Comparison of Loss of Resistance to Air Technique and Saline Infusion Technique Using Micro - Drip Set for Identification of Epidural Space - A One Year Randomized Study

Abstract

Objective: Epidural anaesthesia is most commonly performed technique in routine anaesthesia practice. The technique of identification of epidural space is very much important step, as it determines the success rate and quality of analgesia. Complications are associated with incorrect identification of epidural space. Different techniques have been suggested for identification of epidural space. This study compares the success rate and quality of analgesia by using two different techniques i.e. loss of resistance with air and saline infusion technique using micro-drip infusion set for identification of epidural space in patients undergoing lower abdominal and lower limb surgeries. Study design: A randomized controlled trial. Methods: Two hundred and twenty patients posted for lower limb or lower abdominal surgeries were randomly allocated into two groups of hundred and ten in each. Tuohy needle was used for identification of epidural space. We identified epidural space, in Group A by loss of resistance technique using air as a medium and in Group S by saline infusion technique using micro-drip infusion set. The success rate and quality of analgesia were noted. Identification of epidural space considered successful when no dripping of CSF, no increase in the heart rate on administration of epidural test dose, adequate sensory ( loss of sensation to pin prick with 22G hypodermic needle in the anterior axillary line ) and motor blockade ( Bromage scale>3 ) were noticed. The level of significance was taken as 0.05. Results: The success rate of identification of epidural space in air group is 98.18% where as for saline group it is 100%. The good quality of analgesia in saline group was found to be 100% when compared to 96.36% in air group. There is no statistically significant difference between IX two groups with the P values 0.498 and 0.122 for success rate and good quality of analgesia respectively. Conclusion: There is no statistically difference between two groups for success rate and good quality of analgesia. The choice of technique for identification of epidural space largely depends up on personal preference of anaesthesia provider. The potential complications observed with loss of resistance technique using air as a medium are absent with saline infusion technique. Hence it is considered to be safe, simple and reliable objective technique.