Case Study — Pediatrics
Pediatric Dehydration NGN Case Study
A Next Gen NCLEX-style unfolding case. Read each step, commit to your own answer — out loud or on paper — and only then reveal ours. The six steps mirror the NCSBN Clinical Judgment Measurement Model exactly as the exam tests it.
15 min activity · Pediatrics
Educational use only. This case is a learning exercise with simplified values, not a treatment protocol — real pediatric rehydration follows provider orders, weight-based calculations, and your facility’s protocols. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
The Scenario
1330, pediatric ED: Amara, 10 months old, is brought in by her father after two days of watery diarrhea and vomiting that started after daycare “had a bug going around.” She vomited the small sips of formula offered this morning. Dad reports only two wet diapers since last night — “normally she soaks six or seven a day” — and that she cried at the babysitter’s “but no tears came out.”
1340 Assessment
- Weight 8.1 kg — well-child visit two weeks ago: 9.0 kg (≈10% below baseline)
- HR 168 · RR 38 · BP 86/52 · Temp 37.9°C · SpO₂ 99%
- Listless but irritable when handled; sunken anterior fontanel; sunken eyes
- Mucous membranes dry; no tears with crying; capillary refill 3–4 seconds; skin recoil slow
- Diaper dry since arrival
Step 1 — Recognize Cues
Which findings are most relevant — and which matter most right now? List the cues you would flag before revealing.
▸Reveal answer
The most objective cue in pediatrics: the weight — 9.0 kg to 8.1 kg is roughly 10% of body weight lost, and in an infant, acute weight loss IS fluid loss. Ten percent grades this severe.
The exam chorus agreeing with the scale: sunken fontanel and eyes, no tears, dry mucosa, capillary refill 3–4 seconds, slow skin recoil, tachycardia at 168, and the history-cue parents always know — diaper count (two since last night vs six or seven normal).
The behavioral cue: listless-but-irritable is the concerning middle of the infant mental-status spectrum; truly lethargic comes next, and that’s decompensation.
The trap: the “normal” BP of 86/52. Children defend their blood pressure until they have lost catastrophic volume — hypotension in a child is a late, pre-arrest finding. Tachycardia and perfusion signs are the early monitors; the BP is the last domino, not the first.
Step 2 — Analyze Cues
What explains the picture, and how severe is it? Labs return: Na⁺ 138 · K⁺ 3.6 · HCO₃ 16 · glucose 88 · BUN 28. Put it together.
▸Reveal answer
Severe dehydration from viral gastroenteritis (most supported): the daycare outbreak story, two days of losses from both ends, and a 10% weight deficit with the full severe-dehydration exam. The labs agree: bicarbonate 16 (losing base in diarrhea plus hypoperfusion), BUN up, electrolytes near-normal — isotonic dehydration, the most common kind.
Worth keeping on the list: intussusception (paroxysmal drawing-up-legs pain, currant-jelly stools — not her picture, but the classic gastro mimic at this age), UTI/sepsis (febrile infant — urine studies when she produces any), and DKA (glucose 88 rules it out).
The grading logic to keep: mild ≈ 3–5% loss (subtle), moderate ≈ 6–9% (the classic exam findings appear), severe ≥ 10% (perfusion failing: prolonged cap refill, mottling, listlessness, anuria). She is severe — which changes the route.
Step 3 — Prioritize Hypotheses
Oral rehydration is the standard for most pediatric dehydration — is it the answer here? Rank the priorities.
▸Reveal answer
Not here — severity chose the route. Oral rehydration therapy is first-line for mild and moderate dehydration (small, frequent volumes — 5 mL at a time beats a bottle she’ll vomit). But severe dehydration with failing perfusion is an IV emergency: she needs volume faster than a teaspoon at a time can deliver it.
1. Restore circulating volume — isotonic fluid bolus now; the listlessness and 4-second cap refill are perfusion running out.
2. Re-evaluate after every bolus — children respond fast or tell you something else is wrong.
3. Then rebuild — replace the deficit and maintenance over the following hours, transition to oral as she proves she can hold it.
Step 4 — Generate Solutions
Build the plan with the actual numbers. She weighs 8.1 kg. What do you anticipate, and what nursing care wraps around it?
▸Reveal answer
The bolus: isotonic crystalloid at 20 mL/kg — about 160 mL — infused rapidly, reassessed immediately, repeated per orders if perfusion hasn’t turned (severe dehydration often takes more than one).
The reassessment markers: heart rate trending down, capillary refill shortening, mental status brightening, and eventually — the one worth announcing to the room — a wet diaper. Weigh diapers (1 g = 1 mL) for honest output.
After perfusion is restored: deficit + maintenance fluids per orders (maintenance by 4-2-1: ≈ 33 mL/hr for 8.1 kg), glucose checks (infants burn through reserves fast), strict I&O, daily — in this case, serial — weights on the same scale.
Family care is clinical care: dad has been pacing for two days — explain each step, recruit him for comfort holds, and start the teaching early: what counts as a wet diaper, how ORT works at home, why the daycare bug did this.
Step 5 — Take Action
1530, judgment moment: after two boluses, Amara is brighter, HR 138, cap refill 2 seconds. The admitting orders include maintenance fluids with 20 mEq/L potassium chloride. She has not yet had a wet diaper. The bag is in your hand. What do you do?
▸Reveal answer
Hold the potassium-containing fluid and verify urine output first. The rule is absolute: no potassium additives until the patient voids — kidneys that aren’t making urine can’t excrete potassium, and an anuric infant on KCl is a hyperkalemia setup. Run potassium-free maintenance per clarified orders until a wet diaper proves the kidneys are back online.
This is a question-the-order moment, done right: the order isn’t wrong for the patient she’ll be in two hours — it’s wrong for the patient she is now. A quick SBAR to the provider (“perfusion restored, no urine yet — confirming we hold the KCl bag until she voids”) protects her and the chart.
Meanwhile: keep reassessing, keep dad updated, and start trialing small oral volumes of rehydration solution as tolerated — the road home runs through her mouth, not the pump.
Step 6 — Evaluate Outcomes
Next morning: weight 8.7 kg, HR 124 sleeping, fontanel flat, three wet diapers overnight, taking oral rehydration solution and diluted formula in small frequent feeds, IV saline-locked. Discharge is planned for this evening if she keeps it up. What shows success, and what does dad take home?
▸Reveal answer
Improving: the weight curve recovering (8.1 → 8.7 kg — the scale giveth the diagnosis and the scale confirmeth the cure), normalized fontanel and perfusion, urine flowing, and — the discharge criterion that matters — tolerating oral fluids.
Dad’s toolkit: oral rehydration solution in small frequent volumes (a syringe or spoon, 5–10 mL every few minutes, more reliable than a bottle), resume normal feeding as tolerated (prolonged “gut rest” is out — early feeding shortens illness), the diaper count as his home monitor, and the return-now list: no wet diaper in 8 hours, no tears, sunken soft spot, listlessness, bloody stools, or vomiting everything offered.
Prevention notes: hand hygiene for the household (these viruses tour entire families), and rotavirus vaccination status checked — the vaccine exists precisely because of admissions like this one.
Debrief — The Pattern to Keep
- ✦Acute weight change is the most objective pediatric fluid measure — ~1 kg = 1 L; grade dehydration by percent of body weight lost.
- ✦A child's blood pressure holds until catastrophe — tachycardia, cap refill, mental status, and diaper count are the real early monitors.
- ✦Mild/moderate dehydration = oral rehydration in small frequent volumes; severe = 20 mL/kg isotonic boluses, reassessed after each.
- ✦No potassium in IV fluids until the patient voids — ever.
- ✦Parents hold the data: diaper counts, tear production, and 'she's just not herself' are assessment findings, not small talk.