A nurse is caring for a client with acute myocardial infarction. Which nursing intervention should be the priority?

Oxygen therapy is the priority for acute MI to ensure tissue oxygenation and reduce cardiac workload. Other options are important but less urgent than addressing hypoxia.

Clinical Context and Priority Setting
In the hyperacute phase of an acute myocardial infarction (AMI), the immediate pathophysiological concern is the imbalance between myocardial oxygen supply and demand. Occlusion of a coronary artery leads to ischemia, which can rapidly progress to necrosis if perfusion is not restored or oxygen demand is not minimized. The nurse’s priority is to intervene in ways that directly support oxygen delivery to the jeopardized myocardium and prevent further decompensation.

Analysis of the Correct Answer
Administering prescribed oxygen therapy and continuously monitoring oxygen saturation is the priority intervention. In the context of AMI, hypoxemia can exacerbate ischemia by further reducing the oxygen content of blood delivered to the already compromised heart muscle. The evidence-based nursing processes for acute chest pain emphasize the critical role of immediate oxygenation assessment and intervention as part of the initial stabilization bundle ^[1][2]. Continuous monitoring allows the nurse to detect downward trends in saturation early, which is essential because a drop in SpO₂ below 90% can significantly worsen cardiac workload and extend the infarct zone. This intervention directly addresses the physiological crisis of inadequate tissue oxygenation.

Why the Other Options Are Not the Priority
- Option 2: Obtaining vital signs every 15 minutes is a necessary component of ongoing assessment, but it is a data-gathering action. It does not, by itself, correct a life-threatening oxygen deficit. While frequent monitoring is part of optimized emergency nursing protocols to track response to treatment ^[1], the immediate therapeutic action to support oxygenation takes precedence.
- Option 3: Encouraging deep breathing exercises is a low-acuity intervention aimed at preventing pulmonary complications in stable patients. In the setting of an AMI, active deep breathing increases intrathoracic pressure and venous return, which can paradoxically increase myocardial wall stress and oxygen demand. This is not appropriate during the acute ischemic event and is not supported by the streamlined, stabilization-focused processes described in the literature ^[1][2].
- Option 4: Assessing understanding of a cardiac catheterization procedure is an important psychosocial and educational task, but it falls under secondary or tertiary priorities once the patient is hemodynamically stable. The optimized care models for acute chest pain focus on reducing door-to-treatment times through rapid clinical intervention, not on detailed procedural teaching during the initial crisis ^[1][2]. Delaying oxygen therapy to provide education would violate the principle of addressing physiological needs first.

Integration of Evidence into Practice
The optimized emergency nursing care processes highlighted in the referenced studies underscore a systematic approach to acute chest pain that prioritizes rapid, protocol-driven clinical interventions ^[1][2]. These protocols are designed to minimize delays in therapies that directly impact survival, such as oxygen administration when hypoxemia is present or suspected. The nurse’s role in this streamlined workflow is to execute these standing medical directives immediately, understanding that maintaining adequate oxygen saturation is a foundational step that supports all subsequent treatments, including reperfusion strategies.