| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Guest Access | Sign In via User Name/Password
|
|
|
|||||||
Guest Access | Sign In via User Name/Password |
|||||||||
1 From the Department of Anesthesia and General Intensive Care, University Hospital of Vienna, Vienna, Austria
The advent of modern Doppler two-dimensional ultrasound technology has overcome the need of invasive measurements of several important cardiac parameters. It allows estimation of preload, contractility, and afterload. Positive end-expiratory pressure (PEEP) is associated with a reduction in cardiac output. The responsible mechanisms are controversial. To evaluate the cardiovascular responses to PEEP, we employed different Doppler hemodynamic indices for the first time, combined with conventional two-dimensional echocardiography. Twenty-one healthy, young, and unsedated volunteers were admitted to the study. Under spontaneous respiration, PEEP level was increased stepwise (0, 5, 7.5, 10, 12.5 cm H2O). At each PEEP level, the following right and left ventricular parameters were assessed with Doppler two-dimensional echocardiography: two-dimensional variables: end-diastolic volume indices (EDVI), ejection fraction (EF), and left ventricular afterload-LaPlace relation (combined with cuff systolic pressure); Doppler variables: cardiac index (CI) (combined with two-dimensional measure of valve area), maximum velocity (Vmax), time velocity integral (TVI), acceleration time (AT), deceleration time (DT), deceleration rate (DR), ratio of early to atrial peak (E/A), ratio of isovolumic contraction time to ejection time (IVCT/ET), and maximum blood acceleration (dv/dt) in aorta and main pulmonary artery. Increasing PEEP resulted in a proportional decrease in biventricular EDVI. Moreover, PEEP application is also causing a drop of CI, which is determined from a decrease in Vmax and TVI, while EF, IVCT/ET, dv/dt, Doppler transatrioventricular parameters, and afterload stay in normal ranges. Employing Doppler hemodynamic indices for the first time in this study setting clearly supports data that the drop in EDVI and CI during PEEP is caused by reduction in ventricular filling due to decreased venous return. Using the Doppler parameters IVCT/ET and dv/dt, changes in myocardial contractility, as well as changes in afterload (LaPlace relation) can be ruled out.
Submitted on July 1, 1993
This article has been cited by other articles:
|
|
 |
|
  J. C. Kubitz, T. Annecke, G. I. Kemming, S. Forkl, N. Kronas, A. E. Goetz, and D. A. Reuter The influence of positive end-expiratory pressure on stroke volume variation and central blood volume during open and closed chest conditions. Eur. J. Cardiothorac. Surg., July 1, 2006; 30(1): 90 - 95. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. R. Pinsky Cardiovascular Issues in Respiratory Care Chest, November 1, 2005; 128(5_suppl_2): 592S - 597S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Reis Miranda, D. Gommers, A. Struijs, H. Meeder, R. Schepp, W. Hop, A. Bogers, J. Klein, and B. Lachmann The open lung concept: effects on right ventricular afterload after cardiac surgery Br. J. Anaesth., September 1, 2004; 93(3): 327 - 332. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Jorgensen, E. Houltz, U. Westfelt, F. Nilsson, H. Schersten, and S.-E. Ricksten Effects of Lung Volume Reduction Surgery on Left Ventricular Diastolic Filling and Dimensions in Patients With Severe Emphysema Chest, November 1, 2003; 124(5): 1863 - 1870. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. MEHTA, P. P. LIU, F. S. FITZGERALD, Y. K. ALLIDINA, and T. DOUGLAS BRADLEY Effects of Continuous Positive Airway Pressure on Cardiac Volumes in Patients with Ischemic and Dilated Cardiomyopathy Am. J. Respir. Crit. Care Med., January 1, 2000; 161(1): 128 - 134. [Abstract] [Full Text]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
