Contraindications for gastric lavage include:

Correct Answer: D

Rationale: Gastric lavage is contraindicated in cases of altered consciousness, hydrocarbon ingestion, and caustic substances.

Correct Answer: B

Rationale: In metabolic acidosis, hydrogen ions shift into cells, causing potassium to move out, leading to hyperkalemia despite normal total body potassium.

Correct Answer: B

Rationale: A single umbilical artery is associated with an increased risk of occult renal anomalies, as it may indicate underlying developmental abnormalities in the urinary system.

Correct Answer: C

Rationale: The steeple sign is a characteristic radiologic feature of croup (acute laryngotracheobronchitis).

Correct Answer: D

Rationale: Digitalis is used for chronic heart failure and specific arrhythmias, not for acute resuscitation efforts requiring rapid cardiac stimulation.