This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by SARI, A. Articles by ODA, T. Search for Related Content PubMed PubMed Citation Articles by SARI, A. Articles by ODA, T.

Factors Affecting A-aDo₂ After Open-Heart Surgery

ATSUO SARI, MD^*, YOSHIAKI OKUDA, MD, HIROSHI TAKESHITA, MD, and TATSUROH ODA, MD

*Assistant Professor, Department of Anesthesiology. Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. Associate Professor, Department of Anesthesiology. Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. Professor, Department of Anesthesiology. Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. Instructor, Department of Surgery. Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan.

Abstract

Intrapulmonary shunt, cardiac output, and O₂ consumption as factors contributing to alveolar-arterial O₂ tension difference (A-aDo₂ were tested in 11 patients after open-heart surgery. A-aDo₂ was well correlated with intrapulmonary shunt, as expected, but no correlation was found between cardiac index (CI) and intrapulmonary shunt. When total shunt (venous admixture) was above 11%, there was an inverse correlation between A-aDo₂ and CI, and it was observed that CI falling below 2.5 L/min/sq m contributed significantly to the enlargement of A-aDo₂. Low Pao₂ (<65 torr, breathing room air) was characterized by larger arterial-mixed venous O₂ content difference than high Pao_r (>65 torr, on room air), indicating that A-aDo₂ was influenced by cardiac output relative to metabolic demand. Intrapulmonary shunt played a main role in increasing A-aDo₂ after open-heart surgery, and systemic factors, including changes in cardiac output and O₂ consumption, also contributed to development of hypoxia.