A Practical Approach to Cardiac Anesthesia (Practical Approach Series) by Hensley Frederick A. & Martin Donald E. & Gravlee Glenn P

Author:Hensley, Frederick A. & Martin, Donald E. & Gravlee, Glenn P. [Hensley, Frederick A.]
Language: eng
Format: epub
ISBN: 9781451177411
Publisher: Lippincot (Wolters Kluwer Health)
Published: 2012-09-24T00:00:00+00:00

The most important factor in evaluating these patients is whether or not there is any obstruction to the pulmonary venous drainage. The presence or absence of obstruction is the main determinant of the patient’s clinical presentation and prognosis. It should be noted that TAPVR is associated with other complex cardiac lesions in a significant percentage of patients.

The patient with obstruction to drainage will be severely symptomatic in the first hours to days of life. The patient will be markedly cyanotic with respiratory distress. The chest x-ray is remarkable for a nearly normal heart size but shows a pulmonary interstitial pattern characteristic of pulmonary venous obstruction. Severe obstruction is most likely in patients with the infracardiac type but can occur in patients with any of the types of TAPVR. Infants with severe obstruction have severe pulmonary hypertension and require surgical intervention within the first few hours to days of life.

Patients without pulmonary venous obstruction will have a much more subtle clinical presentation. In this scenario, the patient may be relatively asymptomatic early but has pulmonary overcirculation of both systemic and pulmonary venous return. Mild cyanosis with oxygen saturation of about 85% to 90% may be difficult to appreciate. These patients are at risk for early development of pulmonary vascular obstructive disease.

b. Surgical procedures. Patients with TAPVR with obstruction must be surgically repaired expeditiously because medical management is not effective. Their condition can rapidly deteriorate and lead to death. The goal of correction is to connect the pulmonary venous system back into the left atrium, eliminate the anomalous connection to the systemic venous system, and close the ASD. Hypothermic CPB with circulatory arrest is commonly used. In the supracardiac type, the common pulmonary trunk is connected directly to the posterior left atrium, the ASD is closed, and the vertical vein is ligated. With the intracardiac type, the coronary sinus is “unroofed” and a patch is used to divert the pulmonary venous return (and the coronary sinus blood) into the left atrium across the ASD. For the infracardiac type, the common pulmonary vein is directly anastomosed to the left atrium, the descending vein is ligated, and the ASD is closed.

c. Anesthetic considerations

(1) Preoperative. Neonates with TAPVR and obstruction represent a true surgical emergency. The only therapy that may be considered preoperatively would be a balloon or blade atrial septostomy in the cardiac catheterization laboratory if the ASD is restrictive. This intervention will increase flow into the left atrium and potentially improve systemic perfusion. This is only a temporizing measure, and surgical intervention should occur as soon as possible. These neonates typically present with severe pulmonary hypertension, cyanosis, metabolic acidosis, and poor perfusion. They are often already intubated and receiving inotropic support. PGE1 may decompress a hypertensive PA system and even open a ductus venosus, relieving a degree of pulmonary venous obstruction.

(2) Intraoperative. A technique should be used to minimize myocardial depression, typically with intravenous narcotics and paralytics. Inhalational anesthetics are generally not tolerated in the sick neonate but may be acceptable in the older child without obstruction and minimal symptoms.

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