Cardiac Assessment of Newborns

General Information

• Professor/Instructor: Professor Cochran
• Topic: Cardiac assessment of newborns
• Communication: Students can text the professor with questions or nursing topics.

Fetal Circulation

• Exchange Mechanism: Placenta and umbilical cord facilitate oxygen & waste exchange without blood mixing between maternal and fetal circulation.
• **Blood Flow Pathway:
  • Umbilical Vein: Carries blood from the placenta to the fetus.
  • Liver: Half the blood volume goes into the liver.
  • Ductus Venosus: Other half enters this structure, shunting blood to the inferior vena cava.
  • Foramen Ovale: Shunts blood from the right atrium to the left atrium.
  • Ductus Arteriosus: Shunts blood from pulmonary artery to the aorta, bypassing lungs.
• Fetal Hemoglobin: Higher oxygen-carrying capacity than adult hemoglobin.

Postnatal Circulation

• Closure Mechanisms:
  • Foramen ovale closes due to pressure changes.
  • Ductus arteriosus closes, causing a transient murmur (audible within the first 2 hours of life; fades in 24-48 hours).
• Persistent Murmur: Indicates patent ductus arteriosus (PDA).

Patent Ductus Arteriosus (PDA)

• Definition: Failure of the ductus arteriosus to close.
• Evaluation: Needed, especially if newborn shows symptoms like trouble breathing.
• Murmur Characteristics: described as “whoppy, woppy, woppy.”
• Higher Risk: More common in premature infants.
• Treatment Options:
  • Medications: IV indomethacin or ibuprofen (anti-inflammatories).
  • Surgical: Piccolo procedure (surgical ligation) if medications fail.
• Consequences of Untreated PDA: Can cause excessive blood flow to the right heart and lead to heart failure.

Pulmonary Assessment

• Skin Color Evaluation: Observe for pink, pale, dusky, or blue coloring.
• Assess for Acrocyanosis: Blue extremities but pink overall.
• Respiratory Effort: Check if easy or labored.
• Signs of Respiratory Distress:
  • Visible retractions (supraclavicular, intercostal, or subcostal).
  • Grunting at end of exhalation.
• Auscultation Guidelines:
  • Use an infant-sized stethoscope.
  • Listen for heart sounds (S1, S2), any extra sounds, or irregularities.
  • Normal Heart Rate: 120-160 bpm, acceptable range >100 and <180.
• Normal Respiratory Rate: 30-40 breaths per minute.

Distinction Between Transient Tachypnea and Respiratory Distress Syndrome (RDS)

• Transient Tachypnea:
  • Symptoms include soft wheezes and moderate acceleration of respiratory rate; usually self-resolves within 24 hours.
• RDS:
  • Severe condition, typical in premature infants; involves labored breathing, use of accessory muscles, and requires interventions like oxygenation/ventilation.

Additional Respiratory Considerations

• Breath Sounds: Reduced or absent on one side may indicate atelectasis.
• Monitor for Bilateral Chest Movement: Equal rise and fall during respiration.
• Assessment for Meconium Expulsion: Infants with meconium expulsion before birth should be monitored closely for respiratory distress.
• Oxygenation Monitoring: Use a pulse oximeter.
• Infant's Cry Dynamics: Loud, lusty vs. weak or abnormal pitch can indicate underlying issues.

Blood Pressure in Newborns

• Abnormalities: Rare in healthy newborns.
• Normal Range for BP:
  • Systolic: 50-70 mmHg
  • Diastolic: 25-45 mmHg

Congenital Heart Disease

• Developmental Timing: Heart formation completed by 8 weeks gestation.
• Indications for Cardiac Anomalies: Respiratory distress, abnormal skin color, cardiac murmurs, feeding difficulty.

Types of Cardiac Defects

• Cyanotic Defects: Causes dusky blue or blue-gray skin due to oxygen deficiency.
• Obstruction Defects: Involves blocked vessels or valves.
• Septal Defects: Openings between heart chambers leading to backflow issues.
• Hypoplasia: Underdevelopment of either the right or left ventricle.

Common Congenital Heart Defects

• Ventricular Septal Defect (VSD)
• Atrial Septal Defect (ASD)
• Patent Ductus Arteriosus (PDA)
• Pulmonary Stenosis
• Coarctation of Aorta
• Aortic Stenosis
• Tetralogy of Fallot
• Transposition of Great Vessels

Specific Defect Descriptions

• Pulmonary Stenosis:
  • Makes up 7-10% of cardiac defects; obstructs right ventricle blood flow, causing hypertrophy, higher venous pressure, and potential heart failure.
• Coarctation of the Aorta:
  • Congenital narrowing of the descending aorta, often asymptomatic in early stages; can lead to leg pain or claudication in later life.
• Aortic Stenosis:
  • Aortic valve abnormality that narrows and restricts blood flow (6% of cases), may present with failure to thrive and respiratory symptoms.
• Tetralogy of Fallot:
  • Includes four defects; surgical intervention is required due to its cyanotic nature.
• Transposition of Great Vessels:
  • Results in systemic and pulmonary circulation mismatch, leading to significant hemodynamic compromise requiring correction.

Genetic Conditions and Factors in Newborns

• Polycystic Kidneys: Autosomal recessive condition leading to cyst formation, resulting in kidney dysfunction and failure to produce urine.
• Autosomal Recessive Conditions: Require two mutated genes; a 25% chance of offspring affected if both parents carry gene.
• Dominant Conditions: Involve only one parent with the mutated gene.
• Sex-Linked Conditions: Reside on X or Y chromosome.
• Prader-Willi Syndrome: Caused by deletion on chromosome 15, leading to several metabolic and growth issues.

Labor and Delivery Communication Board

• Tracking Information: Important metrics include number of pregnancies (Gravida), past births (Para), and patient details.
• Example for Gravida and Para: Gravida 6, Para 5 indicates six pregnancies, five live births.

Medications During Labor and Delivery

• Medication Purposes: Include sustaining pregnancy, facilitating delivery, controlling bleeding, pain management, and optimizing newborn condition.

Prematurity Considerations in Newborns

• Main Concerns: Underdeveloped lungs due to lack of surfactant. Without adequate surfactant, alveoli collapse, reducing oxygen exchange.
• Vitamin K Administration: Given to reduce hemorrhage risk (e.g., intraventricular hemorrhage).
• Monitoring in Premature Babies: Includes growth assessment, respiration patterns, and signs of apnea.

Retinopathy of Prematurity (ROP)

• Risk Factors: High oxygen exposure in premature infants, leading to retinal bleeding and potential blindness.
• Screening Recommendations: Specialty assessment by pediatric ophthalmologists within days of birth.

Other Considerations for Premature Babies

• Assess stool and evaluate all signs of maturation including movement and vital signs.
• Attention to maternal use of drugs is critical as withdrawal may affect newborns. Monitoring of potential issues like contact with drugs and infection is essential.

Stages of Labor Overview

• Pre-labor Signs: Braxton Hicks contractions, lightening, mucus plug loss, nesting instinct.
• First Stage (Early Labor): Cervix effaces and dilates to ~3cm; contractions last 30-45 seconds, spaced irregularly.
• First Stage (Active Labor): Contractions strengthen, cervix dilates from 3 to 7cm.
• First Stage (Transition): Most intense phase, cervix dilation from 7 to 10cm, contractions lasting longer and more frequent.
• Second Stage: Actual birth with pushing.
• Third Stage: Delivery of the placenta, needing active management to prevent hemorrhage.

Postpartum Complications Management

• Hemorrhage Prevention/Management: Quick recognition and intervention for signs of hemorrhage, retained placental fragments, or a boggy uterus.

Fundus Assessment Post-Delivery

• Massage: Needed to ensure firm contraction after delivery to avoid hemorrhagic complications.

Normal Findings and Interventions in Postpartum Period

• Assess Lochia: Blood discharge forms stages, first bright red, transitioning to serous.
• Vital Signs Monitoring: Essential for establishing baselines and identifying issues like hemorrhage or infection.

Postpartum Hemorrhage Initiatives

• AWHONN: Nursing and hospital guidelines designed to streamline and improve patient care to reduce maternal mortality.

APGAR Scoring and Importance

• Categories: Appearance, Pulse, Grimace, Activity, Respiratory effort - critical for assessing newborns immediately after birth, helps inform immediate care needs.
• Scoring Interpretation: Ranging from 0 to 10; indicates immediate resuscitation needs if scores are low.

Gestational Hypertension and Preeclampsia

• Symptoms: Include elevated blood pressure, swelling, headaches, and can progress to eclampsia if untreated.
• Management: Antihypertensives and potential use of magnesium sulfate; monitoring is crucial.

Teratogenic Effects on Newborns

• Toxic Substances: Various medications and lifestyle factors during pregnancy can have extensive effects on fetal development; examples like thalidomide bring awareness to careful medication use during pregnancy.

Conclusion

• Timely identification and intervention in complications associated with pregnancy, delivery, and neonatal conditions are crucial in preserving maternal and neonatal health.