A 4-month-old infant is brought to the emergency department by parents who report that the child has been vomiting forcefully after feedings for the past week. What is the most important initial assessment the nurse should perform?
1Measure the infant's head circumference
2Check the infant's temperature and heart rate
3Assess the infant's bowel sounds in all four quadrants
4Evaluate the infant's hydration status and skin turgor✓ 정답
해설
Evaluating hydration status is the priority for an infant with persistent vomiting, as dehydration can develop rapidly and become life-threatening. Other assessments like head circumference or bowel sounds are less urgent.
Core Nursing ExplanationKey Concept Analysis: This question tests the application of nursing prioritization and the ABCs (Airway, Breathing, Circulation) framework in a pediatric patient. The core issue is a 4-month-old infant with a history of projectile vomiting for one week. While the description is classic for pyloric stenosis, the question asks for the most important initial assessment. In any patient, especially an infant, the priority is always to assess for life-threatening conditions. Persistent vomiting leads to fluid and electrolyte loss, making Key Point!dehydration and electrolyte imbalance the most immediate threats to the infant's circulation and overall stability.
Answer Rationale: The correct answer is to Evaluate the infant's hydration status and skin turgor. This directly assesses the "Circulation" component of the ABCs. Infants have a high body surface area to weight ratio and immature kidneys, making them exceptionally vulnerable to rapid and severe dehydration. Assessment includes checking for sunken fontanelles, dry mucous membranes, poor skin turgor (tenting), decreased urine output, and altered mental status. This assessment will guide immediate interventions like IV fluid resuscitation, which is often the first life-saving step before definitive diagnosis.
Distractor Analysis:
Measure head circumference: While an important part of a comprehensive pediatric assessment and relevant for monitoring conditions like hydrocephalus, it is not the priority in an acutely ill infant with vomiting. It is a diagnostic, not an immediate life-threat assessment.
Check temperature and heart rate: Vital signs are always important, but they are a component of the broader assessment. A heart rate check alone is insufficient; it must be interpreted in the context of hydration status (e.g., tachycardia can indicate dehydration). This option is too narrow compared to the comprehensive evaluation of hydration.
Assess bowel sounds: This is a focused gastrointestinal assessment. While hyperactive or abnormal bowel sounds provide data, they do not address the most urgent physiological derangement caused by the vomiting—fluid volume deficit. This is a lower-priority assessment after stability is ensured.
Related Concepts: The classic presentation of projectile, non-bilious vomiting in a 4-month-old should immediately raise suspicion for hypertrophic pyloric stenosis (HPS). However, nursing priority is always stability before diagnosis. Management of HPS involves correcting dehydration and electrolyte imbalances (often a hypochloremic, hypokalemic metabolic alkalosis) before surgical intervention (pyloromyotomy).
Concept Summary
Concept
Key Takeaway
Nursing Prioritization (ABCs)
Airway, Breathing, Circulation are always the first priorities. Dehydration threatens Circulation.
Infant Vulnerability
Infants dehydrate quickly due to high metabolic rate, large body surface area, and immature renal function.
Projectile Vomiting
Forceful, non-bilious vomiting after feeds in a 4-6 week old infant is a hallmark of pyloric stenosis.
Medium Priority. Provides diagnostic clues but does not treat instability.
After ABCs are addressed, to help determine cause of abdominal symptoms.
Anatomy, Physiology & Pharmacology Points
Pathophysiology of Pyloric Stenosis: Hypertrophy of the pyloric muscle causes gastric outlet obstruction. This leads to projectile vomiting, loss of HCl (stomach acid), resulting in hypochloremic metabolic alkalosis and hypokalemia.
Fluid Compartments in Infants: Infants have a higher percentage of total body water (∼75%) than adults, but they turn it over much faster, leading to rapid deficits.
Pharmacology: Initial treatment involves IV fluids (e.g., 0.9% NaCl with potassium chloride) to correct dehydration and electrolyte imbalances prior to surgery.
Memory Tips
ABCs for Babies: "Airway, Breathing, Circulation & Crying (hydration)." Dehydration stops the crying and compromises circulation.
Hydration Signs: "The baby is DRY" - Decreased tears, Respiratory changes (tachypnea), Yawning fontanelle (sunken).
High-Frequency NCLEX Topics
The NCLEX-RN loves to test prioritization in pediatric patients. You must be able to look past the "textbook diagnosis" (like pyloric stenosis) and identify the most immediate threat to the patient's life. Questions often combine a classic symptom presentation with a need to choose the first nursing action.
Watch Out for Question Variations!
Shift from Assessment to Intervention: "The nurse identifies the infant is dehydrated. What is the priority intervention?" Answer: Initiate IV fluid therapy as prescribed.
Shift to Post-operative Care: "After a pyloromyotomy, what is the priority nursing action?" Answer: Manage pain and monitor for return of bowel function, often starting with small frequent feeds of clear liquids.
Shift to Parent Education: "What should the nurse teach the parents about recognizing dehydration at home?" Answer: Monitor for < 6 wet diapers/day, no tears when crying, sunken soft spot, lethargy.
Nursing Clinical Practice GuideClinical Scenario: You are the triage nurse in the Pediatric ED. Parents rush in with their 4-month-old, Liam, stating he has been "vomiting across the room" after every bottle for the past 5 days. He is listless, has not had a wet diaper in 8 hours, and his lips look dry.
Nursing Intervention Strategy:
Immediate Triage Assessment (ABCs):
Airway/Breathing: Ensure patent airway. Note respiratory rate and effort (tachypnea can indicate metabolic acidosis/alkalosis).
Circulation: Key Point! Perform rapid hydration assessment: Check capillary refill (>3 seconds is delayed), palpate fontanelles (sunken), assess skin turgor on abdomen (tenting), check mucous membranes (dry). Weigh the infant immediately (weight loss is the most objective sign of dehydration).
Priority Actions:
Alert the physician/advanced practice provider STAT.
Obtain IV access (often a 24g in a scalp or hand vein) and draw blood for labs (CBC, BMP to check electrolytes).
Administer an IV fluid bolus (e.g., 20 mL/kg of 0.9% NaCl) as ordered to rapidly expand intravascular volume.
Comprehensive Assessment & Monitoring:
After initial stabilization, proceed with a full head-to-toe, including abdominal exam (palpate for olive-shaped mass in RUQ, observe for peristaltic waves).
Insert a urinary catheter if ordered to strictly monitor output (1-2 mL/kg/hr is goal).
Monitor for signs of worsening alkalosis (irritability, muscle twitching).
Patient Safety and Precautions:
NPO Status: The infant will be made NPO (nothing by mouth) until the cause of obstruction is ruled out and hydration is corrected. Do not offer feeds.
Electrolyte Imbalance: Rapid correction of sodium and potassium is dangerous. Administer IV fluids with electrolytes as ordered, monitoring for fluid overload (crackles, increased respiratory effort).
Family Support: Parents are often terrified. Explain all procedures simply. "We need to give Liam fluids through a tiny tube in his vein to help him feel better before we figure out why he's vomiting."
Nursing Procedure & Medication FlowProcedure: Pediatric IV Fluid Administration
Calculate Fluid Rate: Use maintenance + replacement calculations. For initial bolus: 20 mL/kg over 30-60 minutes.
Example: 5 kg infant. Bolus = 20 mL/kg * 5 kg = 100 mL. Infuse over 30 min via infusion pump.
Monitoring: Assess for signs of improvement (better perfusion, urine output) and overload (tachypnea, crackles) every 15 minutes during the bolus.
Medication: IV Potassium Chloride (KCl)
Precaution: NEVER give IV push. Must be diluted and infused via pump. Concentration for peripheral lines is typically no greater than 40 mEq/L.
Monitoring: Monitor ECG for peaked T-waves (sign of hyperkalemia). Ensure good urine output before administering.
A Word from Your Senior Nurse
"In the ED, your gut feeling is powerful. When you see a limp, dry infant, your brain should scream 'FLUIDS!' before it even thinks 'pyloric stenosis.' Mastering prioritization means you save the detailed diagnostic assessments for after you've addressed the threat to life. On the NCLEX and in real life, always ask yourself: 'What will kill my patient first?' In this case, it's not the diagnosis—it's the dehydration. That's the heart of safe, effective nursing."