EVALUATION OF CHEST WALL KINEMATICS DURING REST AND RESPIRATORY MUSCLE ENDURANCE IN OBESE PATIENTS

Abstract

Background: Obesity may affect the respiratory system, causing changes in respiratory function and in the pulmonary volumes and flows. Objectives: To evaluate the influence of obesity in the movement of thoracoabdominal complex at rest and during maximal voluntary ventilation (MVV), and the contribution between the different compartments of this complex and the volume changes of chest wall between obese and non-obese patients. Materials and Methods: We studied 16 patients divided into two groups: the obese group (n = 8) and group non-obese (n = 8). The two groups were homogeneous in terms of spirometric characteristics (FVC mean: 4.97 ± 0.6 L - 92.91 ± 10.17% predicted, and 4.52 ± 0.6 L - 93.59 ± 8.05%), age 25.6 ± 5.0 and 26.8 ± 4.9 years, BMI 24.93 ± 3.0 and 39.18 ± 4.3 kg/m2 in non-obese and obese respectively. All subjects performed breathing calm and slow and maneuver MVV, during registration for optoelectronic plethysmography. Statistical analysis: we used the unpaired t test and Mann-Whitney. Results: Obese individuals had a lower percentage contribution of the rib cage abdominal (RCa) during breathing at rest and VVM. The variation of end expiratory (EELV) and end inspiratory (EILV) lung volumes were lower in obese subjects. It has been found asynchrony and higher distortion between compartments of thoracoabdominal complex in obese subjects when compared to non-obese. Conclusions: Central obesity impairs the ventilation lung, reducing to adaptation efforts and increasing the ventilatory work.