Date Published: May 16, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Nils Bjerregaard, Lone Nikolajsen, Thomas Fichtner Bendtsen, Bodil Steen Rasmussen.
Purpose. Transversus abdominis plane (TAP) blocks have been shown to reduce pain and opioid requirements after abdominal surgery. The aim of the present case series was to demonstrate the use of TAP catheter injections of bupivacaine after major abdominal surgery. Methods. Fifteen patients scheduled for open colonic resection surgery were included. After induction of anesthesia, bilateral TAP catheters were placed, and all patients received a bolus dose of 20 mL bupivacaine 2.5 mg/mL with epinephrine 5 μg/mL through each catheter. Additional bolus doses were injected bilaterally 12, 24, and 36 hrs after the first injections. Supplemental pain treatment consisted of paracetamol, ibuprofen, and gabapentin. Intravenous morphine was used as rescue analgesic. Postoperative pain was rated on a numeric rating scale (NRS, 0–10) at regular predefined intervals after surgery, and consumption of intravenous morphine was recorded. Results. The TAP catheters were placed without any technical difficulties. NRS scores were ≤3 at rest and ≤5 during cough at 4, 8, 12, 18, 24, and 36 hrs after surgery. Cumulative consumption of intravenous morphine was 28 (23–48) mg (median, IQR) within the first 48 postoperative hours. Conclusion. TAP catheter bolus injections can be used to prolong analgesia after major abdominal surgery.
Epidural analgesia is commonly used for the treatment of postoperative pain after major abdominal surgery despite the well-known risks and the long list of contraindications [1, 2]. During the last few years, interest has grown concerning the use of transversus abdominis plane (TAP) block as an alternative to epidural analgesia. A TAP block provides analgesia of the anterolateral abdominal wall through blockade of the lateral and anterior cutaneous branches of Th7 to L1 as shown in volunteers by McDonnell et al. . Clinical trials have shown that a bilateral single-shot TAP block reduces pain after large bowel resection and total abdominal hysterectomy [4, 5].
The case series was registered at http://www.clinicaltrials.gov/, ID: NCT01395043, and approved by the regional ethical committee. Fifteen patients undergoing elective lower major abdominal surgery with laparotomy and colon resection were prospectively included. As this was a case series, only registration of the patients accepting to participate was done. Enrolment started in September 2010 and finished in June 2011. Written informed consent was obtained before enrollment. Primary exclusion criteria were allergies to morphine or bupivacaine or inability to provide informed consent. Secondary exclusion criteria were reoperation within the first 48 hours or postoperative mechanical ventilation.
Fifteen patients, 7 males and 8 females, aged 54 to 80 years, were included in the study (see Table 1 for baseline characteristics). All patients received bilateral TAP catheters after induction of anesthesia. Six patients underwent extensive surgery due to infiltration of the primary cancer leading to further resection of nearby tissue such as pelvic floor, urinary bladder, gastric ventricle, and liver. None of the patients underwent reoperation or mechanical ventilation within the first 48 hr.
Ultrasound guided TAP block is a relatively new technique and data on the efficacy of TAP block for abdominal analgesia are sparse and conflicting [13–17]. Very limited data describe the use and effect of TAP catheters in order to prolong the analgesic effect of TAP block by continuous infusion or repeated bolus injections of local analgesics. In the present case series, bolus injections were used in order to achieve repeated hydrodissection of the TAP and a significant spread of local anesthetic in the entire TAP. We showed that administration of repeated bolus doses of bupivacaine as part of a multimodal analgesic regimen resulted in acceptable pain-scores and relatively low opioid requirements, comparable to what has been found in other studies [11, 12].
TAP catheter bolus injections can be used after major abdominal surgery as part of a multimodal analgesic regimen. The technique is probably best suited for non-extensive surgery where the pain is derived primarily from the abdominal wall incision. This case series presents the use of ultrasound-guided bilateral transversus abdominis plane catheters, placed using the posterior approach, with intermittent bolus injections of bupivacaine, as part of a multimodal analgesic regimen after major abdominal surgery.