Final answer:
The primary purpose of an arterial blood gas analysis in a preterm infant with respiratory distress syndrome (RDS) is c) To evaluate respiratory function and acid-base balance.
Step-by-step explanation:
This analysis measures pH levels, partial pressures of carbon dioxide (PCO₂), and bicarbonate (HCO3-) concentration in the blood. This is essential for assessing the severity of RDS, which can result from insufficient production of pulmonary surfactant, making it difficult for the lungs to inflate, leading to decreased oxygen levels and increased carbon dioxide levels in the blood. This lab test helps determine if there is an acidosis or alkalosis condition, whether the cause is respiratory or metabolic, and how well the body is compensating for it.
For infants with RDS, it is crucial to monitor these parameters as they provide insights into the effectiveness of the lungs in performing gas exchange and maintaining proper acid-base balance, which is critical for the survival and well-functioning of the infant. In the case of RDS, the lungs struggle to perform gas exchange due to the collapse of the air sacs and low surfactant levels, leading to hypoxia and acidosis.
In clinical practice, such a lab test is a vital diagnostic tool for guiding medical decisions, including respiratory support and interventions to improve the baby's acid-base status and overall health.