Application of positive airway pressure in restoring pulmonary function and thoracic mobility in the postoperative period of bariatric surgery: a randomized clinical trial

Abstract

Objective: To evaluate whether the application of bilevel positive airway pressure in the postoperative period of bariatric surgery might be more effective in restoring lung volume and capacity and thoracic mobility than the separate application of expiratory and inspiratory positive pressure. Method: Sixty morbidly obese adult subjects who were hospitalized for bariatric surgery and met the predefined inclusion criteria were evaluated. The pulmonary function and thoracic mobility were preoperatively assessed by spirometry and cirtometry and reevaluated on the 1st postoperative day. After preoperative evaluation, the subjects were randomized and allocated into groups: EPAP Group (n=20), IPPB Group (n=20) and BIPAP Group (n=20), then received the corresponding intervention: positive expiratory pressure (EPAP), inspiratory positive pressure breathing (IPPB) or bilevel inspiratory positive airway pressure (BIPAP), in 6 sets of 15 breaths or 30 minutes twice a day in the immediate postoperative period and on the 1st postoperative day, in addition to conventional physical therapy. Results: There was a significant postoperative reduction in spirometric variables (p<0.05), regardless of the technique used, with no significant difference among the techniques (p>0.05). Thoracic mobility was preserved only in group BIPAP (p>0.05), but no significant difference was found in the comparison among groups (p>0.05). Conclusion: The application of positive pressure does not seem to be effective in restoring lung function after bariatric surgery, but the use of bilevel positive pressure can preserve thoracic mobility, although this technique was not superior to the other techniques.

Improvement in Lung Insufflation in Spontaneously Breathing Tracheostomized Patients by Using a New Pulmonary Expansion Device: A Pilot Study

“…We observed MIV values ranging from 725 mL (600-820) to 870 mL (750-950). These values are consistent with those observed in earlier studies that reported values of maximal inspiratory volumes in tracheostomy patients that ranged from 250 mL to 1000 mL [21,31]. In contrast, when using the PED we observed greater inspiratory volumes.…”

“…No adverse events were reported. In contrast, improvement in lung volume was observed, probably associated with therapeutic implementation of lung re-expansion using the PED as an adjunct to medical management [31]. Worsening of pleural effusion and decreased lung expansion were observed in only one case, possibly due to worsening of other comorbidities associated with the patient's underlying disease.…”

Inspirômetro de incentivo no pós-operatório de cirurgia torácica: uma revisão sistemática

“…O colapso pulmonar é descrito como uma complicação de elevada incidência em pacientes submetidos à intervenção cirúrgica sob anestesia geral devido ao relaxamento da musculatura, causando a diminuição da CRF, alteração na relação ventilação/perfusão e hipoxemia 20 . A inspirometria de incentivo é estudada nesse contexto por provocar o aumento da pressão negativa natural do espaço pleural e aumentar o gradiente de pressão transrespiratória, melhorando a fluidez dos gases e gerando uma maior expansão pulmonar, porém, estudos mostram que o uso de pressão positiva é necessário para abertura de áreas colapsadas 21,22 . Sendo assim, é possível considerar que a inspirometria de incentivo exerce maior efeito na manutenção do volume corrente, enquanto que a pressão positiva, em suas diversas formas de uso, é mais eficaz no restabelecimento dos volumes pulmonares por ser mais efetiva na reexpansão de alvéolos colapsados 20,21,22 .…”

Bilevel positive airway pressure in two moments after bariatric surgery

“…Several studies have reported the benefits of preand postoperative chest physical therapy for the restoration of lung volumes and capacities and thoracic-abdominal mobility in obese patients 11,12 . The use of positive pressure devices not only contributes to the restoration of pulmonary function, but it is also important for the prevention of atelectasis in the post-operative period [13][14][15] .…”