[abstract] MINIMUM <DELTA>P FOR BUBBLE FORMATION IN PULMONARY VASCULATURE.

Rubicon Research Repository/Manakin Repository

[abstract] MINIMUM <DELTA>P FOR BUBBLE FORMATION IN PULMONARY VASCULATURE.

Show full item record


Title: [abstract] MINIMUM <DELTA>P FOR BUBBLE FORMATION IN PULMONARY VASCULATURE.
Author: Sass, DJ
Abstract: Intravenous injection of FC 80 liquid fluorocarbon causes a gas-blood phase separation in the pulmonary capillaries. The gas pressure in the initial bubble equals atmospheric + FC 80 vapor pressure (55 mmHg; 37°C). Theoretically, bubbles should form only in uppermost lung regions where total blood gas tension is capillary blood pressure + pressure due to surface forces at the gas-liquid interface. Lung regions with bubbles can be found by comparing the spatial distributions of pulmonary blood flow (SDPBF) before and after bubbles form. The minimum overpressure (<delta>P = gas -liq. pressure) necessary for bubble formation can be estimated with measurements of regional intrathoracic pressures. Six anesthetized dogs were positioned left lateral decubitus. Saline-filled catheters were introduced percutaneously and positioned, with aide of thoracic bi-plane X-ray films, in the right atrium, thoracic aorta, pulmonary artery, and esophagus for recording pressures, and into the right ventricular outflow tract for injections. Differentially labeled radioactive microspheres (15 ± 5m) were injected before and 30 min. after bolus injection of 0.1 ml/Kg FC 80. Three dogs were then immediately rolled to right lateral decubitus and a third microsphere injection was made. The lungs were resected, dried in air while inflated with constant tracheal pressure (40 cm H0), and embedded in pour-in-place-foam. SDPBF was determined for each injection at > 2500 locations in a three-dimensional grid throughout the entire lung. After bubbles formed, the fractional distribution of cardiac output changed. There was a 41.7% decrease in the right, uppermost, lung and a 9.2% decrease in lung ventral to the trachea. Flow was unmeasureable in extreme apical and diaphragmatic sections. The results indicate that <delta>P's of only 5-10 mmHg cause bubbles to evolve in blood. Thus, small <delta>P's can cause gas embolism in divers.
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held May 12-13, 1976. Carillon Hotel, Miami Beach, FL (http:www.uhms.org)
URI: http://archive.rubicon-foundation.org/5257
Date: 1976

Files in this item

Files Size Format View
abstract.txt 259bytes Text file View/Open

This item appears in the following Collection(s)

  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

Show full item record

Browse

My Account