Mechanisms of pulmonary gas exchange abnormalities during experimental group b streptococcal infusion

ABSTRACT ABSTRACT: Group B streptococcal sepsis in newborns produces pulmonary arterial hypertension and hypoxemia. The purpose of this study was to investigate the mechanisms by which

hypoxemia occurs. Ten anesthetized, ventilated piglets were infused with 2 × 109 colony forming units/kg of Group B streptococci over a 30-min period. Pulmonary arterial pressure rose from

14 ± 2.8 to 38 ± 6.7 torr after 20 min of the bacterial infusion (_p_ < 0.01). During the same period, cardiac output fell from 295 to 184 ml/kg/min (_p_ < 0.02). Arterial Po2 declined

from 97 ± 7 to 56 ± 11 torr (_p_ < 0.02) and mixed venous Po2 fell from 39.6 ± 5 to 28 ± 8 torr (_p_ < 0.05). The multiple inert gas elimination technique was used to detect increases

in shunt and alterations in ventilation-perfusion matching. Intrapulmonary shunt did not increase during or after the infusion with group B streptococci. However, there was a significant

increase (_p_ < 0.05) in the SD of pulmonary blood flow, an index of VA/Q mismatching, 20 min after initiation of the infusion of bacteria. All the above changes reverted toward baseline

during the 2-h period following discontinuation of the infusion. We conclude that the hypoxemia occurring in the early phase of group B streptococcal sepsis does not develop solely because

of increased shunt, but rather is produced by a decline in cardiac output in conjunction with mismatching of pulmonary perfusion to alveolar ventilation. SIMILAR CONTENT BEING VIEWED BY

OTHERS A HIGH FRACTION OF INSPIRED OXYGEN DOES NOT MITIGATE ATELECTASIS-INDUCED LUNG TISSUE HYPOXIA OR INJURY IN EXPERIMENTAL ACUTE RESPIRATORY DISTRESS SYNDROME Article Open access 14

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Division of Neonatal and Respiratory Diseases, Department of Pediatrics RD-20, University of Washington School of Medicine, Seattle, 98195, Washington Gregory K Sorensen, Gregory J Redding 

& William E Truog Authors * Gregory K Sorensen View author publications You can also search for this author inPubMed Google Scholar * Gregory J Redding View author publications You can

also search for this author inPubMed Google Scholar * William E Truog View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and

permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Sorensen, G., Redding, G. & Truog, W. Mechanisms of Pulmonary Gas Exchange Abnormalities during Experimental Group B Streptococcal

Infusion. _Pediatr Res_ 19, 922–926 (1985). https://doi.org/10.1203/00006450-198509000-00011 Download citation * Received: 19 February 1985 * Accepted: 24 April 1985 * Issue Date: 01

September 1985 * DOI: https://doi.org/10.1203/00006450-198509000-00011 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link

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