Page 54 - Critical Care Notes

4223_Tab02_045-106 29/08/14 10:00 AM Page 48

CV
according to hospital policy. Dose should not exceed 400 mcg/min; check
for contraindications such as hypotension, or if taking the following
meds: Viagra, Cialis, or Levitra.
■ Administer morphine sulfate IV if symptoms persist after receiving NTG
or in patients who have pulmonary congestion or severe agitation.
■ Administer beta blocker: metoprolol (Lopressor).
■ Administer ACE-IS in patients with LV dysfunction or HF with HTN; not
recommended in patients with renal failure.
■ Administer calcium channel blockers: verapamil (Calan, Isoptin) or dilti-
azem (Cardizem) if patient not responding to beta blocker or nitrates.
*Use severe caution when combining blocking agents*
■ Administer antiplatelet: aspirin 162–325 mg, chewed.
■ Administer GP IIb/IIIa inhibitor: eptifibatide (Integrilin) or tirofiban
(Aggrastat) if no contraindications (i.e., bleeding, stroke in past month,
severe HTN, renal dialysis, major surgery within the past 6 wk, or platelet
count <100,000 mm 3 ).
■ Administer antithrombotic: heparin.
■ Administer anticoagulant: enoxaparin (Lovenox).
■ Administer clopidogrel (Plavix).
■ Administer direct thrombin inhibitor (hirudin, bivalirudin).

Acute Myocardial Infarction (AMI)
AMI is the acute death of myocardial cells resulting from lack of oxygenated
blood flow in the coronary arteries. It is also known as a heart attack.
Pathophysiology

Injury to the artery’s endothelium → increases platelet adhesion → inflammatory
response causing monocytes and T lymphocytes to migrate in the intima →
macrophages and smooth muscle distend with lipids, to form fatty streaks and a
fibrous cap → thinning of cap increases susceptibility to rupture or hemorrhage →
rupture triggers thrombus formation and vasoconstriction → result: thrombus
with narrowing artery. If occlusion lasts more than 20 min, can lead to AMI.
Clinical Presentation
AMI manifests with chest pain or discomfort lasting 20 min or longer. Pain can
be described as pressure, tightness, heaviness, burning, or a squeezing or
crushing sensation, located typically in the central chest or epigastrium; it may
radiate to the arms, shoulders, neck, jaw, or back.
48