2.2 Cardiac Surgery & Catheterization
Key Takeaways
- Single-ventricle palliation (Norwood/Sano or Blalock–Taussig shunt) creates a fragile parallel circulation; avoid pulmonary overcirculation and protect coronary diastolic pressure
- Arterial switch for d-TGA hinges on coronary reimplantation—ECG changes, troponin trends, and sudden deterioration suggest coronary insufficiency
- After TOF repair, residual RVOTO, residual VSD, right ventricular restriction, and junctional ectopic tachycardia (JET) are high-yield PICU complications
- Cardiac catheterization risks include vascular injury, arrhythmia, device embolization, contrast nephropathy, and hemodynamic collapse in ductal-dependent infants
- Post-op monitoring integrates filling pressures, NIRS, lactate, chest-tube output, rhythm, and auscultation for residual lesions—not SpO₂ alone
2.2 Cardiac Surgery & Catheterization
Quick Answer: Postoperative congenital heart ICU care is lesion-specific physiology. After Norwood or systemic-to-pulmonary shunt, balance Qp:Qs and protect diastolic coronary perfusion. After arterial switch, obsess over coronary ischemia. After TOF repair, watch residual obstruction/VSD, RV diastolic dysfunction, and JET. Catheterization adds vascular, arrhythmic, and acute hemodynamic risks that require the same ductal and mixing mindset used preoperatively.
Norwood and Shunt Physiology
The Norwood procedure (stage I single-ventricle palliation for HLHS and variants) reconstructs a neoaorta from the pulmonary root, creates an unobstructed atrial septum, and provides controlled pulmonary blood flow via a modified Blalock–Taussig (BT) shunt (systemic artery to pulmonary artery) or a Sano (RV–PA) conduit. The right ventricle becomes the systemic pump.
BT shunt nursing implications:
- Pulmonary flow is continuous from systemic pressure; diastolic runoff can lower aortic diastolic pressure and coronary perfusion pressure
- Hypotension, anemia, and over-vasodilation worsen coronary supply–demand mismatch
- Sudden desaturation may mean shunt thrombosis or distortion—this is an emergency (heparin per protocol, volume/pressure support, notify surgical team immediately)
- Excessive oxygen and low PaCO₂ drop PVR → pulmonary overcirculation → systemic hypoperfusion (same Qp:Qs logic as pre-op HLHS)
Sano conduit notes: Flow is more pulsatile and less continuous diastolic steal than a BT shunt, but conduit obstruction, bleeding, and RV incision-related issues remain concerns. Target saturations are commonly in the mid-70s to low 80s when balanced—know your center’s pathway, but understand the physiology behind the number.
Early Post-Norwood Checklist
| Domain | Watch for | Why it matters |
|---|---|---|
| Perfusion | Lactate, urine, NIRS, cool extremities | Parallel circulation fails toward shock quickly |
| Shunt/conduit | Acute SpO₂ drop, murmur change | Thrombosis or anatomic obstruction |
| Bleeding | Chest-tube output, tamponade signs | Suture lines, coagulopathy after bypass |
| Rhythm | Bradyarrhythmia, ectopy | Surgical trauma, ischemia, electrolytes |
| Necrotizing enterocolitis risk | Feeding intolerance, bloody stool | Diastolic runoff + low cardiac output |
Delayed sternal closure is common; treat the open chest as a surgical field—sterile technique, mediastinal drain care, and readiness for urgent re-exploration.
Arterial Switch Operation (ASO)
For d-TGA, the arterial switch moves the great arteries to their correct ventricles and reimplants the coronary arteries into the neoaortic root. The ICU hallmark complication is coronary insufficiency from kinking, compression, thrombosis, or technical issues at the reimplantation sites.
Coronary red flags after ASO:
- Sudden ST-segment changes, ventricular ectopy, or unexplained low cardiac output
- Rising troponin beyond expected postoperative pattern with wall-motion concerns
- Difficulty weaning vasoactives with signs of ischemia
Nursing actions: continuous ECG ST monitoring when ordered, prompt communication of rhythm/ischemia changes, maintain coronary perfusion pressure (avoid profound diastolic hypotension), and prepare for urgent echo/cath/return to OR per team. Pulmonary hypertension can still occur after ASO, especially in older or stressed neonates—avoid hypoxemia, acidosis, and agitation that spike PVR.
Left ventricular “prep” issues are less common in newborns than in older infants with TGA/IVS and a deconditioned LV, but residual LV dysfunction still requires careful afterload reduction (often milrinone) and filling optimization.
TOF Repair ICU Care
Complete TOF repair closes the VSD and relieves RVOTO (infundibular resection ± transannular patch). Postoperative physiology differs from shunt physiology.
High-yield complications:
- Residual RVOTO or residual VSD — persistent cyanosis/CHF physiology; echo confirms
- Right ventricular restrictive physiology — stiff RV, elevated CVP, low cardiac output, often needing higher filling pressures and atrial pacing contribution
- Junctional ectopic tachycardia (JET) — loss of AV synchrony early after repair; treat fever, correct electrolytes, sedation, cooling protocols, antiarrhythmics, and temporary pacing strategies per unit pathway
- Pulmonary regurgitation (especially after transannular patch) — volume load to RV over time; acute ICU issue is usually manageable but watch RV dilation and arrhythmias
- Heart block — less common than after some VSD repairs but still possible; temporary wires are not optional equipment—they are lifelines
Extubation readiness includes bleeding control, acceptable hemodynamics without escalating support, and airway protection after prolonged bypass and opioid exposure.
Cardiac Catheterization: Procedures and Complications
Interventional cath in pediatrics includes balloon atrial septostomy, pulmonary or aortic valvuloplasty, coarctation angioplasty/stent, device closure of ASD/VSD/PDA, and diagnostic hemodynamics before staged single-ventricle surgery.
| Complication | Clues | Nursing priorities |
|---|---|---|
| Vascular injury / hematoma / pulse loss | Limb mottling, Doppler signal loss | Notify team, anticoagulation decisions, limb checks q15–30 min initially |
| Arrhythmia / heart block | During wire/catheter manipulation | Defibrillator readiness, temporary pacing capability |
| Device embolization | Sudden murmur/SpO₂/BP change | Emergency retrieval pathway |
| Hemodynamic collapse | Ductal-dependent or fragile single ventricle | PGE1 continuity, volume, airway, ECMO readiness in high-risk labs |
| Contrast-related issues | Oliguria, rising creatinine | Hydration per protocol, minimize further contrast |
| Tamponade (rare but critical) | Equalizing pressures, muffled tones, PEA | Pericardiocentesis readiness |
Pre-cath nursing: NPO status, baseline pulses marked, PGE1 infusion verified uninterrupted for ductal-dependent infants, crossmatch available for high-risk cases, and clear handoff of lesion physiology to the cath team.
Post-Operative Monitoring Framework
Do not reduce monitoring to SpO₂. A complete PICU cardiovascular survey after congenital surgery or cath includes:
- Oxygen delivery: SpO₂ in context of lesion, hemoglobin, SvO₂/NIRS trends
- Pump function: BP, pulse pressure, lactate clearance, urine output, capillary refill
- Preload/afterload: CVP/LAP when available, vasoactive titration rationale
- Rhythm: atrial wire ECGs when helpful; capture and sensing checks on temporary pacemakers
- Surgical site: chest-tube character (sudden bright red output, abrupt cessation suggesting clot/tamponade), sternotomy integrity
- Neurologic: pupil checks, seizure watch after deep hypothermic arrest or long bypass when relevant
- Residual lesion suspicion: new murmur, failure to wean support, unexplained cyanosis—escalate for echo
Exam tip: Match the procedure to the signature complication—shunt thrombosis/overcirculation for stage I, coronary ischemia for arterial switch, JET/residual RVOTO for TOF, and limb ischemia/arrhythmia for cath—then choose the intervention that restores that lesion’s critical physiology.
Two hours after modified BT shunt placement, a neonate’s SpO₂ falls from 80% to 55%, blood pressure is low-normal, and the continuous shunt murmur is no longer audible. What is the most urgent concern?
After arterial switch for d-TGA, which finding should trigger the highest suspicion for coronary reimplantation compromise?
Which postoperative dysrhythmia is classically associated with tetralogy of Fallot repair in the early PICU period and causes loss of atrioventricular synchrony?