Comparison of analgesic efficacy of subcostal transversus abdominis plane blocks with epidural analgesia following upper abdominal surgery

Transcription

1 doi: /j x ORIGINAL ARTICLE Comparison of analgesic efficacy of subcostal transversus abdominis plane blocks with epidural analgesia following upper abdominal surgery G. Niraj, 1 A. Kelkar, 1 I. Jeyapalan, 1 P. Graff-Baker, 1 O. Williams, 1 A. Darbar, 2 A. Maheshwaran 3 and R. Powell 1 1 Consultant Anaesthetist, 2 Specialist Trainee in Anaesthesia, 3 Core Trainee in Anaesthesia, Department of Anaesthesia and Pain Management, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK Summary Subcostal transversus abdominis plane (TAP) catheters have been reported to be an effective method of providing analgesia after upper abdominal surgery. We compared their analgesic efficacy with that of epidural analgesia after major upper abdominal surgery in a randomised controlled trial. Adult patients undergoing elective open hepatobiliary or renal surgery were randomly allocated to receive subcostal TAP catheters (n = 29) or epidural analgesia (n = 33), in addition to a standard postoperative analgesic regimen comprising of regular paracetamol and tramadol as required. The TAP group patients received bilateral subcostal TAP catheters and 1 mg.kg )1 bupivacaine 0.375% bilaterally every 8 h. The epidural group patients received an infusion of bupivacaine 0.125% with fentanyl 2 lg.ml )1. The primary outcome measure was visual analogue pain scores during coughing at 8, 24, 48 and 72 h after surgery. We found no significant differences in median (IQR [range]) visual analogue scores during coughing at 8 h between the TAP group (4.0 ( [0 7.5])) and epidural group (4.0 ( ) [0 8.5])) and at 72 h (2.0 ( [0 5]) and 2.5 ( [0 6]), respectively). Tramadol consumption was significantly greater in the TAP group (p = 0.002). Subcostal TAP catheter boluses may be an effective alternative to epidural infusions for providing postoperative analgesia after upper abdominal surgery.... Correspondence to: Dr G Niraj nirajgopinath@yahoo.co.uk Accepted: 18 February 2011 A substantial component of the pain experienced by patients after abdominal surgery is derived from the abdominal wall incision [1]. Transversus abdominis plane (TAP) block is an effective method of blocking the sensory afferents supplying the anterior abdominal wall. There are two types of TAP blocks described: posterior and subcostal. Single-shot posterior TAP blocks have been shown to provide analgesia after lower abdominal surgery [2 8]. Subcostal TAP block, first described by Hebbard et al., has been reported to provide analgesia for incisions extending above the umbilicus [9 11]. There have been no clinical trials examining the analgesic efficacy of either single-shot subcostal TAP blocks or subcostal TAP catheters after upper abdominal surgery. Thoracic epidural analgesia has been considered the gold standard in providing pain relief after surgery on the upper abdominal wall [12, 13]. Initial pilot data collected in our centre revealed that subcostal TAP catheters are an acceptable alternative to thoracic epidurals in patients undergoing upper abdominal surgery [10]. This study compared the efficacy of subcostal TAP catheters with that of epidural infusion in providing postoperative analgesia over 72 h following major hepatobiliary or renal surgery. Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 465

2 G. Niraj et al. Æ Subcostal transversus abdominis plane blocks following upper abdominal surgery Methods After obtaining approval from our local research ethics committee and written informed consent from the patients, we included 62 patients of ASA physical status 1-3, scheduled for elective major upper abdominal surgery, in a randomised, controlled, open-label trial between August 2009 and July The principal inclusion criterion was the dermatomal level of the surgical incision and drain sites. Upper abdominal surgical incisions where the lower end was at or above the thoracic T10 dermatome were included. The incisions included extended right subcostal incision for partial hepatectomy, rooftop (chevron) incision for radical nephrectomy and transverse incision for pancreatic surgery. Pancreatic surgery included Whipple s procedure, total pancreatectomy and distal pancreatectomy. We excluded patients with a history of relevant drug allergy or chronic pain and if the lower end of the incision extended below T10 or extended laterally beyond the anterior axillary line. The peri-operative management was identical in both groups apart from the insertion of subcostal TAP catheters at the end of surgery in the TAP group. All patients had an epidural inserted pre-operatively. We randomly allocated patients via a computer-generated sequence to receive either epidural analgesia or bilateral subcostal TAP catheter analgesia during the postoperative period. Patients were managed postoperatively on a surgical ward or on our high dependency unit at the discretion of a responsible anaesthetist. In the epidural group before surgery, we sited an epidural catheter in the thoracic T7 T9 region (RP, IJ, CH, PGB). We induced general anaesthesia with intravenous propofol (1.5 2 mg.kg )1 ) and fentanyl (1 2 lg.kg )1 ). We performed tracheal intubation following administration of a non-depolarising neuromuscular blocking drug. We maintained general anaesthesia with desflurane in oxygen and air. The epidural catheter was used to provide analgesia during the surgery. We administered 20 ml bupivacaine 0.25% through the epidural catheter during surgery. We also gave prophylactic ondansetron (0.05 mg. kg )1 ). On emergence from anaesthesia, we transferred patients to the recovery area and commenced patient controlled epidural analgesia (PCEA) with a background infusion of bupivacaine 0.125% with fentanyl 2 lg.ml )1. The PCEA bolus was 2 ml with a lockout period of 30 min. The epidural infusion was started at 6 ml.h )1 and was increased in 2-ml.h )1 increments up to 12 ml.h )1 depending on the block height tested with ethyl chloride spray in recovery. The block height was routinely tested using ethyl chloride spray every 6 h. In the TAP catheter group, we sited an epidural catheter and administered general anaesthesia in the same manner as the epidural group. We gave the patients 20 ml bupivacaine 0.25% via their epidural catheters to provide analgesia during surgery. At the end of the surgery, while patients were still under general anaesthesia, we sited bilateral TAP catheters in the subcostal transversus abdominis plane and injected 1 mg.kg )1 bupivacaine 0.375% through each. The research team sited all the TAP catheters (NG, AK). After preparing the skin with 2% chlorhexidine solution, we placed a high frequency (5 10 MHz) ultrasound probe (S-Nerve TM ; SonoSite Inc., Bothell, WA, USA) obliquely on the upper abdominal wall, along the subcostal margin near the midline. After identifying the rectus abdominis muscle, we gradually moved the ultrasound probe laterally along the subcostal margin until we identified the transversus abdominis muscle lying posterior to the rectus muscle (Fig. 1). A 16-G, 8-cm Tuohy needle (Portex; Smiths Medical International Ltd, Kent, UK) was then introduced medially in the plane of the ultrasound beam and directed towards the transversus abdominis plane. On entering the neuro fascial plane, we injected 10 ml saline 0.9% to open it. We observed the injectate spreading in the transversus abdominis plane as a dark oval shape (Fig. 2). We then used gentle pressure to thread an epidural catheter (Portex; Smiths Medical International Ltd) 6 7 cm into the space created and cut the catheter at the 30-cm mark before attaching a filter that we taped to the chest wall in the midline. Following emergence from anaesthesia, we transferred the patients to recovery and then to a surgical ward or our high dependency unit. Patients were given 8-hourly bolus injections of 1 mg.kg )1 bupivacaine 0.375% through each TAP catheter during the first 72 h after surgery. If the epidural was ineffective in recovery in the epidural group, we re-sited it. We treated pain during re-siting with intravenous morphine (up to 10 mg). If, during the next 72 h, the patient complained of pain in spite of maximal epidural background infusion (12 ml.h )1 ), we gave a 7.5-ml bolus of bupivacaine 0.25%. The block height was then re-tested to cold using ethyl chloride spray. If two boluses of 7.5 ml bupivacaine 0.25% over 60 min were unsuccessful in controlling the pain and there was no demonstrable 466 Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland

3 G. Niraj et al. Æ Subcostal transversus abdominis plane blocks following upper abdominal surgery Peritoneum Rectus muscle Transversus muscle Subcostal TA plane Figure 1 Subcostal transversus abdominis (TA) plane. The fascial plane is shown between the rectus abdominis muscle and the transversus abdominis muscle. Peritoneum Saline hydrodissection of subcostal TAP Rectus muscle Transversus muscle Needle tip in subcostal TAP Figure 2 Epidural needle in the subcostal transversus abdominis plane (TAP). Hydro-dissection with saline has caused the teardrop shaped opening of the TAP between the rectus abdominis muscle and transversus abdominis muscle. block on sensory testing with ethyl chloride spray, we gave the patients a patient controlled analgesia (PCA) device containing morphine and an epidural infusion of plain bupivacaine 0.125%. The decision to commence PCA with morphine was taken by the clinical team looking after the patient. We defined therapeutic failure in the epidural group as the addition of PCA with morphine. In the event of epidural catheter displacement, we commenced the patients on PCA with morphine and excluded the patient from the study. In the TAP catheter group, if either catheter was ineffective (pain not controlled on the ipsilateral side) in recovery, then we re-sited one or both catheters under local anaesthesia. We treated pain during re-siting with intravenous morphine (up to 10 mg). If the patient continued to complain of pain following re-siting of the catheters, we removed the catheters and commenced epidural analgesia. On the surgical ward, if the patient complained of unilateral or bilateral pain, we administered a rescue bolus of 10 ml bupivacaine 0.25% into one or both catheters. If the patient continued to complain of pain from the wound site, we re-sited one or both catheters under local anaesthesia. If the patient still complained of pain, we removed the TAP catheters and commenced epidural analgesia. The decision to commence the epidural infusion was taken by the clinical team looking after the patient. If the TAP catheters became displaced, we re-sited them in the ward under local anaesthesia. We defined therapeutic failure in the TAP catheter group as inadequate pain control from the entire surgical wound and drains. We defined technical failure as the inability to insert TAP catheters as a result of poor tissue planes. We used a standard postoperative analgesic regimen, consisting of regular paracetamol 1 g 6-hourly and intravenous tramadol mg 6-hourly, as required, in both groups. A member of the research team assessed the presence and severity of pain and nausea. These assessments were performed 30 min after arrival into recovery and thereafter for a further eight time periods (4, 8, 16, 24, 36, 48, 60 and 72 h after surgery). We asked all patients to give visual analogue scores for their pain at rest and on coughing, and nausea scores (none = 0, mild = 1, moderate = 2 and vomiting = 3) at each time period. We offered rescue antiemetics to any patient who had a nausea score 2. We assessed patient satisfaction (poor = 1, fair = 2, good = 3, excellent = 4) with their analgesia at 72 h after surgery. The primary outcome measures were visual analogue pain scores on coughing between the two groups at 8, 24, 48 and 72 h after surgery. Secondary outcome measures were visual analogue pain scores at rest, postoperative nausea scores, tramadol usage, patient satisfaction at 72 h, success rate, therapeutic failure rate and catheter re-siting rate. We also noted any complications with the techniques. Reviewing the literature, we did not identify any previous studies comparing TAP catheters with epidural analgesia suitable for sample size estimation in our study. Based on a study comparing epidural Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 467

4 G. Niraj et al. Æ Subcostal transversus abdominis plane blocks following upper abdominal surgery analgesia with PCA morphine in patients undergoing abdominal surgery, we performed a power analysis using visual analogue scores for postoperative pain during coughing as the primary outcome variable [14]. We calculated a sample size of 27 patients per group with a between-group mean (SD) difference in visual analogue scores of 20 (25) mm. This gave a type-1 and -2 error probability of 5% and 20%, respectively. Assuming a drop-out rate of 20%, we calculated a final sample size of 66 patients (33 per group). Statistical analysis was performed using a standard statistical program STATA 9.2 (StataCorp LP, College Station, TX, USA). We assessed normality using histograms. We analysed nausea and visual analogue scores with Mann Whitney U-tests and categorical data using Fisher s exact test. We set alpha levels for all analyses as p < Results Table 1 Characteristics of patients receiving TAP catheters or epidural analgesia. Values are number (%) or mean (SD). Epidural TAP catheter (n = 27) Male 20 (64%) 18 (66%) ASA status (64%) 20 (74%) 3 11 (36%) 7 (26%) BMI; kg.m ) (45%) 15 (55%) (29%) 8 (30%) (16%) 1 (4%) (10%) 3 (11%) Age; years 64 (11) 64 (12) We randomly allocated 62 patients into the study (Fig. 3). We excluded two patients from the epidural group and two from the TAP catheter group. We excluded two patients due to lateral extension of the surgical incision, one patient due to damage to the lumbar plexus during surgery and one patient following multiple dural punctures. Of the remaining 58 patients, we randomised 31 to the epidural group and 27 to the TAP group. Groups were comparable in terms of age, sex, body mass index and ASA classification (Table 1). There were seven failures in the epidural group and 10 failures in the TAP group as defined by our study criteria (Table 2). The patients in whom the technique failed were included in the final analysis on an intention to treat basis. Data until the time either PCA with morphine (epidural group) or epidural infusion (TAP Randomised (n = 62) Allocated to epidural group (n = 33) Received allocated intervention (n = 33) Allocated to TAP group (n = 29) Received allocated intervention (n = 29) Excluded after randomisation (n = 2) Lateral extension of surgical incision Avulsion of lumbar plexus Excluded after randomisation (n = 2) Accidental dural puncture (multiple) Lateral extension of surgical incision Analysed Analysed (n = 27) Figure 3 CONSORT diagram. 468 Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland

5 G. Niraj et al. Æ Subcostal transversus abdominis plane blocks following upper abdominal surgery Table 2 Secondary outcomes in patients receiving TAP catheters or epidural analgesia. Values are number (proportion) or median (IQR [range]). Epidural TAP catheter (n = 27) p value Surgery Partial hepatectomy 13 (42%) 8 (30%) Pancreatic surgery 8 (26%) 10 (37%) Radical nephrectomy 8 (26%) 5 (18%) Biliary bypass 2 (6%) 4 (15%) Failure 7 (22%) 10 (37%) Success 24 (78%) 17 (63%) 0.55 Satisfaction 0.74* Poor 1 (3%) 6 (22%) Fair 6 (19%) 1 (4%) Good 13 (42%) 11 (41%) Excellent 11 (36%) 9 (33%) Total tramadol; mg 200 ( ( [0 800]) [0 1200]) Bupivacaine; mg.day )1 < (81%) 0 (0%) < 0.001* (13%) 9 (33%) > (6%) 18 (67%) *p values represent overall comparison between all subgroups in category. Table 3 Visual Analogue Scale (VAS) scores at different time points in patients receiving TAP catheters or epidural analgesia. Values are median (IQR [range]). Epidural TAP catheter (n = 27) p value VAS scores coughing 8 h 4.0 (2.5, 5.3 [0 8.5]) 4.0 (2.3, 6.0 [0 7.5]) h 4.0 (1.8, 4.6 [0 8.5]) 3.5 (1.8, 5.5 [0 8.0]) h 3.0 (1.0, 4.5 [0 7.5]) 3.0 (0.3, 4.3 [0 7.0]) h 2.5 (1.0, 5.0 [0 6.0]) 2.0 (0.8, 4.0 [0 5.0]) 0.15 VAS scores at rest 8 h 1.5 (0.5, 2.5 [0 5.0]) 2.0 (1.0, 3.0 [0 5.0]) h 1.5 (0.5, 2.1 [0 4.5]) 1.0 (0.0, 2.0 [0 4.0]) h 1.0 (0.0, 1.5 [0 4.0]) 1.5 (0.0, 2.0 [0 3.5]) h 0.5 (0.0, 2.0 [0 4.0]) 0.5 (0.0, 1.5 [0 3.0]) 0.51 group) was commenced were included in the final analysis. There was no significant difference in the VAS scores (Table 3) on coughing between the two groups (p = 0.60) and the difference did not vary over time. There was no significant difference in the VAS scores at rest between the two groups (p = 0.46) and the difference did not vary over time. Nausea scores were not significantly different between the two groups at any of the times examined (p = 0.20) although we had not powered the study to examine this outcome. Satisfaction scores were similar in both the groups (Table 2). Tramadol consumption over 72 h was significantly higher in the TAP group compared to the epidural group (Table 2). We re-sited epidural catheters in recovery in two patients (7%) in the epidural group and resited one or both catheters in 12 patients (45%) in the TAP group within the first 24 h after surgery. We did not perform any re-sitings on day two or three after surgery. There was one incidence of accidental catheter displacement in the TAP group. The epidural group had a success rate of 78% and a therapeutic failure rate of 22% (7 31). The TAP catheter group had a success rate of 63% and a therapeutic failure rate of 30% (8 27). This included five patients with poorly controlled pain in the lateral margin of the surgical incision and three others who had pain from the surgical drains placed laterally in the T10 dermatomes. Technical failure rate was 7% (2 27). The complications with epidural catheters included two accidental dural punctures in the same patient and epidural filter disconnection in two patients. There were no complications with TAP catheters. Discussion Optimal analgesia is an important facet of adequate recovery after major abdominal surgery. This study is the first comparison between thoracic epidural infusion and subcostal TAP catheter boluses for providing analgesia after open upper abdominal surgery. The study was based on our experience with TAP catheters that suggested the technique was effective when the lower end of the surgical incision was limited to the T10 dermatome. The TAP catheter technique had a therapeutic failure rate of 30% compared with 22% in the epidural group. Failure in the TAP catheter group was mainly associated with uncontrolled pain from the lateral margin of transverse incisions extending beyond the anterior axillary line. Thus, a major limitation of the technique appears to be that its efficacy wanes as the transverse surgical incision approaches the anterior axillary line (but we did not specifically test the patients for loss of sensation following the blocks). Tramadol consumption was significantly higher in the TAP group. This could be explained by the inability of TAP catheter technique to cover visceral pain. The TAP catheters required re-siting in 45% of cases; Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 469

6 G. Niraj et al. Æ Subcostal transversus abdominis plane blocks following upper abdominal surgery however, the re-sited catheters were effective in nearly two thirds of the patients. Our study design was influenced by ethical and pragmatic considerations. The design was open label and the assessors were not blinded, which could have introduced bias in the outcome assessments. Most of the patients in the study had significant morbidity and a diagnosis of cancer. We considered it unethical to deny them optimal analgesia so we designed the study to make epidural analgesia available to both groups, with the epidural catheters available to provide rescue analgesia in the TAP group. The epidural was used intra-operatively and this could have resulted in a prolonged duration of action in the postoperative period. As only local anaesthetic solution was used in the epidural, the effect would have probably lasted no longer than 6 8 h into the early postoperative period. Our study did not include patients undergoing an upper midline incision, as elective procedures requiring such an incision are not routinely carried out at our centre. The efficacy of the subcostal TAP catheter technique appears to be the greatest for upper midline incisions [9]. This study compared an epidural infusion regimen with a TAP catheter bolus schedule. Our pilot data using TAP catheter boluses suggested that this was an effective technique for providing analgesia in patients undergoing major upper abdominal surgery [10, 15]. We therefore selected a bolus technique for the TAP catheters to allow greater patient mobility (no pump attachments required). We chose 0.375% bupivacaine to provide both an effective concentration and volume for the bolus regimen. There are two standard techniques of providing postoperative analgesia in this group of patients, namely epidural infusion and PCA with opioids. Epidural analgesia has been considered as the gold standard as it provides excellent analgesia. However, there are wellknown side effects and potentially catastrophic risks to this technique as well as a reported failure rate ranging from 17% to 37% [16 18]. Opioid-based analgesia carries a low risk profile. However, patients may be comfortable at rest but can experience significant pain on movement [12]. The well-known side effects are likely to be more pronounced in patients following significant hepatic resection or those with liver dysfunction due to accumulation of active metabolites. Subcostal TAP catheters may have advantages when compared with these two techniques. There have been few reported complications reported following TAP blocks and they provide both static and dynamic analgesia [19]. There are minimal effects on the cardiovascular system, the motor and sensory function of the lower limbs is spared and the technique is nonsedating. These characteristics could enhance patient ambulation and speed recovery after major surgery. In conclusion, we found no significant advantage of epidural analgesia over subcostal transversus abdominis plane TAP catheter bolus analgesia. We had to re-site nearly half of the subcostal TAP catheters, but when effective in combination with oral analgesia, they provided prolonged analgesia comparable with epidural infusion in patients undergoing upper abdominal surgery where the incision was limited to at or above the T10 dermatome. Subcostal TAP catheters may be an effective alternative for providing postoperative analgesia after upper abdominal surgery. Acknowledgements The authors would like to thank sincerely Mr D. Berry, Mr M. Metcalfe, Mr R. Kockelbergh and Prof. J. Mellon for their support for this trial. This work was supported by the University Hospitals of Leicester NHS Trust. No competing interests declared. References 1 Tran TMN, Rozen W, Ashton M, Barrington M, Ivanusic J, Taylor G. Redefining the course of the intercostal nerves: a new understanding of the innervation of the anterior abdominal wall. Clinical Anatomy 2008; 21: O Donnell BD, McDonnell JG, McShane AJ. The transversus abdominis plane (TAP) block in open retropubic prostatectomy. Regional Anesthesia and Pain Medicine 2006; 31: McDonnell JG, O Donnell BD, Curley GCJ, Heffernan A, Power C, Laffey JG. The analgesic efficacy of transversus abdominis block after abdominal surgery: a prospective randomized controlled trial. Anesthesia and Analgesia 2007; 104: McDonnell JG, Curley GCJ, Carney J, et al. The analgesic efficacy of transversus abdominis block after caesarean delivery. Anesthesia and Analgesia 2008; 106: Carney J, McDonnell JG, Ochana A, Bhinder R, Laffey JG. The transversus abdominis plane block provides effective postoperative analgesia in patients undergoing total abdominal hysterectomy. Anesthesia and Analgesia 2008; 107: El-Dawlatly AA, Turkistani A, Kettner SC, et al. Ultrasound-guided transversus abdominis plane block: description of a new technique and comparison with 470 Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland

7 G. Niraj et al. Æ Subcostal transversus abdominis plane blocks following upper abdominal surgery conventional systemic analgesia during laparoscopic cholecystectomy. British Journal of Anaesthesia 2009; 102: Niraj G, Searle A, Mathews M, et al. The analgesic efficacy of ultrasound guided transversus abdominis plane (TAP) block in patients undergoing open appendicectomy. British Journal of Anaesthesia 2009; 103: Belavy D, Cowlishaw PJ, Howes M, Phillips F. Ultrasound-guided transversus abdominis plane block for analgesia after Caesarean delivery. British Journal of Anaesthesia 2009; 103: Hebbard P. Subcostal transversus abdominis plane block under ultrasound guidance. Anesthesia and Analgesia 2008; 106: Niraj G, Kelkar A, Fox A. Oblique subcostal TAP catheters: an alternative to epidural analgesia after upper abdominal surgery? Anaesthesia 2009; 64: Harish R. Low-dose infusion with surgical transverse abdominis plane (TAP) block in open nephrectomy. British Journal of Anaesthesia 2009; 102: Bonnet F, Berger J, Aveline C. Transversus abdominis plane block: what is its role in postoperative analgesia? British Journal of Anaesthesia 2009; 103: McDonnell JG, Laffey JG. Transversus abdominis plane block. Anesthesia and Analgesia 2007; 105: Mann C, Pouzeratte Y, Boccara G, et al. Comparison of intravenous or epidural patient-controlled analgesia in the elderly after major abdominal surgery. Anesthesiology 2000; 92: Niraj G, Kelkar A, Powell R. Ultrasound guided subcostal transversus abdominis plane block: a review. International Journal of Ultrasound and Applied Technologies in Perioperative Care 2010; 1: Dolin SJ, Cashman JN, Bland JM. Effectiveness of acute postoperative pain management: evidence from published data. British Journal of Anaesthesia 2002; 89: Scott DA, Chamley DM, Mooney PH, Deam RK, Mark AH, Hagglof B. Epidural ropivacaine infusion for postoperative analgesia after major lower abdominal surgery a dose finding study. Anesthesia and Analgesia 1995; 81: Stenseth R, Sellevold O, Breivik H. Epidural morphine for postoperative pain: experience with 1085 patients. Acta Anaesthesiologica Scandinavica 1985; 29: Jankovic Z. Transversus abdominis plane block: the holy grail of anaesthesia for (lower) abdominal surgery. Periodicum Biologorum 2009; 111: Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 471