Pediatric Cardiovascular Functioning and Congenital Heart Defects (CHD) Notes

Pediatric Cardiovascular Functioning and Congenital Heart Defects (CHD)

Circulatory Changes at Birth

  • Umbilical Cord Clamping & Lung Expansion: Triggers closure of fetal shunts.
    • Umbilical Vein/Arteries: Supplies oxygen and nutrients to the fetus pre-birth.
    • Foramen Ovale: Closes when left atrial pressure exceeds right atrial pressure.
    • Ductus Arteriosus: Closes in response to increased oxygen levels.

A&P Overview of Fetal to Pulmonary Circulation

  • Shift occurs hours post-birth.
    • Higher Left Atrial Pressure: Closes foramen ovale.
    • Higher Oxygen Levels: Facilitates ductus arteriosus closure.

Pediatric Differences in Cardiac Functioning

  • Volume & Pressure Sensitivity: Infants have limited heart capacity but increased metabolic needs for high cardiac output.
  • Risk for Heart Failure: Factors include less structural organization and compliance, along with reduced stroke volume.

Overview of Congenital Heart Disease (CHD)

  • More than 35 Known Defects: Develop within the first eight weeks of gestation.
    • Survivability is over 85%.
  • Blood Flow Changes: Classified into categories:
    • Increased pulmonary blood flow
    • Decreased pulmonary blood flow
    • Obstructed systemic blood flow
    • Mixed systemic and pulmonary blood flow.

Older Classifications of CHD

  • Acyanotic: Can develop cyanosis over time.
  • Cyanotic: Can appear pink; may develop congestive heart failure.

Key Questions Regarding CHD

  • Location of defect.
  • Disruption of normal blood flow.
  • Diagnostic evaluation and signs/symptoms.
  • Treatment options available.

Therapeutic Management Goals

  • Improve Cardiac Function: Focus on enhancing systemic perfusion.
  • Fluid Management: Remove excess fluids and sodium.
  • Decrease Cardiac Demands: To relieve stress on the heart.
  • Improve Tissue Oxygenation: Ensure sufficient oxygen delivery to tissues.

Increased Pulmonary Blood Flow Conditions

  • Atrial Septal Defect (ASD):

    • Symptoms: May present asymptomatic; murmur; potential for right atrium enlargement and pulmonary hypertension long-term.
    • Treatment: Watch for spontaneous closure before 4 years; cardiac catheterization with patching if necessary.

  • Ventricular Septal Defect (VSD):

    • Symptoms: Might be asymptomatic; accompanied by a loud, harsh murmur, potential heart failure.
    • Treatment: Often requires cardiac catheterization for patching.

  • Patent Ductus Arteriosus (PDA):

    • Symptoms: Machine-like murmur; may be asymptomatic; tachycardia, tachypnea.
    • Treatment: Ligation or use of medications (Ibuprofen or Indomethacin) to close.

Obstructive Defects

  • Coarctation of the Aorta:

    • Symptoms: Increased blood pressure/pulses in upper body; weak/absent pulses in lower body, headaches, and fainting spells.
    • Treatment: Balloon angioplasty.

  • Aortic Stenosis:

    • Symptoms: Murmur, left ventricular enlargement, chest pain, potential syncope.
    • Treatment: Balloon angioplasty and valve replacement.

  • Pulmonic Stenosis:

    • Symptoms: Murmur; mild cases may be asymptomatic; right ventricular enlargement, potential for reopening of foramen ovale.
    • Treatment: Balloon dilation.

Mixed Blood Flow Conditions

  • Hypoplastic Left Heart Syndrome:

    • Symptoms: Require foramen ovale for blood flow; signs include tachycardia, fatigue, poor feeding.
    • Treatment: Prostaglandin E and multiple surgeries.

  • Transposition of the Great Vessels:

    • Symptoms: Cardiomegaly; cyanosis due to ‘blue’ blood circulation.
    • Treatment: Requires maintaining PDA until surgical correction.

Clinical Assessment for CHD

  • Inspection: Look for cyanosis, pallor, fatigue.
  • Auscultation: Murmurs, tachypnea, fluid in lungs.
  • Palpation: Diminished pulses and peripheral edema.

Nursing Care Considerations

  • Pre-operative: Assess for CHF; educate families on surgical expectations.
  • Post-operative: Pain management; monitoring for complications; gradual increase in activity.
  • Patient Education: Medication awareness (side effects, administration), nutritional guidance, emotional support for families.

Congestive Heart Failure (CHF) in Infants and Older Children

  • Infants: Symptoms include fatigue during feeding, irritability, poor weight gain.
  • Older Children: Exercise intolerance, dyspnea, peripheral edema, mottled skin.

Nursing Diagnoses and Interventions for CHF

  • Common Diagnoses:
    • Decreased cardiac output, fluid volume excess, ineffective family coping.
  • Interventions: Medication management, optimizing rest and nutrition, education on signs of worsening heart failure.

Heart Surgery Considerations

  • Nursing Responsibilities: Pre-and post-operative care focuses on preventing complications and improving outcomes.