# Sepsis Recognition and Management: Pediatric and Adult Paradigms

## Introduction

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. It remains a leading cause of morbidity and mortality in both children and adults. While the underlying pathophysiology is similar, **definitions, recognition criteria, and resuscitation protocols differ significantly** between pediatric and adult populations. The med-peds physician must be fluent in both paradigms.

## Definitions

### Adult Sepsis (Sepsis-3, 2016)
**Sepsis**: Infection plus organ dysfunction defined by an increase of 2+ points in the **SOFA score**. **Septic shock**: Sepsis plus vasopressor requirement to maintain MAP 65 mmHg and lactate >2 mmol/L despite adequate fluid resuscitation. **qSOFA** (Quick SOFA): Altered mentation, SBP 100 mmHg or less, RR 22 or more (screening tool, not diagnostic)

### Pediatric Sepsis (Phoenix Criteria, 2024)
**Pediatric sepsis**: Infection plus organ dysfunction defined by **Phoenix Sepsis Score 2+** (respiratory, cardiovascular, coagulation, neurologic domains) **Pediatric septic shock**: Sepsis with cardiovascular dysfunction (vasoactive requirement or lactate >5 mmol/L) Replaces the prior 2005 consensus definitions that used SIRS criteria.

### Key Differences
Adult Sepsis-3 abandoned SIRS criteria; pediatric definitions have now followed. Pediatric vital sign thresholds are **age-dependent**. Hypotension is a late finding in children; tachycardia and poor perfusion are earlier signs.

![Comparison table of adult Sepsis-3 vs pediatric Phoenix criteria](images/sepsis-definitions-comparison.jpg)

## Pathophysiology

Infection triggers innate immune response: cytokine release, complement activation, coagulation cascade. **Pro-inflammatory cascade**: TNF-alpha, IL-1, IL-6 lead to vasodilation, endothelial dysfunction, capillary leak. Organ dysfunction results from microcirculatory failure, cellular hypoxia, and mitochondrial dysfunction. Children have greater physiologic reserve but can deteriorate rapidly once compensatory mechanisms fail.

## Recognition

### Adult Warning Signs
Fever or hypothermia with suspected infection; Tachycardia, tachypnea, hypotension; Altered mental status; Elevated lactate (>2 mmol/L); New organ dysfunction (rising creatinine, bilirubin, coagulopathy).

### Pediatric Warning Signs
**Tachycardia** disproportionate to fever; Delayed capillary refill (>3 seconds) or flash capillary refill; Altered mental status (irritability, lethargy); Decreased urine output; Mottled or cool extremities (cold shock) vs. warm, flushed skin (warm shock).

### Screening Tools
Adult: qSOFA, NEWS (National Early Warning Score), institutional sepsis alerts. Pediatric: Pediatric early warning scores (PEWS), age-adjusted vital sign parameters.

## Management: The First Hour

### Adult Sepsis Bundle (Surviving Sepsis Campaign)
**Measure lactate**; remeasure if initial lactate >2 mmol/L. Obtain **blood cultures** before antibiotics. Administer **broad-spectrum antibiotics** within 1 hour of recognition. Begin **30 mL/kg crystalloid** for hypotension or lactate 4 mmol/L or more. Apply **vasopressors** if hypotensive after initial fluid resuscitation (norepinephrine first-line)

### Pediatric Sepsis Bundle
Obtain blood cultures; administer **broad-spectrum antibiotics** within 1 hour. **Fluid resuscitation**: 10-20 mL/kg isotonic crystalloid boluses; reassess after each bolus. Avoid excessive fluid: reassess for signs of fluid overload (hepatomegaly, rales, worsening respiratory status) **Vasoactive agents**: Epinephrine for cold shock; norepinephrine for warm shock. Consider **stress-dose hydrocortisone** for catecholamine-resistant shock.

![Flowchart for pediatric sepsis initial resuscitation](images/pediatric-sepsis-resuscitation.jpg)

## Antibiotic Selection

### Common Empiric Regimens

| Population | Empiric Regimen | Coverage |
|---|---|---|
| Neonates | Ampicillin + gentamicin | GBS, E. coli, Listeria |
| Children | Ceftriaxone +/- vancomycin | Pneumococcus, Meningococcus, S. aureus |
| Adults (community) | Ceftriaxone + azithromycin or piperacillin-tazobactam | Gram-negatives, pneumococcus, atypicals |
| Adults (nosocomial) | Vancomycin + piperacillin-tazobactam or meropenem | MRSA, Pseudomonas, resistant gram-negatives |

### Source-Specific Considerations
Tailor antibiotics once source is identified. De-escalate based on culture results and clinical improvement. Duration typically 7-10 days; procalcitonin-guided de-escalation reduces antibiotic exposure.

## Fluid Resuscitation: Evolving Evidence

**FEAST trial** (pediatric, resource-limited): Fluid boluses increased mortality in febrile children with impaired perfusion in Africa. **CLASSIC trial** (adult): Restrictive fluid strategy was noninferior to liberal fluids in adult septic shock. Current consensus: Fluid resuscitation remains essential but requires **frequent reassessment** for response and fluid overload. Balanced crystalloids (lactated Ringer's) may be preferred over normal saline.

## Vasopressor and Inotrope Considerations

**Adults**: Norepinephrine first-line; add vasopressin as second agent; dobutamine for low cardiac output. **Children**: Epinephrine or norepinephrine first-line depending on shock phenotype; milrinone for low cardiac output with high SVR. Central access preferred but peripheral vasopressors acceptable in emergency.

## Adjunctive Therapies

**Corticosteroids**: Hydrocortisone 200 mg/day IV for adults with refractory shock; stress-dose for children with suspected adrenal insufficiency. **Blood transfusion**: Target hemoglobin 7 g/dL in adults; less clear threshold in children. **Source control**: Drain abscesses, remove infected devices. **Glucose management**: Avoid hypoglycemia (especially in neonates and young children)

![Diagram showing the sepsis resuscitation algorithm for adults](images/adult-sepsis-algorithm.jpg)

## Clinical Pearls

Sepsis is a medical emergency; every hour of delayed antibiotics increases mortality by approximately 4%. In children, **hypotension is a late sign**; do not wait for it to diagnose shock. The Phoenix Sepsis Score provides a standardized, globally applicable definition for pediatric sepsis. Reassess frequently after each fluid bolus; more is not always better. Med-peds physicians on call must be comfortable managing both pediatric and adult sepsis protocols simultaneously.

## References

1. Singer M, Deutschman CS, Seymour CW, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). *JAMA*. 2016;315(8):801-810.
2. Schlapbach LJ, Watson RS, Sorce LR, et al. International consensus criteria for pediatric sepsis and septic shock. *JAMA*. 2024;331(8):665-674.
3. Evans L, Rhodes A, Alhazzani W, et al. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021. *Intensive Care Med*. 2021;47(11):1181-1247.
4. Maitland K, Kiguli S, Opoka RO, et al. Mortality after fluid bolus in African children with severe infection (FEAST). *N Engl J Med*. 2011;364(26):2483-2495.