Changes in bronchial and pulmonary arterial blood flow with
progressive tension pneumothorax.
Carvalho, Paula, Jacob Hildebrandt, Nirmal B. Charan.
Pulmonary Research Laboratory, Department of Veterans Affairs
Medical Center, Boise, Idaho 83702, Department of Medicine, Division
of Pulmonary and Critical Care Medicine, University of Washington,
Seattle, Washington 98195
APStracts 3:0241A, 1996.
We studied the effects of unilateral tension pneumothorax and its
release on bronchial and pulmonary arterial blood flow and gas
exchange in 10 adult, anesthetized, and mechanically ventilated sheep
with chronically implanted ultrasonic flow probes. Right pleural
pressure (Ppl) was increased in 2 steps from -5 cm H2O to +10 and +25
cm H2O, then decreased to +10 and -5 cm H2O. Each level of Ppl was
maintained for 5 min. Bronchial blood flow (QBr), right and left
pulmonary arterial flows (QRPA and QLPA), cardiac output (QT),
hemodynamic measurements and arterial blood gases were obtained at
the end of each period. Pneumothorax resulted in a 66% decrease in
QT, QBr decreased by 84%, and QRPA decreased by 80% at Ppl +25 cm H2O
(p<0.001). At peak Ppl, the majority of QT was due to blood flow
through the left pulmonary artery. With resolution of pneumothorax,
hemodynamic parameters normalized, although abnormalities in gas
exchange persisted for 60 to 90 minutes after recovery and were
associated with a decrease in total respiratory compliance.
Received 1 December 1995; accepted in final form 7 May 1996.
APS Manuscript Number A1246-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96