# A 4-month-old infant with tetralogy of Fallot is admitted to the pediatric unit. Which assessment finding would be most concerning and require immediate nursing intervention? > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=541960 > language: ko > subject: Child Health ## 문제 A 4-month-old infant with tetralogy of Fallot is admitted to the pediatric unit. Which assessment finding would be most concerning and require immediate nursing intervention? ## 보기 1. Clubbing of fingers and toes noted on physical exam 2. Heart murmur grade 3/6 heard on auscultation 3. Oxygen saturation of 85% on room air 4. Hypercyanotic spell with loss of consciousness **✔ 정답** **정답: 4** ## 해설 Hypercyanotic spells with loss of consciousness are a medical emergency in tetralogy of Fallot, requiring immediate intervention to prevent severe hypoxia and cardiac arrest. Other findings like clubbing, murmur, and baseline oxygen saturation of 85% are expected but not immediately life-threatening. ## 심화 해설 Clinical Reasoning and Priority Setting This question tests the ability to differentiate between expected chronic manifestations of tetralogy of Fallot (TOF) and an acute, life-threatening complication requiring immediate intervention. TOF involves four structural defects: pulmonary stenosis, ventricular septal defect, overriding aorta, and right ventricular hypertrophy. The resulting pathophysiology is a right-to-left shunt, which leads to chronic hypoxemia. The nurse must recognize which assessment finding signals an acute decompensation versus a chronic adaptation. Analysis of Options - **Option 1: Clubbing of fingers and toes.** Clubbing is a classic, *chronic* physical sign resulting from long-standing tissue hypoxia. In the context of TOF, particularly in settings where surgical repair is delayed, chronic hypoxia triggers compensatory mechanisms. As noted in the literature, a delay in treatment results in complications "related to chronic hypoxia" [4]. While clubbing is an important finding that documents the duration and severity of hypoxemia, it develops over months to years and does not represent an acute change requiring immediate intervention in a 4-month-old. - **Option 2: Heart murmur grade 3/6.** A heart murmur in TOF is an *expected* finding. The murmur is typically caused by turbulent blood flow across the stenotic pulmonary valve. The intensity of the murmur can vary and does not directly correlate with the severity of a hypercyanotic episode. In fact, during a severe spell, the murmur may paradoxically become softer or disappear as flow across the pulmonary valve decreases. A stable murmur is a chronic finding and not the priority over an acute neurological change. - **Option 3: Oxygen saturation of 85% on room air.** An oxygen saturation of 85% represents significant hypoxemia. For an infant with unrepaired TOF, this is a concerning but often *baseline* finding that reflects the constant right-to-left shunt. These children live with chronic hypoxemia, which contributes to complications like growth failure, most pronounced in the first year of life [2]. While this finding requires continuous monitoring and supportive care, it is a chronic state. The question asks for the *most* concerning finding requiring *immediate* intervention, which points to an acute change on top of this chronic baseline. - **Option 4: Hypercyanotic spell with loss of consciousness.** This is the correct answer. A hypercyanotic spell, or "Tet spell," is an acute, life-threatening emergency. The pathophysiology involves an acute increase in right-to-left shunting, often triggered by crying, feeding, or defecation. This leads to a sudden, profound drop in systemic oxygen saturation. The loss of consciousness indicates severe cerebral hypoxia. This is a dramatic decompensation that requires immediate nursing intervention, such as placing the infant in a knee-chest position, administering oxygen, and giving prescribed morphine to suppress the respiratory drive and relax the pulmonary infundibulum. The chronic hypoxia of TOF leads to long-term complications like right ventricular dysfunction and poor psychomotor development, but an acute spell with loss of consciousness is an immediate threat to life [4]. The nurse must prioritize this finding to prevent cardiac arrest and irreversible brain injury. Key Takeaway When caring for a patient with a chronic condition like TOF, the nurse must be able to distinguish between the expected chronic manifestations of the disease (clubbing, murmur, baseline low oxygen saturation) and an acute exacerbation that signals a life-threatening event. A change in neurological status, such as a loss of consciousness during a hypercyanotic spell, always takes the highest priority. References (research sources) - [2]Growth Failure in Children with Congenital Heart Disease.Research articleLee J, Marshall T, Buck H, Pamela M, Daack-Hirsch S. (2025) · DOI: 10.3390/children12050616 - [4]Tetralogy of Fallot in Low- and Middle-Income Countries.Research articleDib N, Chauvette V, Diop MS, Bouhout I, Hadid M, Vô C, Khairy P, Poirier N. (2024) · DOI: 10.1016/j.cjcpc.2023.12.002 ## 임상 시나리오 Clinical Scenario A 4-month-old infant with known Tetralogy of Fallot presents with a sudden onset of severe cyanosis and loss of consciousness. The caregiver reports the episode began during a crying spell. This is the infant's first such event. Immediate Nursing Actions - Place the infant in a knee-to-chest position immediately to increase systemic vascular resistance and reduce the right-to-left shunt. - Administer 100% oxygen via a non-rebreather mask or blow-by to maximize oxygenation. - Activate the rapid response team or code blue per facility protocol. - Stay with the patient and provide calm, gentle handling to minimize further agitation and oxygen consumption. Pharmacologic Management - **Morphine sulfate:** Administer as ordered (usually 0.1-0.2 mg/kg IV/IM/SC) to suppress the respiratory center, reduce infundibular spasm, and decrease systemic venous return. - **Propranolol:** A beta-blocker may be given IV during an acute spell to relax the right ventricular outflow tract and reduce heart rate. - **Volume expansion:** An IV fluid bolus of normal saline may be administered to increase preload and right ventricular filling. - **Sodium bicarbonate:** May be used to correct severe metabolic acidosis resulting from prolonged hypoxia. Ongoing Monitoring - Continuously monitor oxygen saturation, heart rate, and respiratory rate. - Assess level of consciousness and responsiveness every 5-15 minutes until stable. - Monitor for signs of cerebral hypoxia (seizure activity, posturing). - Document the duration of the spell, precipitating factors, interventions, and patient response. Family Education Teach caregivers to recognize early signs of a hypercyanotic spell (increased irritability, deepening cyanosis, rapid breathing) and to immediately place the child in a knee-to-chest position. Emphasize the importance of avoiding dehydration and prolonged crying. Ensure the family has an emergency plan and knows when to call 911. ## 핵심 개념 - **Hypercyanotic spell** — A sudden, severe episode of cyanosis and hypoxia in TOF patients, often triggered by crying or feeding, caused by increased right-to-left shunting. - **Tetralogy of Fallot** — A congenital heart defect with four components: pulmonary stenosis, ventricular septal defect, overriding aorta, and right ventricular hypertrophy. - **Clubbing** — A physical sign of chronic tissue hypoxia where the fingertips enlarge and the nail bed angle flattens. - **Right-to-left shunt** — A circulatory pattern where deoxygenated blood bypasses the lungs and enters systemic circulation, causing hypoxemia. ## 같은 주제 문제 - [A 2-month-old infant with tetralogy of Fallot is brought to the emergency department by th…](https://mymerci.kr/pages/nclex_q.php?qn_id=541961) - [A 4-month-old infant with tetralogy of Fallot is brought to the emergency department by th…](https://mymerci.kr/pages/nclex_q.php?qn_id=541962) - [A 6-month-old infant with tetralogy of Fallot is admitted to the pediatric unit. The nurse…](https://mymerci.kr/pages/nclex_q.php?qn_id=541963) - [A 6-month-old infant with tetralogy of Fallot is in the pediatric ICU. The infant suddenly…](https://mymerci.kr/pages/nclex_q.php?qn_id=541964) - [A 3-year-old toddler with tetralogy of Fallot is admitted to the pediatric unit. The nurse…](https://mymerci.kr/pages/nclex_q.php?qn_id=541965) - [A 9-month-old infant with tetralogy of Fallot is admitted to the pediatric unit. During as…](https://mymerci.kr/pages/nclex_q.php?qn_id=541966) - [A 4-year-old child with tetralogy of Fallot is admitted to the pediatric unit. Which nursi…](https://mymerci.kr/pages/nclex_q.php?qn_id=541967) - [A 3-month-old infant with tetralogy of Fallot is admitted to the pediatric unit. During as…](https://mymerci.kr/pages/nclex_q.php?qn_id=541968) --- More free questions: [기출문제](https://mymerci.kr/) _학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._