The Influence of Class III Obesity on Subarachnoid Depth of Turkish Parturient: A Prospective Observational Study

Abstract

Introduction: This observational study aimed to investigate the effects of morbid obesity on the subarachnoid depth and spinal anaesthesia technique. Methods: Sixty American Society of Anesthesiologists Classification II women with term pregnancy who were candidates for elective caesarean section under spinal anaesthesia were enrolled in this prospective, observational study. Only patients with a Body Mass index (BMI) of <30 kg/m(2) (control group) or BMI >= 40 kg/m(2) (obesity group) were included in the study. Spinal anaesthesia was performed in the sitting position via a midline approach at either L3-4 or L4-5 level by using a 25G 90-mm Quincke spinal needle with an introducer. Demographic data of the parturient, visual characteristics of the lumbosacral region, palpation of landmarks, depth of the spine, technical characteristics of the block, time of block performance and satisfaction of patients were recorded. Results: the spinal depth of the control and obesity groups were 51.7 +/- 4.4 and 69 +/- 10.4 mm, respectively (p<0.001). Although needle change was not necessary for any of the patients in the control group, a 120-mm long needle change was required in six patients in the obesity group (p<0.024). We found that the incidence of patients with landmarks that were difficult to palpate was higher in the obesity group, and significantly increased attempt number, skin puncture and needle pass were also required in this group. Conclusion: Anaesthesiologists should be prepared for a longer attempt in patients with obesity but should not be discouraged as the increase in the number of attempts or prolonged initiation time of spinal anaesthesia was not associated with patient dissatisfaction or discomfort.