USMLE forum
Step 1
Step 2 CK
Step 2 CS
Matching & Residency
Step 3
  <<   < *  Step 2 CK   *  >   >>  

* NBME CK question
  toyonaka - 05/25/14 15:55
  A 1-week-old newborn is brought to the physician because of a 1-day history of difficult breathing & discoloration of the extremities. He was born at term following and uncomplicated delivery. Apgar scores were 8 & 9 at 1 & 5 min, respectively. He appears ill,. His rectal temperature is 36.4C (97.5F), pulse 160/min, respiration 52/min, Bp 60/36 mmHg in the upper extremities & unobtainable in the lower extremities. The skin, mucosa membranes and nail beds appear dusky, and there is mottled discoloration of the extremities. Exam shows moderate intercostal retractions and grunting. The lungs are clear to auscultation. A grade 3/6 holosystolic murmur is heard along the left sternal border. The liver edge is palpated 4 cm below the right costal margin, arterial blood gas analysis on room air: pH = 7.15, PCO2 = 28 mmHg, PO2 = 98 mmHg.

Intubation, mechanical ventilation and an IV fluid bolus of saline are initiated. One hour later, there is no significant improvement. A chest X-ray shows cardiomegaly and pulmonary congestion. Which is the most likely explaination for this newborn's condition?

(A) Closure of the ductus arteriosus
(B) Decreased pulmonary vascular resistance
(C) Increased pulmonary vascular resistance
(D) Intracardiac right-to-left shunting
(E) Opening of the ductus arteriosus

D is not the correct one, thx for help!
Report Abuse


* Re:NBME CK question
  wolverine99 - 05/25/14 16:48
Report Abuse

* Re:NBME CK question
  monter - 06/25/15 17:51
  maybe A ?

closure of PDA because of 4Fallot?

anyone else can confirm?
Report Abuse

* Re:NBME CK question
  monter - 06/25/15 18:15
  or maybe C?  
Report Abuse

* Re:NBME CK question
  doc0610 - 06/25/15 18:24
  i was going more towards C as the pulmonary congestion is seen on X ray!
Also, PDA is not required for a kid to sure on TOF
Report Abuse

* Re:NBME CK question
  monter - 06/25/15 19:09
  I think you are right.


if it is TOF , the prognosis is dictated by vascular resistance.

(PDA is not part of TOF, but if it is there, they try to keep it open (a good distractor and a second choice))
Report Abuse

* Re:NBME CK question
  doc0610 - 06/25/15 20:17
  No,what I meant was, TOF is not dependent on PDA, i.e., it doesn't matter if it is open or close. Pad depend ones are tricuspid atresia, TAPV, transposition and hypo plastic left heart. These are the conditions where the status of pda matters.  
Report Abuse

* Re:NBME CK question
  monter - 06/25/15 23:56
  the correct answer to this q is A.

all 5 T cyanotic newborn disorders will benefit from open PDA (per Dr Barone)
Report Abuse

* Re:NBME CK question
  druzma126 - 06/26/15 05:47
  HypoPlastic Left Heart Syndrome...New Born With Hypotension n shock with cyanosis  
Report Abuse

* Re:NBME CK question
  monter - 06/26/15 09:10
  thank you druzma
that explains it.
Report Abuse

* Re:NBME CK question
  dee12345 - 06/26/15 13:35
  So thr right answer is D for hlhs.  
Report Abuse

          Page 1 of 2     [Next >]     [Last >>]

[<<First]   [<Prev]  ... Message ...  [Next >]   [Last >>]

Logon to post a new Message/Reply




Step 1 Step 2 CK Step 2 CS Matching & Residency Step 3 Classifieds
LoginUSMLE LinksHome