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

We explored the feasibility of use of continuous positive airway pressure (CPAP) with 15- and 4-cmH2 O for a randomized controlled trial with patients with pleural drainage. Ten patients with traumatic pleural effusion drained within 24hr, with controlled pain received randomly CPAP with 0-, 4-, and 15-cmH2 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. The lung area under CPAP with 15cmH2 O (median=3,913mm2 ; IQR=3,416-4,390mm2 ) was greater than 4 (median=3,495mm2 ; IQR=3,075-3,954mm2 ) and 0cmH2 O (median=3,382mm2 ; IQR=2,962-3,658mm2 ; p<0.001). There was no difference between lung areas under CPAP with 4 and 0cmH2 O. All levels of pressure were well tolerated by patients. No air leak was observed during the assessments. CPAP with 15cmH2 O is able to expand lungs of patients with pleural drainage. CPAP with 4cmH2 O seems not have therapeutic effect. In addition, CPAP with 15cmH2 O is well tolerated and safe in this population.