Topographical distribution of pulmonary perfusion and ventilation, assessed by PET in supine and prone humans

Guido Musch; J. Dominick H. Layfield; R. Scott Harris; Marcos F. Vidal Melo; Tilo Winkler; Ronald J. Callahan; Alan J. Fischman; Jose G. Venegas

doi:10.1152/japplphysiol.00223.2002

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Topographical distribution of pulmonary perfusion and ventilation, assessed by PET in supine and prone humans

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Topographical distribution of pulmonary perfusion and ventilation, assessed by PET in supine and prone humans

Guido Musch, J. Dominick H. Layfield, R. Scott Harris, Marcos F. Vidal Melo, Tilo Winkler, Ronald J. Callahan, Alan J. Fischman and Jose G. Venegas

Journal of applied physiology (1985), Vol.93(5), pp.1841-1851

11/01/2002

DOI: 10.1152/japplphysiol.00223.2002

PMID: 12381773

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Abstract

Using positron emission tomography (PET) and intravenously injected 13 N 2 , we assessed the topographical distribution of pulmonary perfusion (Q˙) and ventilation (V˙) in six healthy, spontaneously breathing subjects in the supine and prone position. In this technique, the intrapulmonary distribution of 13 N 2 , measured during a short apnea, is proportional to regional Q˙. After resumption of breathing, regional specific alveolar V˙(sV˙a, ventilation per unit of alveolar gas volume) can be calculated from the tracer washout rate. The PET scanner imaged 15 contiguous, 6-mm-thick, slices of lung. Vertical gradients ofQ˙ and sV˙a were computed by linear regression, and spatial heterogeneity was assessed from the squared coefficient of variation (CV 2 ). Both CV[Formula: see text] and CV[Formula: see text] were corrected for the estimated contribution of random imaging noise. We found that 1) both Q˙ and V˙ had vertical gradients favoring dependent lung regions, 2) vertical gradients were similar in the supine and prone position and explained, on average, 24% ofQ˙ heterogeneity and 8% of V˙ heterogeneity, 3) CV[Formula: see text] was similar in the supine and prone position, and 4) CV[Formula: see text] was lower in the prone position. We conclude that, in recumbent, spontaneously breathing humans, 1) vertical gradients favoring dependent lung regions explain a significant fraction of heterogeneity, especially ofQ˙, and 2) although Q˙ does not seem to be systematically more homogeneous in the prone position, differences in individual behaviors may make the prone position advantageous, in terms of V˙-to-Q˙ matching, in selected subjects.

Details

Title: Subtitle: Topographical distribution of pulmonary perfusion and ventilation, assessed by PET in supine and prone humans
Creators: Guido Musch - Departments of Anesthesia and Critical Care
J. Dominick H. Layfield - Massachusetts Institute of Technology
R. Scott Harris - Pulmonary and Critical Care Associates
Marcos F. Vidal Melo - Departments of Anesthesia and Critical Care
Tilo Winkler - University Hospital Carl Gustav Carus
Ronald J. Callahan - Harvard University
Alan J. Fischman - Massachusetts General Hospital
Jose G. Venegas - Departments of Anesthesia and Critical Care
Resource Type: Journal article
Publication Details: Journal of applied physiology (1985), Vol.93(5), pp.1841-1851
DOI: 10.1152/japplphysiol.00223.2002
PMID: 12381773
NLM abbreviation: J Appl Physiol (1985)
ISSN: 8750-7587
eISSN: 1522-1601
Number of pages: 11
Language: English
Date published: 11/01/2002
Academic Unit: Anesthesia
Record Identifier: 9985141862002771

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