13.1 Sepsis & SIRS

Why Pediatric Sepsis Looks Different on the Exam

Sepsis in children is life-threatening organ dysfunction caused by a dysregulated host response to infection. On the CCRN-Pediatric exam, the clinical emphasis is not adult SOFA arithmetic; it is early recognition of perfusion failure and disciplined execution of pediatric resuscitation bundles. Infants and children have high resting metabolic rates, limited stroke-volume reserve, and strong compensatory vasoconstriction, so they often preserve systolic blood pressure until late. Waiting for hypotension to diagnose septic shock is a classic failure mode—and a frequent exam trap.

Historically, the International Pediatric Sepsis Consensus Conference (IPSCC) operationalized sepsis as suspected or proven infection plus Systemic Inflammatory Response Syndrome (SIRS) with severity stratified by cardiovascular dysfunction or acute respiratory distress syndrome (ARDS) and other organ failures. Newer research frameworks such as the Phoenix Sepsis Score define pediatric sepsis through measured organ dysfunction rather than SIRS counts. For bedside CCRN thinking, treat both ideas as complementary: infection plus new organ or perfusion dysfunction = sepsis, and SIRS alone is never enough to label a child septic.

Pediatric SIRS Criteria and Their Limits

SIRS requires abnormal values in at least two of four categories, with at least one being temperature or leukocyte abnormality in many teaching frameworks:

Children meet SIRS criteria easily. Fever plus tachycardia is common in viral illness, after surgery, with pain, or during agitation. That high sensitivity and low specificity is the core limitation: SIRS is a screen for systemic inflammation, not a synonym for infection and not a diagnosis of sepsis. Exam items often present a postoperative toddler with fever and tachycardia who does not have sepsis until you demonstrate infection plus organ or perfusion dysfunction. Conversely, an immunocompromised child may be septic with muted fever and leukocyte responses—so clinical perfusion and organ function outweigh checkbox SIRS.

Practical screening tools used in pediatric ICUs and wards include Pediatric Early Warning Score (PEWS) variants and institutional sepsis screens that combine vital-sign trends, caregiver concern, and high-risk comorbidities (oncology, transplant, central lines, asplenia, technology dependence). Adult qSOFA is a poor fit for children and should not be used as a standalone pediatric screen.

Recognition: Compensated Versus Decompensated Septic Shock

Compensated septic shock features signs of inadequate tissue perfusion with normal age-adjusted blood pressure: sinus tachycardia, delayed capillary refill (>2–3 seconds) or flash refill with bounding pulses in warm shock, mottling, cool extremities, oliguria, lactic acidosis, and irritability or lethargy. Decompensated shock adds hypotension (systolic pressure below age thresholds) and often signals imminent cardiovascular collapse. Cold (low-output) septic shock—cool skin, prolonged refill, weak pulses—is common in children; warm (vasodilated) shock—flash refill, bounding pulses—also occurs, especially early or with certain pathogens.

A worked pattern: a 4-year-old with pneumonia has HR 168, CRT 4 seconds, cool legs, urine 0.3 mL/kg/h, and BP 92/55. This child is in compensated septic shock despite a "normal" blood pressure and needs immediate bundle care—not a watch-and-wait approach.

Bundle Concepts for Children

Pediatric sepsis bundles compress recognition-to-treatment time. Core elements aligned with Surviving Sepsis Campaign guidance for children and ACCM/PALS septic-shock teaching include:

1. Obtain IV/IO access rapidly; do not delay care for a perfect peripheral line.
2. Draw blood cultures (and other indicated cultures) before antibiotics when doing so will not meaningfully delay therapy.
3. Give broad-spectrum antimicrobials within 1 hour of recognition in septic shock; each hour of delay increases mortality risk.
4. Give isotonic crystalloid in weight-based boluses (commonly 20 mL/kg), reassessing after each bolus for perfusion improvement versus hepatomegaly, crackles, or rising oxygen need.
5. In the first hour, many children with fluid-responsive septic shock receive approximately 40–60 mL/kg total if there is no sign of cardiac dysfunction or fluid overload; stop or slow fluids and start vasoactive support earlier if overload appears.
6. Begin vasoactive infusions for fluid-refractory shock—often epinephrine as a first-line agent in pediatric septic shock; norepinephrine when warm vasodilated physiology predominates after volume restoration.
7. Pursue source control (line removal, abscess drainage, debridement) as soon as feasible.

Balanced crystalloids are generally preferred over large volumes of 0.9% saline when available, to limit hyperchloremic acidosis. Glucose must be monitored closely—hypoglycemia is common in infants with sepsis and worsens neurologic injury.

Vasopressors and Adjuncts (Pediatric Framing)

Unlike adult SSC defaults that start with norepinephrine for almost all septic shock, pediatric practice is physiology-guided. Epinephrine supports heart rate and contractility while raising systemic resistance—useful when cold shock or myocardial depression is suspected. Norepinephrine is favored for warm shock with low systemic vascular resistance after adequate preload. Dopamine is no longer preferred as first-line when epinephrine or norepinephrine is available. Stress-dose hydrocortisone is considered for catecholamine-resistant shock or known adrenal insufficiency/chronic steroid therapy. Inotropes such as dobutamine or epinephrine titration address persistent low cardiac output despite vascular tone support.

Nursing Priorities That Change Outcomes

Critical care nurses drive the time-critical pathway: escalate PEWS or sepsis-screen triggers, obtain weight-based dosing readiness, prioritize IO access when IV attempts fail, time-stamp antibiotic hang times, and reassess perfusion after every fluid bolus. Document capillary refill, pulse quality, mentation, urine output (target often ≥1 mL/kg/h once resuscitated), lactate trends, and evolving respiratory effort. Advocate for source imaging or operative drainage when the child fails to improve despite correct bundle steps. Family communication matters: explain that early antibiotics and fluids are treatments, not "just tests," while preparing caregivers for possible ICU vasoactive therapy and respiratory support.

Common Exam Traps

• Equating SIRS with sepsis in a febrile tachycardic child who has no organ or perfusion failure.
• Waiting for hypotension before treating pediatric septic shock.
• Giving adult-style 30 mL/kg once without pediatric 20 mL/kg bolus-and-reassess logic.
• Choosing dopamine first when epinephrine or norepinephrine is the better physiology-matched agent.
• Delaying antibiotics for a complete imaging workup in a child already in shock.