Surfactant administration is a medical procedure involving the delivery of pulmonary surfactant into a patient’s lungs. This therapy aims to supplement or replace the naturally occurring substance that helps lung function. It is primarily used to improve breathing in individuals experiencing respiratory difficulties due to a deficiency or inactivation of this substance. The procedure is performed by medical professionals in a clinical setting.
What Lung Surfactant Is
Pulmonary surfactant is a complex mixture of lipids and proteins produced by specialized cells within the lungs called type II alveolar cells. Approximately 80% of its composition consists of phospholipids. The remaining portion includes neutral lipids like cholesterol and specific surfactant proteins.
The primary function of lung surfactant is to reduce the surface tension at the air-liquid interface within the alveoli, which are the tiny air sacs where gas exchange occurs. This reduction in surface tension prevents the alveoli from collapsing completely during exhalation, allowing them to remain open and stable for efficient oxygen absorption and carbon dioxide removal. Without sufficient surfactant, the alveoli would stick together, leading to significant breathing difficulties and impaired gas exchange. Both natural surfactants, often derived from animal lungs, and synthetic versions are used in medical treatments.
Why Surfactant Is Administered
Surfactant administration treats medical conditions characterized by a lack or dysfunction of natural lung surfactant. Its most common use is in premature infants suffering from Respiratory Distress Syndrome (RDS). Premature babies often have underdeveloped lungs that haven’t produced enough surfactant for independent breathing.
This deficiency leads to reduced lung compliance and increased surface tension, making it difficult for the infant to inflate their lungs and maintain open air sacs. RDS is a leading cause of death among premature infants. While predominantly associated with neonates, surfactant therapy may also be considered in certain severe adult lung conditions, such as Acute Respiratory Distress Syndrome (ARDS), meconium aspiration syndrome, or pneumonia.
How Surfactant Is Administered
Surfactant is delivered as a liquid suspension directly into the patient’s lungs. The standard method often involves endotracheal intubation, where a breathing tube is inserted into the trachea. Through this tube, the surfactant is instilled. The procedure requires monitoring of the patient’s heart rate and oxygen levels.
Newer, less invasive techniques minimize the need for prolonged mechanical ventilation. These include Less Invasive Surfactant Administration (LISA) or Minimally Invasive Surfactant Therapy (MIST). With these methods, a thin, flexible catheter delivers surfactant into the trachea while the infant breathes spontaneously and is supported by continuous positive airway pressure (CPAP). Another approach is the INSURE method, which involves brief intubation for surfactant administration followed by rapid extubation to CPAP. Medical professionals perform these procedures and manage potential side effects.
Results of Surfactant Administration
Surfactant administration has improved outcomes for patients with respiratory distress, particularly premature infants. The therapy reduces the incidence of respiratory distress syndrome, leading to a decrease in mortality rates among very-low-birth-weight infants. It can also lower the risk of complications such as pulmonary air leaks.
Surfactant therapy decreases the risk of chronic lung disease and improves overall survival rates. For infants with meconium aspiration syndrome, surfactant treatment improves oxygenation and reduces the need for extracorporeal membrane oxygenation (ECMO). This therapy has changed the care and prognosis for vulnerable newborns experiencing respiratory failure due to surfactant deficiency.