Dx: Acute Pulmonary Hypertension
from Quick Essentials Emergency Medicine 4.0, EMresource.org
Clinical: Dyspnea, chest pain, angina, syncope. Narrow split S2, RV hypertrophy, right sided CHF.
Tests: CXR: large pulmonary artery. Echo: dilated RV & pulmonary artery
Causes: Hypoxia, chronic lung dz, drugs, cirrhosis, chronic PE’s, scleroderma/SLE, cardiac shunt
Drugs: Methamphetamine, cocaine, Fen-phen
Rx-chronic: O2, fix pH, prostacycline, dig, Revatio, Bosentan, Coumadin, nifedipine, lung transplant
Rx-acute: Diuresis, phlebotomy, thrombectomy, pressors. Avoid intubation & overly aggressive fluidz
There are a number of conditions you should be looking for in the setting of shock. A bedside ultrasound scan can help you narrow down your differential: pericardial tamponade, PE, MI, hypovolemia, aortic dissection, and ruptured AAA are some at the top of the list. Since there is not room to show all of these here, you may want to check out the free ultrasound image library at www.erpocketbooks.com as you read on.
With cardiomegaly on the chest X-ray, especially if you don’t know that it’s chronic, your first consideration should be cardiac tamponade from a large pericardial effusion. A bedside echo should be able to rule this out quite easily. On a quick look, your patient does not have any signs of an effusion, so you move on. Given the heart murmur, your next consideration should probably be cardiogenic shock, and if this were the case you would expect to see a dilated, hypokinetic left ventricle (LV). However the LV is actually small and it is the right ventricle (RV) that appears enlarged. This should make you suspect a pulmonary embolism, however this was eventually ruled out with a pulmonary angiogram. As it turned out this patient was eventually diagnosed with acute pulmonary hypertension, possibly due to a combination or cirrhosis and methamphetamine abuse (see above for facts on pulmonary hypertension).
Other conditions that the ultrasound machine could be helpful with include hypovolemic shock, where you would expect to see a small rapidly beating heart and a shrunken or flat inferior vena cava. If you look carefully in the right patient, it is possible to pick up an intimal flap from an acute aortic dissection. Imaging the belly for an abdominal aortic aneurysm or free fluid from a ruptured spleen or hemorrhagic pancreatitis might also be helpful in narrowing down the cause of shock in a sick patient. In the setting of a new murmur, valvular pathology or an acute MI should also be considerations. Imaging for these conditions however, is beyond the scope of most emergency physicians, so when you are worried about these a formal echocardiogram is desirable.
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