A 3-year-old child presents with prolonged diarrhea. Serum sodium is 115 mEq/L, urinary sodium excretion is 8 mEq/L. What is the most accepted explanation for this sodium abnormality?

Correct Answer: C

Rationale: The child has hyponatremia due to sodium depletion from prolonged diarrhea. Low urinary sodium suggests total body sodium loss rather than water overload.

Correct Answer: B

Rationale: Coarctation of the aorta typically causes weak femoral pulses but does not affect the right brachial pulse significantly, as the narrowing is usually distal to the right subclavian artery.

Correct Answer: C

Rationale: The correct answer is C. For infants younger than 1 year, the American Academy of Pediatrics recommends the use of breast milk or iron-fortified formula. If breastfeeding is discontinued before 1 year, it is important to switch to a commercial iron-fortified formula to ensure the infant is receiving all the necessary nutrients for growth and development.

Correct Answer: D

Rationale: The Heimlich maneuver is performed to expel a foreign body from the airway in choking individuals. In unconscious patients, abdominal thrusts are avoided in favor of back blows and chest compressions.

Correct Answer: B

Rationale: Inhaled short-acting beta-agonists (SABAs) are the preferred rescue medication for acute asthma symptoms, as they provide rapid relief by relaxing airway muscles.