In a two-group experimental , crossover design with repeated-measures , 45 lung transplant recipients ( 27 single , 18 bilateral ; 64 % male ; mean age , 57 years ) were randomized to receive CPT at 10:00 AM and 2:00 PM followed by HFCWO at 6:00 PM and 10:00 PM ( n = 22 ) or vice versa ( n = 23 ) on postoperative day 3 .