Signs of Potential Sepsis in Premature Infants
Recognize septic shock in premature infants by identifying temperature instability, altered mental status, and abnormal peripheral perfusion (capillary refill >2 seconds) before hypotension develops—waiting for blood pressure to drop is a critical and potentially fatal error. 1, 2
Core Clinical Signs to Assess Immediately
Temperature Abnormalities
- Hypothermia or hyperthermia are key early warning signs that should trigger immediate evaluation 1
- Temperature instability alone, while common, is too non-specific to confirm or exclude sepsis but must be considered in context 3
Cardiovascular Signs (Most Critical)
- Heart rate <90 bpm or >160 bpm in infants is associated with increased mortality and represents a threshold requiring immediate intervention 1, 2
- Capillary refill time >2 seconds is a critical "red flag" sign indicating impaired perfusion 1, 2
- Poor or absent distal pulses with differential pulse quality between extremities 2, 3
- Hypotension is a late finding indicating decompensated shock—diagnosis must occur before this develops 1, 2
Neurological Signs
- Altered mental status including lethargy, decreased responsiveness, or irritability 1, 2
- Progressive lethargy or somnolence that worsens over hours 1
- Poor feeding or decreased interaction 1
Respiratory Signs
- Tachypnea (increased respiratory rate) 1
- Respiratory distress with increased work of breathing, grunting, and retractions 1
- Apnea episodes (though too non-specific alone to confirm sepsis) 1, 3
- Need for increased respiratory support from baseline 3
Skin and Perfusion Signs
- Grey skin color is strongly associated with sepsis 3
- Mottled or cool extremities indicating poor peripheral perfusion 2
- Peripheral vasodilation (warm shock) or vasoconstriction (cold shock) 1
Progressive Mortality Risk Pattern
The American College of Critical Care Medicine identifies escalating mortality risk based on hemodynamic patterns 1, 2:
- Normal heart rate with normal perfusion: 1% mortality
- Tachycardia or bradycardia alone: 3% mortality
- Hypotension with capillary refill <3 seconds: 5% mortality
- Normal blood pressure with capillary refill >3 seconds: 7% mortality
- Hypotension with capillary refill >3 seconds: 33% mortality 1
Special Considerations for Very Premature Infants
Very Low Birth Weight (<1000g, <32 weeks)
- Require more cautious fluid resuscitation due to risk of intraventricular hemorrhage, particularly in infants <30 weeks gestation 1, 2
- Monitor closely for hypoglycemia due to reduced glycogen stores and limited muscle mass for gluconeogenesis 1, 2
- Patent ductus arteriosus complicates management—rapid fluid administration may increase left-to-right shunting causing pulmonary edema 1, 4
Heart Rate Characteristics in Preterm Infants
- Reduced baseline heart rate variability and transient decelerations can precede clinical deterioration by up to 24 hours 5, 6, 7
- These abnormal patterns may occur before other clinical signs become apparent 7
Critical Pitfalls to Avoid
Do not wait for hypotension to diagnose shock—this is a late finding indicating decompensation, and early recognition based on perfusion abnormalities (capillary refill, mental status, heart rate) is essential for survival 1, 2
Do not assume adequate perfusion with normal blood pressure—compensated shock can exist with normal blood pressure but abnormal capillary refill and altered mental status 2
Do not rely on single non-specific signs like temperature instability, apnea, or feeding difficulties alone—these are too non-specific but gain significance when combined with perfusion abnormalities 3
Monitoring Parameters During Evaluation
Continuous assessment should include 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 active resuscitation 2