Neonatal resuscitation

Neonatal resuscitation

• Newborn refers to first minutes to hours after birth
• Neonatal is first 28 days of life
• Infancy up to 12 months
• The exact age at which to transition to paediatric techniques is unknown, especially for very small premature infants
• When required?
  • 85% of babies born at term will initiate spontaneous resps within 10-30 seconds of birth
  • 10% will respond with drying and stimulation
  • 3% following PPV
  • 2% will require intubation to support respiratory function
  • 0.1% will require chest compressions and/or adrenaline
  • Need for resus in low risk births is <1%

Transitional physiology

• Physiology
  • Lungs from liquid to air filled
  • Pulmonary blood flow increases dramatically 5-6x (fall in pulmonary vascular resistance)
  • Foramen ovale closes
  • Ductus arteriosus closes
  • Fetal lung fluid moves from airways to lung tissue, then reabsorbs over hours into circulation
  • Preterm or respiratory distressed babies may have lung water move back into airways requiring repeated clearance. CPAP prevents and treats this
  • Oxygen levels from 60% during labour taking 5-10 minutes to reach SpO2 90%
    • 25^th centile for O2 at 5 minutes is 80%
  • Normal HR 3-4 minutes after birth from 110 to 160
  • Acidosis and hypoxaemia during birth process can impair respiratory and cardiac drive

Transitional physiology

• Preterm infants
  • Surfactant deficiency prevents normal lung aeration due to reduced compliance
• Infants born by C-section may not clear lung fluid as well as vaginal born infants (due to benefits of labour)
• Meconium
  • Advanced gestation makes this more common
  • Inhalation can lead to airway inflammation
  • Complications are more common if SGA, post-term or with significant perinatal compromise
• Perinatal infections and congenital anomalies can also cause failed transition

Environment

• Temperature
  • Prevention of heat loss and overheating are both important
  • For term and near term infants, dry thoroughly
  • Skin-to-skin helps to keep infant warm
  • Need heat source for resuscitation
  • Non-asphyxiated babies of all gestations should be kept between 36.5 and 37.5 degrees
  • Admission temperatures should be recorded as a quality of care measure
  • Mortality increases 28% for each degree below 36.5 at admission
  • Hypothermia associated with hypoglycaemia, poor respiratory outcomes, late onset sepsis and intraventricular haemorrhage
  • Hyperthermia has unknown effects but babies born to mothers with fevers (>38) have increased risk of neonatal death, perinatal respiratory depression, neonatal seizures and cerebral palsy

Environment

• Induced hypothermia
  • For infants 35 weeks and above with evolving moderate to severe hypoxic ischaemic encephalopathy reduces degree of brain damage
  • Maintain normothermia until signs of encephalopathy identified and decision made to induce hypothermia
  • D/W NICU immediately

Cord clamping

• Deferred clamping to 30-60 seconds is associated with increased placental transfusion, increased cardiac output and higher/more stable blood pressure
• For uncomplicated term birth, delayed clamping showed higher neonatal Hb levels, iron levels but increased risk of phototherapy for jaundice
• For uncomplicated preterm birth, delayed clamping for at least 30 seconds improves BP during stabilisation and at 4 hours post-birth, reduces risk of periventricular leukomalacia and IVH, lowers risk of NEC, increases blood volume and reduces risk of blood transfusion (low quality RCT data)
• Guidelines suggest delayed cord clamping for preterm infants not requiring immediate resuscitation
• Insufficient evidence to recommend use in infants requiring resuscitation – these measures must take priority

Risk factors

• Maternal risk factors for requiring resuscitation
  • PROM >18 hours
  • Bleeding in 2^nd or 3^rd trimester
  • Pregnancy-induced HTN
  • Chronic HTN
  • Substance abuse
  • Drug therapy (e.g. MgSO4, anticonvulsants, opioids, lithium, beta-blockers)
  • DM
  • Chronic illness
  • Maternal pyrexia
  • Maternal infections
  • Chorioamnionitis
  • Heavy sedation
  • Previous fetal or neonatal death
  • No antenatal care

Risk factors

• Fetal risk factors
  • Multiple gestation
  • Preterm <35 weeks
  • Post-term >41 weeks
  • Large for dates
  • Fetal growth restriction
  • Alloimmune haemolytic disease
  • Polyhydramnios/oligohydramnios
  • Reduced foetal movements before onset of labor
  • Congenital abnormalities
  • Intrauterine infections
  • Hydrops fetalis

Risk factors

• Intrapartum risk factors
  • Non-reassuring FHR or CTG
  • Acidosis
  • Abnormal presentation
  • Prolapsed cord
  • Prolonged second stage of labor
  • Precipitate labour
  • Antepartum haemorrhage
  • Meconium-stained amniotic fluid
  • Narcotics within 4 hours of delivery
  • Forceps/vacuum delivery
  • Maternal GA

Assessment

• Tone + Breathing + Heart rate
• Tone
  • Good tone = Moving limbs with flexed posture
  • Floppy and not moving = Very likely to require resuscitation
• If good tone, start breathing and HR >100 soon after birth – No resuscitation required. 
• If these responses are absent or weak, dry and stimulate
  • For preterm or very LBW infants placed in polyethylene bag, just dry head
    • Can still perform tactile stimulation through bag
  • In non-vigorous, meconium-exposed infants, if decision to intubate for mec suction is made, should not stimulate before intubation
• If infant does not breath despite this, start assisted ventilation

Breathing

• Should establish regular breaths to achieve HR >100 within 1-2 minutes
• Of term and near-term infants, 85% start breathing within 30 seconds and 95% within 45 seconds
• If tone is low, HR <100, then PPV (if not breathing) or CPAP can be initiated
• Recession, retraction or indrawing + grunting are signs that baby is struggling to clear fluid from lungs and if persistent should warrant CPAP initiation

Heart rate

• Listening with stethoscope is more reliable than base of cord pulse
  • Although both relatively insensitive compared to pulse oximetry at 90 seconds
• Absence of pulses elsewhere are not reliable
• Pulse oximetry works within 30 seconds and ECG even more rapidly
• Prompt pulse oximetry recommended in any baby requiring resuscitation
• No evidence for improved outcomes with early ECG use
• Normal newborn HR 110-160 (average 130)
• HR should be consistently >100 within 2 minutes
• Increasing or decreasing HR are the best sign that infants condition is improving or deteriorating respectively
• If <100, start CPAP or PPV

Colour

• Poor means of judging oxygenation
• Cyanosis is best seen in good ambient light in mouth
• If appears persistently blue, check SpO2
• Extreme pallor, especially if persistent after ventilatory support, suggests severe acidosis, hypotension due to impaired CO, hypovolaemia or severe anaemia

Pulse oximetry

• Should switch device on and sensor placed next to infant’s right hand before connecting the sensor to the cable instrument
• Should periodically check that pulse oximetry pulse is accurate (with stethoscope or ECG)
• Can provide HR within 60 seconds and SpO2 within 90 seconds of application (as long as sufficient blood flow)
• Recommended if resuscitation required, CPAP/PPV required, persistent cyanosis or if supplemental oxygen used

Airway

• Neutral or slightly extended (towel under shoulders is ideal)
• If respiratory efforts present but not ventilating, support lower jaw, open mouth, maintain adequate positioning and suction mouth if obstructed
  • Pharyngeal suction can cause laryngeal spasm, trauma to soft tissues, bradycardia, prolonged cyanosis, delayed onset of spontaneous breathing
    • Should not be used unless necessary and then done very carefully

Airway

• Mec-stained liquor
  • Suctioning of mouth or pharynx intrapartum makes no difference and is not recommended
  • Endotracheal suction
    • If vigorous, routine suctioning is not recommended as does not improve outcome and may cause harm
    • If not vigorous, available evidence not clear. Infants appear to be at greater risk of MAS but unclear if suctioning shows benefit
      • Not recommended at this stage. Emphasis on achieving adequate ventilation and resuscitation
    • If performed, should not be stimulated until afterwards
    • No evidence for repeated intubation for suctioning

Ventilation

• If after stimulation, HR <100 and breathing inadequate – start PPV
• Primary measure of effectiveness is rise in HR
• If little or visible chest wall rise, change technique (i.e. two-person) and if still fails, try increasing pressure until chest wall movement and HR rises
  • Start at 30cmH20 (or 20-25 if preterm)
  • May require airway suctioning or oropharyngeal airway (i.e. large tongue)
  • If still fails, consider ETT or LMA
• ANZCOR suggest T-piece device due to improved PEEP delivery, routine use of manometry and reliable titration of oxygen concentration (no strong evidence for this over self-inflating bag)
• Self-inflating bag cannot deliver CPAP and may not provide PEEP even if valve in place

Ventilation

• Initiation
  • Aims are to clear lung liquid, establish lung aeration and enable gas exchange
  • Term infant – Initial pressure 30cmH20
  • Preterm infant – Initial pressure 20-25cmH20
  • PEEP of 5 recommended for all
  • Adjust pressures as per response
  • May require higher inflation pressures initially due to poor compliance
  • In many infants, once chest rise and HR increases, pressures and rate can be reduced
  • Continue subsequent ventilations at 40-60/min with inspiratory time of 0.3-0.5s

PEEP

• Effective in improving lung volumes, reducing oxygen requirements, reducing incidence of apnoea in premature babies with RDS
• PEEP 5-8cmH20 recommended during resus
• PEEP >8 should be used with great caution

Ventilation

• For spontaneously breathing term newborns with respiratory distress, recommended to try CPAP (no studies to support this)
  • If >25 weeks gestation and in respiratory distress, no difference between CPAP and I&V (w.r.t. survival at 38 weeks)
  • If 25-28 weeks and spontaneously ventilating, CPAP prevents I&V (100% vs. 46%) and reduces surfactant use (77% to 38%)
  • Aim to ensure established ventilation by 60 seconds

Oxygen

• Supplemental Oxygen
  • Improved survival in neonates resuscitated initially on 21% vs 100% O2
  • Term infants requiring IPPV, 100% O2 conferred no short-term advantage and led to increased time to first breath/cry
  • No studies comparing anything other than 21% vs 100%
  • Regardless of gestation, goal of O2 administration should be to achieve normal SpO2 for that time after birth (see next slide)
  • The IQR rises above 90% but in guidelines, target should not exceed this
  • Term and near-term infants should receive 21% initially and uptitrate as required despite ventilatory support

Neonatal resus – Oxygen

Intubation

• Intubation
  • Preterm gestation or VLBW should be the only deciding factors
  • Indications
    • Ventilation via facemask or LMA unsuccessful or prolonged
    • Congenital diaphragmatic hernia or extremely LBW
    • Born without detectable heart beat, intubate as early as possible
  • ET sizing
    • Gestation age in weeks / 10
    • <1kg – 2.5mm
    • 1-2kg – 3mm
    • 2-3kg – 3.5mm
    • >3kg – 3.5-4mm

Intubation

• Intubation
  • Laryngoscope blade size
    • Straight blade size 1 for term and larger preterm infants
    • Size 0 for <32 weeks
    • Size 00 for extremely LBW infants
    • Some experienced operators use curved blades
  • Depth of insertion
    • Weight in kg + 6cm from upper lip
    • Recommend using table (see next slide) for extremely low birth weight infants and premature infants outside neonatal period

Neonatal resuscitation

Intubation

• Verification of tube position
  • Effective of ventilation confirmed by
    • Chest moves with each inflation
    • HR rises >100
    • O2 sats improve
  • Visualisation of passing through cords
  • Mist condenses on inside of tube
  • CO2 detector (colourimetric)
    • False negative if minimal pulmonary blood flow
  • Symmetrical air entry over lung fields
• Signs not in trachea
  • No chest movement, HR <100, no expired CO2, no improvement in SpO2, absence of breath sounds in both axillae
• Recommend against end-tidal CO2 monitoring and routine use of flow/volume monitoring

LMA

• Consider if >34 weeks/2000g if facemask ventilation unsuccessful
• Great backup if intubation fails
• May be considered as primary alternative if >34 weeks or >2000g although insufficient evidence for routine use
• Size 1 LMA for up to 5kg
• Accuracy of colourimetric CO2 detection has not been established
• Has not been evaluated during chest compressions

Chest compressions

• Indications – HR <60 despite adequate ventilation for 30 seconds
• Once started, interrupt as little as possible
• As soon as decision made to start compressions, preparation for IV access and adrenaline delivery should be made
• Lower third of sternum (not ‘middle of chest’), 1/3 of chest (same as everyone)
• Two thumb technique recommended
  • Superior peak systolic and coronary perfusion pressure, more consistent over long periods, easier and less tiring than two-finger technique
  • Two finger only if single resuscitator
• 3:1 ratio with 90 compressions per minute and 0.5s pause after every 3 compressions to deliver breath
• Continuous compressions at 120/min in intubated patient
• Chest should completely re-expand between breaths but thumbs not leave chest

Chest Compressions

• Once compressions started, increase O2 to 100% and then wean as soon as possible once HR recovered
• Signs of improvement
  • Spontaneous rise in HR
  • Rise in SpO2
  • Spontaneous movement or breaths
• Chest compressions should continue until HR >60

Meds and fluids

• If HR <60 despite adequate ventilation and chest compressions
• Ideally adrenaline as rapid bolus via umbi vein catheter
• Can be given via ET but if fails to achieve HR >60, repeat as intravascular dose if possible
• IO lines can be an alternative but very tricky in neonate
• Umbilical artery NOT recommended due to potential complications of hypertonic/vasoactive drug administration

Adrenaline

• 10-30mcg/kg IV (0.1-0.3mL/kg of 1:10 000) by quick push followed by saline flush
• Repeat every few minutes if HR remains <60
• Higher doses risk increased post-resus mortality and ICH
• ET dose is 50-100mcg/kg (unknown efficacy and safety)

Fluids

• If suspected blood loss and not responded to alternative resuscitation
• Saline or Hartmann’s may require follow-up blood if acute blood loss
• Can trial fluid if not responding as blood loss can be occult
• 10mL/kg IV push is recommended with repetition after period of observation

Special circumstances

• Prematurity
  • If <28 weeks: Polyethylene bag under warmer without drying (other than head)
  • May need ambient temp >28, exothermic warming mattress, warmed humidifed resus gases and covering head with hat
  • CPAP
    • If spontaneously breathing but requiring support, initiate CPAP in first minutes rather than I&V
    • Reduced combined outcome of death, bronchopulmonary dysplasia
    • No improvement in death, BPD, air leak, severe ICH, NEC or severe ROP
    • 5mmHg either nasal or face mask
    • Role of intubation-surfactant-extubation (INSURE) approach is not proven

Special circumstances

• Prematurity
  • Initial sustained inflation breaths
    • Not recommended at this stage
  • Surfactant
    • Consider endotracheal surfactant early during stabilisation of premature infants who have required intubation for resuscitation
  • Oxygen
    • In premature infants <32 weeks, 21% or 100% as compared to blended air/oxygen mix was more likely to result in hypoxaemia or hyperoxia
    • High initial concentrations (65-100%) result in no benefit w.r.t. mortality before discharge, BPD, IVH, ROP
    • Recommend room air or blend up to 30% initially and titrate as required

Special circumstances

• Congenital upper airway obstruction
  • If pink when crying but cyanotic with/without laboured breathing when quiet consider choanal atresia
    • Oral airway may suffice
  • If small pharynx then prone positioning or placement of nasal ET may improve situation
  • Compromising craniofacial abnormalities may require LMA/ETT and expert consultation
• Congenital diaphragmatic hernia
  • Should not receive BMV
  • Early intubation or LMA recommended to prevent GI tract insufflation
  • Wide-bore OG tube should be inserted to empty bowel of gas
  • Ventilation must be gentle with low tidal volumes (as often only one functional lung)
• Unexpected congenital abnormalities
  • If life-limiting/threatening, often best to continue resuscitation attempts and then evaluate in neonatal unit after successful resuscitation

Special circumstances

• Pneumothorax
  • Rare. Indicated by failure to respond or usual signs
  • CXR best diagnostic test
  • Transillumination helpful in preterm infants
    • May be falsely negative in term infants
• Pleural effusion/ascites (foetal hydrops)
  • Can cause lung hypoplasia. Ventilation usually possible with higher pressures followed by USS/CXR then thoracocentesis

Special circumstances

• Congenital heart disease
  • If remain cyanotic despite adequate ventilation, oxygenation and circulation, consider this
  • Need echo and NICU admission
• Abdominal wall defects
  • Gastroschisis or large omphalocoele require protection and prevention of bowel expanding with air
  • Food wrap over bowel and position in side-lying
  • Orogastric to remove air immediately
  • If respiratory support required, avoid CPAP or IPPV via face mask as insufflates bowel
  • Low threshold for intubation or LMA if required

Special circumstances

• Fetal haemorrhage
  • Maternal vaginal bleeding before birth may indicate fetal haemorrhage
  • Major transplacental haemorrhage can cause severe neonatal hypovolaemia without signs of bleeding
  • Typically very pale even after good heart rate restored
  • Often difficult to resuscitate and may require IV fluid
• Umbilical artery blood gas
  • Should be measured in every resuscitated neonate
  • Most objective way to assess condition just before birth
  • One criterion for determining if intrapartum cause of cerebral palsy
  • Compare paired vein/artery samples due to risk of incorrectly identified umbilical vessels
  • See next slide

Special circumstances

Post-resus care

• APGAR at 1 and 5 minutes then every 5 minutes until HR and breathing are normal
• Post-resus, should be admitted to NICU or SCN
• Ongoing monitoring of saturation, HR, RR, WOB, BP, BSL and blood gas
• Blood glucose should be checked soon after resuscitation
  • More likely to suffer hypoglycaemia
  • Maintain above 2.5
  • Infusion of 4-6mg/kg/min is usually sufficient
  • Large boluses should be avoided (>100mg/kg)

Post-resus care

• Consider early septic screen and empirical antibiotics
• Induced hypothermia for HIE
  • 35 weeks or more with evolving moderate to severe HIE
  • Need to meet:
    • Prolonged resus >10min
    • APGAR at 10 min <= 5
    • pH <7.0 or BE >-12 at or just after birth
  • Should commence within 6 hours of birth, cool to 33-34, continue for 72 hours and re-warm gradually

Ethical issues

• Best approach is to resuscitate and discuss withdrawal later
  • Exception is anencephaly or extreme prematurity (no set cut-off)
  • Resuscitation not indicated if gestation, birth weight or congenital anomalies with almost certain early death and unacceptably high morbidity
  • Parents views on resuscitation should be supported if uncertain prognosis, with borderline survival and relatively high rate of morbidity
  • Prognostic scores not recommended at this stage for <25 weeks
• Discontinuing resus
  • If newly born late pre-term or term infant, reasonable to stop if HR undetectable and remains so for 10 minutes
    • Depends on optimal resuscitation, availability of NICU care, presumed aetiology, gestation and parental wishes
  • Absence of spontaneous breathing or APGAR of 1-3 at 20 minutes if >34 weeks but with detectable HR are strong predictors of mortality/significant morbidity
    • Consult with neonatologist but often reasonable to stop

Last Updated on October 13, 2020 by Andrew Crofton