TRANSVERSUS ABDOMINAL PLANE BLOCK

EFFICACY OF MAGNESIUM SULPHATE AS AN ADJUVANT TO BUPIVACAINE IN TRANSVERSUS ABDOMINAL PLANE BLOCK IN ABDOMINAL HYSTERECTOMY PATIENTS.

Abstract

Objectives: To determine the efficacy of co-administration of magnesium
sulphate (MgSO4) with bupivacaine in enhancing the analgesic efficacy of Transversus
abdominus plane block (TAP block) in patients undergoing total abdominal hysterectomy.
Study Design: Randomized clinical single blinded trial. Setting: Department of Anesthesia,
Nishtar Medical University/Hospital Multan. Period: 07 months from March 2017 to October
2018. Methods: We included female patients who presented with uterine or ovarian cancer and
planned for total abdominal hysterectomy. In group B patients (n=30) TAP block was given
using 0.25% bupivacaine (20 ml). In group M patients (n=30), 19.4 ml 0.25% bupivacaine plus
0.60 ml Mg sulphate. Mean arterial blood pressure, heart rate, VAS pain score and time of
1st rescue analgesia and total dose of rescue analgesia was noted in all patients. For data
analysis we used independent sample t-test (Mann-Whitney U test for skewed data) to compare
quantitative variables. Chi-square test we used for comparison of ASA status. P-value < 0.05
was taken as significant difference. Results: Mean VAS pain score after 1 hour was 3.27+1.70
in group B and 2.23+1.35 in group M (p-value 0.012), after 2 hours mean VAS pain score was
4.03+2.10 in group B and 2.47+1.25 in group M (p-value 0.001), after 6 hours mean VAS score
was 4.53+2.62 in group B and 3.27+1.36 in group M (p-value 0.02). Mean VAS pain score after
12 and 24 hour of shifting the patient in recovery room was no significantly different between the
groups (p-value 0.55 & 0.08 resp.). Mean time of 1st rescue analgesia was 7.53+4.92 hours in
group B versus 13.96+2.25 hours in group M. Conclusion: Administration of 200 mg of MGSO4
with bupivacaine for TAP block significantly improves the duration of analgesia and reduces the
requirement of rescue analgesics in patients undergoing total abdominal hysterectomy.