The Influence Of Obesity Type On Hypotension After Spinal Anesthesia And The Prediction Analysis Of Obesity Index

Objective:To explore the influence of obesity types on hemodynamics after spinal anesthesia,and then analyze the risk factors of hypotension after spinal anesthesia in obese patients,and evaluate the obesity-related measurement indexes to predict the effect of hypotension after spinal anesthesia.Methods:The research is divided into two parts.Part i:228 overweight or obese patients who underwent simple hernia surgery in the lower abdomen or internal fixation surgery for fracture of both lower limbs under spinal canal anesthesia in the first affiliated hospital of shihezi university medical college from June2018 to June 2019 were selected.Patients with female abdominal circumference?80 cm or male abdominal circumference?90 cm were included in the central obesity group according to the abdominal circumference,while the rest were classified as peripheral obesity group.All patients were given intraspinal anesthesia,and the changes in hemodynamics and the number of adverse events were recorded before and after anesthesia.Linear regression analysis was used to investigate the relationship between abdominal circumference and mean arterial pressure drop after spinal anesthesia.Repeated measure analysis of variance was used to compare the differences of hemodynamic parameters and their changes with time between the two groups.Part ii:228 overweight or obese patients who met the inclusion and exclusion criteria were selected and divided into two groups according to whether hypotension occurred within 10minutes of supine position after spinal anesthesia,hypotension group and non-hypotension group.Binary logistic regression was used to analyze the risk factors of hypotension after intravertebral anesthesia in obese patients,and receiver operating characteristic curve(ROC)was used to compare the effect of obesity related indicators to predict hypotension after intravertebral anesthesia.Results:In the first part of the study,there was a significant positive correlation between abdominal circumference(X)and mean arterial pressure drop(Y)after spinal anesthesia(Y=0.834X-46.75,R~2=0.8131).The incidence of hypotension and supine hypotension in the central obese group was significantly higher than that in the peripheral obese group(P<0.001).In the second part of the study,a total of 97 patients(42.5%)had hypotension after spinal anesthesia.Dyslipidemia(OR=3.593,95%CI1.974-6.541)and abdominal obesity(OR=1.980,95%CI 1.068-3.668)are independent risk factors for hypotension after spinal anesthesia in obese patients.Among the obesity-related indicators,waist circumference was the most sensitive indicator to predict hypotension after spinal anesthesia in obese patients,with the optimal cut-off point of 87.5 in males and 83.5 in females.Conclusion:Central obesity is directly related to the occurrence of hypotension after spinal anesthesia,most of which are manifested as supine hypotension.Preoperative attention to the blood lipids and waist circumference of obese patients are helpful to predict hypotension after spinal anesthesia.Among them,males with waist circumference?87.5cm and females with waist circumference?83.5cm are high-risk of hypotension after spinal anesthesia,which should be given high attention before anesthesia.