Institute for Continuing Education

Surfactants in Respiratory Care

Course Objectives

Upon successful completion of this module, you will be able to:

• Define the term surfactant and explain its role in the pulmonary system.
• Explain the composition and function of pulmonary surfactant.
• Identify and differentiate between types of exogenous surfactant preparations.
• Describe the clinical effects, complications, and hazards of exogenous surfactant therapy.

Course Information

In the 1920s the importance of surface tension in pulmonary physiology was first realized. However, it was not until the 1950s that surfactant was first described, when it was found that material obtained from alveolar washes could significantly reduce surface tension on dynamic film compression. Soon after these early reports, it was speculated that a deficiency of pulmonary surfactant may play an important role in the pathophysiology of various pulmonary conditions. Following these reports there has been an explosion of information on surfactant composition, metabolism, biophysical, and physiological activity. This has led to a better understanding of surfactant deficient and dysfunctional disease states, and the potential therapeutic benefits of surfactant replacement therapy.

The major role of surfactant is to allow large variations in surface tension during lung expansion and deflation. This action promotes alveolar stability, reduces atelectasis, decreases edema formation and minimizes the work of respiration. These physiological functions are dependent on the biophysical properties of surfactant which include: rapid adsorption to the air-liquid interface, respreadability after compression, and the ability to alter surface tension during dynamic compression and expansion.