Resuscitation of the Baby at Birth

Question 1

How does resuscitation of babies at birth differ from resuscitation of all other age groups? What process does it involve?

Answer 1

Involves the process of assisting transition from intra- to extra- uterine life.

Interruption of this process leads to hypoxia.

Question 2

Describe the normal physiological changes that occur at birth in the respiratory and cardiovascular systems.

Answer 2

NORMAL PHYSIOLOGY

CHANGES AT BIRTH

RESPIRATORY

• Lungs are fluid filled
• Gas exchange occurs across the placenta
• Before birth - cellular changes in lung tissue prime for reabsorption of intra-alveolar fluid
• 1st breath usually occurs w/i ~60-90 secs
• Stimuli for 1st breath
  
  • relative cold (ex-utero)
  • physical stimulus (being handled)
  • hypoxia (umbilical cord clamping)
• How is fluid expelled from the lungs?
  
  1. Physical forces during passage through birth canal ~35 ml expelled from upper airway
  2. ~100 ml from lower airways & alveoli into interstitial lung tissue –> lymphatics –> blood vessels, establishing baby’s FRC– assisted by:
     
     • expiratory breaking (Inspiratory phase > expiratory phase)
     • backpressure caused by breathing out against a partially closed glottis (crying/ grunting sound)
     • LARGE -ve inspiratory pressure generated by first few breaths to overcome:
       
       • viscocity & surface tension of fluid
       • elastic recoil &
       • resistance of - chest wall, lungs, airways

CIRCULATION

• lung inflation and alveolar distension
• vasomotor compounds released
• Pulmonary vascular resistance reduced
• Blood rapidly drawn into pulmonary vessels
• Oxygenation increases
• Increased pressure in the left side of the heart
• Closure of the foramen ovale
• Ductus arteriosus closes in the next few days

Question 3

Describe the pathophysiology that results from interrupted or reduced placental oxygen supply.

Answer 3

NEWBORN RESUSCITATION

PATHOPHYSIOLOGY

1. Placental O2 supply interrupted or severely reduced
2. Hypoxia
3. Fetus attempts to breathe in utero
4. Failure of oxygenation as surrounded by amniotic fluid
5. Baby becomes unconscious
6. PRIMARY APNOEA
   
   • 2-3 mins after hypoxia starts
   • HIGHER RESPIRATORY CENTRE becomes inactive
   • stops driving respiratory movements
   • breathing stops
7. Bradycardia
   
   • longer ventricular filling time
   • increased stroke volume
   • helps to maintain BP
8. Peripheral vasoconstriction - intense
   
   • diverts blood away from non-vital organs
   • helps to maintain BP
9. Loss of descending neural inhibition by the higher resp. centre
10. PRIMARY APNOEA IS BROKEN
11. Primitive SPINAL CENTRES initiate forceful, gasping breaths
    
    • maximal whole body insp. effort using all accessory muscles
    • deep, irregular gasps
    • 6-12 breaths per min
    • reflex activity
12. Failure/ Hypoxia continues
13. TERMINAL APNOEA
    
    • takes up to 20 mins to occur (longer than at any other time of life)
    • no further innate respiratory effort
    • intervention needed
14. Circulation starts to fail
    
    • ONLY occurs after ALL resp. activity stops
    • heart has large glycogen reserves
    • these allow prolonged anaerobic respiration to generate energy in the cardiomyocytes
    • once baby is ventilated, oxygen is carried to the heart –> brain
    • resuscitation is simple as long as it starts BEFORE ALL BREATHING STOPS i.e. before the circulation starts to fail
15. CPR needed to deliver oxygenated blood to the heart

Question 4

What is the MINIMUM equipment required to resuscitate a baby?

Answer 4

NEWBORN RESUSCITATION

MINIMUM EQUIPMENT

1. Firm, flat surface
2. Warmth
3. A way to deliver air or oxygen to the lung to displace fluid in the airways if the baby does not breathe itself e.g. mouth to mouth, equipment-based techniques

Question 5

Outline the strategy for assessing and resuscitating the baby at birth. Describe in detail the first 4 steps up to & including initial assessment.

Answer 5

STRATEGY

ASSESSING AND RESUSCITATING

APNOEIC NEWBORN BABY

1 - 4 completed simultaneously

1. SHOUT for help
2. START clock / note the time of birth
3. Dry & wrap in warmed dry towels - maintain baby’s temperature
4. ASSESS situation
5. A
6. B
7. C - including vascular access
8. Drugs

1. SHOUT for help ​​
2. START clock / note the time of birth
3. Dry & wrap
   
   • ​​no need to rush to clamp the cord
   • maintain baby’s temp 36.5 - 37.5
   • most heat loss = evaporation (wet) + convection (draught)
   • large surface area: WT
   • for every 1 degree lower = 28% mortality increase (for otherwise healthy term babies)
   • increase rate of O2 consumption, more likely to become acidotic & hypoG
   • eliminate draughts from the room (close windows/ doors), heat to 23 for term/ infants and 25 for pre-term babies
   • remove wet towel & wrap in warmed dry towels
   • v. small/ preterm - wet baby into food grade plastic bag (or all gestations if OOH, after drying and swaddling)
   • overhead/ radiant heater
   • HAT onto all babies (head = large surface are for heat loss) + cover skin
   • OOH + > 30 weeks gestation + breathing –> nurse skin to skin / kangaroo mother care + cover exposed skin
4. ASSESS situation
   
   • ​​during and after drying
   • Is Intervention/ Resuscitation needed?
     
     • YES –> clamp and cut cord
     • NO –> wait 1 min from complete delivery before clamping
   • heart rate & breathing most useful - ONLY items that need regular reassessment to assess effectiveness of intervention
   • Assess A, B, C in parallel
     
     • When drying: assess breathing movement, colour, tone
     • During drying by a 2nd responder or immediately after: auscultate heart
   • A & B
     
     1. regular
     2. gasp / irregular/ ineffective
     3. none (apnoea)
     • 3 or 2 (after drying) –> intervention
     • well, term babies take 1st breath 60-90 secs after delivery
     • w/i 3 mins of birth: establish spontaneous, regular breathing to maintain HR =/> 100 bpm
     • Acceptable pre-ductal sats (mins from birth)
       
       • 2 min: 60%
       • 3 min: 70%
       • 4 min: 80%
       • 5 mins: 85%
       • 10 mins: 90%
   • C
     
     • HR: fast, slow, very slow/ absent
     • increase in HR = the 1st sign of success during resus
     • Method
       
       • auscultate apex (best)
       • ECG (rapid, accurate, continuous)
       • neonatal probe pulse oximetry
         
         • RIGHT hand/ wrist (pre-ductal sats - oxygenated blood returning to heart)
         • ​correlate w/ auscultation
         • good signal strength needs to be achieved 1st - accurate HR & sats w/i 90 secs
         • not suitable to use probes for older children
         • do not interrupt resus to attach
       • • Pulses
       • NOT peripheral - not practical
       • Umbilical
         
         • may not be palpable if there is HR detectable by auscultn
         • only reliable if =/> 100 bpm
         • otherwise auscultate to check
   • D
     
     • Tone: well flexed, reduced tone, floppy
     • floppy = likely unconscious (& subject to hypoxia)
     • note how it changes during resus
   • E
     
     • Colour
     • no longer formally assessed
     • Normal = born blue –> pink w/i 1st mins
     • Pale & white =
       
       • shut down due to intense peripheral vasoconstriction
       • sig. CV response to peripartum compromise
       • more likely to be acidotic & hypovolaemic (esp if bradycardia also)
     • Note whether, when & how it changes during resus

(SEE SEPARATE NOTE):

1. A
2. B
3. C - including vascular access
4. Drugs

Question 6

What timing gives the best chance of success with respect to resuscitating babies?

Answer 6

NEWBORN RESUSCITATION

• more likely to be successful if commenced before terminal apnoea (at which point circulation starts to fail)
• babies in primary apnoea can resuscitate themselves if airway is clear
• during the initial assessment not possible to reliably distinguish b/w primary and terminal apnoea so the algorithm is suitable for all apnoeic babies

Question 7

Describe the 3 categories that babies may be put into following the initial assessment.

Answer 7

OUTCOME OF THE INITIAL ASSESSMENT

3 Groups

1. A/B: vigorous breathing or crying, C: HR =/> 100 bpm, D: good tone
   
   • = healthy babies
   • dry and keep warm
   • no need for immediate cord clamping
   • give to mum
   • nurse skin to skin, put to the breast, cover to protect from draught
2. A/B: irregular/ inadequate breathing or apnoea, C: HR < 100 bpm, D: N or reduced tone
   
   • try drying (& wrapping) as gentle stimulation to induce effective breathing
   • failure - clamp and cut cord for resus (cord milking/ stripping vs. delayed clamping - uncertain benefits)
   • open airway
   • BVM ventilation - may need to continue until resp drive recovered
   • HR increase = successful resus
3. A/B: inadequate breathig/ gasping/ apnoea, C: HR very slow < 60 bpm or absent; D: globally floppy, E: blue or pale

Question 8

Describe the resuscitation of the newborn baby.

Answer 8

NEWBORN BABY RESUSCITATION

• A
  
  • head in neutral position (may be difficult as babies have large, moulded occiput which causes neck flexion when flat)
  • can place a 2cm folded towel under the neck & shoulders
  • jaw thrust esp. if floppy
  • avoid overextension which causes collapse of the pharyngeal airway
• B
  
  • Priority = ventilation
  • BVM with well fitting mask
  • LMA
    
    • alternative to FM for PPV
    • IF
      
      • > 2000g or =/> 34 weeker
      • AND
      • FM ventilation unsuccessful + I+V unsusccessful or not feasible
  • intubation - only 1:500 babies need intubation if correct positioning of head and mask applied properly
  • intubation = gold standard ONLY if
    
    • ETT correctly placed
    • does not interrupt ongoing ventilation
    • no trauma to oropharynx / trachea
  • ETT useful:
    
    • prolonged resus
    • extremely preterm
    • tracheal blockage
  1. 5 inflation breaths
     
     • 2-3 secs
     • chest may not move during THE FIRST 3 BREATHS as fluid is displaced out of the lungs
     • ideally use air, NOT O2
       
       • O2 toxicity - sig. morbidity in preterm
       • use pre-ductal O2 sats as a guide to O2 Tx requirement
     • cont. gas supply, pressure-limited device (30 cmH2O) + appropriate sixe mask (big enough to cover nose and mouth)
     • or 500 ml self inflating bag and blow off valve set to 30- 40 cm H2O if compressed air or O2 not available (do not use a smaller size - insufficient capacity to sustain breath over 2-3 secs)
  2. Reassess breathing
  3. Adequate ventilation is shown by HR
     
     • rapidly increasing or
     • maintained @ =/> 100 bpm
  4. Cont. ventilation at 30-40 per min 1 sec breaths until regular spontaneous breathing established – AFTER:
     
     • chest inflated AND
     • HR has increased OR
     • chest seen to move
  5. If HR does not respond
     
     1. Check for chest rise (after first 3 breaths)
        
        • NB do NOT auscultate - fluid in the lungs, sound of air passing through may sound like BS even if lungs not properly inflating
     2. Check airway opening manoeuvres/ readjust
     3. Repeat inflation breaths
     4. Check for obstruction e.g. thick & viscid meconium
        
        • direct visualisation of oropharynx with laryngoscope
        • gentle suction with wide bore catheter (NOT > - 20 kPa/ - 150 mmHg)
        • do NOT do blind deep laryngeal suction - can cause EXTENSIVE TISSUE INJURY & VAGAL NERVE STIMULATION –> BRADYCARDIA & LARYNGOSPASM
  • Meconium aspiration
    
    • meconium stained liquor (light green tinge) common - 10% of births
    • meconium ASPIRATION rare
      
      • occurs in utero as fetus approaches term
      • fetal compromise severe enough to cause reflexive passage of meconium and gasping resp. movements
      • priority is initiation of resuscitation + ventilation w/i 1st min, not clearance of meconium
      • no benefit to suctioning the airways, routine intubation + suctioning - leads to delay in resus
      • only aspirate oropharynx under direct visualisation if thick meconium causes blockage
• C
  
  • WHEN TO START Chest compressions
    
    • Despite adequate lung inflation + ventilation for 30 secs with visible chest movement
    • HR v. slow < 60 bpm or absent
  • HOW
    
    • encircle chest with both hands
    • one thumb over the other
    • lower 1/3 of sternum
    • compress by 1/3 AP diameter of chest
    • allow full recoil of ant. chest wall (coronary arteries fill)
    • 3:1 compression: ventilation
    • results in 120 events/ min (90 compressions & 30 ventilations)
  • increase the inspired O2 conc. guided by pulse ox.
  • Usually only 20-30 secs of compressions needed before heart responds (increase in HR)
  • Reasses HR at 30 sec intervals
  • Can stop when HR > 60 bpm and rising
  • BUT continue ventilations until effective spontaneous breathing occurs - otherwise may need MV
  • Aim of chest compressions = to move oxygenated blood to the coronary arteries to initiate cardiac recovery
  • This usually results in switch from anaerobic to aerobic energy generation, increasing HR, allowing adequate CO to perfuse organs incl. brain
  • => need to establish good quality ventilation BEFORE compressions for resus to be successful
  • avoid continuous compressions w/ asynchronous ventilation even when intubated (if the 2 coincide, the compressions will reduce the effectiveness of the breath)
• Drugs
  
  • WHEN
    
    • if adequate CPR (lung inflation & ventilation + compressions) does not lead to HR > 60 bpm + rising
    • do NOT give unless airway opening manoeuvres + ventilation + compressions are adequate as they are unlikely to help
  • Outcome poor if drugs needed
  • ROUTE
    
    • centrally via umbilical venous line
    • IO in term babies
  • AB-FG-N
    
    • ADRENALINE
    • BICARBONATE
    • FLUIDS
    • GLUCOSE
    • NALOXONE
  • ADRENALINE
    
    • a-adrenergic effect
    • increased coronary artery perfusion
    • more O2 delivered to the heart
    • WHEN
      
      • severe, unresponsive bradycardia
      • circulatory standstill
    • DOSE
      
      • 10 mcg/ kg (0.1 ml/ kg 1:10,000) IV
      • always follow with saline flush (to help it reach circulation)
      • further doses of 10 - 30 mcg/ kg (0.1 - 0.3 ml of 1:10,000) if no response
    • Tracheal route
      
      • insufficient data
      • 50 - 100 mcg/ kg
  • BICARBONATE
    
    • ​WHEN
      
      • ​severe, unresponsive bradycardia
      • no CO despite all resus effort
      • AFTER adequate CPR (ventilations & compressions) established
      • NOT during short periods of CPR
    • WHY
      
      • babies in terminal apnoea have sig. metabolic acidosis
      • met. acidosis depresses cardiac function
      • raises the pH => enhances the effects of O2 & adrenaline in prolonged resus
    • DOSE
      
      • 1-2 mmol/ kg
      • 2-4 ml/kg of 4.2% solution
  • FLUIDS
    
    • ​WHEN
      
      • pale & shocked
      • bradycardia despite drugs
      • not usually needed unless blood loss/ septicaemic shock
      • Hypovolaemia Causes
        
        • Blood loss
          
          • antepartum haemorrhage
          • placenta/ vasa praevia
          • bleeding from a separated but unclamped cord
        • Loss of vascular tone following asphyxia - less common
    • WHAT
      
      • 0.9% sodium chloride 10 ml/ kg e.g. septicaemic shock
      • Blood - if blood loss likely
        
        • Uncross-matched
        • CMV -ve
        • O RhD-negative
      • NOT albumin
    • Avoid fluid overload
      
      • worse cardiac function if prolonged asphyxia
      • increase risk of IVH & pulmonary haemorrhage in preterms
  • GLUCOSE
    
    • WHY
      
      • ​Neonatal heart has endogenous glycogen supplies
      • These may get used up during prolonged resus
      • Exogenous source of glucose then needed
      • HypoG - adverse neuro outcomes + cerebral damage in animal studies
      • HyperG after a hypoxic/ ishchaemic event is NOT harmful
    • TESTING
      
      • avoid strip glucometers (less reliable)
    • WHEN
      
      • prolonged resus
    • DOSE
      
      • BOLUS 2.5 ml/kg 10% glucose IV
      • –> 100 ml/ kg/ day 10% glucose (to prevent rebound)
  • NALOXONE
    
    • WHEN
      
      • baby effectively resuscitated, pink, HR =/> 100 bpm
      • BUT not breathing spontaneously
      • AND mother taking opioids
      • resp. depressant effect suspected
      • do NOT give acutely
    • DOSE
      
      • 200 mcg IM (full term) - lasts a few hrs
      • 10 mcg/ kg IM + repeat (only lasts 20 mins)
      • short half life

Question 9

Describe the successful response to resuscitation. What is the first indication of this? How and when do breathing, skin colour and tone improve in response to resuscitation?

Answer 9

RESPONSE TO RESUSCITATION

• C
  
  • Increase in HR = 1st indication of successful progress in resuscitation
• A/B
  
  • recovery of resp drive takes longer
  • babies in primary apnoea - recover normal breaths (may start at any stage of resus)
  • babies in terminal apnoea - gasp initially before restarting normal respiration s
• D
  
  • Tone = proxy for consciousness
  • last key metric to improve
  • after heart function, circulation and spontaneous effective breathing are restored
• E
  
  • skin colour may recover quickly or slowly
  • depends on circulatory status

Question 10

When & how should the decision be made to discontinue resuscitation?

When is it suitable to stop resuscitation before 10 mins or not start?

Answer 10

DISCONTINUATION OF RESUSCITATION

• NO detectable HR for > 10 mins after birth
  
  • outcome v. poor
  • death or severe neurodisability likely
  • most senior clinician decides
  • Many variables to consider
    
    • parental beliefs
    • parental feelings about the potential for sig. morbidity
    • aetiology
    • reversibility
    • availability of intensive care Rx e.g. therapeutic hypothermia
• HR persistently < 60 bpm w/o improvement after 10-15 mins of CPR
  
  • decision to stop less clear
  • evaluate on case by case basis
• STOP before 10 mins/ NO resus appropriate if
  
  • extreme prematurity < 23 weeks
  • BW < 400g
  • lethal abnormalities e.g. anencephaly
  • confirmed trisomy 13/ 18

Question 11

What sizes of ETT should be available when trying to intubate a newborn baby?

Answer 11

NEWBORN BABY

INTUBATION

ETT SIZES - internal diameter

3. 5 mm - normal, full-term
4. 3, 3.0, 4 mm

Question 12

How is correct tracheal tube placement evaluated in newborns?

Answer 12

TRACHEAL INTUBATION

NEWBORN BABY

PLACEMENT ASSESSMENT

• Visual
• Rapid response in HR (when ventilating via ETT)
• ETCO2 (colorimetric or quantitative) – adjunct if CO present (do not use in isolation; NB colorimetric detectors can get contaminated by drugs, may also be false +ve if R main bronchus intubated)
• Listen to air entry in both axillae (to ensure R main bronchus not intubated - false +ve capnographic test)

Question 13

Babies of what gestation can be managed in the same way as term babies? Which babies need extra support during their transition to extrauterine life?

Answer 13

Babies can be managed in the same way as term babies if

Gestation 34-36 weeks (moderately preterm).

Babies need extra support to prevent problems from a hypoxic event if:

• 31 - 33 weeks (some)
• < 31 weeks (all)

Question 14

In what way does temperature management of preterm babies differ from that of term babies?

Answer 14

PRETERM BABIES

TEMPERATURE Mx

• higher surface area: body WT ratio
• more likely to get cold
• more likely to get hypoG (fewer glycogen stores)
• Plastic/ polyethylene bags/ wraps may be used to keep babies warm
  
  • large food grade for microwaving/ roasting w/ V cut out of closed end OR purpose-made
    
    • cover from shoulders to head
    • head protrudes through V cut
    • dry the head
    • can make hole above umbilicus if needed
    • OOH - also wrap in warm towels and ensure a warm ambient temp
  • < 30 weeks or < 1000g
    
    • only dry the exposed body parts
    • leave the rest wet
  • > 30 weeks
    
    • same as term babies
    • or can dry and wrap in warmed towel
  • < 32 weeks
    
    • do not dry
    • wrap the head and body, not the face –> place under radiant heater
    • warms the baby through the bag trapping a warmed humidified atmosphere around it
    • prevents heat loss by evaporation
    • keep in bag until on NICU and humidity in incubator at desired level
    • may also need to use thermal mattress, warmed humidified resp gases for ventilation

Question 15

Describe the main respiratory issues affecting premature babies at birth and how these are addressed.

Answer 15

PREMATURITY

RESPIRATORY PROBLEMS

1. Surfactant deficiency
   
   • secreted by Type II alveolar pneumocytes
   • released at birth due to aeration and distension of alveoli
   • reduces alveolar surface tension and prevents collapse on expiration
   • small amounts produced from 20 weeks onwards but surge only occurs after 30-34 weeks
   • Production reduced by
     
     • Hypothermia < 35 degrees
     • Hypoxia
     • Acidosis pH < 7.25
   • Deficiency
     
     • can occur at any gestational age
     • common if < 32 weeks esp. after unexpected or precipitate delivery
     • even more likely if < 30 weeks
   • Mx
     
     • Nasal CPAP reduces the need for I+V
     • Exogenous surfactant (esp if I+V needed)
2. Lungs fragile
   
   • susceptible to damage from overdistension
   • use lower inflation pressures (20-25 cm H2O = 2 - 2.5 kPa)
   • can increase to 30 cm H2O (2.9 kPa) if no HR response
   • PEEP 5 cmH2O (0.5 kPa) can help to prevent airway collapse duringe expiration
   • BEWARE - VERY OBVIOUS chest wall movement in < 28 weeks = potentially damaging TV (tidal volume)
   • avoid if preterm baby has good sats and HR =/> 100 bpm
3. Hyperoxia - More susceptible to toxic effects of
   
   • sig. longterm adverse effects
   • use pulse oximetry to monitor
   • use same acceptable pre-ductal sats as in term babies
   • acceptable to start resus at O2 conc 21 - 30%

Question 16

What are the risks of intubation in newborn babies?

Answer 16

INTUBATION

NEWBORN BABIES

RISKS

1. Delaying ongoing resuscitation due to task fixation
2. Traumatic injury to oropharynx and trachea
3. Irreversibly destabilising an otherwise well baby

Question 17

What is the first line intervention for respiratory support in spontaneously breathing preterm babies? How can this be adminstered?

Answer 17

PRETERM

RESPIRATORY SUPPORT

• CPAP = 1st line for spontaneously breathing babies in need of resp. support
• esp. in areas where personnel not skilled in intubation or infrequenty practice
• Can be given
  
  • by mask if using mask plus T piece w/ PEEP valve
  • small nasal masks or prongs

Question 18

What actions should be taken in the event of poor initial response to resuscitation in preterm babies?

Answer 18

PRETERM BABIES

POOR INITIAL RESPONSE TO RESUS

ACTIONS TO TAKE

CHECK FOR THE FOLLOWING

1. A: Head position, airway patency & breathing
2. B:
   
   • Technical fault
     
     • BVM: effective? Chest rising? Leak around mask? Longer inflaton time or higher pressure?
     • Intubated:
       
       • ETT in trachea?
       • listen at the mouth for large air leak
       • check chest movement
       • auscultate axillae (? in R main bronchus)
       • capnometry (? in correct position ? blocked)
       • Remove and re-try BVM
   • Slow rise in sats –> consider increase O2 conc. (least likely cause of poor responsiveness)
   • PTX?
     
     • 1% of newborn babies - spontaneous
     • needing action in delivery unit - rare
     • Findings:
       
       • asymmetrical BS
       • hyperilluminating area (cold light source used to transillluminate the chest)
     • Mx - tension PTX
       
       • GREEN (21 gauge) butterfly needle
       • BLUE (22 gauge) cannula + 3 way tap
       • BEWARE causing PTX
3. C:
   
   • Congenital heart malformation e.g. duct dependent OR persistent pulm. HTN:
     
     • cyanosed DESPITE
     • regular breathing pattern & no increased WOB
     • good HR
   • Severe anaemia or Hypovolaemia
     
     • Large blood loss –> 10-20 ml/kg O Rh -ve blood
4. D: DRUGS
   
   • Maternal opiates - consider IF:
     
     • Not breathing effectively DESPITE
     • pink & good HR
   • Mx: Naloxone 200 mcg IM

Question 19

Outline the NLS algorithm.

Answer 19

NLS algorithm

See image.