Influence of body mass index on hemodynamics in hypertensive and normotensive patients undergoing intravenous sedation

Abstract

Statement of the Problem: Nearly two-thirds of adults in the United States are overweight, and nearly a third of these are obese. Obesity is a major contributor to cardiovascular diseases requiring careful monitoring of hemodynamics during intravenous sedation. The purpose of this project was to determine the influence of BMI on hemodynamics in hypertensive and normotensive patients undergoing intravenous sedation for office-based oral and maxillofacial surgery procedures. Materials and Methods: A retrospective chart analysis of 248 patients divided into five BMI groups: Underweight (BMI 18.5), Normal weight (BMI 18.5-24.9), Overweight (BMI 25.0-29.9), Obese (BMI 30.039.9), and Extremely Obese (BMI 40). Data recorded were noninvasive baseline and intraoperative hemodynamic measurements at ten-minute intervals for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), pulse (P), and rate-pressure product (RPP). Method of Data Analysis: Statistical analysis of mean values between groups was performed using multivariate linear regression analysis, Pearson’s correlation coefficient, and Student’s t test and found significant for P .05. Results: Average hemodynamic values for normotensive patients were significantly lower (P .05) for all groups except for pulse (P .25) in the normal group, pulse (P .71) and RPP (P .05) in the obese group, and DBP (P .16) in the extremely obese group. Significant positive moderate correlations were seen in the normotensive groups for MAP (r .7170, P .001) and PP (r .8417, P .001). For the hypertensive group, there was only a significant positive moderate correlation with PP (r .5939, P .001). Significant changes from baseline were for greater increases in SBP (P .001) and decreases in DBP (P .001) and MAP (P .05) in underweight hypertensive. Greater increases in the normotensive group were for PP (P .001) and RPP (P .05) in the normal BMI group and for pulse (P .05) and RPP (P .05) in the obese group. All baseline changes were within 20% of baseline (range, 12.6% to 17.0%). Conclusion: In general, normotensive patients had lower hemodynamic values than hypertensive patients in all BMI groups. There were no strong positive or negative correlations between BMI and hemodynamics in normotensive and hypertensive patients. Great variability was seen in baseline changes for all BMI groups, but a substantial majority of changes were within 20% of baseline. Intravenous sedation for oral and maxillofacial surgery procedures maintained a stable hemodynamic state in both hypertensive and normotensive patients regardless of BMI.