Effect of low dose Bupivacaine with Fentanyl on hemodynamic response: A Prospective cohort study

Abstract

Background: A conventional dose of local anesthetics is used during spinal anesthesia. However an unwanted hemodynamic effect by administration of adjuvants with low dose of local anesthetics has been observed. The purpose of the study was to compare the effect of low dose Bupivacaine with Fentanyl versus normal dose Bupivacaine alone on hemodynamic response in elderly patients. Methods: A Prospective cohort study was employed on a total of 64 elderly patients undergoing lower extremity orthopedics surgery. An exposed group (group BF) received 10mg of 0.5% isobaric bupivacaine with 25mcg of fentanyl and a non-exposed group (Group B) received 15 mg of 0.5% isobaric bupivacaine alone. Systematic random sampling technique was used to select study participants. Parametric data was analyzed by using independent t-test, nonparametric data by using Mann-Whitney U-test and homogenous categorical data by using chi-square test and fisher exact test. The level of statistical significance for all tests was found to be P < 0.05. Results: The incidence of hypotension was higher in group B than group BF (37.5% vs. 9.4%, respectively) and statistically significant differences was observed (p=0.008). The onset of sensory block and regression of motor block to zero were faster in group BF than in group B (p <0.05). TAR was also prolonged in group BF (P<0.05). Conclusion: Low dose Bupivacaine with Fentanyl has lower incidence of hypotension, fast onset of sensory block and prolonged first analgesia request time than bupivacaine alone Therefore, we recommends the use of low dose bupivacaine with fentanyl to have a better hemodynamic stability than conventional dose of bupivacaine for elderly patients who undergoes lower extremity surgery.