Comparing high and low levels of continuous positive airway pressure on lung aeration in patients with pleural drainage: A feasibility study for a randomized controlled trial

Abstract

ObjectiveWe explored the feasibility of use of continuous positive airway pressure (CPAP) with 15- and 4-cmH(2)O for a randomized controlled trial with patients with pleural drainage. MethodsTen patients with traumatic pleural effusion drained within 24hr, with controlled pain received randomly CPAP with 0-, 4-, and 15-cmH(2)O. Computed tomography was used to assess the lung aeration. Patients reported the level of tolerability. Air leak was also observed as a parameter of safety. The levels of pressure were compared using the Friedman test followed by the Tukey test as post hoc. ResultsThe lung area under CPAP with 15cmH(2)O (median=3,913mm(2); IQR=3,416-4,390mm(2)) was greater than 4 (median=3,495mm(2); IQR=3,075-3,954mm(2)) and 0cmH(2)O (median=3,382mm(2); IQR=2,962-3,658mm(2); p<0.001). There was no difference between lung areas under CPAP with 4 and 0cmH(2)O. All levels of pressure were well tolerated by patients. No air leak was observed during the assessments. ConclusionCPAP with 15cmH(2)O is able to expand lungs of patients with pleural drainage. CPAP with 4cmH(2)O seems not have therapeutic effect. In addition, CPAP with 15cmH(2)O is well tolerated and safe in this population.