A nurse is assessing a 2-week-old infant with suspected congenital adrenal hyperplasia (CAH). Which assessment finding would be most indicative of this condition?
1Excessive weight gain and edema
2Ambiguous genitalia and salt-wasting symptoms✓ 정답
3Cyanosis and respiratory distress
4Jaundice and hepatomegaly
해설
Congenital adrenal hyperplasia (CAH) most commonly presents with ambiguous genitalia in females and salt-wasting symptoms due to cortisol and aldosterone deficiency. Other options represent findings not typical for CAH.
Core Nursing ExplanationKey Concept Analysis: This question assesses the ability to identify classic clinical manifestations of Congenital Adrenal Hyperplasia (CAH), a group of autosomal recessive disorders affecting adrenal steroid hormone synthesis. The most common form (21-hydroxylase deficiency) leads to a deficiency in cortisol and often aldosterone, while causing an excess of androgen precursors. This dual hormonal imbalance creates the two hallmark presentations: Key Point!Virilization (ambiguous genitalia in females) due to excess androgens in utero, and a salt-wasting crisis due to aldosterone deficiency, which can be life-threatening in the first few weeks of life.
Answer Rationale: Option ②, "Ambiguous genitalia and salt-wasting symptoms," is correct because it directly captures the two primary, defining features of classic salt-wasting CAH. In genetic females, excess prenatal androgens cause clitoromegaly and labial fusion, leading to ambiguous genitalia at birth. The salt-wasting symptoms (e.g., poor feeding, vomiting, dehydration, hyponatremia Na+ < 135 mEq/L, hyperkalemia K+ > 5.5 mEq/L) result from aldosterone deficiency and typically manifest around 1-4 weeks of age, making this assessment critical for a 2-week-old infant.
Distractor Analysis:
Option ① (Excessive weight gain and edema): This is more characteristic of conditions like congenital hypothyroidism or heart failure, not CAH. CAH typically presents with weight loss and dehydration from salt-wasting.
Option ③ (Cyanosis and respiratory distress): These are classic signs of Watch out for confusion! cardiac or pulmonary issues (e.g., congenital heart defects, respiratory distress syndrome). While a CAH infant in severe metabolic crisis may become lethargic and have poor perfusion, cyanosis is not a primary or indicative finding.
Option ④ (Jaundice and hepatomegaly): These findings point toward hepatic or biliary disorders, such as biliary atresia or neonatal hepatitis. They are not associated with the primary adrenal hormone pathway defects seen in CAH.
Related Concepts: It's crucial to differentiate the "salt-wasting" form from the "simple virilizing" form of CAH (which has androgen excess but no significant mineralocorticoid deficiency). Newborn screening for CAH is standard in many countries. The priority nursing intervention for a suspected salt-wasting crisis is stabilizing fluid and electrolyte balance (IV fluids with sodium chloride) and administering stress-dose steroids (hydrocortisone).
Jaundice, poor feeding, constipation, hypotonia, large fontanelles
Endocrine (Thyroid hormone)
Biliary Atresia
Persistent jaundice, dark urine, acholic (pale) stools, hepatomegaly
Gastrointestinal (Biliary tree)
Critical Congenital Heart Disease
Cyanosis, respiratory distress, poor feeding, failure to thrive
Cardiovascular
Anatomy, Physiology & Pharmacology Points
Adrenal Cortex Layers: Remember "GFR" from outer to inner: Glomerulosa (Aldosterone), Fasciculata (Cortisol), Reticularis (Androgens). CAH affects the fasciculata and often glomerulosa.
Hormone Pathway: 21-hydroxylase deficiency blocks conversion of 17-OHP to 11-deoxycortisol, shunting precursors into the androgen synthesis pathway.
Drug Therapy:Hydrocortisone replaces cortisol. Fludrocortisone is a synthetic mineralocorticoid that replaces aldosterone to promote sodium retention and potassium excretion.
Think "SALT & SEX":Salt-wasting and ambiguous SEX characteristics are the clues.
Lab Values: Remember "Low Salt, High Potassium" (Low Na+, High K+).
High-Frequency NCLEX Topics
CAH is a classic pediatric endocrine disorder. The NCLEX-RN loves to test on:
Identifying the priority assessment finding (salt-wasting crisis = dehydration/shock).
Understanding the need for lifelong steroid replacement and stress-dose steroid administration during illness.
Providing psychosocial support and education for families regarding ambiguous genitalia and long-term condition management.
Watch Out for Question Variations!
From Symptom to Intervention: "The nurse is caring for a 3-week-old infant with CAH who is vomiting and lethargic. Which action should the nurse take first?" (Answer: Initiate IV access for fluid/electrolyte resuscitation).
From Finding to Education: "The parents of a newborn female diagnosed with CAH ask why their baby looks different. How should the nurse respond?" (Answer: Explain the effect of excess male hormones on fetal development in a sensitive, factual manner).
Lab Interpretation: "Which lab result would the nurse expect to find in an infant with salt-wasting CAH?" (Answer: Serum sodium 130 mEq/L and potassium 6.0 mEq/L).
Nursing Clinical Practice GuideClinical Scenario: You are a nurse in the newborn nursery. During a routine assessment of a 2-week-old female infant who was discharged a few days prior, the mother reports the baby has been "very sleepy," not feeding well, and has vomited twice today. You note the infant's fontanelle is sunken, skin turgor is poor, and she has mild clitoromegaly noted on the initial birth exam that was pending follow-up.
Nursing Intervention Strategy:
Immediate Assessment (ABCs): Assess airway, breathing, and circulation. Check heart rate, respiratory rate, blood pressure (may be low), temperature (risk of hypothermia), and capillary refill (likely >3 seconds). Weigh the infant immediately and compare to birth/discharge weight (significant loss expected).
Priority Actions: Alert the provider STAT. Anticipate orders for:
STAT serum electrolytes (Na+, K+, glucose), blood gas.
IV access establishment for 0.9% NaCl bolus.
Stress-dose hydrocortisone IV.
Cardiac monitoring (due to hyperkalemia risk).
Ongoing Care & Monitoring: Strict I&O (Intake and Output), monitor for signs of worsening dehydration or shock. Protect the infant from infection (cortisol-deficient patients are immunocompromised). Provide calm, supportive care to the anxious parents.
Patient/Family Education: Once stable, begin education on the lifelong nature of CAH, the importance of daily medication (never skip a dose), the need for stress-dose steroids during illness/fever/surgery, and how to recognize early signs of adrenal crisis (lethargy, vomiting).
Patient Safety and Precautions:
Never delay treatment for confirmatory testing in a symptomatic infant. A salt-wasting crisis is a medical emergency.
Hyperkalemia can cause fatal cardiac arrhythmias. Be prepared for interventions like calcium gluconate, insulin/glucose, or sodium polystyrene sulfonate (Kayexalate) if ordered.
When administering hydrocortisone, monitor for signs of overdose with long-term use (e.g., Cushingoid features, hypertension).
Indication: Physiologic stress (illness, fever >38.5°C, surgery, trauma) in a patient with adrenal insufficiency.
Dose: Typically 2-3 times the daily maintenance dose, given IV or IM. For an infant in crisis, follow specific weight-based protocols (e.g., 25-50 mg/m² IV bolus).
Administration: Verify the order and patient identity. Reconstitute powder with provided diluent. Administer IV push slowly or via IV infusion as ordered. Monitor vital signs closely during and after administration.
Key Point: The family must be taught to have an emergency injection kit (IM hydrocortisone) at home and know when and how to use it.
A Word from Your Senior Nurse
"CAH is a perfect example of why we don't just assess by the textbook, but by the whole story. That 'sleepy, poor-feeding' infant could be many things, but when you combine it with a history of ambiguous genitalia, the pieces click into place for a life-threatening adrenal crisis. Your sharp assessment and swift action in those first hours can literally save a life. On the NCLEX, they're testing if you see the connection between pathophysiology (hormone deficiency) and clinical presentation (salt-wasting). In real life, you're the one making that connection at the bedside. Think it through, trust your knowledge, and act with purpose!"
Congenital Adrenal Hyperplasia — A group of autosomal recessive disorders characterized by enzyme deficiencies in adrenal steroid synthesis, most commonly 21-hydroxylase deficiency, leading to cortisol deficiency, potential aldosterone deficiency, and androgen excess.
Salt-Wasting Crisis — A life-threatening condition in classic CAH due to aldosterone deficiency, presenting with hyponatremia, hyperkalemia, dehydration, vomiting, and shock, typically occurring in the first few weeks of life.
Ambiguous Genitalia — Genitalia that are not clearly male or female in appearance. In genetic females with CAH, it results from in utero exposure to excess androgens, causing clitoromegaly and labial fusion.
21-Hydroxylase Deficiency — The most common enzyme defect in CAH (>90% of cases). It impairs the synthesis of cortisol and aldosterone while causing an accumulation of androgen precursors.
Stress-Dose Steroids — An increased dose of glucocorticoid (e.g., hydrocortisone) administered during illness, surgery, or trauma to prevent adrenal crisis in patients with adrenal insufficiency, such as those with CAH.