Pediatric SIRS (PSIRS)

Criteria: abnormal temperature, abnormal heart rate, abnormal respiratory rate, and abnormal leukocyte count/band forms. SIRS is present when two or more are abnormal, and at least one of those is abnormal temperature or leukocyte count. This is a screening construct to prompt reassessment and sepsis consideration.

Use values captured in the same clinical window; mixed-timepoint vitals and labs can create false positives.

Use age-appropriate reference ranges for heart rate, respiratory rate, and leukocytes. Fever >38.5°C or hypothermia <36°C fulfill the temperature criterion.

• Heart/respiratory rate: reference the Pediatric Vital Signs calculator for PALS-style bands; sustained tachy/brady with clinical concern matters most.
• Leukocytes/bands: use local lab age norms; bandemia or low WBC can meet the criterion. Immunocompromised patients may not mount leukocytosis.

• Screen: If SIRS positive with suspected infection, initiate your pediatric sepsis pathway (cultures, labs, fluids, antibiotics per policy).
• Reassess: Repeat vitals, perfusion checks, mental status, and lactate (if used locally). Track urine output and capillary refill.
• Escalate: Early involvement of critical care for hypotension, altered mental status, or escalating support needs.
• Source: Evaluate for pneumonia, UTI, abdominal source, skin/soft tissue, CNS infection; obtain imaging/labs guided by presentation.

1. Confirm age-appropriate thresholds and verify data timing consistency.
2. If SIRS-positive with infection concern, trigger local sepsis bundle actions immediately.
3. Recheck perfusion, blood pressure trend, mental status, and urine output after initial interventions.
4. Escalate to senior/critical care support early for hypotension or worsening organ perfusion signs.
5. Document criterion-level findings and planned reassessment interval in handoff.

• After initial positive screen and first interventions: repeat focused vitals/perfusion check in the same care block per protocol.
• If improving and hemodynamically stable: continue serial reassessment at local sepsis-pathway intervals.
• If any concerning deterioration or trajectory mismatch: immediate repeat assessment and escalation.

• Non-infectious causes: trauma, burns, autoimmune flares, post-op states, endocrine crises, toxin/ingestion.
• Chronic baseline: some patients (e.g., congenital heart disease, chronic lung disease) may have baseline tachycardia/tachypnea—interpret trends, not single values.
• Neonates/infants: thresholds differ; follow neonatal sepsis pathways where applicable.

Use SIRS to nudge action, but let clinical judgment and serial exams drive disposition and therapy.

• Counting transient fever/tachycardia after agitation without repeat assessment.
• Applying non-age-adjusted ranges to infants and misclassifying risk.
• Treating SIRS as a diagnosis instead of a prompt for broader clinical workup.
• Delaying escalation while waiting for complete labs despite worsening perfusion signs.

• Persistent perfusion abnormalities or hypotension despite initial resuscitation.
• Rapid deterioration in mental status, respiratory effort, or urine output.
• SIRS-positive child with high-risk comorbidity and uncertain source control.
• Clinical decline despite nominally improved individual criteria values.

• Which SIRS criteria were met and exact age-adjusted thresholds applied.
• Source evaluation status and sepsis bundle actions completed/pending.
• Trend summary for perfusion, blood pressure, mental status, and urine output.
• Current antimicrobial/fluid strategy and response window.
• Escalation trigger and next reassessment interval.

• Pediatric Vital Signs for age-adjusted bands.
• Pediatric Blood Volume and Transfusion Volume when resuscitating.
• Pediatric eGFR when dosing renally cleared antibiotics.

• Goldstein B, et al. International pediatric sepsis consensus definitions (2005).
• Weiss SL, et al. Pediatric sepsis definitions and outcomes (2017).
• Surviving Sepsis Campaign: pediatric guidelines (2020).