Dataset Information

Relation between shunt, aeration, and perfusion in experimental acute lung injury.

ABSTRACT:

Rationale

In a pulmonary process characterized by spatially heterogeneous loss of aeration, the impairment of gas exchange is expected to depend on the regional distribution of perfusion relative to that of aeration.

Objectives

To investigate how regional aeration, shunt, and perfusion are interrelated at different levels of end-expiratory pressure and how their interplay relates to global shunt fraction in acute lung injury.

Methods

Regional shunt and perfusion were assessed by imaging with positron emission tomography the pulmonary kinetics of [(13)N]nitrogen infused in saline solution in five sheep after lung lavage. The lung field was divided in six horizontal regions.

Measurements and main results

Each animal showed an inverse relation between regional shunt (Fs) and gas (Fg) fractions: Fs = -m . Fg + Fs(0). This relation was similar among animals (m = 1.25 +/- 0.14, Fs(0) = 0.75 +/- 0.15) and invariant with end-expiratory pressure, despite lack of correlation between global shunt and gas fractions and large interanimal variability in global shunt fraction. When this relation was used to estimate global shunt fraction as a perfusion-weighted average of the estimates of regional shunt fraction derived from regional gas fraction, 72% of the interanimal variability in global shunt fraction could be explained.

Conclusions

Despite large interanimal variability in global shunt fraction, there was a consistent inverse relation between regional shunt and gas fractions, independent of end-expiratory pressure. Most of the interanimal variability in global shunt fraction could be explained by the combined effect of this relation and the distribution of perfusion on regional shunt, rather than by differences in global aeration.

SUBMITTER: Musch G

PROVIDER: S-EPMC2218852 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature

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Publications

Relation between shunt, aeration, and perfusion in experimental acute lung injury.

Musch Guido G Bellani Giacomo G Vidal Melo Marcos F MF Harris R Scott RS Winkler Tilo T Schroeder Tobias T Venegas Jose G JG

American journal of respiratory and critical care medicine 20071011 3

<h4>Rationale</h4>In a pulmonary process characterized by spatially heterogeneous loss of aeration, the impairment of gas exchange is expected to depend on the regional distribution of perfusion relative to that of aeration.<h4>Objectives</h4>To investigate how regional aeration, shunt, and perfusion are interrelated at different levels of end-expiratory pressure and how their interplay relates to global shunt fraction in acute lung injury.<h4>Methods</h4>Regional shunt and perfusion were assess ...[more]

PMID: 17932380

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Dataset Information

Relation between shunt, aeration, and perfusion in experimental acute lung injury.

Rationale

Objectives

Methods

Measurements and main results

Conclusions

Publications

Relation between shunt, aeration, and perfusion in experimental acute lung injury.

Similar Datasets

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