surfactant
Pronunciation: SUR-fak-tant
A substance produced by the lungs that reduces surface tension in the alveoli, preventing lung collapse and facilitating normal breathing.
Full Definition
Pulmonary surfactant is a complex mixture of lipids and proteins produced by type II pneumocytes in the lungs that plays a crucial role in respiratory function. It reduces surface tension at the air-liquid interface within the alveoli, preventing alveolar collapse during expiration and reducing the work of breathing. Surfactant production begins around 24-28 weeks of gestation but may not reach adequate levels until 34-36 weeks, which is why premature infants are at high risk for respiratory distress syndrome. Exogenous surfactant replacement therapy has revolutionized the care of premature infants with RDS, significantly improving survival rates and reducing complications.
Usage
Usage note: In pediatric medicine, always refers to pulmonary surfactant unless otherwise specified.
In Context
- "Surfactant replacement therapy was administered immediately after intubation for severe RDS." — NICU procedure note
- "Adequate surfactant production is essential for successful transition to extrauterine breathing." — Medical education material