R Krishna Kumar*
Pediatric Cardiology, AIMS, Kochi. *
|Circumstances: Neonates and infants with |
critical congenital heart disease requiring interventions.
Balloon Atrial Septostomy: Performed for transposition and occasionally for tricuspid atresia or total anomalous pulmonary venous drainage with restrictive atrial communication.
- Balloon valvotomy for critical aortic and pulmonary stenosis: This is performed as a definitive procedure. These newborns are often critically ill with duct dependent systemic or pulmonary blood flow.
- Perforation of the atretic pulmonary valve for pulmonary atresia with intact ventricular septum: The procedure is performed using a radiofrequency wire or the stiff end of a coronary angioplasty guide wire.
- Stenting of the patent arterial duct: Newborns and infants with duct dependent pulmonary circulation can undergo this procedure as an alternative to an emergency surgical Blalock-Taussig Shunt.
Coarctation dilation/stenting: Although surgery is preferred for neonatal coarctation, balloon dilation or stenting may be required for extreme emergencies.
- Closure of the patent arterial duct in the critically ill pre-term infant or infant with refractory pneumonia: Catheter closure is preferable in these patients who often have severely compromised lung function.
- Pericardiocentesis: This emergency procedure may be required in the postoperative setting or in occasional situations were cardiac tamponade results from massive pericardial collection.
Temporary transvenous pacing: Newborns or infants with complete heart block and symptomatic bradycardia.
Interventions in the Postoperative State:
- Pulmonary arterial Stenosis: Residual peripheral pulmonary arterial stenosis may require balloon dilation or stenting to enable reductions in elevated right ventricular systolic pressures.
- Blocked BT shunt: This is a particularly life-threatening emergency that may be temporarily salvaged through transcatheter recanalization using balloons with or without stents. Alternative infusion of thrombolytic agents in the blocked shunt may be considered.
- Balloon dilation of the atrial septum: Following certain operations such as repair of Tetralogy of Fallot, it may be necessary to create a good sized opening in the atrial septum to enable maintenance of systemic blood flow in the early postoperative period.
- Coil embolization of collaterals: Large aortopulmonary collaterals can have significant adverse hemodynamic effects in the early postoperative period and may require occlusion through coil embolization.
- Device closure of residual VSD and other unwanted communications: Residual hemodynamically significant VSDs can interfere with postoperative recovery.
- Device closure of residual VSD and other unwanted communications: Residual hemodynamically significant VSDs can interfere with postoperative recovery and may require to be closed in the catheterization laboratory to avoid the stress on another open heart surgery.
- Periventricular VSD device closure: This procedure is performed in the operation theater under echocardiographic guidance without the assistance of cardio-pulmonary bypass. This technique can also be applied for residual VSDs and VSDs that have been inadvertently missed during the initial operation.
- Balloon Dilation of atretic pulmonary valve: As an alternative to catheter based perforation of the pulmonary valve, this technique can be performed in the operation theater under echocardiographic guidance.
- Initial palliation for hypoplastic left heart syndrome: Many institutions have now adopted the hybrid approach as an alternative to the Norwood operation. In this operation, the patent arterial duct is stented and both pulmonary arteries are banded individually. This ensures a reliable systemic blood flow together with reduction of the pulmonary artery pressures in order that the patient remains a suitable candidate for an eventual single ventricle repair.
Pros and Cons of Doing Procedure in ICU versus the Catheterization Lab.
May be hazardous in a sick child with multiple supports, lines and tubes.
| Easily ensured.
Relatively difficult to ensure.
Sterile Field for the Procedure
Relatively difficult to ensure than in the cath lab. This is
important if relatively long catheters and guide-wires are required.
Easy to ensure.
| Imaging Guidance
Echocardiographic guidance only; sufficient for most balloon
atrial septostomy procedures and for pericardiocentesis. Not sufficient
for most other procedures.
Fluoroscopic as well as echocardiographic guidance. Vital for most interventions.
All requirements have to be planned in advance. Sometimes
special wires (such as angioplasty wires) may be required for obtaining
access. These are typically not stocked in an ICU.
Most hardware requirements are easily fulfilled in the catheterization lab.
Doing Procedures in ICU Balloon Atrial Septostomy and Pericardiocentesis:
- Meticulous planning of every step is vital. There is often sufficient time to organize the procedure and plan for eventualities.
- The area of operation should be prepared. The operative field should be uncluttered.
- The personnel involved should be identified and their responsibilities should be clearly spelt out. For example, who will provide echocardiographic guidance? Who will provide hardware etc.
- The positioning of the patient relative to the echo machine, the orientation of the screen etc., should all be worked out before hand.
- Sedation and Anesthesia need to be ensured, particularly for those patients who are not being ventilated.
- One personnel should be designated to ensure sterility of the area. It is especially important for the echocardiographer to wear a sterile gown because he or she is likely to come very close to the area of access.
- Echocardiographic guidance should be reliable.
- Hardware: Requirements should be anticipated in advance and procured. These include guidewires, introducer sheaths septostomy balloons etc.
- Access: Positioning of the patient is vital for obtaining access expeditiously. For groin access it is necessary to elevate the groin with rolls underneath the buttocks and fix the lower limbs at the knees.
- Monitoring during procedure: While most of the attention is directed at performing the procedure the patient should be monitored throughout carefully. Attention must be plaid to the airway in particular. Accidental displacement of the endotracheal tube may occur in ventilated patients.
Doing Procedures in the Cath Lab: The following aspects require attention:
- Transport to and from the Catheterization lab in ventilated children.
- Temperature control in the cath lab: The ambient temperatures of the catheterization laboratory are often lower than what is acceptable for small children. Appropriate arrangements to ensure the child is kept warm throughout the procedure are particularly important. This can be ensured using a Bear Hugger. The air-conditioning for the cath lab may have to be turned off at least half an hour before the procedure is begun.
- Airway (elective ventilation vs. conscious sedation): Elective ventilation is preferred for procedures with prospects of hemodynamic stability. These include VSD device closure, PDA stenting, balloon valvotomy for selected patients with critical AS or PS. Endotracheal intubation is also preferred if transesophageal monitoring is required of if the patient has to remain completely still during the procedure.
- Supports and other medications should be delivered via a reliable peripheral or central line that is not placed in the limb that is used to obtain access.
- Monitoring: It is advisable to have an anesthetist throughout the procedure to ensure adequate monitoring and safety of the child throughout the procedure.
- Control of access sites after the procedure is completed. Serious inadvertent blood loss may result if meticulous attention is not paid to the groin access sites after the procedure is completed.
Post Procedure Management: Attention needs to be paid to the following:
- Access sites for bleeding
- Distal pulses, temperatures and perfusion in the catheterized limb
- Monitoring for rhythm, hemodynamics and temperature
- Mechanical ventilation: Duration, specific strategies
- Maintenance fluids
- Inotropic supports, vasodilators and other medication
- Manipulation of physiology if substantially altered by the procedure. For example the pulmonary blood flow may increase to unacceptable levels following stenting of the patent arterial duct. These patients may require systemic vasodilation, ventilation with lower FiO2, etc
Potential complications such as blood loss, altered physiology (such as after stenting of PDA), hypothermia, arrhythmias and heart block and sepsis should be appropriately managed.
|How to Cite URL :|
|Kumar K R.. Available From : http://www.pediatriconcall.com/fordoctor/ Conference_abstracts/report.aspx?reportid=292|