Pathophysiology
Clinical meaning
Children are more susceptible to dehydration than adults due to higher body surface area-to-weight ratio (greater insensible losses), higher metabolic rate, immature renal concentrating ability, and greater total body water percentage (70-80% in infants vs. 60% in adults). Dehydration occurs when fluid output exceeds intake, most commonly from gastroenteritis (vomiting and diarrhea), fever, or inadequate oral intake. Dehydration is classified as mild (3-5% weight loss), moderate (6-9%), or severe (≥10%). The type (isotonic, hypotonic, or hypertonic) affects clinical presentation and treatment approach. The nurse monitors hydration status, administers oral rehydration and IV fluids as ordered, measures intake and output, and reports clinical changes to the RN.