Signs and Symptoms of Neonatal Sepsis
Neonatal septic shock should be clinically diagnosed before hypotension occurs by recognizing key clinical signs including temperature instability (hypothermia or hyperthermia), altered mental status, and abnormal peripheral perfusion patterns—either peripheral vasodilation (warm shock) or vasoconstriction with capillary refill >2 seconds (cold shock). 1
Core Clinical Presentation
Cardiovascular Signs
- Tachycardia or bradycardia: Heart rate <90 bpm or >160 bpm in infants is associated with increased mortality 1
- Impaired perfusion: Capillary refill time >2 seconds indicates abnormal perfusion and serves as a critical "red-flag" sign 1, 2
- Poor peripheral pulses: Weak or absent distal pulses with differential pulse quality 1
- Color changes: Poor color, mottled or pale skin 2, 3
- Hypotension: Late finding indicating decompensated shock; diagnosis should occur before this develops 1
Respiratory Signs
- Tachypnea: Increased respiratory rate 2, 3
- Respiratory distress: Increased work of breathing, grunting, retractions 2, 3
- Apnea: Particularly in premature infants 3
Neurological Signs
- Altered mental status: Lethargy, decreased responsiveness, or irritability 1, 3
- Poor tone: Hypotonia or decreased muscle tone 3
- Seizures: May occur in severe cases 3
- Bulging fontanels: Suggests increased intracranial pressure 3
Temperature Instability
- Hypothermia or hyperthermia: Either extreme is concerning in neonates 1
- Requires attention to external warming in premature infants due to immature thermogenesis mechanisms 1
Additional Clinical Features
- Poor feeding: Decreased oral intake or feeding intolerance 3
- Hepatomegaly: May indicate right ventricular failure, particularly in neonates with persistent pulmonary hypertension (PPHN) 1
- Tricuspid regurgitation: Associated with decompensated right ventricular failure in PPHN 1
- Oliguria: Urine output <1 mL/kg/hour indicates inadequate renal perfusion 4
Shock Classification Patterns
Cold Shock
- Vasoconstriction with capillary refill >2 seconds 1
- Cool extremities with poor peripheral perfusion 1
- Most common presentation in neonatal sepsis 1
Warm Shock
- Peripheral vasodilation with bounding pulses initially 1
- May progress to cold shock as condition worsens 1
Special Considerations in Premature Infants
Very low birth weight (VLBW) infants (<32 weeks gestation, <1000g) present unique challenges as their hemodynamic response is least understood and clinical signs may overlap with respiratory distress syndrome 1. These infants require:
- More cautious fluid resuscitation approach due to risk of intraventricular hemorrhage 1
- Attention to hypoglycemia due to reduced glycogen stores 1
- Monitoring for patent ductus arteriosus complications 1
- Consideration of thyroid and calcium deficiencies 1
Critical Monitoring Parameters
The American Academy of Pediatrics recommends continuous monitoring including 2:
- Temperature monitoring
- Preductal and postductal pulse oximetry
- Intra-arterial blood pressure when available
- Continuous electrocardiogram
- Serial capillary refill assessments every 5-15 minutes during resuscitation 4
Progressive Severity Indicators
Mortality risk increases progressively with specific hemodynamic patterns 1:
- Eucardia: 1% mortality
- Tachycardia/bradycardia: 3% mortality
- Hypotension with capillary refill <3 seconds: 5% mortality
- Normotension with capillary refill >3 seconds: Higher mortality risk
Common Pitfalls
- Waiting for hypotension to diagnose shock: Hypotension is a late finding; early recognition based on perfusion abnormalities is critical 1
- Overlooking subtle signs in premature infants: Clinical presentation may be nonspecific and overlap with other conditions 1, 5
- Delaying intervention: Any delay in recognition and treatment may cause death, as initial signs are often slight and nonspecific 6
- Assuming adequate perfusion with normal blood pressure: Compensated shock can exist with normal blood pressure but abnormal capillary refill and mental status 4