Haemodynamic Effects of Unilateral Spinal Anaesthesia with Low Dose Of 0.5% Hyperbaric Bupivacaine – A Clinical Study

Abstract

Background and Objectives Unilateral spinal anaesthesia is a promising alternative to traditional, widely used techniques of central neuraxial blocks, as it restricts markedly the anaesthetized area thereby, decreases the risk of adverse events and complications. The present study was taken up to assess the haemodynamic effects of low dose 0.7 ml ( 3.5 mg ) of 0.5% hyperbaric Bupivacaine and also to assess the level achieved and duration of block. Methods The present one year clinical trial was conducted in the Department of Anaesthesiology, during the period of January 2010 to December 2010 at KLES Dr. Prabhakar Kore Hospital and Medical Research Centre, Belgaum attached to Jawaharlal Nehru Medical College, Belgaum on 100 patients undergoing unilateral lower limb surgery under unilateral spinal anaesthesia with bupivacaine. 0.7 ml of ( 3.5 mg ) 0.5% bupivacaine heavy was injected with patient in lateral position with the limb to be operated on the lower side. Results In this study out of 100 patients studied 72 ( 72% ) were males and 28 ( 28% ) were females with male to female ratio of 2.57:1. Majority of the patients ( 45% ) were aged between 46 to 60 years. Overall mean age was 47.79±13.91 years and mean weight was 57.90±8.56 Kgs. The SBP, DBP and MBP showed a gradual fall with maximum fall noted at 40 minutes and gradually increased, subsequently reaching the baseline levels at 90 minutes. The maximum increase IV in HR was seen at 40 minutes after giving spinal and it gradually reduced coming to baseline levels at 90 minutes. Maximum sensory level of L1 was achieved. The block remained unilateral in all the cases. Motor blockade was adequate in the limb to be operated. Conclusion and interpretation Subarachnoid block with 0.7 mL ( 3.5 mg ) of 0.5% hyperbaric bupivacaine used in this study does not produce any adverse haemodynamic changes and lasts for short duration that is 90 minutes and can be used in surgeries of shorter duration.