NBME Step 2 CK Form 8 Intravenous administration of prostaglandin (NBME Answers)

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submitted by ∗step_prep3(25)

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Newborn with cyanosis found to have a heart murmur and hypoxia unresponsive to supplemental oxygen, which is consistent with a severe intracardiac shunt)
Patient should be treated with alprostadil (or another prostaglandin analog) in order to keep the PDA open until the heart defect can be operatively managed

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seagull Doesn't it take like 2-7 days for the duct to close? Why is this hour old newborn already cyanotic? +1

kingfriday early cyanosis might be consistent with transposition of the great vessels and those can be associated with ejection murmurs and a loud S2 +3

welpdedelp Following ABCs, why wouldn't you intubate first? I understand shunt doesn't get corrected, but it would seem you would still take control of airway since kid seems to be crashing. +

quaranqueen I think that intubation wouldn't make a difference if it's transposition of the great arteries because the oxygenated blood would just end up going back to the right heart and back through its closed circuit +2

etherbunny Start prostaglandin early to prevent the duct from closing, don't wait until it starts to close. The child is already cyanotic because they have intracardiac mixing of deoxygenated and oxygenated blood. They are unresponsive to oxygen; delivery of even more oxygen via intubation wouldn't help because the problem lies not in delivery of well-oxygenated blood to the heart, but that it gets mixed with deoxygenated blood before being pushed out to the systemic circulation. Drugs for intubation and laryngoscopy could cause also further cardiovasular instability. Delivery of extra oxygen can actually make things worse through pulmonary vasodilation, leading to "steal" of cardiac output to the lungs rather than pushing it out to the systemic circulation. +5

akjs16 Does the murmur mean there's a VSD? Then why we still need the ductus arteriosus open? +

charcot_bouchard systolic ejection murmur at apex...not vsd..that HSM at left sternal border +

drzed It doesn't matter what the cause of the murmur is. If all they told you was "baby is blue at birth and oxygen does not help" you immediately know it's an intracardiac shunt, which means intubating will not help (because all that is doing is delivering oxygen closer to the lungs, but the problem is an intracardiac shunt!) +1