Autor: | Diederik Gommers, D. Reis Miranda, Ard Struijs, J Van Bommel, J Meekel, Ad J.J.C. Bogers, Lennart Klompe |
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Rok vydání: | 2006 |
Předmět: |
Mechanical ventilation
medicine.medical_specialty medicine.diagnostic_test business.industry medicine.medical_treatment respiratory system Doppler echocardiography Critical Care and Intensive Care Medicine respiratory tract diseases Cardiac surgery Afterload medicine.artery Anesthesia Pulmonary artery Breathing medicine Expiration business Tidal volume circulatory and respiratory physiology |
Zdroj: | Critical Care. 10:P31 |
ISSN: | 1364-8535 |
Popis: | 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. The total PEEP in the OLV group was 14 ± 4 compared with 5 ± 1 cmH2O in the CMV group. During expiration, the Acmean of both ventilation strategies was comparable. Inspiration caused a significant decrease of Acmean compared with expiration during CMV (Table (Table1).1). Surprisingly, this did not occur during OLV. Table 1 We conclude that despite the use of 'relatively' high PEEP, OLV with low tidal volume does not increase RV afterload during inspiration and expiration. |
Databáze: | OpenAIRE |
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