Comparison of efficacy of thoracic paravertebral block with oblique subcostal transversus abdominis plane block in open cholecystectomy

Abstract

Background and aims: Sensory afferent nerve branches of lower six thoracic and upper lumbar nerves innervate the anterior abdominal wall and are the therapeutic focus of local anesthetics to provide analgesia for the abdominal surgical incision. Central neuraxial and regional analgesia can provide better control of pain due to right subcostal incision used in open cholecystectomy and attenuate the need for opioids. The earlier studies which showed the benefit of the thoracic paravertebral block (TPVB) for analgesia after upper abdominal surgeries did not compare TPVB with oblique subcostal transversus abdominis plane (OSTAP) block. Therefore, the current study compares the analgesic efficacy of TPVB and OSTAP block in open cholecystectomy.

Material and methods: Seventy consenting adults scheduled for open cholecystectomy were allocated to one of the two groups: ultrasound-guided TPVB (Group I) and ultrasound-guided OSTAP block (Group II). The primary objective of this study is to assess and compare tramadol consumption in 48 h in both the groups along with VAS in post anesthesia care unit, and then at 2, 4, 6, 8, 12, 24, and 48 h. The secondary objective of the study is to assess the incidence of PONV.

Results: The number of doses of rescue analgesia required was less in Group I when compared with Group II (P < 0.001). Patients in Group I had significantly lower pain scores than Group II. Although in the initial 8 h, both groups had comparable pain scores, after 8 h, these scores were significantly lower in patients in Group I. Less postoperative nausea and vomiting was seen in Group I patients (11.7%) in comparison to Group II (18.1%).

Conclusion: Ultrasound-guided TPVB is superior to OSTAP block because of its association with decreased postoperative opioid consumption, lower VAS score, and reduction in opioid-related side effects. Thus, it should be strongly considered as a part of multimodal analgesia regimen in upper abdominal surgeries.

Keywords: Analgesia; levobupivacaine; open cholecystectomy; postoperative nausea and vomiting; visual analog scale.

Figure 1

Comparison of number of doses of rescue analgesia between the two groups

Figure 2

Cumulative pain scores for 48 h at rest, movement, and coughing. The line within each box indicates the median. The lower and upper limits of the box are 25^th and 75^th centiles. The lines extending above and below the box are 10^th and 90^th centiles

Figure 3

Kaplan Meir showing proportion of patients in each group with continuous pain relief until the administration of first rescue analgesic