1. Newborn: Apnea, Hypothermia
and Hyperthermia
Dr. Kalpana Malla
MD Pediatrics
Manipal Teaching Hospital
Download more documents and slide shows on The Medical Post [ www.themedicalpost.net ]

2. CONTENTS
• Apnea and its types.
• Hypothermia
• Hyperthermia

3. APNEA
DEFINITION
• Cessation of breathing for longer than
20sec, or any duration if accompanied by
cyanosis and sinus bradycardia

4. APNEA AND TYPES
• Common in preterm infants : Idiopathic
apnea of prematurity
• Associated illness
• Periodic breathing
• Central apnea
• Obstructive apnea
• Mixed apnea

5. OBSTRUCTIVE APNEA
• Absence of identifiable predisposing diseases
• Pharyngeal instability
• Neck flexion
• Nasal occlusion
• Characterized by absent airflow but persistent
chest wall motion
• Pharyngeal collapse may follow the negative
airway pressures generated during
inspiration, or it may result from incoordination
of the tongue and other upper airway muscles
involved in maintaining airway patency

6. CENTRAL APNEA
• Decreased central nervous system (CNS)
stimuli to respiratory muscles, airflow
and chest wall motion are absent

7. CAUSES
Central nervous system Respiratory
• Intraventricular • Pneumonia
hemorrhage • Obstructive airway
• Drugs lesions
• Seizures • Upper airway collapse
• Hypoxic injury • Atelectasis
• Herniation • Extreme prematurity
• Neuromuscular disorders • Phrenic nerve paralysis
• Severe hyaline
Infectious membrane disease
• Sepsis • Pneumothorax
• Necrotizing enterocolitis • Hypoxia
• Meningitis

8. CAUSES
Gastrointestinal Metabolic
• Oral feeding • Hypoglycemia
• Esophagitis • Hypocalcemia
• Intestinal perforation • Hyponatremia
• Gastroesophageal reflux • Hyperammonemia
• Organic acidemia
Cardiovascular • Hypothermia
• Hypotension
• Hypertension Other
• Heart failure • Immaturity of respiratory
• Anemia center
• Hypovolemia • Sleep state
• Vagal tone

9. IDIOPATHIC APNEA OF PREMATURITY
• Mixed etiology (50–75%)
• Obstructive apnea preceding (usually) or following
central apnea
• Short episodes of apnea are usually central, whereas
prolonged ones are often mixed.
• Apnea is sleep state dependent
• Frequency increases during active (rapid eye
movement) sleep
• Paradoxical chest wall movement (inspiratory abdominal
expansion and inward chest wall movement) is common
during active sleep and may cause a fall in Pao2 because
of ventilation-perfusion defects
• Inhibition of pharyngeal muscle tone during active sleep
may contribute to upper airway collapse and obstructive
apnea.

10. CLINICAL MANIFESTATIONS
• The incidence of idiopathic apnea of
prematurity varies inversely with
gestational age
• preterm : rare on the D1, occurs on D2–D7
• Cessation of breathing
• Bradycardia
• Cyanosis
• Apnea of prematurity usually resolves by
36 wk postconceptional age

11. TREATMENT
• Gentle cutaneous stimulation :mild and
intermittent episodes
• immediate bag and mask ventilation :
recurrent and prolonged apnea
• Oxygen
• Methylxanthines(theophylline or caffeine)
enhance ventilation through a central
mechanism or by improving
diaphragmatic strength.

12. TREATMENT (CONTD…)
• Loading doses of 5mg/kg of theophylline
(orally) or aminophylline (intravenously)
- followed by doses of 1–2mg/kg given every 6–
8hr by the oral or intravenous routes
• Loading doses of 10mg/kg of caffeine
- followed 24hr later by maintenance doses of
2.5mg/kg/24hr qd orally.
• Therapeutic levels: theophylline: 6–10µg/mL;
caffeine: 8–20µg/mL

13. TREATMENT (CONTD…)
• Transfusion of packed red blood cells
• Treat gastroesophageal reflux :antireflux
medications controversial
• Nasal continuous positive airway pressure
(CPAP)
• Continuous positive pressure splints the
upper airway and thereby prevents
obstruction.
• Neck extension with a shoulder pad

14. Hypothermia

15. Introduction
• After birth, skin temperature falls by
0.3 C/min and core temperature by 0.1 C/min.
• 15% of NB develop hypothermia in developing
countries.

16. Neonatal Considerations
• Relative to body wt, BSA of NB 3
times higher than that of adult.
• LBW insulating layer of s/c fat lesser.
• Preterms have less developed stores
of brown fat.

17. Neonatal Consideratios
• Underdeveloped shivering & sweating
mechanisms.
• Limited calorie intake to provide
nutrients for thermogenesis.
• Inability to maintain flexed posture in PT
to reduce effective surface area.

18. Response To Cold
• Metabolic thermogenesis-
Fetal brown fat laid down in 3rd
trimester, neck, interscapular, axilla, groin, kid
ney & adrenals.
Local release of noradrenaline-TG oxidised to
glycerol & fattyacids-heat.

19. Loss Of Heat
• Radiation-heat dissipates from infant to colder
object in environment. Eg wall, window.
• Conduction-heat loss from infant to surface on
which baby lies.
• Convection- loss from skin to moving air.
• Evaporation-imply loss of heat by moisture
vaporising from skin surface.

20. Hypothermia
• Recording of temperature – Rectal, Axilla, Skin
• Skin temperature <35.5 C
• Core temperature <36 C
• Etiology
-excessive heat loss
-inability to conserve heat
-poor metabolic heat production

21. Severity of hypothermia
• Cold stress- core temperature 36 C- 35.5 C
• Moderate hypothermia 32 C-35.9 C
• Severe hypothermia <32 C

22. Clinical Features
• Uncomfortable Restless
• Cries to generate heat Sluggish
• Inactive Cold, mottled
skin
• Bradycardia Low BP
• Slow breathing
• Poor weight gain,brain growth affected
• Low immunity
• Hypothermia predisposes to
sepsis, kernicterus etc

23. How To Keep Babies Warm
• Labour room- prewarmed room, radiant heat
source, immediate drying, skin to skin contact
with mother, early breast feeding, delay bath.
LBW/PT-transfer to NICU ideally in transport
incubator.
• Lying in a ward- next to mother, adequate
clothing, saps, sponging/bath.

24. How To Keep Babies Warm
• Nursery- environ temp maintained at 26
degree C. Prewarm all surfaces in contact with
baby. Perspex heat shield, liquid paraffin.
Incubator/Open care has manual and servo
control modes.

25. Open Care System

26. Incubator

27. How To Keep Babies Warm
• Operation theatre-cold ambient environ, prewarm IV
fluids & anesthetic gases, continuous temp
monitoring. Humidified oxygen.
• Transport- Uterus ideal transport incubator! Well
covered, skin to skin contact. Thermocole box with
hot water bottles.
• Home care- Cot away from walls, contact with
mother, train to assess temperature, Oil massage

28. KANGAROO MOTHER CARE
• Kangaroo Mother Care
• Biologically controlled heat source
• Ventral surface of baby in contact with
mother’s boson
• Dorsal surface covered with clothes
• Poor cultural acceptability in our society

29. Prevention of Hypothermia
• Identification of high risk mother
• Create warm micro-environment to
welcome the baby
• Delay bath
• Maintain NICU at 26 degree Celsius
• Standby incubator ready
• Babies effectively clothed
• Special care to prevent Hypothermia during
transport and Procedures

30. Prevention of Hypothermia
• Application of Oil and Liquid paraffin can
reduce evaporation from skin
• Skin to skin contact
• Educate mother and health workers

31. HYPERTHERMIA
• Common in tropical country.
• Sunlight exposure for jaundice.
• Iatrogenic hypothermia.
• PT below 32 wks do not sweat.
• Transient fever of newborn- raised environ
temp, immaturity of heat regulating
centre, inefficient sweating.

32. Thank you
Download more documents and slide shows on The
Medical Post [ www.themedicalpost.net ]