This tool implements the International Pediatric Sepsis Consensus Conference definitions (Goldstein et al., 2005) for SIRS, sepsis, severe sepsis and septic shock in children.

Stage	Definition implemented
SIRS	At least 2 of the following 4 criteria, with ≥1 being abnormal temperature or leukocyte count: • Abnormal core temperature >38.5°C or <36°C. • Tachycardia >2 SD above normal for age, or for children <1 year, bradycardia <10th percentile for age, not explained by external factors. • Tachypnoea >2 SD above normal for age or acute mechanical ventilation not due to chronic neuromuscular disease or elective anaesthesia. • Leukocyte count elevated or depressed for age, or >10% immature neutrophils, not due to cytotoxic therapy.
Sepsis	SIRS plus suspected or proven invasive infection (bacterial, viral, fungal, or rickettsial).
Severe sepsis	Sepsis plus any of: • Cardiovascular dysfunction (e.g. hypotension, need for vasoactive medication, or signs of hypoperfusion despite adequate fluid resuscitation), or • Acute respiratory distress syndrome (ARDS), or • ≥2 non-cardiovascular organ dysfunctions (respiratory, neurologic, renal, hepatic, haematologic) attributable to sepsis.
Septic shock	Sepsis with cardiovascular dysfunction (hypotension below the 5th percentile or <2 SD below normal for age, requirement for vasoactive support, or other evidence of shock) despite adequate fluid resuscitation.

Age-specific normal ranges for heart rate, respiratory rate and leukocyte count follow Goldstein et al. and must be applied clinically when deciding whether each criterion is met.

Pediatric SIRS, Sepsis, and Septic Shock Criteria