Pulmonary surfactant films affected by solvent vapors

Area of Science:

• Pulmonary physiology
• Anesthesiology
• Biochemistry

Background:

• Pulmonary surfactant, primarily phospholipids, forms a critical air-liquid interface in the lungs.
• Inhaled solvent vapors pose a potential risk to the integrity of the surfactant monolayer.
• Understanding solvent effects on surfactant is crucial for assessing inhalation risks.

Purpose of the Study:

• To evaluate the impact of common anesthetic solvent vapors on pulmonary surfactant function.
• To determine the concentration thresholds for solvent-induced surfactant destabilization.
• To assess the risk of inhaled solvents on the pulmonary surfactant monolayer.

Main Methods:

• Pulmonary surfactant from rabbit lung lavage was tested using a pulsating bubble surfactometer.
• Vapors from halothane, chloroform, enflurane, acetone, and diethyl ether were introduced to the surfactant film.
• Surface tension at minimal bubble size was measured during solvent vapor exposure and subsequent air exposure.

Main Results:

• Halothane and chloroform vapors significantly increased surface tension, indicating surfactant destabilization.
• High concentrations (≥20%) of halothane and 25% enflurane vapors showed destabilizing effects.
• Acetone and diethyl ether vapors, poor solvents for DPPC, did not affect surface tension.
• Reintroduction of room air promptly restored normal surfactant function.

Conclusions:

• High concentrations of halothane and chloroform vapors can rapidly impair pulmonary surfactant function.
• Anesthetic concentrations of halothane do not appear to pose a risk to pulmonary surfactant.
• The solvent properties of inhaled agents are critical in determining their effect on lung surfactant.