RSPT 2353 Neonatal Pediatric Respiratory Care

1. RSPT 2353 Neonatal Pediatric Respiratory Care STAGES OF FETAL LUNG DEVELOPMENT

2. Objectives • Discuss anatomy and physiology of fetal circulation • Compare and contrast fetal circulation to infant circulation • Define specialized structures of fetal circulation • Discuss normal cardiac circulation (infant and adult) • Discuss cardiac defects

3. Stages of Lung Development • Embroynal 26 -52 days development of trachea and major bronchi • Pseudoglandular 52 days-week 16 Development of remaining conducting airways • Canalicular week 17- week 28 Development of vascular bed and acinus • Saccular week 29 - week36Increased complexity of saccules • Alveolar week 36 – Term 40 weeks Development of alveoli sufficient to sustain gas exchange • Post Term > 41 weeks

4. Factors That Limit Normal Lung Growth • Hyperoxia • Cigarette smoking • Diaphragmatic hernia • Nutritional deprivation • Problems with amniotic fluid • Hormonal imbalances • Drug abuse • ETOH abuse

5. Surfactant Surfactant Production • Type II pneumocytes produces surfactant in the alveoli • Alveoli must be formed to make surfactant • < 33 weeks the alveoli are insufficient to form surfactant Surfactant Function • Decreases surface tension • Maintains compliance and FRC Tests for Adequate Surfactant Production • Shake test • LS Ratio test • Amniocentisis

6. Fetal Lung Fluid What happens to all that fluid that has been filling the lungs for 9 months? Fetal lung fluid is evacuated from the newborns lungs via: • Absorption- lymphatic system • Clearance- pulmonary capillaries • Contraction – birth canal, birth squeeze

7. Placenta • Provides Gas exchange & waste removal. • Supplies nutrient to the fetus • Placenta is the lung for the fetus

8. Fetal Circulation

9. Fetal Circulation • Cardiac development occurs between the 4th and 7th week ofgestation. • The foramen ovale is a one-way flap in the atrial septal wall. Blood bypasses the lungs because of the high right sided pressures. • The ductus arteriosis is a connection between the PA and the Aorta - shunts blood away from the lungs. • Fetal PVR is high, within 24hr after birth, PVR should fall to 1/2 SVR • The ductus should close within 10-24 hrs after birth. • Fetal CO is very high, therefore tissue hypoxia usually does not occur, even when oxygen saturations are 60-70%

10. Fetal Circulation Low pressure circuit Gas Exchange occurs in the Placenta Fetal lungs do not participate in gas exchange Roughly 10% of blood goes to lungs for tissue development

11. Fetal Oxygenation • Best-oxygenated blood • Right atrium, Foramen ovale, Left atrium • Supplies the upper body, specifically the brain • Less-oxygenated blood supplies the rest of the body via the Ductus Arteriosus

12. How Does Blood Bypass the Lungs? High PVR in utero creates a desireable R to L shunting Foramen Ovale Ductus Arteriosus Question: Why is a R to L shunt desirable in – utero ?

13. PaO2 in Fetal Circulation Large gradient between mom’s PaO2 and fetal PaO2 Promotes the transfer of O2 Higher Hgb concentration in fetus Fetal Hgb Greater affinity for O2 Higher SaO2 for the same PaO2 than adult Hgb Left shift of fetal oxyhemoglobin dissociation Curve

14. Conversion from Fetal to Infant Circulation • Cord is clamped - closing low pressure system • SVR increases • Lungs inflate w/ air (due to several factors, one of which is atmospheric pressure changes) • PVR decreases • Lung inflation (only slightly changes it) • Changes in O2, CO2 and pH

15. Conversion from Fetal to Infant Circulation • R to L shunting decreases Increased pressures in LA results in: • Closing of Foramen Ovale • Closing of Ductus Arteriosus • PaO2 changes • Prostaglandin level changes

16. Overview of Conversion • Umbilical cord is clamped • Loose placenta • Closure of ductus venosus • Blood is transported to liver and portal system • Loss of placenta also leads to first breath • Lungs expand and fluid is expelled • Decreased pulmonary vascular resistance • Increased systemic vascular resistance

17. Overview of Conversion • Increased pressure in left atrium • Closure of foramen ovale • Loss of placenta • Increased systemic resistance • Pressure in right atrium decreased • Change from right to left shunting to left to right blood flow • Increased O2 levels in pulmonary circulation • Closure of the ductus arteriosus

18. Fetal vs. Infant Circulation • Fetal • Low pressure system • Right to left shunting • Lungs non-functional • Increased pulmonary resistance • Decreased systemic resistance • Infant • High pressure system • Left to right blood flow • Lungs functional • Decreased pulmonary resistance • Increased systemic resistance

19. NORMAL HEART

20. Antenatal Assessment and High-Risk Delivery Fetal and Newborn Assessment in the L and D

21. Objectives At the completion of this lecture the student will: • Be able to discuss relevant points concerning Antenatal Assessment • Be able to ID the L and D cases which may present a high-risk delivery • Know the parameters on which to base antenatal/perinatal assessments

22. Antenatal Assessment and High- Risk Delivery Indications of a High-Risk Delivery: • Incompetent Cervix • Toxic habits in Pregnancy • Hypertension and Diabetes Mellitus • Preclampsia • Severe Preclampsia • Infectious Disease • Multiple birth

23. Antenatal Assessment and High- Risk Delivery • Indications of a High-Risk Delivery: • Long cord, Nuchal cord, cord knots • Placenta Abruption • Placenta Previa • Disorders of aminiotoic fluid • Abnormalities of Umbilical cord • Oligohydraminos, Polyhydraminos

25. Antenatal Assessment Antenatal = Around birth time, usually considered prior to L and D • Ultrasound • Amniocentesis • Shake test • Fetal Biophysical profile • Preterm Pregnancy • Less than 37 weeks

26. Indications of High-Risk Delivery • Magnesium sulfate is given to stop contractions • Blood gas with Ph less than 7.15 can be an indication of asphyxia • Post-term Labor • Pregnancy continued beyond 42 weeks • Pre-term less than 33 weeks ges age • Lack of prenatal care

27. Neonatal Assessment and Resuscitation Neonatal Resuscitation Considerations While Assessing the Patient • Maintain warmth • Cold stress increases oxygen consumption • Maintain an airway • Placing a small roll under the shoulders will correct the position • Suction the airway • Stimulation • Obtain vascular access • Provide resuscitative drugs PRN

28. Assessing the Neonate • Vital signs • Apgar score • Neonatal resuscitation • When is Positive pressure ventilation Indicated? • When is Intubation Indicated? • When are chest compressions indicated? • When are Medications indicated?

29. Supportive Care Ongoing care Routine Care Provide warmth Clear Airway Dry Breathing Ventilating HR >100 Pink HR >100 Pink Yes Clear of Meconium? Breathing or Crying? Good Muscle Tone? Color Pink ? Term gestation? Provide warmth Position Clear Airway (as necessary) Dry, stimulate Reposition, Give O2 Evaluate: Respirations Heart rate Color PPV Birth NO Apnea or HR<100 Approximate Time 30 sec Resuscitation of New Born 30 sec

30. HR < 60 PPV Chest Compressions Administer Epinephrine Time HR <60 HR >60 30 sec

31. Assessment of Neonatal Patient • Vital signs • Skin • Mottling • Irregular areas of dusky skin alternating with pale skin • Capillary refill

32. Respiratory Function Assessment • Apnea • Periodic breathing • Grunting • Nasal flaring • Retractions • Silverman score • Stridor • X-ray

33. Nasal Flaring and Sub-sternal Retractions

34. Nasal Flaring and Substernal Retractions

35. Silverman score

36. Cardiac Assessment Heart, how is it working? • HR, RR,BP • Cardiac murmur – PDA • Weak pulse Coarctation of Aorta • Hypo plastic Left heart syndrome • Adequate MBP= gestational age + 5

37. Abdomen • Diaphramatic hernia • Omphalocele • Gastroschisis • Umblical cord • A single umblical artery • Congenital anomalies • Thin cord • Thick cord-diabetics

38. Head and Neck Assessment • Microstomia-small mouth • Micrognathia-small jaw • T-E fistula • Pierre robin syndrome • Choanal Artesia • Macroglossia

39. Assess an Infant’s Cry • Loud and vigorous- healthy infant • Grunting cry- RDS • Hoarse cry-laryngeal edema • Cat like cry- chromosme abnormality • High-pitched cry- neurological deficit

40. Pediatric Assessment Pedi assessment is focused on different indications: • History and assessment • Chief complaint • Medical history • Family history • Environmental history

41. Elements of Pediatric Physical Assessment • Assessment • Inspection • RR • Retractions • AP diameter • Digital clubbing • Palpation • Tactile fremitus • Position of trachea • Percussion • Auscultation