hyperoxia test
Diagnostic test using 100% oxygen to differentiate between cardiac and pulmonary causes of cyanosis in newborns.
Full Definition
A bedside diagnostic procedure where the infant is administered 100% oxygen while monitoring arterial oxygen levels to distinguish between cyanotic congenital heart disease and primary lung disease. In pulmonary causes of hypoxemia, the partial pressure of arterial oxygen typically rises significantly above 150 mmHg, while in right-to-left cardiac shunts, the response is blunted with arterial oxygen remaining below 100-150 mmHg. The test requires careful monitoring as prolonged exposure to high oxygen concentrations can be harmful to preterm infants. Results help guide immediate management decisions and the need for cardiac evaluation versus respiratory interventions.
Usage
Usage note: Hyphenate when used as compound modifier; distinguish from hyperoxemia in documentation.
In Context
- "The hyperoxia test showed minimal improvement in arterial oxygen, suggesting cardiac etiology." — Diagnostic evaluation report
- "A positive hyperoxia test helped rule out cyanotic congenital heart disease in this term infant." — Cardiology consultation