A nurse is evaluating the effectiveness of IV furosemide in a child with congestive heart failure (CHF). Which finding indicates improvement?

Choice A rationale

Decreased urine output (oliguria, typically <1 mL/kg/hour in a child) is a sign of poor renal perfusion due to reduced cardiac output and is characteristic of later, decompensated shock. In early, compensated septic shock, systemic vascular resistance (SVR) is often reduced (warm shock), and the compensatory mechanisms may still maintain adequate renal blood flow and normal urine output.

Choice B rationale

Cool extremities result from intense peripheral vasoconstriction as a compensatory mechanism to shunt blood to vital organs. This is characteristic of hypovolemic or cold septic shock (high SVR). However, in the more common early warm septic shock in children, peripheral vasodilation (low SVR) leads to flushed, warm extremities, not cool ones.

Choice C rationale

Normal blood pressure (BP) (systolic BP within the normal range, which varies by age, e.g., >90 mmHg in a school-aged child) is the hallmark of compensated shock. Compensatory mechanisms, primarily tachycardia and mild vasoconstriction, are successfully maintaining cardiac output and thus adequate mean arterial pressure, despite underlying circulatory dysfunction.

Choice D rationale

Tachycardia (elevated heart rate, normal range varies by age, e.g., >130 bpm in a toddler) is one of the earliest and most reliable signs of all forms of shock in children. It represents a critical cardiovascular compensatory mechanism to increase cardiac output (Cardiac Output = Stroke Volume×Heart Rate) in response to systemic vasodilation and early hypovolemia characteristic of sepsis.

Choice A rationale

Viral croup (laryngotracheobronchitis) is characterized by inflammation and edema of the larynx and subglottic trachea. This narrowing causes the distinctive, turbulent airflow sound of inspiratory stridor and the barking, seal-like cough due to vocal cord irritation, making this an accurate match.

Choice B rationale

Asthma is a chronic inflammatory disorder of the airways leading to hyperresponsiveness, reversible airflow obstruction, and bronchoconstriction. The turbulent airflow through multiple narrowed small airways generates the characteristic polyphonic (musical) expiratory wheezing and the accompanying sensation of chest tightness, reflecting increased airway resistance.

Choice C rationale

Epiglottitis is a bacterial infection causing rapid and severe inflammation of the epiglottis. The swollen, cherry-red epiglottis mechanically obstructs the airway and makes swallowing extremely painful, leading to the classic triad of drooling, dysphagia (difficulty swallowing), and a muffled or "hot potato" voice.

Choice D rationale

Bronchiolitis, often caused by Respiratory Syncytial Virus (RSV), involves inflammation and necrosis of the small airways (bronchioles). This process causes narrowing and mucus production, resulting in wheezing from turbulent airflow and crackles (rales) from the "popping" open of fluid-filled or collapsed alveoli and bronchioles during inspiration.