Fetal Resuscitation Flashcards
Neurologic injury in the fetus depends on?
Duration of hypoxia from disruption of placental flow of oxygen and nutrients
Maternal infection and inflammation can cause what?
Neuro developmental abnormalities
- schizophrenia
- autism
What is complete asphyxia?
Total placental abruption
Umbilical cord occlusion
What is incomplete asphyxia?
Anytime oxygen delivery is inadequate to meet needs
Causes of incomplete asphyxia
Aortocaval compression
HTN
Hypotension…
Fetal assessment: neurobehavioral scale
HR
Motor activity
Existing behavioral state
Responsiveness to external stimuli
Anesthesia and fetal brain injury
All needs more studies
- labor anesthesia
- parenteral opioids
- neuraxial
- inhalation agent
What drug is thought is help with neuroprotection?
Magnesium
What may improve outcomes in neonates at risk for hypoxic ischemic encephalopathy?
Hypothermia
Fetal circulation
Placenta Umbilical vein and ductus venosus To inferior vena cava Right heart Foremen ovale to Left heart Ascending aorta Patent ductus arteriosis Descending aorta Blood returns to placenta via umbilical arteries
What affect does clamping the umbilical cord have?
Increase SVR
Why does lower oxygenated blood supply the lower body while the more oxygenated blood supplies the upper?
PVR is higher than SVR so most of the blood from the RV is pushed through ductus arteriosis into lower body circulation
-lower body also requires less O2 than brain and heart
Decreased PVR occurs from what? Leading to what?
Expansion of the lungs and increased alveolar oxygen tension and pH
Greater pulmonary artery blood flow
What does increased pulmonary artery blood flow cause?
Improved oxygenation and higher LA pressure > diminishes shunting across foramen ovale
What causes constriction of the ductus arteriosis and closure of the foramen ovale?
Increased PO2 and SVR
Decreased PVR
Fetal breathing movements are seen when? How do they change?
11 weeks gestation
Increase with gestational age
Decrease days before onset of labor
What is contained in the fetal lungs?
Ultra-filtrate of plasma (fluid)
- partial reabsorption
- 2/3 expelled
What increases residual fluid in fetal lungs?
Preterm
C-section
-vaginal delivery helps push out some fluid
First breath occurs when? Establishes what?
~ 9 seconds after delivery
FRC
When is surfactant present in the alveoli?
By 20 weeks gestation
When is surfactant present within the lumen of the airways?
28-32 weeks gestation
When are significant amounts of surfactant in terminal airways?
34-38 weeks gestation
When is induction of labor held off till 36-38 weeks?
For surfactant
Transition to extrauterine life is asssociated with what?
Catecholamine surge
-helps surfactant production
How do neonates respond to cold?
Increase their metabolic rate and release norepinephrine
What does this increase in metabolic rate and release of norepinephrine response facilitate?
Oxidation of brown fat
The oxidation of this mitochonrida containing brown fat results in what?
Non-shivering thermogenesis
What percentage of neonates require some form of resuscitation?
10%
What can help predict the need for some form of neonatal resuscitation?
Preterm
Intrauterine insults
Congenital anomalies
What is normal fetal HR?
120-160
Book says 110-160
What does a normal fetal HR indicate?
Normal uteroplacental perfusion
Intact CNS
Normal fetal pH of 7.25-7.45
What fetal pH is pre-pathological and what measures can be taken to help correct it?
7.20-7.25
O2 supplementation to mom
Change position (aortocaval compression)
What causes early decelerations? When do they occur?
Occur simultaneous with uterine contraction
Head compression
What causes late decelerations? When do they occur?
Begin after uterine contraction and end after completion of contraction
Decreased uteroplacental perfusion due to maternal hypotension, hypovolemia, maternal acidosis, preeclampsia, HTN
What causes variable decelerations? When do they occur?
Umbilical cord compression or other reduced blood flow states like HTN and decreased arterial O2 tension
What decelerations are normal?
Early
Which deceleration are bad?
Late
Which deceleration may or may not be tolerated?
Variable
When are APGAR scores performed?
1 and 5 minutes after delivery
A P G A R
Appearance Pulse Grimace Activity Respirations
How is each category rated?
Scale of 0-2
Zeros for APGAR
Appearance: blue; pale Pulse: absent Grimace: floppy Activity: absent Respirations: absent
1s for APGAR:
Appearance: pink body; blue extremities Pulse: below 100 Grimace: minimal response to stimulate Activity: flexed arms and legs Respirations: slow and irregular
2s for APGAR:
Appearance: pink Pulse: above 100 Grimace: prompt response to stimuli Activity: active Respirations: vigorous cry
What is the normal RR for neonate?
30-60
What should the initial assessment of the fetus look like?
RR: 30-60
Neurologic: vigorous activity
HR: 80-205
Gestational age
What can delayed cord clamping increase?
Iron stores
BP
What does high concentration of O2 raise?
Production of oxygen free radicals
What are oxygen free radicals linked to?
Hypoxia-deoxygenation injury
How old for LMA use in infant?
34 weeks gestation or later
O2 level use by age
Term: room air
Preterm: FiO2 30-90% lower asap
What is this high concentration of O2 linked to?
Vision loss Childhood cancer (supplements O2 over 3 minutes)
Saturation of what for a neonate is acceptable
85-92%
