student

1. Post-Operative Care of
Congenital Heart Disease
Patients
A brief pediatrics perspective

2. Electrolytes
• Severe electrolyte abnormalities
– Cause: Pump solutions, saline solutions, fluid
shifts.
– Most important are those with effects on heart
• Potassium (arrhythmogenic)
• Calcium (affects contractility and arrhythmias)
• Magnesium (same as Ca)
– Also, but less important
• Sodium and phosphate

3. Glucose
• Hyperglycemia (outside of neonatal period)
• Causes:
– Stress response
• Endogenous steroids
• Epinephrine
– Steroids given for bypass
• Tx: Incr sedation & pain control

4. Renal Effects
• All due to decr MAP and non-pulsatile flow.
• Release of
– Angiotensin
• Causes HTN
– ADH
• Causes retention of free water leading to hyponatremia
– Catecholamines
• Causes HTN and faster heart rate.
• Tx: Antihypertensives, Lasix.

5. Renal Effects, cont.
• Acute Renal Insufficiency (incidence 8%)
– Oliguria
– Incr creatinine
– Fluid retention
• Tx:
– MUF
– Lasix

6. Pulmonary Effects
• Causes
– Leukocyte & complement activation
– Surfactant loss
• Results:
– Capillary leak… pulmonary edema.
– Atelectasis
• Tx: ventilation with increased PEEP

7. Pulmonary, cont.
• Pulmonary Hypertension
– Constriction of pulm vascular bed
– Leads to poor oxygenation
– Caused by acidosis & high CO2
– Tx: Hyperventilation.
• Reperfusion injury
– Unique to Pulmonary Stenosis
• Very common in pediatric CHD (esp. ToF)
• Related to procedure itself, not bypass.
• Presents as pulmonary edema
– Tx: Diuretics.

8. Coagulopathy
• Causes:
– Activation of clotting factors in tubing
– Real clotting to stop surgical bleeding
– Hemodilution
– Heparin in pump
• Tx:
– FFP
– Protamine

9. Hemodynamic Effects
• Tissue ischemia, capillary sludging due to
low MAP and non-pulsatile flow.
• Leads to Lactic Acidosis.
– May exacerbate electrolyte disturbances
• Potassium driven into cells with acidosis
– Worse with longer bypass duration.
• Tx: shorten bypass time, bicarb, vent.

10. Hemodynamics, cont.
• Hemodilution from pump priming solutions,
iv fluids & renal insufficiency.
• Result worsens HCT than just surgical
blood loss.
• Tx:
– Modified Ultrafiltration (MUF)
– Lasix
– PRBC

11. Hemodynamics, cont.
• Myocardial dysfunction
– Usually Right Ventricle in children (unlike
adults)
– Increased CVP, decreased Bp and UOP
• Tx:
– Dopamine
– Epinephrine
– Dobutamine

12. Hemodynamics, Cont.
• Capillary leak… diffuse edema
– Caused by inflammatory mediators activated
against tubing of bypass.
– Worse in children than adults
• Length of tubing is longer in relation to the length of
the child’s vascular system.
– Tx: Lasix, limiting of IV fluids.

13. Conclusions
• Overall the pathophysiology of bypass is
similar to Systemic Inflammatory Response
Syndrome seen in patients with sepsis.
• Similar derangements in coags, capillary
permeability and tissue ischemia occur in
both.
• Bottom line: minimize the pump time!