Background: Manual hyperinflation (MHI) and ventilator hyperinflation (VHI) are two methods of recruitment maneuvers used in ventilated patients to improve lung compliance and secretion mobilization. The use of VHI may minimize the adverse effects of disconnection from the ventilator, but it is uncertain whether high levels of positive end-expiratory pressure (PEEP) would decrease the peak expiratory flow rate (PEFR) and consequently affect secretion clearance.
Objectives: The aim of this study was to compare the effectiveness of MHI and VHI in terms of clearing pulmonary secretions (sputum wet weight and PEFR), improving static respiratory system compliance and oxygenation (arterial oxygen tension/fraction of inspired oxygen), and altering mean arterial pressure, heart rate, and carbon dioxide output at different levels of PEEP.
Methods: This was a randomized crossover study involving 14 general intensive care patients who were intubated and mechanically ventilated.
Results: Sputum production was similar in both techniques and levels of PEEP. There were no differences in improvement in oxygenation and static respiratory system compliance between MHI and VHI. However, VHI increased Cst significantly at 30 minutes posttreatment (P = .012), and a significant difference was observed between levels 5 and 7.5 cmH(2)O (P = .02) of PEEP for MHI. MHI generated higher PEFR than VHI (P < .05). No adverse change in heart rate or mean arterial pressure was observed during either technique; however, VCO(2) was significantly different for techniques (P = .045) and over time (P = .05).
Conclusion: The VHI technique seems to promote greater improvements in respiratory mechanics with less metabolic disturbance compared with MHI. Other variables such as sputum production, hemodynamics, and oxygenation were affected similarly by both techniques.