Correlation between Body Mass Indeks and Incidence of Hypotension on Pregnant Mothers Undergoing Caesarean Section under Spinal Block Anesthesia

Background Spinal block anesthesia, a regional anesthesia technique that is still widely used for the operation sectio Caesarea. The most frequent complication was hypotension caused by sympathetic block with bad effects to the mother and fetus. In pregnant arising nausea, vomiting to decreased awareness, whereas in infants can cause blood flow uteroplacental hypoperfusion affecting the transfer of oxygen and nutrients that affect fetal fetus. Actions can be done to overcome hypotension mother left lateral position, oxygen supplementation, fluid preload and prophylactic ephedrine IV / IM, but no satisfactory results. Therefore, it needs a predictive factor before intervention. Obesity is classified according to the WHO by the Body Mass Index (BMI), is suspected to be a predictive factor of hypotension on spinal block anesthesia. Methods The study included 38 patients of pregnant women aged 20-40 years of ASA PS 1 and 2, which will be done sectio Caesarea measured BMI, systolic blood pressure, diastolic, Mean Arterial Pressure (MAP) and pulse as a baseline. Patients were given 500 ml RL for loading + 15 mins positioned further to the left oblique. Then spinal block is perform  according to the procedure using Spinocan 26 G, using 5% Lidodex Adrenalin 0.2 mg + 75mg. With the target height of the block Thoracal VI-IV. The patient is positioned left lateral tilt. Measurement and recording of blood pressure, systolic, diastolic, MAP and pulse continuously every 2.5 minutes until the 30th minute. Then categorized into 3 groups based on BMI which is the Normal (BMI 30 kg/m2). Results The 38 samples that met criteria for inclusion in the Normal, Overweight and Obese consecutive experiencing  hypotension 4/9 (44.4%), 14/17 (82.4%) and 11/12 (91.7% ) with  p = 0.031 (p <0.05). While Relative Risk for overweight patients compared to normal was 1.85, being obese compared with normal was 2.06. Conclusion Obtained the relationship between BMI and the incidence of hypotension in pregnant women who do sectio Caesarea using spinal block anesthesia in dr Soetomo’s hospital, Surabaya. The greater BMI the greater incidence of hypotension, Overweight subjects experienced hypotension incidence of 1.85 times greater than normal, while the Obese 2.06 times.