Which of the following is a typical method to assess a child's oxygen saturation levels?

Pulse oximetry is a non-invasive method commonly used to assess a child's oxygen saturation levels in the bloodstream. This method utilizes a small device, typically placed on a fingertip, toe, or earlobe, which emits light to measure the amount of oxygenated hemoglobin compared to deoxygenated hemoglobin in the blood. This provides an immediate and accurate reading of the oxygen saturation percentage, allowing healthcare providers to quickly evaluate the child's respiratory status and determine if further intervention is needed.

Other methods listed, such as chest X-rays and complete blood counts, serve different purposes in assessing a child's health. Chest X-rays primarily visualize lung structures and can aid in diagnosing conditions like pneumonia or lung abnormalities, but they do not directly measure oxygen saturation. A complete blood count is used to evaluate overall health and detect a variety of disorders like anemia or infection, but it does not provide information about the oxygen levels in the blood. Pulmonary function tests assess lung function and capacity but are more suited for older children and are not a direct measure of immediate oxygen saturation levels like pulse oximetry is.