Comparative Study Between Conventional Landmark Versus Ultrasound-Guided Paravertebral Block in Patients Undergoing Laparoscopic Cholecystectomy: A Randomized Controlled Study.

Introduction: Thoracic paravertebral block (TPVB) has emerged as an effective and safe regional technique for providing postoperative analgesia. We aimed to compare the ease and efficacy of conventional landmark and ultrasound-guided (USG) paravertebral blocks for postoperative analgesia in patients undergoing laparoscopic cholecystectomy.

Methods: This was a randomized controlled study. Seventy-six patients of either sex, age 18-40 years, body mass index (BMI) 18-29 kg/m, American Society of Anesthesiologists physical status classifications I and II posted for elective laparoscopic cholecystectomy under general anesthesia were randomly allocated into two groups of 38 each. Patients in group A were administered a paravertebral block using the anatomical landmark technique (ALT), and group B using an ultrasound-guided paravertebral block in the sitting position. In both groups, 20 ml of 0.5% bupivacaine injection was administered at the T7 vertebral level on the right side. The primary outcome was the first-pass success rate. Secondary outcomes were the number of passes and attempts, duration of analgesia, visual analog scale (VAS) score for pain during 24 h postoperatively and complications if any, were recorded.

Results: No patients were excluded in the study. Demographic characteristics were comparable in both groups. The number of passes was less in group B (1.45±0.5) compared to group A (2.42±0.95) and was reported to be statistically significant (p = 0.001). The number of attempts was less in group B (1.00±0) as compared to group A (1.29±0.46) and was statistically significant (p = 0.001). The duration of analgesia was longer in group B (530.00±326.33 minutes) compared to group A (345.60±252.95 minutes) and was observed to be statistically significant (p<0.05). The VAS score was significantly lower in group B (1.87±0.78, 2.24 ±0.82) compared to group A (2.42±0.72, 3.13±1.07) at the secondand fourth hours, respectively (p = 0.001).  Conclusion: We concluded that paravertebral block using an ultrasound-guided technique is more efficacious than the conventional landmark technique for postoperative analgesia in patients undergoing laparoscopic cholecystectomy.