Final answer:
The most immediate action by the nurse in a patient admitted with acute decompensated heart failure (ADHF) would be required for the assessment finding of a low O2 saturation of 88%.
Step-by-step explanation:
In a patient admitted with acute decompensated heart failure (ADHF), the most immediate action by the nurse would be required for the assessment finding of a low O2 saturation of 88%. ADHF is a serious condition in which the heart is unable to pump enough blood to meet the body's needs. A low O2 saturation indicates inadequate oxygen supply to the tissues and requires immediate intervention, such as administering supplemental oxygen or initiating respiratory support.