Open lung ventilation does not increase right ventricular afterload in cardiac surgery patients
© Biomed central limited 2001
Published: 21 March 2006
Open lung ventilation (OLV) consists of recruitment maneuvers, followed by low tidal volume and elevated positive end-expiratory pressure (PEEP). Elevated PEEP is associated with an increased right ventricular (RV) afterload. We investigated the effect of OLV on RV afterload during inspiration and expiration in patients after cardiac surgery using Doppler echocardiography.
In 28 patients scheduled for cardiac surgery, two ventilation strategies were applied in a randomized cross-over design. During OLV, recruitment maneuvers were applied until PaO2/FiO2 > 375 Torr was achieved (reflecting an open lung) and were maintained by the use of sufficient levels of PEEP. The tidal volume was 4–6 ml/kg. During conventional mechanical ventilation (CMV) the ventilation was with a low tidal volume (6–8 ml/kg) with 5 cmH2O PEEP, without recruitment maneuvers. The acceleration time (Acmean) of the pulmonary artery was measured with transesophageal echocardiography in a long-axis view of the pulmonary artery during end-inspiration and end-expiration.
9.6 + 2.2
10.0 + 2.9*
10.2 + 3.3
8.6 + 2.9†
We conclude that despite the use of 'relatively' high PEEP, OLV with low tidal volume does not increase RV afterload during inspiration and expiration.