CCP 340 Neonatal Anatomy and Physiology πΆπ» Flashcards
Neonatal airway anatomical features
aka from an ANATOMICAL perspective why do neonates suck to intubate
- VERY Small, compressible airway
2. Relatively large tongue and occipital area
Neonatal airway physiologic features
aka from an PHYSIOLOGIC perspective why do neonates suck to intubate
- Low Functional Residual Capacity
2. High metabolic rate and oxygen consumption (desaturate FAST)
Emergency evaluation of the newborn should be framed by three questions
- Was it a term birth? (37 weeks)
- Does the neonate have good tone?
- Is the neonate breathing or crying effectively?
Negative responses to any of the above questions should prompt further evaluation and likely initiation of resuscitation procedures.
Positive responses to all questions and no additional provider concerns indicate that resuscitation is likely not needed and the infant can stay with the mother.
main aetiologies for Neonatal distress and arrest
common: respiratory
rare: severe anemia or congenital/cardiac
location for PRE-ductal pulse oximetry
right upper extremity
what percent of term infants require drying and stimulation to trigger breathing reflex
10%
what percent of term infants will breathe spontaneously within the first 30 s of life and require no additional management
85%
what percent of term infants require positive pressure ventilation to trigger breathing reflex
3%
what percent of term infants require intubation for respiratory support
2%
what percent of full-term infants require chest compressions and epinephrine to achieve transition
0.1%
detail of the pathophysiology related to rapid shift in fetal circulation upon delivery
aka, how does CVS/respiratory shit change for baby once it gets outta mom
- Clamping of the umbilical cord β the babyβs SVR
- Blood flow through the ductus venosus β and gradually closes over the first 3-7 d, thereby β blood flow to the IVC
- Lung expansion causes a β in pulmonary vascular pressure, which β right atrial flow
- The β in right atrial flow ceases the flow through the foramen ovale, which then closes almost immediately.
- These alterations in blood flow through the ductus arteriosus β its closure within the first week of life
- obtaining an SpO2 on the right hand (preductal) gives the most accurate assessment of central oxygen levels.
- This process also explains the gradual shift in appropriate O2 levels from <65% at birth to 85%-95% at 10 min of age
maternal risk factors which increase prenatal stress on the fetus leading to higher rates of neonatal resuscitations
AKA, in what cases should you anticipate an NRP resus
Active infection Gestational diabetes Gestational hypertension Illicit drug use Lack of prenatal care Pre-eclampsia/eclampsia Prescription or hospital-administered drug use (including general anesthesia or magnesium therapy)
The normal neonatal respiratory rate
40-60 breaths per minute
The normal neonatal heart rate
120-160 beats per minute
how does PPV help a neonate βtransitionβ
- The initiation of respiration is the first task in neonates.
- positive-pressure respiratory support aids in fluid absorption in the lungs and expands the lung volume β a decrease in PVR β an increase in right atrial flow β improved CVS/pulmonary dynamics/oxygenation
Pregnancy complications and fetal factors which play a role in an increased likelihood of NRP resuscitation requirements
Multiple gestation (particularly <35 wk) Oligo- or polyhydramnios Hydrops fetalis Fetal congenital malformations Premature rupture of membranes (rupture before labor begins) or prolonged rupture (>18 h) Preterm delivery (<36 wk) Non-reassuring fetal heart rate or bradycardia Meconium-stained amniotic fluid Breech presentation Shoulder dystocia Nuchal cord Emergency cesarean section
define gestational age
Gestational age is loosely defined as the number of weeks between the first day of the motherβs last normal menstrual period (LMP) and the day of delivery
APGAR: βAppearanceβ
Blue, pale (0)
Centrally pink (1)
Pink (2)
APGAR: βPulseβ
Absent (0)
<100 bpm (1)
>100 bpm (2)
APGAR: βGrimaceβ
Floppy (0)
Minimal responsiveness (1 )
Responds to stimulation (2)
APGAR: βActivity (tone)β
Absent (0)
Flexed (1 )
Active (2)
APGAR: βRespirationsβ
Absent (0 )
Slow (1)
Vigorous (2)
neonatal hypoglycaemia definitions
- Hypoglycemia in the first 1-4 h of life is considered at levels <2.2 mmol/L
- From 4-24 h of life, glucose should be >2.5 mmol/L
when does a fetus become viable?
23 weeks +/- 1wk
SGA definition
small for gestational age
AGA definition
appropriate for gestational age
LGA definition
large for gestational age
IUGR definition
intrauterine growth restriction
extreme preterm definition
π΅π΅π΅ MONEY SLIDE π΅π΅π΅
<30 wks
preterm definition
<37 wks
late preterm definition
35-37 wks
term definition (gestational age)
37-42 wks
at what week in embryonic development does the neonate start producing surfactant?
24 wks
at what week in embryonic development does the neonate form alveolar sacs?
36 wks
fluid choice for first 24hr in a neonate
D10W (no electrolytes, because kidneys arenβt working until post 24h)
goal sats preterm infant
88-92%
goal sats term infant
90-95%
ml/kg/min for a neonate minute ventilation
πππCORE CONTENTπππ
200-300 ml/kg/min
side effects of prostinaglandin
- apnea
- hypotension
- fever
discuss the approach to oxygenation as part of the initial neonatal resuscitation
- Oxygenation should not be aggressive. Hyperoxia is associated with β morbidity and mortality.
- Room air (21% oxygen) is sufficient during the initial stages of resuscitation.
- Preductal (right hand) goal SpO2 at 1 min of life is 65%-70% and β by ~5% per min.
- The target SpO2 at 10 min of life is 85%-95%.
- If the HR is <60 after 90 s of resuscitation at lower oxygen concentration, the oxygen concentration may be β to 100% until the heart rate recovers
describe the βMR SOPAβ mnemonic
- Most neonates respond to positive pressure ventilation.
- If positive pressure ventilation is ineffective, the βMR SOPAβ mnemonic may be used to improve ventilation
M = mask (adjust mask for good seal) R = reposition the airway S = suction the mouth then nose O = open the mouth with a jaw thrust P = increase pressure until there is chest rise A = airway control (ie, endotracheal tube)
primary reflexes in baby
suck, moro, grasp
side effect of pyridoxine (vitamin B6)
apnea
phenobarbital dosing for neonatal seizures
20mg/kg
then 10mg/kg x2
persistent projectile vomiting in a previously well baby (usually presents at 3-12 weeks of age)
typically pyloric stenosis
ml/kg/min for a paediatric minute ventilation
100-200mL/kg/min
neonate lung protective tidal volume
4-6mL/kg
peds lung protective tidal volume
6-8mL/kg
VITAMINS mnemonic for peds altered mental status
Vasculitis Infection Toxins Accidental Injury Metabolic intussusception Neoplasm Seizures
calculating Maintenance fluids in Neonates
- the 4-2-1 rule is not used in neonates as it overestimates the fluid requirements in the first few days and underestimates fluid requirements after day 4
- In Neonates we order as total fluid intake (TFI) per day:
For full term infants: Day 1: 60 cc/kg/day Day 2: 80 cc/kg/day Day 3: 100 cc/kg/day Day 4: 120 cc/kg/day Day 5: 140 cc/kg/day Beyond: 150 cc/kg/day
βintakeβ for fluid balance includesβ¦
Intake includes:
- IV fluids
- Medications (IV, NG/GT)
- Oral Solids & Fluids
- NG/GT feeds
- All flushes (NG, GT etc.)
- Blood Products
- TPN & Lipids
initial fluid choice for first 24hr of life in a neonate
- D10W
- maintenance electrolytes generally are not given before 24 hours of life because of the relatively volume-expanded state and normal isotonic losses during the first days of life
discuss the use of electrolyte containing fluids in the first 24 of life in a neonate
- For infants receiving parenteral fluids, maintenance electrolytes generally are not given before 24 hours of life because of the relatively volume-expanded state and normal isotonic losses during the first days of life
- Use D10W
Major Objectives of Maintenance Fluid Therapy include:
Provide WATER to meet physiologic needs/losses
Provide essential ELECTROLYTES (Na, K, Ca)
Provide minimum CALORIC needs
Maintenance Fluid Therapy definition
Represents the fluid and electrolyte requirements needed by the average individual with normal intracellular(ICF)and extracellular(ECF) fluid volumes OVER a 24-hr PERIOD.
why do Infants have HIGHER fluid requirements?
π΅π΅π΅ MONEY SLIDE π΅π΅π΅
- β Rates of Metabolism and Growth
- β Caloric Expenditure translates into β Fluid Requirements
- β Insensible Fluid and Electrolyte losses d/t an β BSA to Weight Ratio (almost 3x)
- Lower Tubular Concentrating Ability, β higher obligatory fluid loss.
- β Respiratory Rates result in β insensible losses
factors to consider in terms of Choice of Intravenous Fluids
- Age of the patient
- Nutritional status and Mandatory Glucose Energy Requirements
- Level of cellular injury and trauma
- Type and volume of ongoing fluid losses and/or fluid shifts
discuss Glucose Requirements for Neonates and Infants
- Glucose is the predominant fuel for the newborn brain and it depends on it exclusively.
- Hypoglycemia (especially in the early neonatal period) predisposes to long-term neurological damage.
- Normal adaptive mechanisms like gluconeogenesis and glycogenolysis are immature in neonates and infants. Hypoglycemia is particularly of concern in the premature and sick infant.
- Therefore, it is important to consider maintenance glucose administration in these infants
discuss maintenance fluids in the first 24hr of a neonates life (assume healthy, normal term birth)
- Neonates have β total body water at birth, which must be redistributed and excreted.
- Physiologic diuresis is observed during the first few days of life which leads to a decrease of 5-15% in body weight by the end of week 1
- Therefore, no electrolytes are added to hourly maintenance fluids on DOL1 and sometimes up to DOL2.
- D10W remains the primary hourly maintenance fluid on DOL-1. Thereafter as UO β, maintenance rates are β and electrolytes (Na, K, Ca) added to the maintenance fluid mix (D10Β½NS or D10NS w/ K+)
- Neonates and Infants who present for transfer should have their dextrose containing maintenance fluids continue during the transfer (except for brief interruptions). This will prevent intra-transfer hypoglycemia
name the Two right-to-left shunts occur in the fetus
- Foramen ovale β Blood shunted from the right to left atrium
- Ductus arteriosus β Blood shunted from the pulmonary artery to the aorta
umbilical vein carries oxygenated or deoxygenated blood?
oxygenated blood
umbilical artery carries oxygenated or deoxygenated blood?
deoxygenated