Resuscitation, Stabilization, & Thermoregulation
RNC Review
Objectives
� Recognize and understand fetal circulation� Identify physiologic changes that must occur at birth to
lead to a successful transition� Identify the sequence of steps of NRP� Recognize early signs of compromise and describe how
to best manage these patients� Articulate the importance of thermoregulation and risk
factors for hypothermia for the newborn baby
Complexity of the Fetal Circulation
� Differences between fetal circulation vs. newborn circulation○ Placenta (low resistance organ) serves as organ
oxygenating fetus vs. lungs○ Fluid filled gas exchange (lungs are a high resistance
organ) vs. air exchange○ Fetal shunts are open: ductus venosus, ductus
arteriosis, and foramen ovale
Fetal Shunts
� Ductus Venosus ○ UV to IVC (remember UV blood is oxygenated/red blood)○ “Shortcut” to get oxygenated blood to the heart and out to the rest
of the body� Ductus Arteriosus
○ PA to proximal descending aorta○ Shunts deoxygenated/blue blood from the RV, bypassing the fluid
filled lungs, to the lower extremities and out ○ Allows deoxygenated blood to leave fetus via UAs, back to the
placenta to get more oxygen� PFO
○ Shunt between atria ○ RA oxygenated blood to LV, out aorta, and to the body
� All shunts get the most highly oxygenated blood from the placenta to where it is needed most: the fetal brain and heart!
The Changes Needed for Successful Transition
Cord is cut; placenta is no longer part of the circulation….now what?
� UAs & UV will constrict� SVR increases due to removal of this low resistance
organ� Left side of the heart now has an increased workload� LV pressures rise and RV pressures decrease� Pressure changes lead to functional closure of the fetal
shunts○ Bonus: what would happen if these shunts didn’t
close?
The Changes Needed for Successful Transition
Changes in Ventilation
We love that first big cry!
� Breathing fills lungs with air (not fluid)� Alveoli fluid is reabsorbed into the pulmonary lymphatics� Remember..oxygen is a vasodilator: increased PaO2
leads to pulmonary vessels dilating, thus decreasing resistance to blood flow
Path of least resistance, always!
� Each breath should contribute this process, improving FRC and lung compliance=pink baby!
Newborn Circulation
Further Considerations During Transition
� Maternal history○ Meds, chronic illness etc.
� L&D○ Delivery mode, need for assistance○ Fetal distress
� Resuscitation measures needed
NRP Key Points
� Only about 10% of newborns require some kind of assistance
� Only 1% need major resuscitative intervention� Most importantly...ventilate!� Prolonged inadequate perfusion can lead to brain and
other organ damage, or even death� Primary apnea will improve with tactile stimulation vs
secondary apnea (continued decreasing HR and now decreasing BP too) cannot be improved with stim, but needs assisted ventilation
� PPV during secondary apnea should improve HR� Review antepartum and intrapartum risk
factors...ANTICIPATE!
NRP Key Points
� Every birth must have 1 person whose only responsibility if the baby and they must be capable of initiating resuscitation
� If resuscitation is anticipated, more staff who can complete the resuscitation should be present in the DR before the birth occurs
� Remember, 30 seconds to look for a response for each step of NRP
� Teamwork makes the dream work and effective communication
� Initially: ○ Provide warmth○ Position head and clear airway as needed○ Dry and stim
Review the Steps….
NRP Review: MR SOPA
M - mask
R - reposition the head to open the airway
S - suction mouth then nose *1 before 2*
O - open mouth and lift jaw forward
P - gradually increase pressure every few breaths until you note chest rise
A - artificial airway
NRP: Ventilation
Intubation consideration:
� Meconium aspiration� PPV without improvement, after considering MR SOPA� Chest compressions� Special considerations: prematurity, congenital
malformations, surfactant replacement
NRP: Chest Compressions
� HR < 60 despite 30 seconds of effective PPV� 2-finger technique� Thumb technique: often more effective � Compress to ⅓ the diameter of the chest� Rate of 90 bpm or 1 breath to every third compression
Stayin’ Alive
NRP Review
So how did that resuscitation go?
Let’s score!
NRP: Ventilation
Tube size:
NRP Review: Apgar
Targeted Oxygen Saturation: What is the Significance of Pre-ductal Saturation?
Targeted Preductal Sp02
1 min 60-65%
2 min 65-70%
3 min 70-75%
4 min 75-80%
5 min 80-85%
10 min 85-95%
18
19
88
72
Why Right
Hand??
Thermoregulation
Consider a newborn’s large surface area to their body mass ratio:
3x surface area of an adult!
� Decreased subcutaneous fat and glycogen stores� Decreased muscle mass� Thin skin� Cold environment?
Thermoregulation
� A primary vital sign affecting their ABCs� Warm & dry!� Skin to skin if appropriate and safe
Thermoregulation
Why is it so important?
Reduce O2 use
Maximize metabolic efficiency
Reduce calorie expenditure
Thermoregulation
Neutral Thermal Temperature: Minimize work!
� Minimal metabolic rate� Minimal oxygen consumption
Neutral Thermal Environment: ambient temperature around the baby that helps maintain the neutral thermal temperature
Thermoregulation
Ranges of Core Temperature:
� Normal: 36.5-37.3� Cold Stress: 36-36.4� Moderate hypothermia: 32-35.9� Severe hypothermia: <32
Thermoregulation
Physiological response to hypothermia
� Hypothalamus activates norepinephrine ->pulmonary and peripheral vasoconstriction and increased PVR
Thermoregulation
How do they maintain normothermia?
Metabolic process
Voluntary muscle activity
Peripheral vasoconstriction
Nonshivering thermogenesis: brown fat
Thermoregulation
More on brown fat
� Energy source� Initiated in hypothalamus: norepinephrine release� Metabolized to generate heat: uses oxygen and glucose� Used to generate heat instead of shivering (impossible or
not effective)� Cannot be replaced once used� Term infants: 4-10% of adipose
○ Doesn’t form until 26-30 weeks gestation� Last usually 3-6 months of age unless cold stressed (less
longevity)
Thermoregulation
Provide warm, dry environment
Consider delaying bath
Avoid placing beds by drafty doors/windows
Consider hat/clothing, warm blankets
Skin to skin
Servo control
Thermoregulation
Hypothermia is preventable!
It affects morbidity and mortality.
Maintaining normothermia is critical!
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