What is the primary characteristic of respiratory acidosis?

The primary characteristic of respiratory acidosis is an increase in PaCO2, or the partial pressure of carbon dioxide in arterial blood. This condition occurs when the lungs are unable to effectively remove carbon dioxide from the body, leading to a buildup of CO2. As carbon dioxide accumulates, it reacts with water in the body to form carbonic acid, which lowers the pH of the blood and results in acidosis.

In respiratory acidosis, the body tries to compensate by increasing the bicarbonate levels over time; however, the hallmark of the condition is the elevated PaCO2, indicating impaired ventilation. Understanding this process is critical for recognizing and managing respiratory acidosis, particularly in a neonatal intensive care setting where respiratory function is often compromised.

While pH, bicarbonate levels, and other factors can change in response to respiratory acidosis, the defining and immediate characteristic is the increase in PaCO2.