A previously well 12-day-old term infant is retrieved from a peripheral centre into your emergency department with increasing respiratory distress. 

On arrival:
RR – 70
Sat 89% on nasal cannula at 1L/min 
PR – 150 
BP – 80/40 

a) What is the normal range of oxygen saturation, respiratory rate, pulse rate and blood pressure in a healthy term neonate?


b) Excluding tachypnoea, list four (4) commonly seen clinical signs of respiratory distress in a newborn 


c) List four (4) most likely causes for this presentation.


d) List four (4) factors that predispose neonates to respiratory failure

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College Answer

a)

  • Normal BP for neonate 75/40 mmHg range 60-80 systolic 40-50 diastolic
  • Normal pulse rate for neonate 100-160,100 when asleep 160 when crying
  • Normal RR for Neonate 30-60 – average 40
  • Saturation >93% on room air

b)

  • Distortion of the chest wall (sternal and rib retraction, recession of intercostal, subcostal and suprasternal spaces) Accept alternative terminology
  • Pallor
  • Apnoea
  • Bradycardia
  • Lethargy, listlessness, decreased level of consciousness

c)

  • Upper airway obstruction
  • Bronchiolitis
  • Pneumonia
  • Aspiration
  • Cardiac failure (usually associated with high pulmonary blood flow, VSD, PDA, truncus arteriosus etc; left heart obstructive lesions; coarctation of the aorta; aortic stenosis)
  • Sepsis

d)

  • Increased metabolic demand – oxygen consumption twice that of the adult
  • Structural immaturity of the thoracic cage – ribs short and horizontal, bucket motion is minimal - infant is dependant on diaphragmatic displacement of abdominal contents to increase volume of the thorax any increase in abdominal distension may compromise respiratory function.
  • Infant airways – small and more prone to obstruction
  • Immaturity of immune system increasing susceptibility to infection
  • Immature development of the respiratory system – particularly in premature infants with surfactant deficiency, alveolar instability, reduced lung compliance
  • Immaturity of respiratory control – immature respiratory centre results in inadequate respiratory drive and can lead to apnoea.
  • Congenital abnormalities – either respiratory or cardiovascular may lead to early respiratory failure
  • Perinatal injuries – pneumothorax, neuromuscular including perinatal asphyxia which can result in apnoeas.
 

Discussion

This question addresses the candidate's knowledge of the most recent APLS resuscitation guidelines.

Normally, the majority of these neonatal resuscitation questions are souced directly from the APLS handbook, which one receives as part of the APLS course reading material.

Certainly, for questions b) c) and d) this was the case. However, the values for normal vital signs I found in the 4th edition of the book (for the under-1 age group) were different to those quoted in the college answer. Even a quick Googly frolic through teh interweb yields a bewidering plethora of normal ranges. Exactly where did the college derive its values from?

In the "model answer" I parroted the college values.

The normal values "at birth" in Oh's Manual are as follows:

  • BP = 75/40
  • HR 125 (94-155)
  • RR 50

b) This answer was souced directly from the APLS handbook, page 60 (4th edition)

c) This is a question about the potential causes of respiratory distress in the neonate. Again, there is a list of causes of respiratory failure in the APLS handbook, which the college answer borrows heavily from. There is no real way to improve on a list like this. I have transcribed it almost direclty, excluding causes which are irrelevant to this age group.

d) The same chapter in the APLS handbook also discusses the reasons why neonates are predisposed to respratory failure. Again, it is difficult to improve on this list. You will find it on page 74 of the 4th edition.

References

the APLS handbook, 4th edition; as well as Oh's Manual.