Compliance of chest wall in obese subjects

Abstract

Whereas studies in awake subjects have demonstrated that chest wall compliance (Ccw) is low in obese subjects, the one study performed on paralyzed obese subject found Ccw to be normal. The purpose of this study was to measure Ccw in awake obese subjects with the pulse-flow technique, a method which appears to detect respiratory muscle relaxation. Seven normal males, 14 obese males, and 8 obese females [body mass index (BMI) varied from 20 to 83 kg/m2] were studied in the seated position. Ccw was measured by blowing air at a constant flow into the mouth and lungs for approximately 2 s and calculated by dividing airflow in liters per second by the change in esophageal minus body surface pressure in centimeters of water per second. In normal and obese subjects we found no correlation between BMI and Ccw. We conclude that obesity does not decrease Ccw.

Physiologic correlates of dyspnea in patients with morbid obesity

“…[4][5][6][7][8][9][10] The most frequent pulmonary function tests (PFTs) findings are reduced expiratory reserve volume (ERV), functional residual capacity (FRC) and total lung capacity (TLC), [4][5][6]9 which are generally related to alterations in chest wall mechanics induced by an increased abdominal load. 8 These alterations reduce total respiratory compliance.…”

“…8 These alterations reduce total respiratory compliance. 7 The work of breathing is markedly increased in patients with severe obesity. 11 Maximum voluntary ventilation as well as maximal inspiratory pressure (PImax) can also be low, [6][7][8][9][10] reflecting a decreased inspiratory muscle performance.…”

Estudo dos volumes pulmonares e da mobilidade toracoabdominal de portadoras de obesidade mórbida, submetidas à cirurgia bariátrica, tratadas com duas diferentes técnicas de fisioterapia

“…In conscious patients, the investigations using different methods report a decrease in thoracic compliance 4,27 . In contrast, Suratt et al 28 compared obese and non-obese conscious patients and did not find any correlation between BMI and thoracic wall compliance. According to Nguyen and Wolfe 29 , the decrease in respiratory compliance in the intraoperative period of open bariatric surgeries is due to the rigid mechanical retractors placed in the abdominal wall, while in laparoscopic bariatric surgeries, the reduction in compliance is even greater and due to increased intra-abdominal pressure.…”

Desafios no manuseio peri-operatório de pacientes obesos mórbidos: como prevenir complicações

“…Em pacientes acordados, as investigações, algumas vezes usando diferentes métodos, encontraram diminuição da complacência torácica 29,30 . Em contraposição a esses estudos, Suratt e col., comparando pacientes acordados obesos e não obesos, não encontraram nenhuma correlação entre o IMC e a complacência da parede torácica 31 . Por outro lado, em pacientes obesos mórbidos sedados e curarizados, quando comparados ao normal, Van Lith e col. mostraram que a complacência torácica era menor nos pacientes obesos 32 .…”