Pediatric Assessment Triangle

The Pediatric Assessment Triangle (PAT) is a hands-off look from across the room. It takes about a minute. Before any monitor, stethoscope or hands-on exam, it sorts the child into a physiologic category. Three things get rated: Appearance, Work of Breathing and Circulation to Skin. The PAT anchors the AAP-sponsored Pediatric Education for Prehospital Professionals (PEPP) course. Most standardized American life support courses have built it in, including PALS, APLS and ENPC.

Why Kids Are Different

• Compensation hides shock: kids hold their blood pressure up by raising heart rate and clamping down peripheral vessels. Hypotension shows up late.
• Vital signs lag: the PAT can go abnormal before the numbers do. Don't wait for the monitor to confirm what the child is showing you.
• Handling provokes agitation: touch an infant or toddler and the assessment gets harder. Watch first.
• Breathing drives most events: most pediatric cardiac arrests follow progressive respiratory failure or shock. Catch failing breathing or circulation early. That is the priority. See Pediatric Cardiac Arrest (PALS).

The PAT is a screen, not a diagnosis. It sorts the child. The hands-on primary assessment confirms and refines that impression.

1. Stand back and watch: observe from the doorway or the foot of the bed for about a minute, with the child in the caregiver's arms if possible.
2. Rate Appearance: use TICLS (see the Appearance table).
3. Rate Work of Breathing: look, listen and watch the chest and abdomen, including sounds heard from across the room.
4. Rate Circulation to Skin: check colour, pallor, mottling and central cyanosis on the trunk, lips and tongue.
5. Assign the category: use the Putting the Triangle Together table and record it before the numbers.
6. Move to hands-on ABCDE: begin the primary assessment once the impression is recorded.

Appearance comes first, because it is the most important component. One look tells you how ventilation, oxygenation, brain perfusion and CNS function are doing, all at once. That makes an abnormal appearance the most sensitive sign that a child is seriously ill. Use the TICLS mnemonic: Tone, Interactiveness, Consolability, Look/Gaze and Speech/Cry.

Posture and sounds give you the fastest clues. Work of Breathing (WOB) is visible effort, judged from across the room. Effort is not adequacy. A hard-working child can still oxygenate. A quiet-looking one can be failing.

The skin is an early tell. When cardiac output falls, the body pulls blood away from the skin to protect the brain and heart. Circulation to Skin reflects cardiovascular adequacy, so skin changes show up early and visibly.

Put the three components together and you get one general impression. The categories below follow the PAT teaching convention. Triage validation studies report these pathophysiology groups: respiratory distress, respiratory failure, shock, CNS or metabolic dysfunction, and cardiopulmonary failure.

Other combinations are not named categories. Treat the most abnormal component. Escalate. Reassess.

• Any abnormal component: move to the hands-on ABCDE now and raise urgency. Run the primary assessment on every PAT, normal ones included. Repeat it after each intervention.
• Two abnormal components: escalate. Treat the dominant problem.
• All three abnormal: call for help and bring the team to the bedside. Treat as imminent arrest.

Next: Primary Assessment (ABCDE)

• A, Airway: patent, maintainable or at risk; secretions, stridor, position.
• B, Breathing: rate, SpO₂, effort, chest movement, lung sounds, EtCO₂ where available.
• C, Circulation: heart rate, blood pressure, capillary refill (normal 2 seconds or less; more than 2 seconds is prolonged), checked centrally on the sternum or forehead, skin temperature and pulse quality.
• D, Disability: AVPU or GCS, pupils, blood glucose, posturing.
• E, Exposure: undress the child. Look for rash (petechiae or purpura), injury, deformity and temperature. Apply local protocols for suspected maltreatment.

Where to Go Next by Abnormal Component

• Abnormal breathing: Pediatric Airway Anatomy for airway anatomy and obstruction.
• Abnormal circulation: Pediatric Shock.
• Breathing stopped or three abnormal components: Pediatric Cardiac Arrest (PALS).
• Vital-sign ranges by age: Pediatric Vital Signs by Age.

• Observer variation: reviews report inter-observer variability and inconsistent training. The category depends on who is doing the assessing.
• Neonates and complex chronic conditions: the evidence is thinner. It applies less well here.
• Validation: most studies are observational and single-centre. The psychometric evidence is still limited. The PAT is a structured screen. It is not a validated score for disposition.

Neonates and Young Infants

• The PAT is less proven in neonates. Newborn resuscitation follows the Neonatal Resuscitation Program, not this tool.
• In a newborn, grunting, retractions and central cyanosis are never normal. Escalate early.

Children With Chronic Conditions or Devices

• Tracheostomy, shunts, feeding tubes and home ventilation all move the baseline. Ask the caregiver what normal looks like for this child.
• Looking stable on the PAT does not rule out deterioration in a child with a complex condition. Reassess more often.

Injured Children

• The PAT works for injury as well as medical illness. Check the mechanism and look for external hemorrhage alongside it. A normal PAT does not exclude significant injury.
• The PAT does not measure pain or fever. Record them separately. Reassess after analgesia or antipyresis.

Suspected Maltreatment

• Injuries that do not match the history need escalation. So does an unexplained change in appearance. Document per local protocol.

Prehospital crews use the PAT in the field, not only in the ED. A single-center retrospective cohort tracked pediatric EMS transports to a quaternary pediatric emergency department. Scores of 1 or more were linked to advanced life support transport (odds ratio 67.9). Scores of 2 or more were linked to higher odds of ICU-level care, direct to surgery or death (odds ratio 4.9). Most children (65.9%) scored 0, so the signal sits in the minority with abnormal components. The authors call it a promising adjunct to ED assessment, not a validated disposition score.

• Equipment: have a pediatric length-based reference and pre-calculated or colour-coded doses ready, per local protocol.
• Destination: a pediatric-capable emergency department, PICU or pediatric trauma centre, per the regional plan.
• Restraint: use a child-sized restraint on the stretcher. Never restrain a child on a caregiver's lap.
• Caregiver: keep the caregiver with the child and treat their description of baseline as data.
• Heat loss: cover the head and trunk of an infant and warm the compartment.
• Handoff: report the PAT category first, then the trend across reassessments.