WEEK 3A - Neonatal Resuscitation Flashcards
Maternal risk factors that may require newborn resuscitation
Prolonged rupture of membranes (>18 hours)
Bleeding in 2nd or 3rd trimester
Severe pregnancy-induced hypertension
Chronic maternal illness (cardiovascular, thyroid, neurological, pulmonary, renal)
Diabetes mellitus
Maternal substance abuse
Chorioamnionitis
Polyhydramnios or oligohydramnios
No antenatal care
Young or AMA
Fetal risk factors that may require newborn resuscitation
Multiple gestation
Preterm, especially <35 weeks
Post-dates >41 weeks
LGA/IUGR
Reduced fetal movement before onset of labour
Congenital abnormalities which may affect breathing
Intrauterine infection
Perinatal trauma
Intrapartum risk factors that may require newborn resuscitation
Sinusoidal fetal HR, indicating severe fetal anaemia or prolonged fetal hypoxia
Non-reassuring fetal heart rate patterns on CTG
Abnormal presentation (breech, transverse lie, face, brow, shoulder)
Prolapsed cord
Prolonged labour >24 hours
Prolonged second stage >2 hours
Precipitate labour
Antepartum haemorrhage (abruptio, placenta praevia, vasa praevia)
Meconium in amniotic fluid with non reassuring CTG
Narcotic administration to mother within 4 hours of birth of the baby
Forceps or vacuum-assisted birth
Caesarean section under GA
Considerations when preparing resuscitation equipment
- Is the infant term gestation?
- is the infant breathing or crying?
- does the infant have good muscle tone?
Equipment considerations
- Monitoring equipment (stethescope, pulse oximeter, posy, ECG leads)
- Suctioning equipment (catheters, tubing, access to suction)
- PPV equipment (T piece or neopuff, inflating bag, face masks, supraglottic airways, oropharyngeal airways)
Drugs for resuscitation
- Adrenaline 1:10,000 concentration (0.1mg/ml)
- Volume expanders (0.9% sodium chloride & O Rh negative bloods need to be readily available)
- 0.9% sodium chloride for priming and flushing IV lines
Special considerations for neonates
- Preterm infant < 32 weeks or < 1500 grams
- Infant born through mec stained amniotic fluid
- Multiple births
- Antenatal diagnosis of airway abnormality
- Antenatally diagnosed congenital anomaly that is usually incompatible with life (Trisomy 13, 18, extreme prematurity <23 weeks)
Oxygenation in intrauterine life
- Oxygen diffuses across the placental membrane from the mother’s blood to the fetus
- The fetal alveoli are expanded, but are liquid filled
- Blood flow to the fetal lungs is minimal (~8%)
- Blood vessels perfusing the lungs are constricted
- Due to increased resistance to flow in the constricted vessels in the fetal lungs, blood from the right side of the heart (~92%) takes the path of lower resistance across the ductus arteriosus into the aorta and to the systemic circulation
- Fetal SpO2 is approx 50-60% (and even 40-50% intrapartum) - hence it is normal for a healthy newborn infant to appear cyanotic in the first few minutes after birth
Describe transition to extrauterine life
- Umbilical arteries and vein constrict and are then clamped
- Placental circulation ceases and systemic vascular resistance increases as a result
- To survive, the newborn must take their first breath to initiate the complex series of events that switch gas exchange from the placenta to the lungs
- The normal newborn will make vigorous efforts to inhale air into the lungs
- Hydrostatic pressure during inspiration causes fetal lung liquid to move out of the alveoli and into the surrounding lung tissue (can occur rapidly)
- Liquid is cleared from the tissue via the blood vessels and lymphatics, but this occurs much more slowly
- Increase in blood flow to the lungs due to a drastic decrease in pulmonary vascular resistance
- The decrease in pulmonary vascular resistance and increase in systemic vascular resistance reverses the pressure gradient across the ductus arteriosus, resulting in shunting of blood from the aorta into the pulmonary circulation which contributes to pulmonary blood flow (closure of fetal shunts)
Oxygen saturations after birth
40-50% intrapartum → 60% by one minute of age → 90% by seven to ten minutes of age via pulse oximetry
Assessing the newborn after birth
Response to stimulation:
- The stimulation of being born into the cool environment of the birth room and being dried is usually sufficient to stimulate most newborn infants to breathe
- If the newborn does not respond to stimulation by breathing, the newborn should be moved to the resuscitaire for further assessment and intervention
Breathing:
- Most newborns will establish regular respirations that are effective in maintaining the heart rate above 100 beats per minute
- Apnoea, especially with hypotonia, is a sign of severe compromise. The infant should be moved to the resuscitaire for further assessment and intervention
Muscle tone:
- Normal newborns will move their limbs and assume a posture of flexion
- If the newborn remains hypotonic and is not moving, the newborn is likely to be severely compromised and should be moved to the resuscitaire for further assessment and intervention
Outline & rationale for first response newborn resuscitation (Airway)
- Position the infant supine with the head in a neutral position
- Clear the airway (only if obvious signs of obstruction)
- Dry the infant and stimulate the infant to breathe
- Maintain warmth. Aim to maintain the infant’s temperature between 36.5 and 37.5 degrees C in all non-asphyxiated newborns
- Assess the infant’s breathing and heart rate
Outline & rationale for first response newborn resuscitation (Breathing)
- If the infant is not breathing or HR <100 bpm + poor muscle tone and breathing ineffectively, PPV is indicated
- Provide PPV at a rate of 40 - 60 inflations per minute. Aim for an inspiratory time of 0.3 to 0.5 seconds
- Commence PPV in air (21%) initially for term infants, and up to 30% oxygen for infants <35 weeks gestation
- Apply a pulse oximeter on infant’s right hand or wrist
- Titrate supplemental oxygen administration according to pulse oximetry (wean the oxygen if saturations >90%)
- Reassess the infant after 30 seconds of effective PPV
- Reassess the infant’s breathing and heart rate
Outline & rationale for first response newborn resuscitation (Circulation)
- If HR >60 bpm but <100 bpm, continue PPV until HR > 100 bpm and the infant is breathing spontaneously and effectively
- If HR is <60 bpm, commence external chest compressions and PPV at ratio of 3:1
- Increase FiO2 to 100%
Reassess infant after a further 30 seconds of effective ECC w/ PPV - Reassess the infant’s heart rate
- If HR >60 bpm, ECC can be ceased and PPV continued at 40-60 inflations per minute until the HR >100 bpm and infant is breathing effectively
- If the HR still <60 bpm, advanced resuscitation interventions (IV access and drug administration) are now indicated
Outline & rationale for first response newborn resuscitation (Drugs)
- If the HR remains <60 bpm despite effective ECC w/ PPV, then adrenaline is indicated
- IV Adrenaline 1:10,000 solution
Volume expanders should be considered if the infant appears shocked and/or blood loss is suspected - Endotracheal intubation may be considered at several stages, but particularly if PPV with a mask fails to restore an adequate HR or the infant does not have a detectable HR at birth
Elements of advanced resuscitation (Endotracheal intubation)
If the infant’s heart rate is not >60 bpm with chest compressions and effective PPV 100% oxygen, advanced resuscitation interventions (including drug administration) are now indicated
- Indications are; if masked ventilation is difficult or does not result in the infant’s heart rate increasing to above 100 bpm and the newborn has not made adequate breathing efforts, or the infant is born without a detectable heart rate
- Intubation may be considered if; the infant born the mec stained fluid required brief tracheal suctioning, the preterm infant may be given CPAP from birth via mask or nasal prongs
- “Rule of 6”:
Oral intubation - infants weight in kg plus 6 cm = length at the lip
Nasal intubation - infant’s (weight in kg x 1.5) plus 6 cm = length at the nares
Elements of advanced resuscitation (Supraglottic airway)
- Indicated for; anticipated or unexpected difficult airway, a newborn with an airway anomaly, face mask ventilation unsuccessful, endotracheal intubation unsuccessful or not feasible
- Suitable for term or near-term newborns, >34 weeks, >2000 grams at birth
Elements of advanced resuscitation (Drugs - adrenaline 1:10,000)
Ensure that effective positive pressure ventilation is being provided (check for mask leak or airway obstruction, ensure adequate PIP to move the chest wall)
Administration of adrenaline is recommended if the heart rate remains < 60 bpm despite the above measures
- Action - sympathomimetic agent acting on alpha and beta adrenergic receptors
- Effects - increased heart rate & myocardial contractility, increased blood flow to skeletal muscle/brain/iver/the myocardium, increased cardiac conduction velocity, decreased renal blood flow
- Presentation - 1:10,000 ampoule or mini-jet (0.1 mg/ml)
- Route - IV recommended (umbilical vein or peripheral IV cannula), given as a rapid push followed by a 0.5 mL flush of 0.9% sodium chloride. Can be given via tracheal route if IV access cannot be obtained
- IV dose - 0.1 to 0.3 mL/kg can be repeated
- ETT dose - 0.5 to 1 mL/kg can be repeated
Elements of advanced resuscitation (Drugs - volume expanders)
Volume expanders are indicated when hypovolaemia secondary to fetal blood loss or septic shock is suspected
- Intravascular fluids should be considered when there is suspected blood loss and/or the infant appears to be in shock (pale, poorly perfused, weak pulse) and has not responded adequately to other resuscitative measures
- Choice of volume expander - O negative, uncrossed-matched red blood cells are indicated for hypovolemic/shock secondary to secondary to suspected fetal blood loss. 0.9% sodium chloride is indicated for the treatment of hypotension secondary to other causes of shock
- Action - replacement of circulating blood volume
- Effects - improved heart rate, improved blood pressure, improved perfusion, correction of metabolic acidosis
- Route - IV or IO
- Dose - 10-20 mL/kg can be repeated
