Hypoplastic left heart syndrome — structured clinical encounter

Structured encounter testing the approach to a three-day-old neonate who was feeding well then collapses with uniformly weak pulses, grey mottled skin and metabolic acidosis: the prostaglandin-E1-first resuscitation rule, the echocardiographic confirmation, the ductal-dependent mechanism, the staged palliation, and the conversation with the family about the transfer to a cardiac centre.

structured clinical encounter

Prompt

A three-day-old term male infant, born vaginally at 39 weeks after an uncomplicated pregnancy, was feeding and thriving until this morning. His mother reports poor feeding, grunting and cool, mottled grey skin. In the emergency department he is shocked: heart rate 190, respiratory rate 80, capillary refill six seconds, and central cyanosis that does not fully clear with oxygen. The brachial and femoral pulses are both weak and thready. The blood gas shows a pH of 7.05, a base excess of minus sixteen and a lactate of 11 mmol per litre. Auscultation reveals a single second heart sound and no significant murmur. The working diagnosis is hypoplastic left heart syndrome.

Task 1 — Immediate management

State the first drug you give, the dose, and the principle that governs the timing relative to the echocardiogram. Explain how you balance the pulmonary and systemic blood flow once the duct is open, and how you would respond if the saturations remained profoundly low despite a patent duct. [3]

Task 2 — Bedside reasoning

Explain how the uniformly weak pulses and the auscultatory findings distinguish hypoplastic left heart syndrome from coarctation of the aorta and from septic shock, and state why an unremarkable murmur is not reassuring. [2]

Task 3 — Definitive pathway and counselling

Outline the staged single-ventricle palliation the infant will enter, naming the three operations and the trial that informs the first-stage shunt choice. Discuss the interstage mortality, the home-monitoring strategy, and the neurodevelopmental prognosis you would raise with the family. [1]

References

[2]Feinstein JA; Benson DW; Dubin AM; et al Hypoplastic left heart syndrome: current considerations and expectations. J Am Coll Cardiol, 2012.PMID 22192720
[3]Rychik J Hypoplastic left heart syndrome: can we change the rules of the game? Circulation, 2014.PMID 25052402
[1]Ohye RG; Sleeper LA; Mahony L; et al Comparison of shunt types in the Norwood procedure for single-ventricle lesions. N Engl J Med, 2010.PMID 20505177
[4]Ghanayem NS; Allen KR; Tabbutt S; et al Interstage mortality after the Norwood procedure: Results of the multicenter Single Ventricle Reconstruction trial. J Thorac Cardiovasc Surg, 2012.PMID 22795436

Hypoplastic left heart syndrome — structured clinical encounter

structured clinical encounter

Task 3 — Definitive pathway and counselling

References

[2]Feinstein JA; Benson DW; Dubin AM; et al Hypoplastic left heart syndrome: current considerations and expectations. J Am Coll Cardiol, 2012.PMID 22192720
[3]Rychik J Hypoplastic left heart syndrome: can we change the rules of the game? Circulation, 2014.PMID 25052402
[1]Ohye RG; Sleeper LA; Mahony L; et al Comparison of shunt types in the Norwood procedure for single-ventricle lesions. N Engl J Med, 2010.PMID 20505177
[4]Ghanayem NS; Allen KR; Tabbutt S; et al Interstage mortality after the Norwood procedure: Results of the multicenter Single Ventricle Reconstruction trial. J Thorac Cardiovasc Surg, 2012.PMID 22795436