How to manage a hypothermic intrauterine growth restriction (IUGR) neonate who remains hypothermic despite being under a warmer in a warm environment?

Management of Hypothermic IUGR Neonate Failing to Rewarm

Perform an immediate sepsis workup and start empirical antibiotics (Option B), as persistent hypothermia despite adequate warming strongly indicates an underlying pathologic process, most commonly sepsis, which carries significant mortality risk in IUGR neonates. 1, 2, 3

Why Sepsis Workup is the Priority

Persistent hypothermia in a neonate who fails to rewarm under appropriate thermal management indicates an underlying pathologic process preventing normal thermoregulation, not simply inadequate warming. 2, 3 The American Academy of Pediatrics emphasizes that hypothermia in neonates is strongly associated with late-onset sepsis, independent of other risk factors, and IUGR neonates have increased susceptibility to infection due to their compromised intrauterine environment and reduced immunologic reserves. 2

• IUGR neonates have a 12-fold increase in mortality compared to term infants when hypothermic, making aggressive investigation mandatory. 2
• Delaying sepsis workup while attempting additional warming measures is dangerous, as persistent hypothermia despite adequate warming is a medical emergency. 2

Immediate Concurrent Actions Required

While initiating the sepsis workup, you must simultaneously address other critical issues:

1. Check Blood Glucose Immediately

• Hypothermia strongly predicts hypoglycemia in neonates, particularly IUGR infants. 1, 2, 3
• Administer IV dextrose promptly per standard protocols if hypoglycemia is present. 1, 3
• This addresses Option A, but as a concurrent intervention, not the primary answer. 3

2. Optimize Thermal Management Beyond the Warmer Alone

• Add combination thermal interventions: thermal mattress, warmed humidified gases, cap, and increase room temperature to 23-25°C. 4, 1, 2, 3
• Use a servo-controlled radiant warmer or incubator targeting 36.5-37.5°C. 1, 3
• Monitor temperature continuously to prevent iatrogenic hyperthermia (>38.0°C), which increases mortality, seizures, and neurologic injury. 4, 1, 2, 3
• Evidence is insufficient to recommend either rapid (≥0.5°C/hour) or slow (<0.5°C/hour) rewarming rates. 4, 1, 3

3. Obtain Metabolic Assessment

• Perform arterial or capillary blood gas to evaluate for mixed respiratory and metabolic acidosis. 2
• Improve perfusion and tissue oxygenation for metabolic acidosis rather than administering bicarbonate. 2

Why Other Options Are Inadequate

Option C (Reassure + change environment) and Option E (Increase ambient temperature and assess after 24 hours) are dangerous because they delay critical diagnostic workup. 2 The neonate is already under a warmer and still hypothermic—this is not a simple environmental problem. Waiting 24 hours could result in missed diagnosis and increased mortality. 3

Option D (Skin-to-skin contact) is appropriate for resource-limited settings or for prevention of hypothermia in well newborns during transition, but not for a persistently hypothermic neonate in a hospital setting with available equipment. 4, 5 This neonate requires immediate medical intervention, not alternative warming methods. 5

Complete Sepsis Workup Protocol

• Obtain blood cultures, complete blood count, and C-reactive protein immediately before starting antibiotics. 2
• Perform lumbar puncture if clinically stable to rule out meningitis. 2
• Begin broad-spectrum empirical antibiotics without delay. 2, 3

Critical Pitfalls to Avoid

• Do not assume slow rewarming is safer based on outdated teaching—optimal rewarming rate remains uncertain, but frequent temperature monitoring is essential. 1, 2
• Do not create iatrogenic hyperthermia through overly aggressive rewarming settings—temperatures >38.0°C increase mortality. 1, 2
• Do not forget to check glucose immediately—this is a common oversight with serious consequences. 1
• Do not delay sepsis workup while searching for other etiologies of hypothermia—sepsis is the most common and most dangerous cause. 1, 3