RESPONDING TO the call light, you find John Royce, 72, sitting up in bed. He's anxious, pale, and diaphoretic, and he says he has chest pain that he describes as "like something sitting on my chest."
What's the situation?
Mr. Royce, who was admitted for I.V. antibiotics for treatment of community-acquired pneumonia, has a history of hypertension and hyperlipidemia. You take his vital signs: BP, 155/92; heart rate, 115; respirations, 18; and temperature, 99.5[degrees] F (37.5[degrees] C). He denies feeling short of breath, and his lung sounds are clear. He says the chest pain woke him up about 15 minutes ago, and he has pain in his jaw as well.
What's your assessment?
Based on Mr. Royce's symptoms and history, you suspect acute coronary syndrome (ACS), a term covering three acute cardiac ischemic events: unstable angina, non-ST-segment-elevation myocardial infarction (MI), and ST-segment-elevation MI.
Your priority is to initiate treatment for ACS immediately to preserve myocardial tissue. Assume Mr. Royce (and any other patient with ACS symptoms) has myocardial ischemia or infarction until a cardiac problem has been ruled out.
What must you do immediately?
Ask a colleague to notify the primary care provider while you administer oxygen at 4 liters/minute via nasal cannula. Place Mr. Royce on a cardiac monitor and obtain a 12-lead ECG. Draw blood specimens for CK-MB, troponin, and myoglobin levels. Ensure that his I.V. lines are patent.
Mr. Royce's ECG reveals ST-segment depressions in leads I, aVL, V3, and V4, indicating left anterior lateral ischemia or non-ST-segment-elevation MI. His cardiac enzymes are slightly elevated. According to the ACS risk stratification tool developed by the American College of Cardiology and American Heart Association, Mr. Royce is in the "high likelihood" category for ACS. Don't wait for the lab results before beginning treatment; treat Mr. Royce for ACS based on his symptoms, history, and ECG. As ordered, administer aspirin, a beta-blocker such as metoprolol or atenolol, and sublingual nitroglycerin. Start Mr. Royce on I.V. nitroglycerin and titrate it until he's pain-free. Nitroglycerin dilates coronary arteries, increasing blood flow to the ischemic area and relieving chest pain. But it can also cause hypotension, so monitor Mr. Royce's BP closely. Because nitroglycerin has a short half-life, you can increase the rate by 20 mcg/minute every 5 minutes, if Mr. Royce's BP can tolerate it. If nitroglycerin doesn't relieve the pain in about 20 minutes, the primary care provider may order I.V. morphine.
The primary care provider evaluates Mr. Royce for percutaneous coronary interventions or fibrinolytics. If Mr. Royce couldn't get to the catheterization lab within 90 minutes of symptom onset, or the facility didn't do angioplasty, he'd receive fibrinolytics.
The primary care provider orders I.V. heparin to prevent thrombus formation and an antiplatelet drug such as abciximab, tirofiban, or eptifibatide.
What should be done later?
After Mr. Royce's chest and jaw pain ease, he's transferred to the CCU. He undergoes cardiac catheterization, which reveals a 95% occlusion of his distal left anterior descending coronary artery. A cardiologist opens the artery by balloon angioplasty and places a stent. Mr. Royce is continued on eptifibatide after the procedure.
Mr. Royce is discharged on a beta-blocker, angiotensin-converting enzyme inhibitor, aspirin, and the oral antiplatelet drug clopidogrel. He's referred to an outpatient cardiac rehabilitation program.