Which type of sample is preferred for blood gas analysis?

The preferred type of sample for blood gas analysis is an arterial blood sample. This choice is based on the fact that arterial blood reflects the gas exchange status of the lungs, which is essential for evaluating a patient's respiratory function.

In arterial blood, the levels of oxygen and carbon dioxide are a direct representation of the gas exchange that occurs in the alveoli. This makes arterial samples more reliable for assessing conditions related to ventilation, such as respiratory acidosis or alkalosis, and for determining oxygenation status.

While venous blood samples can provide useful information about metabolic parameters, they are not suitable for accurate blood gas analysis, as they do not reflect the same respiratory status. Capillary blood samples also have limitations; although they are sometimes used in pediatric patients for convenience, they may be affected by local tissue factors, which can skew results. Whole blood samples are not a specific type of sampling choice for blood gas analysis as it is the arterial blood gases that provide the necessary information for respiratory assessment.

Thus, the arterial blood sample is the gold standard for obtaining the most accurate and relevant data regarding the gas exchange status in individuals, making it the preferred choice for blood gas analysis.