Open AccessHigh‐frequency oscillatory ventilation versus conventional ventilation: hemodynamic effects on lung and heart
Author(s) -
Smailys Andrea,
Mitchell Jamie R.,
Doig Christopher J.,
Tyberg John V.,
Belenkie Israel
Publication year - 2014
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.1002/phy2.259
Subject(s) - ventilation (architecture) , hemodynamics , medicine , cardiology , high frequency ventilation , lung , lung ventilation , anesthesia , mechanical ventilation , engineering , mechanical engineering
High‐frequency oscillatory ventilation ( HFOV ) may improve gas exchange in patients who are inadequately ventilated by conventional mechanical ventilation ( CV ); however, the hemodynamic consequences of switching to HFOV remain unclear. We compared the effects of CV and HFOV on pulmonary vascular conductance and left ventricular ( LV ) preload and performance at different airway and filling pressures. In anesthetized dogs, we measured LV dimensions, aortic and pulmonary artery ( PA ) flow, and mean airway ( P ¯AW ) and pericardial pressures. Catheter‐tip pressure manometers measured aortic, LV , left atrial, and PA pressures. The pericardium and chest were closed. At LV end‐diastolic pressure ( P LVED ) = 5 mmHg and 12 mmHg, PEEP was varied (6 cm H 2 O, 12 cm H 2 O, and 18 cm H 2 O) during CV . Then, at airway pressures equal to those during CV , HFOV was applied at 4 Hz, 10 Hz, and 15 Hz. IncreasedP ¯AW decreased pulmonary vascular conductance. As cardiac output increased, conductance increased. At P LVED = 12 mmHg, conductance was greatest during HFOV at 4 Hz. LV preload (i.e., A LV , our index of end‐diastolic volume) was similar during HFOV and CV for all conditions. At P LVED = 12 mmHg, SW LV was similar during CV and HFOV , but, at P LVED = 5 mmHg andP ¯AW 10 cm H 2 O, SW LV was lower during HFOV than CV . Compared to pulmonary vascular conductance at higher frequencies, at P LVED = 12 mmHg, conductance was greater at HFOV of 4 Hz. Effects of CV and HFOV on LV preload and performance were similar except for decreased SW LV at P LVED = 5 mmHg. These observations suggest the need for further studies to assess their potential clinical relevance.