Nursing Management of Common Neonatal Disorders:
Hypothermia and Hyperthermia
Comprehensive Nursing Notes for Students
Table of Contents
IntroductionNeonatal Hypothermia
Definition & Classification Pathophysiology Causes & Risk Factors Clinical Manifestations Nursing Assessment Nursing Management Complications PreventionNeonatal Hyperthermia
Definition Pathophysiology Causes & Risk Factors Clinical Manifestations Nursing Assessment Nursing Management Complications Prevention Comparison Table Case Studies ReferencesIntroduction
Thermoregulation is a critical physiological function that is particularly challenging for newborns due to their immature metabolic systems and relatively large body surface area. Maintaining thermal stability is a key aspect of neonatal nursing care as both hypothermia and hyperthermia can lead to significant morbidity and mortality.
Why is thermoregulation crucial in neonates?
- Neonates have a large surface area-to-body mass ratio (increased heat loss)
- Limited subcutaneous fat (reduced insulation)
- Immature temperature control mechanisms
- Limited ability to generate heat through shivering
- Immature central nervous system for thermoregulation
Fig 1: Comparison of thermoregulation between adults and neonates
Neonatal Hypothermia
Definition & Classification
Neonatal hypothermia is defined as a core temperature below 36.5°C (97.7°F). It occurs when heat loss exceeds the neonate’s ability to produce heat, leading to a drop in core temperature.
| Classification | Temperature Range | Description |
|---|---|---|
| Cold Stress | 36.0-36.4°C (96.8-97.5°F) | Early stage of hypothermia; compensatory mechanisms are activated |
| Moderate Hypothermia | 32.0-35.9°C (89.6-96.6°F) | Compensatory mechanisms begin to fail; increased metabolic rate |
| Severe Hypothermia | < 32.0°C (< 89.6°F) | Life-threatening; marked depression of metabolism and CNS function |
The normal axillary temperature range for a neonate is 36.5-37.5°C (97.7-99.5°F). Any temperature below 36.5°C is considered hypothermic according to the World Health Organization (WHO).
Pathophysiology
Neonates lose heat through four primary mechanisms:
Evaporation
Heat loss through the conversion of water to vapor from the skin and respiratory tract. Most significant at birth when the neonate is wet with amniotic fluid.
Convection
Heat loss to air currents flowing over the neonate’s skin. Occurs when the neonate is exposed to drafts from doors, windows, or air conditioning.
Conduction
Direct transfer of heat from the neonate’s body to cooler surfaces in direct contact (e.g., cold scales, examination tables, cold hands).
Radiation
Heat loss to cooler objects not in direct contact with the neonate (e.g., cold walls, windows). Objects emit heat waves that move toward cooler objects.
Heat Production in Neonates
Neonates produce heat primarily through:
- Non-shivering thermogenesis (NST): Metabolism of brown adipose tissue (BAT)
- Increased metabolic rate: Higher oxygen consumption and caloric expenditure
- Physical activity: Limited movement and muscle activity
Fig 2: Four mechanisms of heat loss in neonates
Pathophysiological Cascade of Hypothermia
Mnemonic: “COLD STRESS”
- Cyanosis (peripheral)
- Oxygen consumption increases
- Lactic acid production (metabolic acidosis)
- Depletion of glycogen stores
- Surfactant production decreases
- Thermogenesis (non-shivering) activated
- Respiratory distress
- Energy consumption increases
- Sucking ability decreases
- Sepsis risk increases
Causes & Risk Factors
Environmental Factors
- Cold delivery room (< 25°C)
- Cold surfaces (scales, examination tables)
- Drafts from doors, windows, fans
- Delayed drying after birth
- Cold oxygen or medications
- Bathing too soon after birth
- Transportation without adequate warming
Neonatal Factors
- Prematurity
- Low birth weight (<2500g)
- Intrauterine growth restriction (IUGR)
- Reduced subcutaneous fat
- Congenital anomalies (e.g., gastroschisis, omphalocele)
- Central nervous system disorders
- Sepsis
- Hypoglycemia
Maternal Factors
- Maternal diabetes (risk of hypoglycemia)
- Maternal drugs affecting thermoregulation
- Placental insufficiency
- Prolonged rupture of membranes
- Cesarean delivery (lower delivery room temperature)
High-Risk Neonates for Hypothermia
The most vulnerable neonates include:
- Extremely premature neonates (<28 weeks)
- Very low birth weight infants (<1500g)
- Small for gestational age (SGA) infants
- Neonates with reduced brown fat (e.g., growth-restricted infants)
- Neonates with large exposed surface areas (e.g., gastroschisis)
Clinical Manifestations
Initial Responses
- Peripheral vasoconstriction
- Acrocyanosis (blue extremities)
- Cool skin to touch
- Increased muscle tone/flexed posture
- Irritability/crying
Progressive Signs
- Lethargy/decreased activity
- Poor feeding/weak suck
- Respiratory distress
- Tachypnea (fast breathing)
- Bradycardia (slow heart rate)
- Hypotonia (decreased muscle tone)
Severe Hypothermia
- Apnea
- Bradycardia
- Severe metabolic acidosis
- Sclerema (hardening of subcutaneous tissue)
- Bleeding/coagulation issues
- Shock
- Coma/brain damage
Important: Neonatal hypothermia often presents with non-specific signs that may overlap with sepsis, hypoglycemia, or other conditions. Temperature assessment is essential for differential diagnosis.
Physical Examination Findings
| Body System | Findings |
|---|---|
| Integumentary | Pale, mottled, cold skin; peripheral cyanosis; sclerema in severe cases |
| Respiratory | Tachypnea, grunting, nasal flaring, retractions, apnea |
| Cardiovascular | Bradycardia, poor peripheral perfusion, hypotension (late sign) |
| Neurological | Initial irritability followed by lethargy, poor cry, hypotonia, poor reflexes |
| Gastrointestinal | Poor feeding, abdominal distension, vomiting, delayed gastric emptying |
| Metabolic | Hypoglycemia, metabolic acidosis, jaundice |
Nursing Assessment
Initial Assessment
- Measure and document temperature (axillary preferred method)
- Assess vital signs (heart rate, respiratory rate, blood pressure)
- Observe skin color, temperature, and perfusion
- Check capillary refill time (normal <2 seconds)
- Assess activity level and muscle tone
- Observe feeding behaviors and suck reflex
- Evaluate respiratory effort and work of breathing
Ongoing Monitoring
- Continuous temperature monitoring during rewarming
- Vital signs monitoring every 15-30 minutes until stable
- Blood glucose monitoring (risk of hypoglycemia)
- Monitoring for signs of sepsis (hypothermia can be a sign)
- Cardiorespiratory monitoring (for bradycardia, apnea)
- Fluid balance assessment (input/output)
- Monitoring response to interventions
Diagnostic Assessments
| Assessment | Purpose | Expected Findings in Hypothermia |
|---|---|---|
| Blood glucose | Assess for hypoglycemia | May be low (<45 mg/dL) due to increased glucose utilization |
| Complete blood count (CBC) | Assess for infection | May show elevated WBC count if sepsis is present |
| Blood gases | Assess acid-base status | Metabolic acidosis (↓ pH, ↓ HCO₃⁻, normal or ↑ PaCO₂) |
| Electrolytes | Assess fluid and electrolyte balance | Possible hyperkalemia, hyponatremia |
| Coagulation studies | Assess for coagulopathy | Prolonged PT/PTT, low platelets in severe cases |
| Blood cultures | Rule out sepsis | Positive in case of infection |
Mnemonic: “WARM CHECK”
Key assessment components for hypothermic neonates:
- Weight and gestational age (risk factors)
- Activity level and muscle tone
- Respiratory status (rate, effort, pattern)
- Metabolic needs (glucose level)
- Color and capillary refill
- Heart rate and rhythm
- Environment (temperature, drafts)
- Core temperature (axillary preferred)
- Keep monitoring during rewarming
Nursing Management
Rewarming Strategies
Rewarming should be gradual to prevent complications. The rate of rewarming should be 0.5-1.0°C per hour.
| Severity | Temperature Range | Rewarming Method | Nursing Interventions |
|---|---|---|---|
| Mild Hypothermia | 36.0-36.4°C | Passive external rewarming |
|
| Moderate Hypothermia | 32.0-35.9°C | Active external rewarming |
|
| Severe Hypothermia | < 32.0°C | Active external + core rewarming |
|
Caution: Avoid rapid rewarming! Rapid rewarming can cause apnea, hypotension, increased oxygen consumption, and increased insensible water loss. The target rewarming rate is 0.5-1.0°C per hour.
Additional Nursing Interventions
Respiratory Support
- Provide warmed, humidified oxygen if needed
- Position to maintain airway
- Monitor oxygen saturation
- Suction gently only if necessary
- Be prepared for respiratory support/resuscitation
Circulatory Support
- Monitor heart rate and blood pressure
- Assess peripheral perfusion
- Establish IV access if needed
- Administer warmed IV fluids
- Be alert for signs of shock
Metabolic Support
- Monitor blood glucose every 1-2 hours
- Administer glucose for hypoglycemia
- Initiate early feeding when stable
- Monitor electrolytes and acid-base status
- Calculate fluid requirements (may need extra)
Monitoring & Documentation
- Continuous temperature monitoring
- Regular vital signs assessment
- Document rewarming progress
- Monitor for complications
- Record fluid balance accurately
Parental Support & Education
- Explain the condition and management plan to parents
- Teach proper swaddling techniques
- Emphasize the importance of maintaining warmth
- Encourage skin-to-skin contact when appropriate
- Teach signs of temperature instability to report
- Demonstrate how to check axillary temperature
- Provide emotional support and regular updates
Management Algorithm for Neonatal Hypothermia
Complications
Metabolic Complications
- Hypoglycemia
- Metabolic acidosis
- Electrolyte imbalances
- Increased caloric expenditure
- Poor weight gain
Respiratory Complications
- Respiratory distress syndrome
- Pulmonary hemorrhage
- Apnea
- Decreased surfactant production
- Persistent pulmonary hypertension
Cardiovascular Complications
- Bradycardia
- Hypotension
- Arrhythmias
- Shock
- Cardiac arrest (severe cases)
Neurological Complications
- Intraventricular hemorrhage
- Seizures
- Brain injury
- Developmental delays
Hematologic Complications
- Coagulopathy
- Thrombocytopenia
- Disseminated intravascular coagulation
- Bleeding
Other Complications
- Increased risk of infection/sepsis
- Necrotizing enterocolitis
- Hyperbilirubinemia
- Acute kidney injury
- Increased mortality
Long-term Outcomes
Severe or prolonged hypothermia may lead to:
- Neurodevelopmental impairment
- Growth delays
- Increased risk of cerebral palsy
- Cognitive and learning disabilities
- Sensory impairments
Prevention Strategies
Prevention of hypothermia follows the WHO’s “Warm Chain” concept, which consists of ten interconnected steps to protect the neonate from heat loss:
Delivery Room Measures
- Warm delivery room (minimum 25°C/77°F)
- Immediate drying after birth (especially the head)
- Skin-to-skin contact with mother
- Early breastfeeding within first hour
- Delay bathing for at least 6-24 hours
Ongoing Preventive Measures
- Appropriate clothing/bedding
- Keep mother and baby together (rooming-in)
- Warm transportation procedures
- Warm resuscitation environment
- Training and awareness for healthcare staff
Special Considerations for High-Risk Neonates
| Neonate Category | Additional Preventive Measures |
|---|---|
| Preterm (<37 weeks) |
|
| Low birth weight (<2500g) |
|
| Neonates requiring resuscitation |
|
| Neonates with congenital anomalies |
|
Mnemonic: “WARM BABY”
Key prevention strategies for neonatal hypothermia:
- Warm delivery room (≥25°C)
- Avoid drafts and cold surfaces
- Rapid drying after birth
- Mother-baby skin-to-skin contact
- Breastfeeding initiated early
- Avoid early bathing (delay 6-24 hours)
- Bundling appropriately
- Yearly staff training on thermoregulation
Fig 3: The WHO “Warm Chain” Concept for preventing neonatal hypothermia
Neonatal Hyperthermia
Definition
Neonatal hyperthermia is defined as a core body temperature above 37.5°C (99.5°F). Unlike fever, which is a regulated increase in body temperature in response to infection, hyperthermia in neonates is usually the result of environmental factors that cause the body to absorb more heat than it can dissipate.
Classification
| Classification | Temperature Range |
|---|---|
| Mild Hyperthermia | 37.6-38.0°C (99.7-100.4°F) |
| Moderate Hyperthermia | 38.1-39.0°C (100.6-102.2°F) |
| Severe Hyperthermia | > 39.0°C (> 102.2°F) |
Hyperthermia vs. Fever
| Feature | Hyperthermia | Fever |
|---|---|---|
| Cause | Environmental factors | Immune response to infection |
| Regulation | Unregulated heat gain | Regulated increase by hypothalamus |
| Response to antipyretics | Poor response | Usually responds well |
While infection should always be considered in a neonate with elevated temperature, environmental hyperthermia is more common in the newborn period. The distinction is important as management approaches differ significantly.
Pathophysiology
Hyperthermia occurs when heat production exceeds heat loss capability. In neonates, this usually results from environmental factors rather than internal heat production.
Heat Balance Equation
Heat Balance = Heat Production – Heat Loss
When Heat Production > Heat Loss → Hyperthermia
Mechanisms of Heat Gain in Neonates
External Heat Sources
- Excessive environmental temperature
- Incubator set too high
- Radiant warmer on high setting
- Direct sunlight exposure
- Phototherapy lights
Impaired Heat Dissipation
- Excessive wrapping/swaddling
- Multiple blankets
- Non-breathable fabrics
- High humidity environments
- Dehydration (reduced sweating)
Limitations in Neonatal Heat Loss Mechanisms
- Immature sweating mechanism: Term neonates have functional sweat glands but reduced capacity; preterm neonates have very limited sweating ability
- Limited vasodilation: Neonates have underdeveloped vasomotor control
- Limited behavioral responses: Cannot remove blankets or clothing independently
Pathophysiological Cascade of Hyperthermia
Mnemonic: “HOT BABY”
- Heart rate increased
- Oxygen consumption elevated
- Temperature regulation overwhelmed
- Blood flow increased to periphery
- Apnea risk increased
- Body fluid losses accelerated
- Yielding to dehydration if untreated
Causes & Risk Factors
Environmental Causes
- Overheated room/nursery (>27°C/80°F)
- Incubator temperature set too high
- Malfunctioning servo-control probes
- Radiant warmer on high setting
- Excessive swaddling/bundling
- Placement near heat sources (radiators, heaters)
- Direct sunlight exposure
- Phototherapy lights (improper distance)
Physiological & Pathological Causes
- Dehydration
- Infection/sepsis
- Maternal fever during labor
- Maternal epidural anesthesia
- Central nervous system disorders
- Hyperthyroidism (rare in neonates)
- Drug withdrawal (neonatal abstinence syndrome)
- Medication effects (e.g., anticholinergics)
Risk Factors for Neonatal Hyperthermia
Neonatal Factors
- Prematurity
- Low birth weight
- CNS abnormalities
- Dehydration
- Limited behavioral responses
Environmental Factors
- Hot climate/season
- Lack of air conditioning
- Inadequate ventilation
- Improper incubator settings
- NICU equipment heat output
Caregiving Factors
- Excessive bundling
- Lack of temperature monitoring
- Lack of knowledge about thermoregulation
- Cultural practices (overwrapping)
- Improper use of warming devices
Special Consideration: Phototherapy
Phototherapy is a common treatment for neonatal jaundice that can contribute to hyperthermia. The radiant heat from phototherapy lamps can significantly increase a neonate’s temperature if not properly monitored. Factors that increase risk include:
- Inappropriate distance between lamps and neonate
- Lack of temperature monitoring during phototherapy
- Use of multiple phototherapy units simultaneously
- Failure to adjust incubator temperature during phototherapy
Clinical Manifestations
Early Signs
- Increased axillary temperature (>37.5°C)
- Warm, flushed skin
- Tachycardia (HR >160 bpm)
- Tachypnea (RR >60/min)
- Mild irritability
- Increased peripheral perfusion
Progressive Signs
- Marked irritability or lethargy
- Poor feeding
- Hypotonia
- Sweating (term neonates)
- Dehydration signs
- Urine output decrease
Severe Hyperthermia
- Temperature >39.0°C (102.2°F)
- Apnea or respiratory failure
- Seizures
- Hypotension
- Altered consciousness
- Cardiovascular collapse
Important: Neonates may not exhibit the classic signs of hyperthermia seen in older children and adults. Subtle changes in behavior, feeding patterns, or vital signs may be the only indications of hyperthermia.
Physical Examination Findings
| Body System | Findings |
|---|---|
| Integumentary | Warm to touch, flushed skin, reduced skin turgor with dehydration |
| Respiratory | Tachypnea, apnea episodes, irregular breathing patterns |
| Cardiovascular | Tachycardia, bounding pulses initially, later weak/thready with dehydration |
| Neurological | Irritability progressing to lethargy, hypotonia, seizures in severe cases |
| Gastrointestinal | Poor feeding, vomiting, increased gastric residuals, abdominal distension |
| Renal | Decreased urine output, concentrated urine |
Signs of Dehydration in Hyperthermic Neonates
- Sunken fontanelle
- Dry mucous membranes
- Reduced skin turgor
- Decreased urine output (<1 ml/kg/hour)
- Weight loss >3% in 24 hours
- Excessive thirst (feeding eagerness followed by fatigue)
Nursing Assessment
Initial Assessment
- Measure and document core temperature (axillary preferred)
- Assess vital signs (heart rate, respiratory rate, blood pressure)
- Evaluate skin color, temperature, and moisture
- Check capillary refill time (may be < 2 seconds)
- Assess level of activity, alertness, and muscle tone
- Evaluate feeding patterns and tolerance
- Check for signs of dehydration
Environmental Assessment
- Check room/incubator temperature
- Evaluate appropriateness of clothing/swaddling
- Assess proximity to heat sources
- Check functioning of temperature servo-control
- Evaluate radiant warmer settings if in use
- Measure distance of phototherapy lights (if applicable)
- Check for direct sunlight exposure
Differentiate Environmental Hyperthermia from Infection
| Assessment | Environmental Hyperthermia | Infectious Fever |
|---|---|---|
| Onset | Usually rapid onset | Generally gradual onset |
| Environmental factors | Clear heat source identified | May be present but not primary cause |
| Skin temperature | Core and skin temperature both elevated | Core temperature elevated more than skin |
| Response to cooling | Rapid temperature normalization | Slower temperature response |
| Associated symptoms | Usually limited to heat-related symptoms | May show other signs of infection |
| Laboratory findings | Usually normal WBC, CRP | May show elevated WBC, CRP |
Diagnostic Assessments
| Assessment | Purpose | Expected Findings in Hyperthermia |
|---|---|---|
| Complete blood count (CBC) | Rule out infection | Usually normal in environmental hyperthermia; may show elevated WBC if infection present |
| Blood cultures | Rule out sepsis | Negative in environmental hyperthermia |
| Urine analysis | Assess hydration status, rule out UTI | May show concentrated urine with dehydration |
| Electrolytes | Evaluate fluid and electrolyte status | May show hypernatremia with dehydration |
| Blood glucose | Rule out metabolic issues | May be normal or elevated |
| C-reactive protein (CRP) | Screen for inflammatory response | Usually normal in environmental hyperthermia |
Mnemonic: “HEAT CHECK”
Key assessment components for hyperthermic neonates:
- Hydration status
- Environmental temperature
- Activity and level of consciousness
- Temperature (core and peripheral)
- Cardiorespiratory status
- Hunt for infectious signs
- Evaluate clothing/bundling
- Consider mechanical factors (equipment)
- Keep monitoring response to interventions
Nursing Management
Cooling Strategies
The primary goal is to normalize temperature gradually. Rapid cooling should be avoided as it can cause stress and complications.
| Severity | Temperature Range | Cooling Method | Nursing Interventions |
|---|---|---|---|
| Mild Hyperthermia | 37.6-38.0°C | Passive cooling |
|
| Moderate Hyperthermia | 38.1-39.0°C | Active cooling |
|
| Severe Hyperthermia | > 39.0°C | Aggressive cooling |
|
Caution: Never use cold water, ice, or alcohol for cooling neonates! These methods can cause rapid temperature drops, leading to shivering, increased metabolic demands, and potential shock.
Additional Nursing Interventions
Environmental Modifications
- Adjust incubator temperature (decrease by 1-1.5°C)
- Move away from direct sunlight or heat sources
- Increase air circulation in the room
- Adjust phototherapy distance if applicable
- Check and calibrate temperature probes
Hydration Management
- Increase feeding frequency if tolerating
- Offer additional fluids if breastfeeding
- Calculate fluid requirements (may need extra)
- Monitor intake and output carefully
- IV fluid administration for dehydration
Monitoring & Assessment
- Continuous temperature monitoring
- Frequent vital signs assessment
- Evaluate neurological status
- Monitor for signs of dehydration
- Observe for seizure activity
Infection Control
- Obtain cultures if infection suspected
- Monitor for signs of sepsis
- Administer antibiotics if ordered
- Assess maternal infectious history
- Practice strict hand hygiene
Managing Special Cases
| Situation | Special Considerations |
|---|---|
| Phototherapy-induced hyperthermia |
|
| Fever of unknown origin |
|
| Severe dehydration with hyperthermia |
|
Parental Support & Education
- Explain the cause of hyperthermia and management plan
- Teach appropriate dressing/swaddling techniques
- Educate about environmental temperature control
- Demonstrate how to check axillary temperature
- Teach signs of temperature instability to report
- Educate about increased fluid needs during hot weather
- Provide emotional support and regular updates
Management Algorithm for Neonatal Hyperthermia
Complications
Metabolic Complications
- Dehydration
- Electrolyte imbalances
- Hypernatremia
- Increased metabolic rate
- Increased glucose utilization
Neurological Complications
- Seizures
- Brain injury
- Cerebral edema
- Developmental delays
- Irritability and altered consciousness
Cardiorespiratory Complications
- Tachycardia
- Increased oxygen consumption
- Respiratory distress
- Apnea
- Cardiovascular collapse (severe cases)
Severity and Prognosis
| Temperature | Potential Complications | Prognosis |
|---|---|---|
| 37.6-38.0°C (Mild) |
|
Excellent with prompt intervention |
| 38.1-39.0°C (Moderate) |
|
Good with prompt management; potential for short-term morbidity |
| > 39.0°C (Severe) |
|
Guarded; potential for long-term neurological sequelae or death if not promptly treated |
Neurologic Impact of Hyperthermia
Hyperthermia can have significant neurological consequences in neonates:
- Temperatures >40°C can cause direct neuronal damage
- May increase blood-brain barrier permeability
- Can exacerbate pre-existing brain injury (e.g., HIE)
- May contribute to neurodevelopmental impairments
- Can trigger seizures due to neuronal hyperexcitability
Prevention Strategies
Environmental Control
- Maintain appropriate room temperature (22-25°C)
- Avoid direct sunlight on neonate
- Proper use of incubators and warmers
- Use servo-control mode when possible
- Regular calibration of temperature probes
- Proper placement of temperature probe
- Keep neonate away from heat sources (radiators, heaters)
- Ensure adequate ventilation in nursery areas
Appropriate Clothing & Bedding
- Dress neonate according to environmental temperature
- Use lightweight, breathable fabrics
- Avoid overdressing/overbundling
- General rule: neonate needs one more layer than adult
- Adjust based on environmental temperature
- Remove hats when in warm environments
- Use appropriate weight blankets for swaddling
Special Considerations for High-Risk Situations
| Situation | Preventive Measures |
|---|---|
| Phototherapy |
|
| Hot weather/climate |
|
| Transport |
|
Staff Training & Parental Education
Healthcare Provider Education
- Proper use of thermal management equipment
- Recognition of early signs of hyperthermia
- Appropriate response to elevated temperatures
- Proper documentation of temperature
- Regular equipment maintenance and calibration
Parent Education
- Appropriate dressing for environmental temperature
- Signs of overheating to watch for
- How to take and interpret temperature
- Managing neonate during hot weather
- When to seek medical attention
Mnemonic: “COOL BABY”
Key prevention strategies for neonatal hyperthermia:
- Comfortable room temperature (22-25°C)
- Observe for early signs of overheating
- Optimize incubator/warmer settings
- Lightweight, breathable clothing
- Be mindful of external heat sources
- Adequate fluids, especially in hot environments
- Be careful with phototherapy distances
- Yearly staff education on thermoregulation
Fig 4: Prevention strategies for neonatal hyperthermia
Comparison: Hypothermia vs. Hyperthermia
Side-by-Side Comparison
| Feature | Hypothermia (<36.5°C) | Hyperthermia (>37.5°C) |
|---|---|---|
| Primary Causes | Heat loss exceeding production | Heat gain exceeding loss |
| Key Risk Factors | Prematurity, low birth weight, cold environment | Overheating, excessive bundling, phototherapy |
| Skin Appearance | Pale, mottled, acrocyanosis | Flushed, warm to touch |
| Heart Rate | Initially tachycardia, later bradycardia | Persistent tachycardia |
| Respiratory Pattern | Initially tachypnea, then respiratory depression | Tachypnea, may progress to apnea |
| Metabolic Response | Increased metabolic rate, non-shivering thermogenesis | Increased metabolic rate, insensible water loss |
| Fluid Balance | Cold diuresis, potential dehydration | Increased evaporative losses, dehydration |
| Neurological Signs | Initially irritable, progressing to lethargy | Irritability, lethargy, potential seizures |
| Primary Interventions | Gradual rewarming (0.5-1.0°C per hour) | Gradual cooling, environmental adjustment |
| Major Complications | Metabolic acidosis, hypoglycemia, pulmonary hypertension | Dehydration, seizures, neurological damage |
| Prevention Focus | Warm chain implementation | Environmental control, appropriate clothing |
Fig 5: Visual comparison of neonatal hypothermia and hyperthermia
Case Studies
Case Study 1: Neonatal Hypothermia
Patient Information
Baby A: 3-day-old male neonate, born at 35 weeks gestation, birth weight 2100g
Chief Complaint: Poor feeding, lethargy, and axillary temperature of 35.2°C
Assessment Findings
- Pale, mottled skin with acrocyanosis
- Capillary refill time: 3 seconds
- Respiratory rate: 68/min with mild retractions
- Heart rate: 162/min
- Weak cry and poor sucking reflex
- Blood glucose: 38 mg/dL
Nursing Interventions
- Placed under radiant warmer with servo-control set to 36.5°C
- Administered IV glucose for hypoglycemia
- Monitored temperature every 15 minutes during rewarming
- Limited rewarming rate to 0.5°C per hour
- Provided warmed, humidified oxygen
- Monitored vital signs continuously
Outcome
Temperature normalized after 3 hours of gradual rewarming. Blood glucose stabilized, and feeding improved. Respiratory distress resolved with warming. Discharged home after 24 hours of observation with parental education on thermoregulation.
Learning Points
- Always monitor blood glucose in hypothermic neonates
- Gradual rewarming prevents complications
- Late preterm infants are at high risk for temperature instability
- Respiratory distress may improve with normalization of temperature
Case Study 2: Neonatal Hyperthermia
Patient Information
Baby B: 5-day-old female neonate, born at 38 weeks gestation, birth weight 3200g
Chief Complaint: Axillary temperature of 38.3°C, irritability, decreased feeding
Assessment Findings
- Flushed skin, warm to touch
- Receiving phototherapy for jaundice (TSB 15 mg/dL)
- Respiratory rate: 64/min
- Heart rate: 175/min
- Multiple layers of clothing despite phototherapy
- Decreased wet diapers in last 8 hours
Nursing Interventions
- Reduced clothing to diaper only
- Increased distance of phototherapy lights
- Decreased room temperature
- Initiated more frequent feedings
- Monitored temperature every 30 minutes
- Assessed for signs of dehydration
- Obtained sepsis workup to rule out infection
Outcome
Temperature normalized to 37.2°C within 2 hours. Blood cultures were negative. Feeding improved, and urine output normalized. Phototherapy continued with appropriate temperature monitoring. Parents educated on proper clothing during phototherapy.
Learning Points
- Phototherapy is a common cause of iatrogenic hyperthermia
- Environmental modification is the first-line intervention
- Sepsis workup may be necessary to differentiate cause
- Parental education is crucial for prevention
References
- World Health Organization (WHO). (1997). Thermal protection of the newborn: a practical guide. Geneva: World Health Organization.
- American Academy of Pediatrics & American College of Obstetricians and Gynecologists. (2017). Guidelines for perinatal care (8th ed.). Elk Grove Village, IL: American Academy of Pediatrics.
- Lunze, K., & Hamer, D. H. (2012). Thermal protection of the newborn in resource-limited environments. Journal of Perinatology, 32(5), 317-324.
- Blackburn, S. T. (2018). Maternal, fetal, & neonatal physiology: A clinical perspective (5th ed.). St. Louis, MO: Elsevier.
- Knobel, R., & Holditch-Davis, D. (2007). Thermoregulation and heat loss prevention after birth and during neonatal intensive-care unit stabilization of extremely low-birthweight infants. Journal of Obstetric, Gynecologic & Neonatal Nursing, 36(3), 280-287.
- Baumgart, S. (2008). Iatrogenic hyperthermia and hypothermia in the neonate. Clinics in Perinatology, 35(1), 183-197.
- Bissinger, R. L., & Annibale, D. J. (2010). Thermoregulation in very low-birth-weight infants during the golden hour: Results and implications. Advances in Neonatal Care, 10(5), 230-238.
- McCall, E. M., Alderdice, F., Halliday, H. L., Vohra, S., & Johnston, L. (2018). Interventions to prevent hypothermia at birth in preterm and/or low birth weight infants. Cochrane Database of Systematic Reviews, 2(2), CD004210.
- Arora, P. (2019). Practical neonatal thermoregulation: The basis of prevention of hypothermia. In Care of the Low Birth Weight Neonates (pp. 201-214). Singapore: Springer.
- Çınar, N. D., & Filiz, T. M. (2006). Neonatal thermoregulation. Journal of Neonatal Nursing, 12(2), 69-74.