Clarissa M. P. Matos

Changes in breathing pattern and thoracoabdominal motion after bariatric surgery: A longitudinal study

This study evaluated the breathing pattern of 30 obese patients [32 ± 9 years old; body mass index (BMI): 42.72 ± 4.10 kg/m(2)] before and after bariatric surgery and compared them with 30 control individuals (31 ± 8 years old, BMI: 21.99 ± 2.22 kg/m(2)). Measurements were performed using calibrated respiratory inductive plethysmography. Six months after bariatric surgery, obese patients exhibited a significant reduction in tidal volume (V(T)), minute ventilation (V(E)) and inspiratory duty cycle (T(I)/T(TOT)) compared with pre-surgical values. The control group had a higher breathing frequency, V(E) and phase angle (PhAng). There were no significant differences in V(T)/T(I), percentage of rib cage motion (%RC) or abdominal motion (%AB). Obese patients exhibited changes in their breathing pattern and asynchrony after bariatric surgery without any changes in thoracoabdominal motion. Certain aspects of the breathing pattern of obese patients became more similar to those of the controls after surgery.

Evolution of respiratory muscle strength in post-operative gastroplasty.

BACKGROUND Obesity is a worldwide health problem that may also induce respiratory dysfunction. Literature linking weight loss and maximum respiratory pressures is inconclusive. OBJECTIVE To evaluate longitudinally the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) of morbidly obese individuals before and after gastric bypass surgery, and to compare them to a control group matched by sex and age. METHODS A vacuum manometer (GeRar®, SP, Brazil) was used to assess the MIP and MEP of 30 morbidly obese participants (24 women), aged 32±8 years and with body mass index (BMI) of 43±4 kg/m², both before and then one and six months after gastric bypass surgery. After an average of 36 months, 17 patients were reevaluated. A control group of 30 individuals with normal lung function (aged 30±8 with a BMI of 22±2 kg/m²) was also studied. An unpaired t-test and ANOVA for repeated measures were used for statistical analysis, with p<0.05 considered as significant. RESULTS No significant differences were observed in the baseline evaluation between the two groups. A significant increase was found in MIP after approximately 36 months of surgery in the obese group. A significant decrease in MEP was observed after one month, as well as a significant increase after 36 months compared with one and six months post-surgery. CONCLUSION The data showed a significant long-term increase in MIP, as well as a significant decrease in MEP after one month followed by a return to pre-operative values, which indicates that gastric bypass surgery has a positive influence on the strength of inspiratory muscles.