Fever, Dehydration and Fluids
Comfort, safe antipyretic use, and rehydration
Fever
- Fever = ≥100.4°F (38.0°C).
- Infant <28 days with fever: full sepsis work-up. Up to 60–90 days: urgent evaluation.
- Treat the child's discomfort, not the number. Fever itself isn't harmful in most children.
- Light clothing, fluids, rest.
UpdatedNo tepid sponging, cold baths or alcohol rubs: they cause shivering and discomfort (alcohol can be absorbed and is toxic) and don't help.
Antipyretics
| Acetaminophen | 10–15 mg/kg every 4–6 h; max 5 doses in 24 h (≤75 mg/kg/day, never more than 4 g) |
| Ibuprofen | 5–10 mg/kg every 6–8 h; max 40 mg/kg/day. Only from 6 months; give with food; avoid if dehydrated |
| Aspirin | Never for fever in children and teens (Reye's syndrome) |
Febrile seizure
6 months–5 years; brief, generalized. Side-lying, protect the head, nothing in the mouth, time it; call for help if >5 min. Antipyretics don't prevent them.
How dehydrated?
| Mild (3–5%) | Moderate (6–9%) | Severe (≥10%) | |
|---|---|---|---|
| Behavior | Alert | Irritable, thirsty | Lethargic |
| Mucous membranes | Slightly dry | Dry; ↓ tears | Parched; no tears |
| Eyes / fontanel | Normal | Sunken | Very sunken |
| Capillary refill | <2 s | 2–3 s | >3 s; cool, mottled skin |
| Heart rate / BP | Normal | Tachycardia | Tachycardia; low BP (late) |
| Urine output | Slightly ↓ | ↓ | Minimal or none |
Oral rehydration (mild–moderate)
- ORS 50 mL/kg (mild) or 100 mL/kg (moderate) over 3–4 h, in small frequent sips (5 mL every 1–2 min by spoon or syringe).
- Replace ongoing losses (~10 mL/kg per loose stool).
- Continue breastfeeding and normal diet once rehydrated.
- Avoid juice, soda and sports drinks (too much sugar).
IV fluids
- Severe dehydration or shock: 10–20 mL/kg isotonic bolus (normal saline or lactated Ringer's); reassess and repeat.
- Maintenance (Holliday-Segar): 100 mL/kg/day for the first 10 kg + 50 mL/kg/day for the next 10 kg + 20 mL/kg/day for each kg above 20.
- Example, 25 kg: 1,000 + 500 + 100 = 1,600 mL/day (~65 mL/h).
- Isotonic maintenance fluids are now preferred (lower risk of hyponatremia). Updated
- Add potassium only after the child voids.
Memory hook
Best measure of fluid status: daily weight (1 kg ≈ 1 L). Minimum urine output: ~1 mL/kg/h for infants and children, 0.5 mL/kg/h for adolescents. Count wet diapers (weigh them: 1 g = 1 mL).