative opioid consumption and opioid-derived adverse effects can be reduced [4,11]. Furthermore, the TAP block may have a lower risk of complications and greater acceptability to patients than epidural analgesia [9]. There have been no reports evaluating the efficacy of the TAP block compared with epidural block for pain relief after lower abdominal surgery, thus, the present study was designed to give the author experience comparing both techniques. The results of the present study showed that, there was significant increase of all intervention time in TAP group when compared to epidural group that means that, TAP procedure needs more time. On the other hand, TAP is associated with decreased visual analogue scale, decreased need for analgesics postoperatively and the time to ask these analgesics is longer in TAP procedure when compared to epidural block, finally, there was significant decrease of cases needed morphine more than 200µg in the first 24 hours in TAP group when compared to epidural group (43.3% vs 73.3% respectively). The results are consistent with previous studies that reported analgesic benefits of TAP block in abdominal surgeries [12]. In addition, McDonnell et al., reported statistically significant reduction in morphine requirements after large bowel resection in patients receiving TAP block with 20mL of 0.375% bupivacaine (p<0.05). Moreover, Hebbard et al., (2008) reported that subcostal TAP b lock provided post-operative analgesia after upper abdominal surgery in a series of 20 patients. In addition, Carney et al., reported that, TAP block provides highly effective post-operative analgesia in the first hours, overall, during the first 24 post-operative hours, the TAP block reduced mean IV morphine requirements by more than 70%. This reduction in opioid requirement resulted in fewer opioid-mediated side effects, and the incidence of post-operative nausea and vomiting was reduced by more than half in the TAP block group, these results are supported by the present work [13]. Epidural analgesia can provide optimal analgesia for abdominal wall structures as well as deep visceral pain, however, it is unquestionably contraindicated in sepsis, hemodynamic instability or anticoagulant medications, which necessitate importance of another safe and reliable technique. In the present study, all the cases were elective and the decision for the course of epidural analgesia was predicted to be safe. In literature, few studies comparing both techniques, for example, Niraj et al., reported that rescue analgesia with tramadol was significantly higher in TAP block (400mg) than epidural group (200mg) (p=0.002), which is inconsistent with result of the present study of low morphine consumption in the TAP group. This can be explained by different protocols used in their study, in addition, the values of visual analogue scores in their groups were statistically insignificant.

5 Tamer M. Kheir 2235 In conclusion, we found significant advantage of TAP over epidural analgesia in efficacy of postoperative analgesia and time of need and quantity of post-operative analgesics, thus, TAP may be an effective alternative for providing post-operative analgesia after lower abdominal surgery. References 1- JANKOVIC Z., AHMADN R. and RAVISHANKAR N.A.: Transversus abdominis plane block: How safe is it? Anesth. Analg., 107: , HEBBARD P. Subcostal transversus abdominis plane block under ultrasound guidance. Anaeth. Analg., 106: 674-5, MUKHTAR K.: Transversus abdominis plane block. The Journal of New York School of regional Anaesthia, 12: 28-33, McDONNELL J.G., O'DONNELL B.D., CURLEY G., HEFFERNAN A., POWER C. and LAFFEY J.G.: The analgesic efficacy of TAP block after abdominal surgery: A prospective randomised controlled trial. Anesth. Analg., 104: 193-7, O'DONNELL B.D.: The Transversus Abdominis Plane (TAP) block in open retropubic prostatectomy. Letter to the Editor. Reg. Anesth. Pain. Med., 31 (1): 91, FAROOQ M. and CAREY M.: A Case of Liver Trauma With a Blunt Regional Anesthesia Needle While Performing Transversus Abdominis Plane Block Regional Anesthesia and Pain Medicine, 33: 274-5, MARRET E., REMY C. and BONNET F.: Meta-analysis of epidural analgesia versus parenteral opioid analgesia after colorectal surgery. Br. J. Surg., 94: , JANKOVIC Z.: Transversus abdominis plane block: The Holy. 9- CHARLTON S., CYNA A.M., MIDDLETON P. and GRIFFITHS J.D.: Perioperative Transversus Abdominis Plane (TAP) blocks for analgesia after abdominal surgery. Cochrane Database of Systematic Reviews, Issue 12. Art. No.: CD007705, McDONNELL J.G., O'DONNELL B.D., TUITE D., FAR- RELL T. and POWER C.: The Regional Abdominal Field Infiltration (RAFI) technique: Computerised tomographic and anatomical identification of a novel approach to the transversus abdominis neuro-vascular fascial plane. Anesthesiology, 101: A899, RANDALL I.M., COSTELLO J. and CARVALHO J.C.A.: Transversus abdominis plane block in a patient with debilitating pain from an abdominal wall hematoma following cesarean delivery. Anesthesia & Analgesia, 106: 1928, NIRAJ G., KELKAR A. and FOX A.J.: Oblique subcostal transversus abdominis plane (TAP) catheters: An alternative to epidural analgesia after upper abdominal surgery. Anaesthesia, 64: , CARNEY J.J., McDONNELL J.G., OCHANA A., BHINDER R. and LAFFEY J.G.: The transversus abdominis plane block provides effective postoperative analgesia in patients undergoing total abdominal hysterectomy. Anesth. Analg., 107: , 2008.