Clinical scenario: resp distress | disparity in pulses | hepatomegaly
A 10-day-old term male infant is admitted with poor feeding, increasing lethargy, and tachypnea for the past 12 hours. He had remained well after birth and was discharged home on day 2 of life. He is being treated with intravenous antibiotics for presumed neonatal sepsis but continues to deteriorate.
On examination, he is pale with cold extremities. His heart rate is 185/min, respiratory rate 72/min, and capillary refill time is 5 seconds. Brachial pulses are normal, whereas femoral pulses are weak and delayed. The liver is palpable 4 cm below the right costal margin. No cardiac murmur is audible.
Investigations reveal:
- Arterial pH: 7.16
- Base deficit: 14 mmol/L
- Serum lactate: 7.2 mmol/L
- Blood glucose: Normal
Which of the following is the most appropriate immediate management?
A. Begin intravenous prostaglandin E₁ infusion
B. Emergency balloon angioplasty
C. Intravenous furosemide and dopamine
D. Immediate surgical repair
E. Repeat fluid boluses until peripheral perfusion improves
Correct answer & Explanation:
Correct Answer
A. Begin intravenous prostaglandin E₁ infusion
Explanation:
This infant has a duct-dependent systemic circulation, most consistent with critical coarctation of the aorta.
The important clues are:
- Well initially, then collapse during the second week of life after physiological ductal closure.
- Progressive shock despite antibiotics for presumed sepsis.
- Weak, delayed femoral pulses with normal brachial pulses.
- Metabolic acidosis with elevated lactate, indicating poor systemic perfusion.
- Hepatomegaly due to left ventricular dysfunction and heart failure.
The priority is to reopen the ductus arteriosus with prostaglandin E₁ (alprostadil) to restore systemic blood flow while arranging urgent echocardiography and definitive surgical repair.
Why the other options are incorrect
B. Emergency balloon angioplasty
- Balloon angioplasty is not the initial treatment for a critically ill neonate with native coarctation. Stabilization with prostaglandin is essential first.
C. Intravenous furosemide and dopamine
- Inotropes and diuretics may be used as supportive therapy but do not relieve the duct-dependent obstruction.
D. Immediate surgical repair
- Surgery is the definitive treatment but should generally be performed after stabilization with prostaglandin and correction of metabolic derangements.
E. Repeat fluid boluses until peripheral perfusion improves
- Excessive fluid administration may worsen heart failure in infants with left ventricular dysfunction and does not address the underlying obstruction.
FCPS / MRCPCH High-Yield Pearl
A neonate who develops shock after an initially normal postnatal period, particularly when sepsis treatment fails, should always be evaluated for duct-dependent congenital heart disease.
The bedside clue that most strongly suggests critical coarctation of the aorta is:
- Weak or delayed femoral pulses compared with upper limb pulses.
Intravenous prostaglandin E₁ should be started immediately when a duct-dependent systemic lesion is suspected, even before echocardiographic confirmation if clinical suspicion is high.
