A nurse is caring for an infant weighing 7.5 kg who has had a total urine output of 93 mL over the past 12 hours.

True or False: Based on this information, the infant's urine output is within the normal range for expected urine output based on age.

Choice A rationale

An oxygen saturation SpO_2 of 88% indicates significant hypoxemia (low blood oxygen), which is the most critical physiological derangement in respiratory distress. Sustained hypoxemia can rapidly lead to cerebral hypoxia, increasing intracranial pressure, and cardiac arrest, necessitating immediate intervention. Normal is ≥ 94-95% in most children.

Choice B rationale

A heart rate of 160 beats per minute in a school-age child (6-12 years) is tachycardia (normal is 75-115 bpm), often an initial compensatory response to hypoxemia and increased work of breathing. While concerning, it is an attempt to maintain cardiac output, making the SpO_2 decline a more immediate life threat.

Choice C rationale

A temperature of 100.4°F is a low-grade fever, which can increase metabolic demand and O_2 consumption, potentially worsening respiratory status. While it warrants management, it is not the most immediate life-threatening sign compared to severe hypoxemia (SpO_2 of 88%). Normal is 97.7°F to 99.5°F.

Choice D rationale

A respiratory rate of 40 breaths per minute in a toddler (1-3 years) is near the upper limit of normal (25-35 bpm) and indicates tachypnea, a compensatory mechanism to improve gas exchange. While significant, it is a sign of compensation, whereas the low SpO_2 suggests decompensation.

Choice A rationale

Cyanosis, a bluish discoloration of the skin and mucous membranes, indicates significant hypoxemia (low oxygen saturation) and is a sign of severe, life-threatening asthma exacerbation, not a mild to moderate presentation. In mild to moderate asthma, the body can usually compensate to maintain adequate tissue oxygenation despite airway constriction and inflammation.

Choice B rationale

Chest tightness is a subjective but common symptom in asthma, resulting from the bronchoconstriction and smooth muscle spasm that narrow the airways. The sensation is often described as a band around the chest, reflecting the increased work of breathing and the mechanical effort required to move air through the restricted bronchial passages.

Choice C rationale

An asthma cough is typically non-productive (dry) or, if secretions are present, it is often a mucoid, tenacious sputum. A consistently productive cough suggests other underlying conditions, such as infection (e.g., pneumonia) or bronchiectasis, rather than being the hallmark of a primary, mild-to-moderate asthma flare.

Choice D rationale

Wheezing, a high-pitched whistling sound, is the classic objective sign of asthma, caused by the vibration of air attempting to move rapidly through the severely narrowed, obstructed small airways (bronchioles) during respiration. It is often most prominent on expiration but can be present on inspiration during a significant episode.

Choice E rationale

Prolonged expiration occurs because the narrowed, inflamed airways obstruct the outflow of air, leading to air trapping and a higher residual volume. The patient must forcefully and slowly push air out against the resistance, making the expiratory phase last significantly longer than the inspiratory phase, a key sign of obstructive lung disease.