TABLE 1.

Summary of randomized studies on hyperinflation

Author (reference), study design	Description of groups and interventions	Outcome measures	Summary of main results
Barker and Adams (16), RCT	Sample: Patients in ICU with ALI requiring MV (pressure support) (n=17) Group 1 (n=5): OS in supine with 30° elevation Group 2 (n=5): OS in ASL with 0° elevation Group 3 (n=7): OS with manual hyperinflation in ASL (0° elevation) All patients were hyperoxygenated	PaO2 PaCO2 Heart rate Blood pressure SvO2 Dynamic compliance	No significant difference between groups for any outcome measure Disconnection of patients with ALI from MV can result in significant derecruitment of the lungs. The use of manual hyperinflation does not appear to override the loss of PEEP and the derecruitment effects
Choi and Jones (17), RCO	Sample: Patients with VAP on MV (n=15) Intervention 1: OS with manual hyperinflation Intervention 2: OS alone	Static lung compliance Airway resistance	Compliance was greater with intervention 1 immediately and 30 min after suctioning (P<0.001). Lower airway resistance with intervention 1 up to 30 min (P=0.02)
Berney and Denehy (18), RCO	Sample: Patients in ICU requiring MV (n=20) Intervention 1: OS, foot of the bed elevated to 35°–45°, six sets of 6 manual hyperinflation breaths Intervention 2: OS, ventilator hyperinflation All patients received six sets of 6 hyperinflations with 30 s of VT breathing between sets Suctioned after every second set	Sputum wet weight Static lung compliance	No significant difference in the sputum weight between interventions. Both interventions improved pulmonary compliance (P<0.001)
Metz et al (19), RCO	Sample: Patients in ICU requiring MV for acute respiratory failure (n=16) Intervention 1: Standard off-ventilator suction Intervention 2: Suctioning through an adaptor with intermittent ETT clamping All patients received hyperoxygenation before and hyperoxygenation and hyperinflation postsuctioning	PaO2	No between-group comparisons reported Within group changes were significant (P<0.05) up to 60 min postsuctioning with intervention 1 causing a decrease in PaO2 and intervention 2 causing an increase in PaO2

ALI Acute lung injury; ASL Alternate side lying; CS Closed suctioning; ETT Endotracheal tube; ICU Intensive care unit; MV Mechanical ventilation; OS Open suctioning; PaCO₂ Arterial pressure of carbon dioxide; PaO₂ Arterial pressure of oxygen; PEEP Positive end-expiratory pressure; RCO Randomized crossover study; RCT Randomized controlled trial; SvO₂ Mixed venous oxygen saturation; VAP Ventilator-associated pneumonia; V_T Tidal volume