Background: Gastroplasty has been increasingly used in the treatment of morbidly obese patients, who typically present pronounced alterations in lung volume and capacity.
Objective: To evaluate post-gastroplasty lung volume, lung capacity,
respiratory muscle strength and respiratory pattern, as well as any postoperative pulmonary complications.
Method: 21 patients (3 of them men), with an average age of 39 ± 9.7 years and an average body mass index of 50.4 kg/m2, all candidates for gastroplasty, were evaluated during the preoperative period and again on the first, third and fifth postoperative days. Tidal volume, vital capacity, minute volume, maximal expiratory pressure and maximal inspiratory pressure, as well as chest and waist circumferences, were measured. Postoperative pulmonary complications and mortality were assessed.
Results: On the first and third postoperative days, respectively, there were drops of 47% and 30.5% in vital capacity, 18% and 12.5% in minute volume, 28% and 21% in tidal volume, 47% and 32% in the diaphragmatic index, 51% and 26% in maximal inspiratory pressure, and 39.5% and 26% in maximal expiratory pressure (p < 0.05). On the fifth postoperative day, all variables analyzed were higher than on the first postoperative day, indicating a linear increase, with only tidal volume, minute volume diaphragmatic index returning to preoperative values. The incidence of postoperative pulmonary complications was 4.7%, and there were no deaths.
Conclusion: Patients submitted to gastroplasty present reduced pulmonary function, following a pattern quite similar to that previously observed following other types of upper abdominal surgery.
Keywords: Key words: Gastroplasty. Obesity. Respiratory function tests. Postoperative care.