Pediatric Assessment and Emergencies

In depth

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How children differ: airway, breathing and circulation

The infant airway is small, high and soft: a large occiput flexes the neck when supine, the tongue is large, and the larynx sits high and anterior under a long, floppy epiglottis. By Poiseuille's law, 1 mm of circumferential edema in a 4-mm infant airway raises resistance 16-fold, against about 3-fold in an 8-mm adult airway. The trachea is only 4–5 cm long at birth, so neck flexion pushes a tube toward the right main bronchus and extension pulls it out.

The diaphragm does most of the work against a compliant chest wall, so gastric distension from bag-mask air impairs ventilation; decompress it with a gastric tube. Oxygen consumption is about double the adult rate (6–8 vs 3–4 mL/kg/min) and functional residual capacity is small, so an apneic infant desaturates fast.

Infant stroke volume is relatively fixed, so cardiac output follows heart rate and bradycardia means falling output, usually from hypoxia. Tachycardia and vasoconstriction hold blood pressure while perfusion fails; in trauma, hypotension means loss of more than 45% of blood volume (ATLS 10th edition). Fever adds about 10–14 beats/min per °C (Thompson 2009).

First look: PAT, primary assessment and weight

The PAT is a hands-off look from the doorway, done in under a minute, that assigns a physiologic category and the first intervention (Dieckmann 2010). Appearance (TICLS: tone, interactiveness, consolability, look or gaze, speech or cry) is the strongest marker of severity. Triage nurses using it reliably identified high-acuity children in a 528-child study (Horeczko 2013).

In the hands-on ABCDE, grunting (expiration against a partly closed glottis) signals alveolar disease or impending failure. Compare central with peripheral pulses, expect capillary refill of 2 s or less and urine output of at least 1 mL/kg/h, check glucose in any child with altered consciousness, and treat fever with purpura as meningococcemia until proven otherwise.

Weigh and record in kilograms only (Joint Commission Sentinel Event Alert 39). Without a scale, parent estimates are the most accurate, then length-based methods, with age formulas such as (age + 4) × 2 last (Young 2016). PALS 2025 notes that Broselow, PAWPER XL and Mercy tapes fall within 10–20% of measured weight and tend to underestimate total body weight while approximating ideal body weight.

Respiratory failure: airway, bronchiolitis, croup, asthma, foreign body

Most pediatric arrests are asphyxial, and respiratory failure is often quiet: a tiring child breathes slower, retracts less and grows drowsy as PaCO₂ rises, while oximetry on oxygen stays reassuring until late. Add capnography or a venous gas.

Bronchiolitis peaks on days 3–5, and infants under about 2 months or born preterm can present with apnea. Care is superficial suction, oxygen and nasogastric or IV fluids; albuterol, epinephrine, routine steroids, antibiotics and hypertonic saline in the ED are not recommended (AAP 2014; Australasian 2025). High-flow nasal cannula reduced ward escalation in PARIS without shortening stay, and Australasian 2025 uses it after low-flow oxygen fails, with CPAP for impending failure.

The Westley croup score (0–17) adds stridor 0–2, retractions 0–3, air entry 0–2, cyanosis 0–5 and consciousness 0 or 5: 2 or less is mild, 3–5 moderate, 6–11 severe, 12 or more impending failure. Every child gets dexamethasone; stridor at rest adds nebulized epinephrine, which wears off in about 2 hours, so observe 2–4 hours after the last dose. Repeated doses or an oxygen need means PICU; intubate with a tube 0.5–1 mm smaller than predicted. A toxic child unresponsive to epinephrine may have bacterial tracheitis.

Status asthmaticus: albuterol every 20 minutes or continuously (0.5 mg/kg/h), ipratropium with the first 3 doses, an early systemic steroid, then IV magnesium 25–75 mg/kg (max 2 g) (EPR-3). Drowsiness, a silent chest or PaCO₂ of 42 mm Hg or more in a tachypneic child signals failure. If intubation is unavoidable, use ketamine, a low rate and a long expiratory time; for hypotension after intubation, disconnect the circuit to release trapped air and look for a pneumothorax.

Foreign-body aspiration peaks at 1–3 years, usually food. A witnessed choking episode is the most sensitive clue; cough, wheeze and one-sided decreased breath sounds are often not all present, and most objects are radiolucent, so a normal film does not exclude it. Rigid bronchoscopy confirms and removes it.

Shock, fluids and sepsis (Phoenix 2024)

Hypovolemia is the most common pediatric shock; distributive, cardiogenic and obstructive shock can coexist (PALS 2025). Give isotonic fluid in 10 or 20 mL/kg aliquots and reassess after every bolus (Class 1) for response and overload: crackles, a descending liver edge, a gallop, a rising oxygen need. Give 5–10 mL/kg over 10–20 minutes if cardiogenic shock is suspected. A neonate in shock with weak femoral pulses or a pre- to postductal saturation gap may be ductal-dependent: start alprostadil 0.05–0.1 mcg/kg/min and be ready for apnea.

FEAST (Maitland 2011) gave 3,141 African children with febrile illness and poor perfusion 20–40 mL/kg boluses or none; 48-hour mortality was 10.6% (albumin), 10.5% (saline) and 7.3% (no bolus), mainly from cardiovascular collapse. Without ICU care, SSC children's guidelines advise no bolus unless the child is hypotensive; with it, up to 40–60 mL/kg in the first hour, stopped at signs of overload. PALS 2025 accepts balanced or unbalanced crystalloid (PRoMPT BOLUS found no difference), while SSC children's guidelines suggest balanced.

For fluid-refractory septic shock start epinephrine or norepinephrine (PALS 2025, 2a), peripherally until central access is in (SSC); dopamine only if neither is available. Stress-dose hydrocortisone may be considered once vasoactives are needed (2b) and is given early for known adrenal insufficiency. Check glucose and ionized calcium.

Phoenix (Schlapbach 2024) replaced the SIRS-based 2005 definitions for children under 18, excluding preterm newborns: sepsis is suspected infection with a score of 2 or more, and septic shock is sepsis with at least 1 cardiovascular point. In-hospital mortality was 7.1% in higher-resource and 28.5% in lower-resource settings for sepsis, and 10.8% and 33.5% for septic shock (Sanchez-Pinto 2024).

Give antimicrobials ideally within 1 hour for septic shock and, after rapid evaluation, within 3 hours for sepsis without shock (SSC children's guidelines).

PALS: arrest, bradycardia, tachycardia and IO access

In hospital, pediatric survival to discharge is 38% after pulseless arrest and 66% when CPR is started for bradycardia with poor perfusion (PALS 2025). With an advanced airway give 20–30 breaths/min. With an arterial line, aim for diastolic pressure of at least 25 mm Hg in infants and 30 from age 1, and never stop resuscitation on an ETCO₂ value alone.

Bradycardia is usually hypoxic, so oxygenate and ventilate first. A heart rate below 60 with cardiopulmonary compromise despite effective ventilation means CPR and epinephrine; atropine is for increased vagal tone or primary AV block, and pacing may be considered for complete heart block or sinus node dysfunction (PALS 2025).

SVT starts abruptly, with absent or abnormal P waves and a fixed rate, usually 220/min or more in infants and 180 or more in children; sinus tachycardia has P waves, a variable rate and a cause. Without compromise try vagal maneuvers (ice water to an infant's face, never ocular pressure), then adenosine with a rapid flush; with compromise, cardiovert. QRS over 0.09 s is wide: cardiovert if compromised, otherwise consult. New in 2025: adenosine for a regular monomorphic wide rhythm and IV sotalol for refractory SVT.

After ROSC, PALS 2025 keeps SBP and MAP above the 10th percentile for age (Class 1; the 5th in 2020), SpO₂ at 94–99% and central temperature at or below 37.5 °C; for comatose children a 5-day course of 32–34 °C then 36–37.5 °C, or 36–37.5 °C throughout, is reasonable. Base prognosis on several tests over days, never on GCS or pupils in the first 24 hours.

Choose IV or IO by availability, expertise and speed; unlike the 2025 adult guideline, PALS does not rank IV first. Use the anteromedial proximal tibia, distal femur or tibia, or the humerus in older children, avoiding fractured or recently punctured bone and infected skin. With the tip on bone, at least one 5-mm mark must show above the skin; the needle should stand alone and flush without swelling. If the child is responsive give preservative-free 2% lidocaine 0.5 mg/kg (max 40 mg) over 2 minutes; watch for extravasation and compartment syndrome and remove within 24 hours (Teleflex).

DKA, cerebral edema and status epilepticus

ISPAD 2022 defines pediatric DKA as glucose over 200 mg/dL, venous pH below 7.3 or bicarbonate below 18 mmol/L, and ketosis (β-hydroxybutyrate 3 mmol/L or more, or moderate to large ketonuria); pH below 7.1 or bicarbonate below 5 is severe. Give 10–20 mL/kg of isotonic fluid over 20–30 minutes, replace the deficit over 24–48 hours, and start insulin at 0.05–0.1 unit/kg/h without a bolus at least 1 hour after fluids. Potassium 40 mmol/L starts with insulin (before it if low, after urine output if high), and dextrose is added when glucose falls to 250–300 mg/dL.

Clinically apparent cerebral injury occurs in 0.5–0.9% of episodes with 21–24% mortality, usually within 12 hours of starting treatment (ISPAD 2022), and PECARN FLUID found that neither saline strength nor infusion rate changed it. Headache, renewed vomiting, a falling heart rate, rising blood pressure or falling consciousness suggest cerebral edema; treat on suspicion with mannitol 0.5–1 g/kg or 3% saline 2.5–5 mL/kg over 10–15 minutes (criteria on the DKA sheet).

Treat convulsive status epilepticus at 5 minutes (ILAE 2015) with a full weight-based benzodiazepine dose, repeat it once, then move to a second-line drug (AES 2016); underdosing and delay are the usual errors. Check glucose at once.

In children, ConSEPT and EcLiPSE (2019) found no difference between levetiracetam 40 mg/kg over 5 minutes and phenytoin 20 mg/kg over 20 minutes as the second-line drug.

Trauma and non-accidental injury

Injury is the leading cause of death after age 1, mostly through head injury. A large head and weak neck concentrate force on the brain and upper cervical spine, and a compliant chest lets lungs bruise without rib fractures, so a rib fracture means high energy. Pad under the shoulders and torso of young children to keep the spine neutral. ATLS (10th edition) gives one 20 mL/kg warmed crystalloid bolus, then blood products at 10–20 mL/kg; PALS 2025 prefers blood products for ongoing resuscitation of hypotensive hemorrhage (2a).

PECARN (Kuppermann 2009) for minor head trauma under age 2: GCS 14, other altered mentation or a palpable skull fracture means CT (4.4% risk of important brain injury); a nonfrontal scalp hematoma, loss of consciousness of 5 seconds or more, a severe mechanism or not acting normally allows observation or CT (0.9%); none of these means no CT (under 0.02%). In severe TBI the Brain Trauma Foundation (2019) treats ICP over 20 mm Hg, keeps CPP at least 40, gives 3% saline 2–5 mL/kg and avoids PaCO₂ below 30 in the first 48 hours.

In Sheets 2013, 27.5% of abused infants had an earlier sentinel injury, such as a small bruise or a torn frenulum, against none of the infants found not abused. Classic metaphyseal lesions and posterior rib, scapular, spinous process and sternal fractures are highly specific. Under 2 years, suspected abuse calls for a skeletal survey repeated about 2 weeks later, neuroimaging considered even without neurologic signs, and screening for abdominal injury (AAP 2015); AST or ALT over 80 IU/L prompts abdominal CT (Lindberg 2009).

• Take each caregiver's history separately, with times, in their own words
• Measure and diagram every injury; photograph per policy

Family-centered care and development

PALS 2025 (Class 1) says to offer parents the option of being present during resuscitation, with a designated team member to support them, and to ask them to leave only if their presence harms care. After a sudden unexplained death it recommends a full autopsy, postmortem genetic testing if no cause is found, and cardiac referral of first-degree relatives.

Score pain with FLACC from 2 months to 7 years or in nonverbal children, Wong-Baker FACES from about age 3 and a 0–10 numeric scale from about 8. Children treated in the most pediatric-ready EDs had 60% (injury) and 76% (illness) lower odds of in-hospital death than in the least ready (Newgard 2023).

Evidence and controversies

Still unsettled: the fluid ceiling where ICU care exists; hydrocortisone for refractory septic shock (SHIPSS has not reported); epinephrine or norepinephrine first; how long post-arrest temperature control should last; whether IV should precede IO in children, as adult 2025 guidance advises; and dosing in obesity. Phoenix was derived retrospectively, and its use at triage is still being studied.

Exam pearls

• Hypotension: SBP <70 + (2 × age) at 1–10 yr; it is late, so act on tachycardia and slow refill
• Bradycardia in a sick child usually means hypoxia; HR <60 with poor perfusion despite ventilation = CPR
• Fluids 10–20 mL/kg isotonic, reassessing after each; 5–10 mL/kg if cardiogenic
• Phoenix: sepsis = infection + score ≥2; septic shock adds ≥1 cardiovascular point
• Epinephrine 0.01 mg/kg (0.1 mL/kg of 0.1 mg/mL); shocks 2 then 4 J/kg; adenosine 0.1 then 0.2 mg/kg
• SVT: infant ≥220, child ≥180, fixed rate, no visible P waves; cardiovert 0.5–1 then 2 J/kg
• Cuffed tube age/4 + 3.5, depth 3 × tube size; no routine cricoid pressure
• Pediatric DKA: no insulin bolus; headache, falling heart rate or rising BP suggests cerebral edema
• Status epilepticus: benzodiazepine at 5 min, at most 2 doses, then levetiracetam, fosphenytoin or valproate
• Any bruise in a non-cruising infant, or a story that does not fit development, needs an abuse evaluation