Effect of Midprone Decubitus on Pulmonary Function Test Values in Young Adults with Undesirable Body Mass Indices (BMI)

Background and purpose: Body positioning is prescribed by Physical Therapists to directly enhance oxygen transport and oxygenation, to minimize the risk of aspiration, and to drain pulmonary secretion in most of the intensive care units. The aim of this study is to assess pulmonary function in sitting, right mid-prone, left mid prone position in healthy young adult subjects and to compare the effect of Body Mass Index (BMI) on pulmonary function in sitting, right and left mid prone position.

Materials and Methods: We recruited 60 healthy male volunteers by using convenience sampling with the mean age 20.5 ranges from 18-30 years. The subjects were divided into two groups based on their BMI (Group A BMI 18.5-24.9kg/m2and Group B BMI>25kg/m2 ). The spirometric test was done to measure Forced Vital Capacity (FVC), Forced expiratory volume in 1 second (FEV1), Slow Vital Capacity (SVC), Maximum Voluntary Ventilation (MVV) in sitting, right side lying and left side lying position, the values of three different positions were compared with in the groups and between the groups.

Results: FVC and FEV1 values show significant changes in three different positions in normal and obese subjects. The MVV of normal and obese groups in sitting, right side lying and left side lying was significantly varied. There was no significant difference in other values.

Conclusion: With right side and left side lying position the FVC and FEV1 values decreased significantly in compare to the sitting position, and there is no difference in lung volumes between normal and obese except MVV. MVV is significantly reduced in right and left side lying position. Upright sitting position will increase the lung volumes and capacities compared to the other positions.