What labs and initial management are recommended for pediatric patients suspected of sepsis?

Pediatric Sepsis: Laboratory Evaluation and Initial Management

For pediatric patients with suspected sepsis, immediately obtain blood cultures, lactate, complete blood count with differential, and basic metabolic panel (including glucose and ionized calcium) while simultaneously initiating aggressive fluid resuscitation and empiric broad-spectrum antibiotics within 1 hour—do not delay treatment for laboratory results. 1, 2

Essential Laboratory Tests at Presentation

Immediate Priority Labs (Within Minutes)

• Blood cultures (before antibiotics if possible, but never delay antibiotics for cultures) 1, 2
• Serum lactate (critical for assessing tissue perfusion and shock severity) 1
• Point-of-care glucose (hypoglycemia must be corrected immediately) 1
• Ionized calcium (hypocalcemia correction is essential during resuscitation) 1
• Complete blood count with differential (including white blood cell count and band count for diagnostic assessment) 3

Secondary Laboratory Panel (Within First Hour)

• Basic metabolic panel (assess renal function, electrolytes, and acid-base status) 1
• Liver function tests (evaluate for organ dysfunction) 1
• Coagulation studies (PT/PTT to assess for disseminated intravascular coagulation) 1
• Arterial or venous blood gas (assess metabolic acidosis and respiratory status) 1
• C-reactive protein (although not specific, helps with trending) 4

Hemodynamic Monitoring Labs

• Central venous oxygen saturation (ScvO2) when central access obtained (target >70%) 1
• Hemoglobin level (target ≥10 g/dL during active resuscitation with ScvO2 <70%) 1

Important caveat: Procalcitonin shows promise for sepsis management but is not yet standard in pediatric guidelines, though it may help guide antibiotic duration decisions after 48 hours. 4

Time-Sensitive Initial Management Algorithm

0-5 Minutes: Immediate Resuscitation

• Establish vascular access (intraosseous if IV cannot be obtained within minutes) 1
• Begin aggressive fluid resuscitation: 20 mL/kg boluses of isotonic crystalloid (preferably balanced/buffered crystalloids over normal saline), up to 60 mL/kg or more in the first hour 1, 2
• Correct hypoglycemia and hypocalcemia immediately 1
• Administer empiric broad-spectrum antibiotics within 1 hour (can give IM or PO if IV access delayed) 1, 2
• Monitor: Pulse oximetry, continuous ECG, blood pressure, capillary refill, mental status, urine output 1

Critical pitfall: Stop fluid boluses only if rales or hepatomegaly develop, but note that rales may be present from pneumonia as the sepsis source—in this case, continue cautious fluid resuscitation with close monitoring of work of breathing. 1

15 Minutes: Fluid-Refractory Shock Management

• Begin peripheral inotropic support (low-dose dopamine or epinephrine) if second IV/IO access available while establishing central line 1
• Intubation considerations: If increased work of breathing, hypoventilation, or altered mental status, intubate with volume loading and inotropic support before/during procedure 1
  • Use ketamine with atropine (not etomidate, which suppresses adrenal axis) 1
• Obtain central venous access for definitive vasoactive medication administration 1

Distinguish shock phenotype clinically:

• Cold shock: Prolonged capillary refill >2 seconds, diminished pulses, cool/mottled extremities, narrow pulse pressure → titrate dopamine centrally, or epinephrine if dopamine-resistant 1
• Warm shock: Flash capillary refill, bounding pulses, wide pulse pressure → titrate norepinephrine centrally 1

60 Minutes: Catecholamine-Resistant Shock

• Administer hydrocortisone (stress dose 50 mg/m²/24h, up to 50 mg/kg/day) for fluid-refractory, catecholamine-resistant shock with suspected absolute adrenal insufficiency 1
  • High-risk patients: severe shock with purpura, prior chronic steroid use, pituitary/adrenal abnormalities 1
  • Obtain serum cortisol level when administering empiric hydrocortisone 1
• Monitor CVP and ScvO2 to guide ongoing resuscitation (target ScvO2 >70%, MAP-CVP normal) 1
• Transfuse packed red blood cells if hemoglobin <10 g/dL and ScvO2 <70% during active resuscitation 1

Refractory Shock (Beyond 60 Minutes)

• Rule out mechanical complications: Pericardial effusion, pneumothorax, intra-abdominal hypertension >12 mmHg 1
• Consider advanced hemodynamic monitoring (pulmonary artery catheter, PICCO, or Doppler ultrasound) to guide therapy 1
• ECMO consideration for refractory pediatric septic shock and respiratory failure 1

Ongoing Laboratory Monitoring

Drug Toxicity Surveillance

• Monitor drug levels closely as drug metabolism is significantly reduced in severe sepsis, increasing risk of adverse events 1, 2

Glycemic Control

• Target glucose <180 mg/dL with insulin therapy, but always provide glucose infusion alongside insulin in neonates and children (some make no insulin, others are insulin-resistant) 1, 2

Coagulation Monitoring

• Serial PT/PTT and platelet counts to identify progressive disseminated intravascular coagulation or thrombotic microangiopathy 1
• Administer fresh frozen plasma for sepsis-induced thrombotic purpura with progressive purpura and prolonged coagulation times 1
• Platelet transfusion follows similar thresholds as adults 1

Hemoglobin Targets After Stabilization

• After shock resolution and recovery from hypoxemia, lower hemoglobin target to <7 g/dL is reasonable (though severe sepsis subgroup data show increased nosocomial infections with restrictive strategy) 1

Antibiotic Strategy Refinement

Toxic Shock Syndrome

• Add clindamycin for children with erythroderma and suspected toxic shock to reduce toxin production 1
• Consider IVIG for refractory toxic shock syndrome 1

De-escalation Protocol

• Daily reassessment starting at 48 hours for antibiotic de-escalation based on culture results and clinical improvement 2
• Narrow or discontinue antibacterials once viral etiology confirmed and bacterial infection excluded (consult infectious disease) 2

Source Control

• Emergent debridement or drainage for necrotizing infections, abscesses, or other drainable sources 1
• Remove infected intravascular catheters after establishing alternative access 2

Fluid Overload Management

• Use diuretics to reverse fluid overload once shock has resolved 1, 2
• Initiate continuous venovenous hemofiltration (CVVH) or intermittent dialysis if diuretics fail, to prevent >10% total body weight fluid overload 1, 2

Key principle: The therapeutic endpoints are capillary refill ≤2 seconds, normal pulses, warm extremities, urine output >1 mL/kg/h, normal mental status, normal blood pressure for age, and normalized glucose/calcium. 1