Comparative study of ultrasound assisted versus conventional surface landmark guided technique for combined spinal epidural anaesthesia in patients with increasaed body mass index and difficult surface anatomy of lower back and spinal deformity

Abstract

Palpatory method is traditionally used in clinical practice to locate the puncture site of combined spinal epidural (CSE) block, but locating the puncture site accurately in obesity and patients with difficult landmark or spinal deformity is usually difficult. For a successful CSE block, the puncture site must be accurately identified. The goal of this study was to see how ultrasonography (USG) affected the success rate of CSE puncture in these patients.This prospective randomized study included 100 patients requiring CSE (needle through needle technique) of American Society of Anaesthesiologists (ASA) grade I/II, age 18-60years, obese (BMI upto 35 kg/m2), patients with difficult landmark, spinal deformity and were randomly assigned to one of two groups: Ultrasound assisted group (USG) (n=50) or Surface landmark group (SLG) (n=50). The primary outcome was to compare the first-pass needle success rate for establishing CSE, with secondary outcomes including the number of needle puncture attempts, time to establish landmarks (t1), time to complete CSE (t2), total procedure time (t), block associated pain and complications.The USG group had a significantly greater first pass needle success rate (92%) than the SLG group (60%) p<0.001. The number of attempts to accomplish CSE in the USG group was lower than in the SLG group (p = 0.001). The USG group had a longer t1 (1.50±0.42) minutes than the SLG group (0.80±0.28), p<.0001. The USG group had a shorter t2 (1.60±0.45) than the SLG group (3.37±1.25) minutes (p <0.001). Block associated pain score was less in USG group as compared to SLG group (p=0.0003).Preprocedural USG improves first pass needle success rate and reduces the number of needle puncture attempts, decrease the procedural time thus lowering the risk of trauma, block associated pain, and discomfort to the patient.