PURPOSE: Performance of the respiratory apparatus can be evaluated not only by means of volumes but also by pressures, especially maximal inspiratory and expiratory pressure. Such variables are commonly used in the assessment of surgical candidates, as they tend to correlate with postoperative complications. Respiratory dysfunction in patients with advanced obesity has been often reported, and it may contribute to exercise intolerance and well as to hospital course. Nevertheless, findings are controversial as normal results have occasionally been reported in this population. The purpose of this study was to assess respiratory muscle strength determined by maximum respiratory pressure (PImax and PEmax).
METHODS: 33 patients with severe obesity aged 45.6 ± 10.0 years, body mass index 46.5±12.4 kg/m2, 91% female participated in the study. Maximum static inspiratory (PImax) and expiratory (PEmax) mouth pressures were determined before bariatric surgery (Lap Band). Patients were free from acute respiratory symptoms, and subjects with chronic obstructive lung disease, lung resections or other serious pulmonary conditions were excluded from the series.
RESULTS: Both PImax and PEmax were significantly below reference values (-64.7±22.0 cmH2O, p=0.001 and 86.2±25.4 cmH2O, p=0.001 respectively), in spite of the favorable clinical condition of that population.
CONCLUSION: Respiratory muscle function was markedly impaired in patients with severe obesity. Fat excess, and particularly visceral obesity, probably interfered with respiratory muscle activity.
CLINICAL IMPLICATIONS: The values of PImax and PEmax will help in the assessment of patients with severe obesity candidates to bariatric surgery.
DISCLOSURE: Shirley Fabris de Souza, No Product/Research Disclosure Information; Other Acknowledgement: The support of FAPESP Foundation, Grant 06/51197-5 is appreciated.