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Sequential latex particle infusion reveals that hemorrhage causes progressive inter‐alveolar perfusion mal‐distribution in the lungs of rats
Author(s) -
Conhaim Robert L.,
Kluesner Karri A,
Dovi William f,
Watson Kal A.,
Harms Bruce A
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1437-c
Subject(s) - perfusion , particle (ecology) , distribution (mathematics) , volume (thermodynamics) , chemistry , blood volume , confocal , pathology , nuclear medicine , medicine , cardiology , biology , mathematics , optics , physics , mathematical analysis , ecology , quantum mechanics
To determine if hemorrhage‐induced inter‐alveolar perfusion mal‐distribution increases over time, we statistically analyzed trapping patterns of 4 μm diam. fluorescent latex particles infused sequentially into the pulmonary circulation of rats after removal of 30% of their blood volume. We infused 1×10 8 red particles at 15 min. and 1×10 8 green particles at 45 min after blood removal. We used confocal fluorescence microscopy to digitally image particle trapping patterns among alveoli in the air‐dried the lungs. We used dispersion index (DI) analysis to measure latex particle distributions (J. Appl. Physiol. 94, –428, 2003) within the images, and used nearest‐neighbor analysis to measure distances among particles of the same and different colors. LogDI values, a measure of perfusion mal‐distribution, increased from 1.00±0.15 at 15 min (red) to 1.62±0.24 at 45 min (green) (p < 0.001). By comparison, these values were 0.99±0.23 (red) and 1.29±0.29 (green) in control (non‐hemorrhaged) lungs (p = 0.01). LogDI values for the green particles (45 min) were statistically different between hemorrhage and control (p = 0.038). Hemorrhage caused the mean green‐to‐red particle distance to decrease from 35.9±6.5 μm to 28.0±5.1 μm (p = 0.024), and the red‐to‐green particle distance to increase from 30.2±5.7 μm to 31.5±10.0 μm (n.s.). We conclude that hemorrhage caused a progressive increase in inter‐alveolar perfusion mal‐distribution, and a non‐reciprocal change in distances between particles of different colors. Supported by a grant from the Dept. of Veterans Affairs.