USMLE Forum Archives - USMLE Step 2 CK - IM 30
IM 30
TheOne - 02-07-07 21:12
A 60-year-old man has been admitted to the hospital after an acute inferior myocardial infarction.
he is noted to be oliguric, and hypotensive (blood pressure of 80/50 mm Hg). A Swan-Ganz catheter is placed, revealing a decreased pulmonary capillary wedge pressure (3 mm Hg), normal pulmonary artery pressure (24/4 mm Hg), and an increased mean right atrial pressure of 15 mm Hg. Which of the following is the most appropriate next step in management?
A. Balloon angioplasty
B. Intravenous Digoxin
C. Intravenous Fluids
D. Intraaortic balloon counterpulsation
E. Intravenous Vasopressors
TheOne - 02-07-07 21:12
A 60-year-old man has been admitted to the hospital after an acute inferior myocardial infarction.
he is noted to be oliguric, and hypotensive (blood pressure of 80/50 mm Hg). A Swan-Ganz catheter is placed, revealing a decreased pulmonary capillary wedge pressure (3 mm Hg), normal pulmonary artery pressure (24/4 mm Hg), and an increased mean right atrial pressure of 15 mm Hg. Which of the following is the most appropriate next step in management?
A. Balloon angioplasty
B. Intravenous Digoxin
C. Intravenous Fluids
D. Intraaortic balloon counterpulsation
E. Intravenous Vasopressors
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#2
Re: IM 30
TheOne - 02-22-07 15:31 Explanation: The correct answer is C. The Swan-Ganz tracing indicates that the patient has an elevated right-sided pressure and a low-filling pressure. Cardiac output is decreased as a result of insufficient left heart filling pressures. This is due to the right ventricular infarct, which causes backing up of venous blood and decreased forward flow, producing a decrease in left ventricular filling, as indicated by the low wedge pressure. The treatment for this patient is aggressive fluid administration.
The patient had a right ventricular infarct, presumably from involvement of the right coronary artery. Balloon angioplasty (choice A) may ultimately be needed to correct the underlying cause of the infarction. However, the acute event has passed, and the patient must first be stabilized. She will ultimately need a cardiac catheterization.
Digoxin (choice B) is not needed in this patient, since she is not in left sided heart failure. Positive inotropy is not needed as much as fluid resuscitation. Also, the patient is not in atrial fibrillation.
If the patient had sustained a left ventricular infarct, she may have needed afterload reduction in the form of intraaortic balloon counterpulsation (choice D). Since the patient sustained a right ventricular infarct, however, afterload reduction is not as important as is preload repletion.
The patient is hypotensive. If the hypotension does not resolve with fluid repletion, then vasopressors such as norepinephrine may be needed (choice E). However, fluid resuscitation must be continued.
#4
Re: IM 30 babbu5508 - 07-06-10 22:59 the patient is likely having right ventricular failure secondary to right ventricular infarct...stabilise the patient with fluids,pain relievers,o2 if needed and then definitive treatment
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