Final answer:
An adult critical care specialist uses a pulse oximeter to measure percent saturation, as well as other clinical signs and tests, to determine a patient's oxygenation status, with a normal range between 95-100 percent. Other assessments include physical exams, listening to abnormal sounds in the lungs, and reviewing imaging studies.
Step-by-step explanation:
To determine if a patient has a problem with oxygenation, an adult critical care specialist will use various diagnostic tools and assessments, including evaluating the patient's blood oxygen levels. One common non-invasive method used is percent saturation assessment with a pulse oximeter. This device measures the percentage of hemoglobin sites occupied by oxygen in the patient's blood, which is referred to as "percent sat." Normal readings on a pulse oximeter range from 95-100 percent, with lower numbers indicating possible hypoxemia, a condition of lower-than-normal blood oxygen levels. In addition to percent saturation, oxygen levels can also be determined by measuring the partial pressure of oxygen (pO2 or PO2) in arterial blood, obtained via an arterial stick, reported in units of millimeters of mercury (mm Hg).
Other physical examination signs such as elevated heart rate, shortness of breath, abnormal lung sounds, and the presence of certain signs on imaging studies, like shadows on chest radiographs, can suggest conditions like pneumonia that compromise oxygenation. The color and characteristics of sputum are also valuable in making a diagnosis. Thus, multiple types of evaluations are used in conjunction to assess a patient's oxygenation status.