Cardiac function and haemodynamics during transition to high-frequency oscillatory ventilation.
OBJECTIVE
This prospective observational study analyses cardiovascular changes in adult patients with acute respiratory distress syndrome (ARDS) during transition from pressure-controlled ventilation to high-frequency oscillatory ventilation (HFOV), using transoesophageal echocardiography (TOE) and invasive haemodynamic monitoring.


METHODS
Nine patients (median age 65 years; range 42-70) with ARDS were studied. HFOV was started and maintained with an adjusted mean airway pressure of 5 cmH2O above the last measured mean airway pressure during pressure-controlled ventilation. Haemodynamic and TOE measurements were performed in end-expiration during baseline pressure-controlled ventilation, and again 5 and 30 min after the start of during uninterrupted HFOV.


RESULTS
Right atrial pressure increased immediately (P = 0.004). After 30 min, pulmonary arterial occlusion pressure increased (P = 0.008), cardiac index decreased (P = 0.01), stroke volume index decreased (P = 0.02) and both left ventricular end-diastolic and end-systolic area indices decreased (P = 0.02). Fractional area change, left ventricular end-systolic wall stress, heart rate, mean arterial pressure and mean pulmonary artery pressure remained unchanged.


CONCLUSIONS
Transition to HFOV at a mean airway pressure of 5 cmH2O above that during pressure-controlled ventilation induced significant, but clinically minor, haemodynamic effects, which are most probably due to airway pressure-related preload reduction.
David
M
M
Johannes Gutenberg University, Department of Anaesthesiology, Mainz, Germany. david@mail.uni-mainz.de
von Bardeleben
R S
RS
Weiler
N
N
Markstaller
K
K
Scholz
A
A
Karmrodt
J
J
Eberle
B
B
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002407:Catheterization, Swan-Ganz / Q000379:methods; D017548:Echocardiography, Transesophageal / Q000379:methods; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006334:Heart Function Tests / Q000379:methods / Q000706:statistics & numerical data*; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006612:High-Frequency Ventilation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors