Neonatal Period Flashcards Preview

Nursing - obstetric component > Neonatal Period > Flashcards

Flashcards in Neonatal Period Deck (97)
Loading flashcards...

1. Weeks 25-30, Type II alveolar cells begin production
2. Mature amount at 35-37 weeks gestation
3. Phospholipid



1. Decrease surface tension of pulmonary fluids
2. Prevents alveolar collapse at end of expiration
3. Facilitates gas exchange
4. Lower inflation pressures needed to open airway
5. Improves lung compliance
6. Decreases labor of breathing

Functions of Surfactant


Marker of fetal lung maturity; test of fetal amniotic fluid to assess for fetal lung immaturity; surfactant

lecithin–sphingomyelin ratio ( L/S ratio): 2:1 or >


A phosphatidic acid that is a constituent in human amniotic fluid and is used as an indicator of fetal lung maturity when present in the last trimester of gestation (36 weeks)

Phosphatidyl glycerol


- Secreted by lungs, amniotic cavity, trachea
- Air must replace lung fluid
- 1/3 removed at birth; 2/3 pulmonary circulation and lymphatic system
- Total time to clear = 6-24 hours after vaginal delivery
- Inadequate clearance = TTN

Lung fluid


1. Term
2. Delivery route - cesarean birth
3. Low dose oxygen thereapy
4. Rapid improvement (3 days)

TTN - Transient Tachypnea of Newborn


1. Mild asphyxia in normal birth - high carbon dioxide and low oxygen
2. Others: thermal, tactile stimulation (flicking the soles of the feet; rubbing the back gently), lights, noise, cord occlusion

Breathing stimuli at birth


Respiratory rate in neonates



1. Diaphragmatic, shallow, irregular depth and rhythm
2. Abdominal, synchronous with chest movement
3. Short periods of apnea
4. Deep sleep - regular breathing
5. REM sleep - periodic breathing
6. Crying/ motor activity - grossly irregular

Characteristics of respirations in neonates


Until age 3 weeks, obstruction → respiratory distress (sleep on the back)
Reflex takes over
Relation to SIDS (Sudden infant death syndrome)
Oral mucus secretions, cough/gag

Obligatory Nose Breathers


Assessment tool to determine the degree of respiratory distress (0,1 or 2) ; > 7 - severe respiratory distress
Features observed:
1. Chest movement
2. Intercostal retraction
3. Xiphoid retraction
4. Nares dilation
5. Expiratory grunt

Silverman-Anderson Index - RDS : respiratory distress syndrome (resulting from lung immaturity and lack of alveolar surfactant )


Decrease blood flow to fetal lungs
Direct blood to the placenta
Increase blood flow to head & heart

Fetal Circulation


Fetal pulmonary BP > adult pulmonary BP
Diverts blood flow away from non-functioning fetal lungs

Decrease Blood Flow to Fetal Lungs


Fetal systemic BP lower than adult
Flow leads to the placenta readily

Direct Blood to the Placenta


1. Umbilical vein - oxygenated blood from the placenta to the fetus
2. Umbilical artery - waste
3. Wharton's jelly - keep vein and artery from tangling ; keep them separated

Umbilical Cord


Ductus venosus
Ductus arteriosus
Foramen ovale

Increase Blood Flow to Head and Heart


Shunts arterial blood into inferior vena cava
Functional closure - few hours after birth
Anatomic closure - turns into ligament

Ductus venosus


Shunts arterial and some venous blood from pulmonary artery to aorta; allows blood to go around lungs
Functional closure
Anatomic closure

Ductus arteriosus


Leads to abnormal blood flow between the aorta and pulmonary artery, two major blood vessels that carry blood from the heart.

Patent Ductus Arteriosus (PDA)


Connects right and left atria ( allows more than half the blood entering the right atrium to cross immediately to the left atrium, passing the pulmonary circulation)
Usually obliterated within hours after birth
Pressure highest right atrium

Foramen ovale


Umbilical cord clamped - neonate draws first breath - Systemic vascular resistance increases- Blood flow through ductus arteriosus decreases - Most of right ventricular output flows through lungs, boosting pulmonary venous return to the left atrium - Left atrial pressure rises in response to the increased blood volume to the lung - This, combined with increased systemic resistance causes functional closure of foramen ovale

Changes to Neonatal Circulation


Neonatal Heart Rate
Check apical for full minute
Also evaluate peripheral pulses (brachial, femoral)

120-150 awake
Range: 70-90 asleep, 180 crying


Blood Pressure
Sensitive to changes in blood volume that occur with transition to neonatal circulation
Most accurate: measure in quiet newborn

At term, 60-80/40-50 mm Hg. (75/42 avg.)


Turbulent blood flow, transient
Abnormal valve, ASD (atrial septal defect) or VSD (ventrical) , too high a blood flow across normal valves
Check all 4 extremity BPs if heard, record MAP, pulse ox.

Heart Murmurs


- blotchy and mottled skin in the extremities; feels "chilly"
- first few hours after delivery
- response to exposure to cold - normal and intermittent



Blue around philtrum & lips
Tongue & mucous membranes pink
Type of acrocyanosis
Resolves spontaneously

Perioral (Circumoral) Cyanosis


10-15% total body weight
Low O2 tension of maternal blood stimulates fetal RBCs (↑ HCT)
About 300 ml.
Mode of delivery effects TBV
Vaginal vs. C/S
- clamping of the umbilical cord : early ( before 30-40 sec) vs late (after 3 min additional 150 ml of blood)

Total Blood Volume


- clamping of the umbilical cord : early ( before 30-40 sec) vs late (after 3 min additional 150 ml of blood)
↓ anemia →↓ transfusions
Stem cells
↓ disorders R/T prematurity

Delayed Cord Clamping benefits


R/T normal destruction of fetal RBCs
Bilirubin transported to liver for conjugation
Immature livers
50%+ develop

Physiologic Jaundice


Hemolysis of erythrocytes (normal after birth) - bilirubin - liver - water soluble pigment - GI system via bile - feces + urine