Final answer:
The client with substernal chest pain and myoglobin levels of 55 ng/mL should be assessed for other potential causes of chest pain through additional diagnostics. Confirming an MI requires more specific tests like ECG, echocardiography, and blood levels of creatine kinase MB and cardiac troponin. Immediate treatments for MI include supplemental oxygen, aspirin, and nitroglycerine.
Step-by-step explanation:
A client presenting with substernal chest pain and a myoglobin level of 55 ng/mL eight hours after admission to the emergency department warrants further assessment. Myoglobin is a muscle oxygen-binding protein released into the bloodstream when muscle damage occurs, including that from myocardial infarction (MI). However, myoglobin is a sensitive marker but not highly specific to cardiac injury and can be elevated in other muscle damage. Therefore, the correct next step is to assess the client to identify another potential cause of the chest pain, rather than immediately preparing for coronary bypass surgery or solely administering nitroglycerin.Additional diagnostics such as ECG alterations in ST and Q components, echocardiography, or blood tests for creatine kinase MB and cardiac troponin levels are more specific to cardiac damage and can help confirm an MI. Should an MI be confirmed, immediate treatments include supplemental oxygen, aspirin, and nitroglycerine to alleviate symptoms and prevent further damage. Longer-term treatments may involve thrombolytic agents, anticoagulants, angioplasty, stents, or even bypass surgery. Knowledge of the client’s medical history, symptoms, and additional diagnostics are crucial to guide appropriate intervention.