16.1 Pediatric Sepsis & Septic Shock: Phoenix Criteria and Initial Management

Pediatric Sepsis and Septic Shock

A child with infection can develop impaired oxygenation, perfusion, coagulation, or consciousness. Evaluate these changes against baseline and begin support when clinical findings warrant it. The Phoenix Sepsis Score classifies established infection-associated organ dysfunction. The Surviving Sepsis Campaign (SSC) addresses treatment when sepsis or septic shock is suspected.

Classify infection-associated organ dysfunction

The 2024 SCCM consensus uses a Phoenix score of at least 2 with suspected or confirmed infection to identify sepsis. The earlier systemic inflammatory response syndrome (SIRS) definition relied on nonspecific inflammatory findings that could also occur in uncomplicated infection. A child with sepsis and at least 1 cardiovascular point meets the Phoenix definition of septic shock. Hypotension is one way to earn a cardiovascular point, so preserved blood pressure does not exclude this classification.

The four domains total 0–13 points. The criteria apply before age 18 and exclude the birth hospitalization and encounters before 37 weeks postconceptional age. Unmeasured variables add no points. Assess a deteriorating child using the history, exam, trajectory, and available studies even if the score is incomplete. Acute kidney injury and other organ dysfunction outside the four score domains still matter clinically.

Respiratory score (0–3)

Divide arterial oxygen partial pressure by the inspired oxygen fraction for the P/F ratio. For the S/F ratio, use pulse oximeter saturation as a percentage number and divide by the inspired oxygen fraction as a decimal. Use S/F only at saturations of 97% or less and match the oxygen measurement to its oxygen setting.

Supplemental oxygen, high-flow nasal cannula, noninvasive positive pressure, and invasive ventilation qualify as respiratory support for the first point. A very low ratio on high-flow alone can still earn only 1 respiratory point. The table follows the published consensus criteria. Some electronic implementations use strict less-than comparisons at 200 and 220; document the version if comparing a boundary result with a clinical system.

Cardiovascular score (0–6)

Add three separate subscores, each worth up to 2 points:

• Vasoactive support for shock: One qualifying systemic infusion scores 1, and two or more score 2. The task force lists epinephrine, norepinephrine, dopamine, dobutamine, milrinone, and vasopressin.
• Arterial or venous lactate: Below 5 mmol/L scores 0, 5 to below 11 scores 1, and 11 or higher scores 2.
• Mean arterial pressure (MAP): Use the age row below. The ranges are shown in whole mmHg and represent Phoenix scoring thresholds.

For example, a 4-year-old with measured MAP 40 mmHg, lactate 6.0 mmol/L, and one qualifying vasoactive infusion has a cardiovascular subscore of $1+1+1=3$. With suspected infection, these cardiovascular points alone are sufficient to meet the Phoenix definition of septic shock. The pressure cutoffs in the score do not prescribe a MAP treatment goal.

Coagulation and neurologic scores

• Coagulation (0–2): Give one point per abnormality, up to two total. The thresholds are platelet count below 100,000/µL, international normalized ratio (INR) above 1.3, D-dimer above 2 mg/L fibrinogen-equivalent units (FEU), and fibrinogen below 100 mg/dL.
• Neurologic (0–2): Bilaterally fixed pupils score 2. Otherwise, a Glasgow Coma Scale score of 10 or lower earns 1. Consider the child’s baseline and drug effects when interpreting the examination.

Start treatment based on clinical concern

The 2026 pediatric SSC guidance recommends checking blood lactate in probable sepsis or suspected septic shock. Obtain blood cultures before antimicrobials when that will not substantially delay treatment. Select empiric therapy for the likely source and pathogens, accounting for host factors and local susceptibility. Narrow coverage when microbiology and the clinical course permit.

Assess promptly for a source that needs a procedure. For example, a child with a large infected pleural collection and shock may need drainage in addition to systemic antibiotics. Coordinate source control while resuscitation and antimicrobials are underway.

Reassess after each fluid bolus

In a system with intensive care available, the guideline suggests up to 40–60 mL/kg over the first hour for septic shock, in 10–20 mL/kg aliquots. Reassess after every bolus using pulse quality, refill, mental status, blood pressure, urine output, and breathing. Stop boluses if shock resolves or signs of fluid overload appear, such as new crackles with increasing oxygen need or a newly enlarged liver. With no intensive care available, the guideline recommends maintenance fluids in place of boluses for sepsis without hypotension and suggests up to 40 mL/kg in the first hour for hypotensive septic shock.

The 2026 guideline conditionally suggests balanced or buffered crystalloids for septic shock boluses. Saline is an alternative and may be preferred for some children with hyponatremia or concern for raised intracranial pressure. The subsequent PRoMPT BOLUS randomized trial did not find a lower rate of major adverse kidney events with balanced crystalloid compared with 0.9% saline. Use the clinical context and monitor response.

Individualize vasoactive and steroid decisions

Cool extremities and weak pulses can suggest low flow, and bounding pulses with a wide pulse pressure can suggest vasodilation. These findings help frame the assessment. They do not measure cardiac output or systemic vascular resistance, and mixed physiology can occur. Use serial assessments and consider cardiac and lung point-of-care ultrasound if expertise is available. Epinephrine can support contractility, and norepinephrine can support vascular tone. The 2026 panel found insufficient evidence to prefer either as the first agent or to require a particular volume before starting vasoactives. When indicated, use peripheral venous access to avoid waiting for a central line, with close site and perfusion monitoring.

Persistent shock calls for reassessment of cardiac function, perfusion, antimicrobial coverage and source control. With high-dose catecholamines the guideline suggests either adding vasopressin or further titrating catecholamines. It suggests against IV hydrocortisone when hemodynamic stability can be restored with fluids and vasoactives and makes no recommendation for or against it for instability that persists despite those measures. Give stress-dose corticosteroids if adrenal insufficiency is suspected or established, such as in a child with known adrenal insufficiency who cannot retain oral stress doses. Treat the infection and the adrenal emergency in parallel.

Primary sources include the 2024 Phoenix consensus and scoring table, Phoenix implementation notes, 2026 pediatric SSC guideline, and the PRoMPT BOLUS randomized trial.