A comparison of oblique subcostal transversus abdominis plane block versus thoracic paravertebral block for postoperative analgesia after open cholecystectomy

Background
A major challenge in the postoperative period is pain management which, if not adequately controlled, may contribute to patient discomfort and decreased patient satisfaction, and possibly increased morbidity and mortality. Both Thoracic paravertebral block and oblique subcostal transversus abdominis plane block can be used as analgesic techniques for abdominal surgeries. Our aim in this research was comparison of cumulative 24-h post-operative morphine consumption between ultrasound-guided oblique subcostal transversus abdominis plane block and ultrasound-guided thoracic paravertebral block in patients who underwent an open cholecystectomy under general anesthesia.
Patients and methods
This study was performed on 46 patients who underwent open cholecystectomy under general anesthesia. All patients were randomly allocated alternatively to one of two equal groups to either undergo ultrasound-guided unilateral oblique subcostal transversus abdominis plane block Group (I) or to undergo ultrasound-guided unilateral thoracic paravertebral block Group (II). Both groups were subjected to a similar analgesic regimen in the immediate post-operative period that involved intravenous patient-controlled morphine analgesia which was used in both groups.
Results
The total morphine consumption in the first postoperative 24 h was lower in thoracic paravertebral block Group (II) (9.9 mg in thoracic paravertebral block group vs. 15.4 mg in oblique subcostal transversus abdominis plane block Group (I) with p < 0.001). The mean time of first request of analgesia in Group (I) was 248.7 min compared to 432.1 for Group (II) with p < 0.001.
Conclusions
Both ultrasound-guided oblique subcostal transversus abdominis plain block and single injection ultrasound guided thoracic paravertebral block are effective analgesic techniques for upper abdominal surgeries and reduces postoperative opioid requirements. However, thoracic paravertebral block is more effective in reducing morphine consumption.