Published ahead of print on December 12, 2002, doi:10.1164/rccm.200208-840OC
© 2003 American Thoracic Society
Left Atrial Pressure Can Be Accurately Transmitted to the Pulmonary Artery despite Zone 1 ConditionsDenver Health Medical Center and Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado; and Department of Medicine, University of Washington Medical Center, Seattle, Washington Correspondence and requests for reprints should be addressed to Richard K. Albert, M.D., Denver Health Medical Center, 777 Bannock, MC 4000, Denver, CO 80204-4507. E-mail: Ralbert{at}dhha.org Pulmonary arterial occlusion pressure is not thought to reflect left atrial pressure (Pla) when alveolar pressure (PA) exceeds pulmonary venous pressure because alveolar capillaries collapse and the required continuous fluid column between the pulmonary artery and left atrium is interrupted. However, arterial-to-venous flow can occur when PA exceeds both the pulmonary arterial pressure (Ppa) and pulmonary venous pressure (i.e., in Zone 1 conditions), indicating the existence of a continuous patent vascular channel. Accordingly, Ppa should reflect Pla under these conditions. To investigate this connection cannulas were placed in the pulmonary arteries and left atria of eight excised rabbit lungs. Ppa and Pla were set 5 cm H2O above PA, which ranged from 0 to 25 cm H2O. Pla was then reduced in 2 to 4 cm H2O decrements while recording Ppa when arterial-to-venous flow ceased. At all PAs greater than 0 cm H2O, Pla was accurately reflected by the Ppa when both were exceeded by PA. The greater the PA, the lower the Ppa could track Pla below PA. Pla can be accurately measured by a pulmonary arterial catheter under Zone 1 conditions.
Key Words: pulmonary circulation • ARDS • pulmonary arterial wedge pressure This article has been cited by other articles:
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