perfusion lung scan?
for anticoagulation, it is reasonable to do a ventilation perfusion scan, at least initially. If, however, a rapid and definitive answer is needed (eg, if the patient is hemodynamically compromised), CT pulmonary angiography should be performed. It is likely to cause no more than a transient increase in creatinine level while providing a definitive answer. In such a situation, it is probably better to start hydration (with normal saline or perhaps with sodium bicarbonate), start intravenous n-AC, and perform CT angiography. Remember, the risks related to contrast agent induced nephropathy primarily depend on the baseline renal function and concomitant factors that place the patient at risk, such as dehydration, congestive heart failure, and recent major surgery. In most cases in which the patient has an elevated serum creatinine level (even if it is fairly markedly elevated), his or her renal function, as reflected in serum creatinine values, will likely worsen but then return to basel
