Neonatology Step 1 PDF

What we’re going to learn about Neonatology Step 1 Dr. M. Valdez Neonatal Cardiologist  Neonatology - subspecialty of Pediatrics that focuses on caring for the newborn from birth until the 1st mo. of life.  Outcome of newborn is determined : intrapartum ,postpartu...

What we’re going to learn about Neonatology Step 1 Dr. M. Valdez Neonatal Cardiologist  Neonatology - subspecialty of Pediatrics that focuses on caring for the newborn from birth until the 1st mo. of life.  Outcome of newborn is determined : intrapartum ,postpartum, antenatal, maternal and fetal factors  Caringfor the fetus beginning from 20 wks of GA onward to 28 days of postnatal life.  Pre-pregnancy care: - Provision of iron and folic acid supplementation - Provision of family planning - Prevention and management of infections - Access to adequate prenatal care at least 4 prenatal visits throughout the course of pregnancy -Provide tetanus toxoid immunization -GBS screening -HBsAg screen Optimizing  Peripartum maternal care: and perinatal - Delivery by skilled birth attendants and outcome obstetrician Maternal characteristics and associated Rislk for fetus and neonates  Age at delivery  Obstetric history -Past history of infant with - Over 40 years preterm birth,jaundice, RDS or - Under 16 years anomalies  Medical conditions -Maternal medications -Diabetes mellitus -Bleeding -Thyroid diseases -Hyperthermia -Renal disease -PROM -UTI -TORCH infections -Heart and or Lung disease  Personal factors -Hypertension -Poverty - Iron deficiency Anemia -Smoking -Drug/alcohol use -Isoimmunization -Poor diet -Thromocytopenia -Trauma (acute/chronic) -STD, HIV -Domestic violence -Hypercoagulable state -Urban slum dwellers -Hemoglobinopathy -Armed conflict area residents -Autoimmune diseases  Multiple gestations  IUGR  LGA and or macrosomia  Abnormal fetal position/presentation  Abnormality of fetal heart rate or rhythm  Decreased activity  Polyhydramnios  Oligohydramnios Fetal characteristics and associatedrisk for fetus or neonate  Preterm delivery  Postterm delivery  Maternal fever  Maternal hypotension  Rapid labor  Prolonged labor  Abnormal presentation  Uterine tetany  Meconium stained AF  Prolapsed cord  Cesarian section  Obstetric anesthesia and analgesia  Placental anomalies Conditions  of labor and delivery and associated risk for fetus or neonates  Preterm birth  Low 5 minute Apgar score  Low 10 minute Apgar score  Pallor or shock  Foul smell AF  SGA  LGA  Postmaturity syndrome Immediately evident neonatal conditions and associated risk for fetus or neonate First trimester screening  Routine testing: nutrition, overall health status, BP, CBC, Urinalysis,HGT  Clinical estimate of gestational age  Fetal UTZ - 8 -12 wks of gestation, determine embryonic viability,GA, and chorionicity -most accurate method of estimating gestational age -Fetal crown-rump length (CRL) can accurate predictor of gestational age Antepartum fetal surveillance  ASSESSMENT OF FETAL WELL BEING 1. Fetal movement monitoring- is the simplest method of fetal assessment -Fetuses normally have a sleep-wake cycle and mothers perceive a diurnal variation in fetal activity. 0 -Active periods average 30-40 minutes -Periods of inactivity >1 hr should alert the physician to the possibility of fetal compromise 2. NST( nonstress test) – a reliable means of fetal evaluation, based on principle that fetal activity results in a reflex acceleration in heart rate. -Fetal well being confirmed if baseline fetal HR is normal (110-160/min) with periodic increases associated with fetal movements.  Criteria for a reactive NST i. Heart rate between 110 and 160 bpm ii. Normal beat to beat variability ( 5 bpm) iii. Two accelerations of at least 15 bpm lasting for not < 15 secs each within a 20 minute period  Non -reactive NST is defined as less than 2 accelerations in 40 minutes Contraction stress test (CST)or Oxytocin challenge test (OCT)- may be used as a backup or confirmatory test when the NST is non-reactive or inadequate -assess fetus at risk for uteroplacental insufficiency - FHR continuously monitored - OCT- produce at least 3 uterine contractions of at least 40-60 second duration within 10 minutes CST – is now used less commonly contraindicated in placenta previa, previous CS, and conditions at risk for premature delivery Biophysical profile (BPP)– developed by Dr. Frank Manning to assess fetal well being when NST is nonreactive –useful after 26- 28 wks - fetal breathing - body movements - fetal tone - amniotic fluid Biophysical profile (Manning score) Variable Normal (2) Abnormal (0) Fetal 1 episode >30s None or episode breathing in 30min 3 movements 1 No fluid pockets or fluid cm pocket 2 is good indicator of lung maturity L/S ratio >3 is needed to assess lung maturity if mothers have diabetes or RH isoimmunization FHR monitoring  Abnormal FHR pattern is 50% predictive of low Apgar score  Baseline FHR FHR >160: baseline tachycardia-sign of maternal fever, infection, fetal hypoxia, maternal sympathomimetic medication, hyperthyroidism FHR >200 bpm are typically associated with fetal dysrrythmias FHR60 from the baseline or the slow HR lasts longer than 60 secs. With beat to beat variability suggest fetal compensation 3. Late decelerations with beat to beat variability- suggest sudden insult to a fetus that is able to compensate physiologically Late decelerations with decreased or absent beat to beat variability indicates fetal hypoxia from uteroplacental insufficiency. i. Decelerations will last longer ii. They will begin sooner following onset of uterine contraction iii. They will take longer to return to baseline iv. The rate to which the fetal heart rate slows will be lower 2nd trimester Screening: Screening by maternal serum analysis  MSAFP/ Quad screen for aneuploidy - Maternal serum α fetoprotein(MSAFP) between 15 and 22 wks gestation screen: High level MSAFP detects 90% NTD’s ( 70-85% open spina bifida,95% with anencephaly) Low level MSAFP- chromosomal abnormalities (Trisomy 18/21),incorrect gestational age estimates, IUGR, -β –HCG ( High levels is associated with Trisomy 21) - Unconjugated estriol levels (Low levels is associated with Trisomy 21 - Inhibin A (High levels associated with Trisomy 21) * Low levels of all markers is associated with Trisomy 18   Combined 1st trimester maternal serum screening: -Combining the first trimester maternal serum markers (maternal serum pregnancy associated plasma protein(PAPP-A) and β- HCG) and fetal UTZ nuchal translucency screening detects 80% of trisomy 21 fetuses  Integrated screening : maternal serum PAPP and fetal translucency in the 1st trimester and measurements MSAP, β- HCG , unconjugated estriol and inhibin A in the 2nd trimester achieve highest detection rate of trisomy 21 (97%) Sequential, and integrated screening Fetuses with Down syndromes have distinctive UTZ features which increase the confidence of antenatal diagnosis,  Fetal karyotype through amniocentesis in the 2nd trimester, fetal blood sampling from PUBS or sampling from fetal cells in maternal blood is more definitive antenatal diagnosis  Screening tests of positive family history of hereditary and genetic metabolic diseases such as Tay-Sachs disease, CF, hemoglobinopathies through: - Chorionic villus sampling( CVS )- performed at 10 wks of gestation - Amniocentesis in 2nd trimester - Elution of fetal cells from maternal blood - Fetal blood from PUBS performed in 2nd trimester - Direct fetal tissue sampling Fetal Ultrasound (UTZ) is useful to/in  determine viability and number of fetus  location of placenta  assessment of gestational age  detection of fetal malformations  guiding diagnostic procedure like CVS and amniocentesis  From 2nd trimester onwards- useful in -assessing fetal anatomical abnormalities, growth, development and well being -guiding amniocentesis, PUBS and other diagnostic and therapeutic interventions in the fetus  Amniocentesis (AF is removed from around the fetus through a needle guided by ultrasonic images)  detection of NTD’s, chromosomal, genetic and biochemical abnormalities, and fetal lung maturity - Therapeutic amniocentesis decompress severe polyhydramnios - Best done in the mid-2nd trimester with UTZ guidance *UTZ guided 2nd trimester Amniocentecis is associated with 0.2-0.5% prenancy loss - Post-amniocentesis leakage of AF through cervix 1 - 2%- self limited  PUBS –percutaneous umbilical blood sampling: -fetal karyotype -accurate diagnosis of hemoglobinopathies (thalassemia, sickle cell), coagulopathies (Hemophilia A, von Willebrand) and other inherited metabolic disorders -fetal blood gas determination -for treatment with specific antimicrobials, blood transfusion, or exchange transfusion  Antenatal MRI- when fetal surgery is contemplated for detailed anatomical assessment  Fetoscopy: invasive procedure for close visualization of the small anatomic parts for the fetus and the performance of corrective or palliative procedures on the fetus Medical therapy of the fetus  Treatment with maternal replacement doses of dexamethasone for the prevention of masculinization of female external genitalia  Treatment of fetal arrhythmias, in-utero infections (HIV,SY, Toxoplasmosis, TB) Neonatal Transition  A process of physiologic change in the newborn infant that begins in utero as the neonate prepares for transition from intrauterine placental support to extrauterine self- maintenance  A newborn can take up to 12 hours to transition from placental support to extrauterine support. Neonatal transition depends on….  Gestational age  Placenta health/condition  Maternal health  Any limitations to major organs  Physical defects/anomalies The infant prepares by…  Fetal breathing (producing surfactant at 34 weeks)  Storing glycogen in the liver  Producing catecholamines  Depositing brown fat Transition During Labor… begins before delivery  placenta  stress hormones  Exchanges O2 and CO2 by simple diffusion  Eliminates waste products  Does the work of the lungs in utero  Uterine venous blood has PCO2=38 mmHg PO2=40-50 mmHg pH=7.36 Review Placental circulation  1 Umbilical Vein-oxygenated blood  2 Umbilical Arteries -deoxygenated blood  Three Fetal Shunts… ▪ Ductus Venosus- hepatic system ▪ Foramen Ovale- between right & left atrium ▪ Ductus Arteriosus- vein connects pulmonary artery to descending aorta Review Fetal Circulation  Characterized by 2 circuits that run parallel and almost separate fro each other except for the presence of 2 shunts Fetal circulation 4 unique FETAL CVS structures  Placenta COURSE OF FETAL CIRCULATION: 1.Placenta: Has the lowest vascular resistance in the fetus. Receives the largest amount of combined ventricular output (55%)  SVC 2.Superior Vena Cava: Drains the upper part of the body, including the brain (15% of combined ventricular output). Most of SVC blood goes to the RV. 3. Inferior Vena Cava: Drains lower part of body and placenta (70% of combined ventricular output) Part of IVC blood with high O2 goes into LA via Foramen ovale. Remaining IVC blood enter RV and PA. Since blood is oxygenated in the placenta, O2 sat in IVC (PO2 -26-28%) is higher than that in SVC (12-14%) COURSE OF FETAL CIRCULATION: Most of SVC blood (less oxygenated blood) goes into RV. Most of IVC blood (high O2 concentration) is directed by the crista dividens to the LA through FO. Rest of IVC blood enters RV & pulmonary artery. Less oxygenated blood in Pulmonary artery flows through DA to descending aorta and then to placenta for oxygenation  At birth Mechanical expansion of lungs Increase in PaO2 Rapid DECREASE in pulmonary vascular resistance Removal of the low-resistance placental circulation closure of the ductus venosus –ligamentum venosum REVIEW-TRANSITIONAL CIRCULATION: INCREASE in systemic vascular resistance.  Right ventricle output now flows entirely into the pulmonary circulation  Pulmonary vascular resistance becomes lower than systemic vascular resistance Shunt through ductus arteriosus reverses & becomes left to right.  High arterial PO2 (In several days)  Constriction of ductus arteriosus ligamentum arteriosum  Increased volume of pulmonary blood flow returning to LA  Increases LA volume and pressure  Closure of foramen ovale (functionally) (Although the foramen may remain probe patent) Becomes Fossa Ovalis  LV is now coupled to the high- resistance systemic circulation its wall thickness and mass begin to increase  RV is now coupled to the low- resistance pulmonary circulation its wall thickness and mass decrease slightly  Adaptation to extrauterine life: Some of these changes are instantaneous with the 1st breath, whereas others develop over a period of hours or days.  Gas exchange: Transferred from the placenta to the lungs.  Systemic blood pressure: After an initial slight fall in systemic BP, progressive rise occurs with increasing age.  Heart rate: Elimination of Placental circulation Increase in systemic vascular resistance Baroreceptor response → Slowing of HR Neonatal Circulation: Neonatal Circulation:  With the onset of ventilation,PVR is markedly decreased, as a consequence of pulmonary vasodilation.  Closure of the ductus arteriosus and the fall in pulmonary vascular resistance result in a decrease in pulmonary arterial and right ventricular pressures.  The major decline in pulmonary resistance from the high fetal levels to the low “adult” levels usually occurs within the 1st 2–3 days but may be prolonged for 7 days or more.  Over the 1st several weeks of life, pulmonary vascular resistance decreases even further, secondary to remodeling of the pulmonary vasculature, including thinning of the vascular smooth muscle and recruitment of new vessels. Differences between neonatal circulation and that of older infants: (1) Right-to-left or left-to-right shunting may persist across patent foramen ovale (2) In the presence of cardiopulmonary disease, continued patency of ductus arteriosus may allow left-to-right, right-to- left, or bidirectional shunting; (3) The neonatal pulmonary vasculature constricts more vigorously in response to hypoxemia, hypercapnia, and acidosis (4)Wall thickness and muscle mass of the neonatal left and right ventricles are almost equal; (5) Newborn infants at rest have high oxygen consumption associated with high cardiac output (6) Newborn cardiac output (about 350 mL/kg/min) falls in the 1st 2 mo of life to about 150 mL/kg/min and then more gradually to normal adult CO of about 75 mL/kg/min. (7) High percentage of fetal hemoglobin present in the newborn may interfere with delivery of oxygen to tissues in neonate, so increased cardiac output is needed for adequate delivery of oxygen CLOSURE of: Foramen ovale :  Functional Closure: 3rd month of life  Anatomical closure: 1 year of age Ductus arteriosus :  Functional Closure: 10–15 hr of life  Anatomic closure: 2 -3 weeks of life  In a full-term neonate, oxygen is the most important factor controlling ductal closure.  The effects of oxygen on ductal smooth muscle may be direct or mediated by its effects on prostaglandin E2 synthesis.  The ductus of a premature infant is less responsive to oxygen, even though its musculature is developed. Maternal and Birth History Provides pertinent information such as the presence of certain risk factors, which could affect the newborn.  Reviewing the maternal chart may identify maternal risk factors that could impact the health of the newborn, as well as complications of labor and delivery that could impact fetal/newborn well being and transition.  Everyone involved in the care of the infant should have knowledge of the relevant maternal history ◦Pre-partum ◦Antenatal ◦Perinatal  This information can routinely be found on the maternal fact sheet in newborn’s chart or in the mother’s chart.  Family History ◦ Inherited diseases (cystic fibrosis, sickle cell disease, metabolic disease, polycystic kidneys, hemophilia, and history of perinatal death)  Maternal History ◦ Age, blood type, chronic diseases, diabetes, hypertension, renal disease, cardiac disease, bleeding disorders, infertility, recent infections/exposures, rubella status, GBS status, and STD’s  Sexually transmitted diseases (STD’s) ◦ HIV ◦ Syphilis (RPR ) ◦ Hepatitis B (HBsAg) ◦ Gonorrhea (GC DNA) ◦ Chlamydia (Cz DNA)  Group B Streptococcus “GBS” ◦ (streptococcus agalactiae) ◦ Rectal/vaginal swab results at 35-37 weeks gestation  Previous pregnancies ◦ Abortions, fetal demise, neonatal death, premature births, postdate births, malformations, respiratory distress syndrome, jaundice, apnea  Drug history ◦ Medications, drugs of abuse, tobacco and alcohol usage during pregnancy  Current Pregnancy ◦ Gestational age ◦ results of fetal UTZ ◦ pre-eclampsia ◦ Antenatal corticosteroids ◦ labor suppressants ◦ Antibiotics ◦ bleeding ◦ trauma ◦ infection ◦ surgery ◦ Polyhydramnios ◦ oligohydramnios Labor and Delivery: Important Factors 1 2 Presentation 3 Manner of Duration of delivery labor Resuscitation Rupture of Analgesia Apgar score membranes Anesthesia Maternal fever FR monitoring Starts with proper positioning followed by:  Drying and Warming  Clearing the airway  Providing stimulation  Apgar score Stabilizing the neonate Essential Intrapartum Newborn Care (EINC) smooth transition from in-utero to extrauterine survival  Thermal protection- Immediate and thorough drying for at least 30 secs prevents hypothermia and stimulate the baby to cry  Maintenance of homeostatic metabolism- skin to skin contact initiates maternal infant bonding, facilitate latching on and subsequent breast feeding  Protection from infection- skin to skin contact and principle of nonseparation between mother and her newborn via , colonization of the newborn by human (maternal) flora, stimulation of neonate mucosa associated lymphoid tissue and less exposure to potentially harmful health care associated microorganisms found in NICU Step I -Immediate and thorough drying of the newborn (30-60 secs) Step II -Placing the baby skin to skin contact on the mother’s chest (within 30 secs) and delaying bathing/washing for at least 6 hours of life Step III-Delayed cord clamping (between 1- 3 minutes) or until cord pulsations stops Step IV -Non-separation of mother and baby until the first breastfeed is achieved (60-90 minutes) First breastfeed provides the newborn with antibody rich colostrum that prevents infection  Apgar score- a newborn scoring system that helps the clinician assess the immediate neonatal condition after birth and indicate the need for resuscitative interventions Parameter 0 1 2 / Score Color Pale/cyanotic acrocyanosis Pink Respiratio Absent/apneic Slow/irregula Good,crying n r, shallow,gasp HR Absent 100/min Reflex No response Facial Vigorous cry Apgar response score Grimace Cough. sneeze Tone Limp/Flaccid Some flexion Active motion  Apgar score is routinely assessed at 1 and 5 minutes and every 5 minutes thereafter as long as resuscitation is continuing  The 1 minute score gives an idea of what was going on during delivery and labor  The 5 minute score gives an idea of response to therapy (resuscitation)  A 5 min score 8-10 normal  Infants with score of 0 - 3 at 5 min or longer compared to infants with score of 7-10 have poor neurologic outcomes Initial Physical Examination  should be performed within 24 hours of birth.  An infant who is 30 minutes old has not yet completed the normal transition (from intrauterine to extrauterine life) ,variability may exist in vital signs and examination of the respiratory, neurological, gastrointestinal, skin, and cardiovascular systems.  Therefore ,a comprehensive examination be performed after the infant has completed transition.  Ina quiet infant, the examination should proceed from the least invasive and noxious elements of the exam (auscultation of heart and lungs) to those most likely to irritate the infant (examination of the hips and eliciting the Moro reflex). Assessment -Well being of an infant can be obtained by a general visual assessment : Healthy (stable) vs ill and Term vs Preterm. Vital Signs RR and HR varies in first few hrs of life RR- 40-60 breaths/min – the RR is obtained by looking at the upper abdomen for a full minute HR- 120-160/min- the HR varies with the neonate’s activity, increases to 180/min when crying, active or breathing rapidly HR decreases to 4000 grams at term = Predisposing factors :obesity, diabetes = Higher incidence of birth injuries and congenital anomalies  Length – measured supine 50 cm at term  Head Circumference- 32-37 cm (Ave 35 cm) at term -usually bigger than the chest circumference at birth  Chest circumference- ratio of transverse to the AP diameter(thoracic index) 1.0 at birth  Gestational age is determined by assessing various physical signs and neurological characteristics that vary according to fetal age and maturity.  Gestational age assessment is pertinent as it allows the clinician to plot growth parameters, and to anticipate potential problems related to prematurity/postmaturity and also to growth abnormalities such as SGA/LGA (small and large for gestational age). Gestational Age Assessment  Assessing gestational age by inspection Term Preterm Sucks well Yes No Flexes arms and legs Yes No Veins seen under skin No Yes Nipples clearly seen Yes No Palpable breast buds Yes No Descended testes Yes No Gestational Age Assessment Covered labia minora Yes No  Gestational Age: ◦ Pre-term: < 37 weeks ◦ Term: 37-41 6/7 weeks ◦ Post-term: 42 or more weeks When delivery is delayed >3 weeks past term, significant increase in mortality Characteristics: Increased BW, Absence of lanugo, Decreased or absent vernix, desquamating pale loose skin, abundant hair, long nails, may be meconium stained if placental insufficiency  Term Infant (weight classification) ◦ LGA: >4000 g ◦ AGA: 2500-3999 g ◦ SGA: