Ultrasound-guided continuous transverse abdominis plane block for abdominal surgery

Abstract

Introduction: Transversus abdominis plane (TAP) block is a new regional analgesic technique for postoperative pain in abdominal surgery. Its efficacy is not clear, and thus it needs to be explored for its regular utilisation on prolonged period. The objective was to study the continuous local anaesthetic infusion effect on postoperative analgesia. Continuous use of TAP block as an analgesic technique has not been evaluated prospectively in clinical trials. This study evaluates the efficacy of ultrasound-guided TAP block in comparison with PCA fentanyl in major abdominal surgery.

Materials and methods: There were 20 patients in the study, allocated to TAP and control groups. The parameters measured were pain scores on a numerical rating scale (NRS) of 0-10 at various time intervals and the amount of fentanyl used as rescue analgesia. Patient satisfaction scores were recorded in the TAP block group and along with any complications related to the block.

Results: The postoperative median pain scores on coughing on day one were 6.0 for control group and 2.0 for the TAP group (P = 0.02); on day two, the equivalent scores were 7.0 and 2.0 (P = 0.01). The fentanyl requirement at one hour was 203 μ for the control group and 78 μg for the TAP group (P = 0.03); at day one, the control and TAP requirements were 1237 μg and 664 μg respectively (P = 0.01). Three TAP patients rated their satisfaction as 'excellent', four as 'satisfied, and two as 'poor'.

Conclusion: TAP block is a promising technique for postoperative analgesia in major abdominal surgeries. Our study demonstrated lower pain scores in the TAP group with reduced fentanyl requirement. Further, a large scale study is needed to establish the efficacy of TAP block in this setting.

Keywords: PCA; postoperative pain; transversus abdominis plane; ultrasound.

Figure 1

Tuohy needle (18-G) inserted anterior to Ultrasound transducer, which is held transversely in plane to perform the TAP block

Figure 2

Sonographic image of the abdominal muscles layers with local anesthetic spread in TAP. EO = External oblique, IO = internal oblique, LA = local anaesthetic in TAP, TA = transversus abdominis muscle