Year : 2012  |  Volume : 15  |  Issue : 2  |  Page : 169--171

Perioperative management of pulmonary atresia with intact ventricular septum in a 5-year old


Mazen Faden 
 Department of Anesthesia, The Hospital for Sick Children, Toronto, Canada

Correspondence Address:
Mazen Faden
Department of Anesthesia, The Hospital for Sick Children, 555 University Avenue, Room 2303, Toronto, ON M5G 1X8
Canada




How to cite this article:
Faden M. Perioperative management of pulmonary atresia with intact ventricular septum in a 5-year old.Ann Card Anaesth 2012;15:169-171


How to cite this URL:
Faden M. Perioperative management of pulmonary atresia with intact ventricular septum in a 5-year old. Ann Card Anaesth [serial online] 2012 [cited 2022 Sep 27 ];15:169-171
Available from: https://www.annals.in/text.asp?2012/15/2/169/95089


Full Text

The Editor,

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare congenital cardiac defect accounting for 1-3% of patients with congenital heart disease. [1],[2] Medical management may be required to keep the ductus open to maintain pulmonary blood flow. We present a 5-year-old boy who was born with PA/IVS and admitted to our institution for corrective cardiac surgery. This child had a stormy intraoperative and postoperative course following dental extraction, which was required prior to definitive repair. This prompted for an urgent cardiac repair, and the intraoperative challenges with both the cardiac and the noncardiac procedures are highlighted.

The patient (15 kg; height 93 cm) was scheduled for pulmonary and tricuspid valve repair along with a Cox-Maze procedure and right atrial size reduction. The patient had an open pulmonary valvotomy at 4 months of age for cyanosis secondary to PA/IVS. Subsequently, the patient presented with heart failure secondary to severe pulmonary regurgitation, right ventricular dilatation and progressive tricuspid valve regurgitation. The initial chest X-ray showed severe cardiomegaly [Figure 1]a. Patient was uncooperative for an echocardiogram. Extensive dental cavities and microabscesses necessitated dental extractions prior to cardiac surgery. Shortly after induction with sevoflurane and administration of cefazolin 50 mg/kg for endocarditis prophylaxis, a bigeminal rhythm developed that quickly progressed to wide complex ventricular tachycardia (242 bpm). Synchronized cardioversion with 5J was performed, but this resulted in atrial fibrillation at a rate of 180-210 bpm. A repeat shock of 5J resulted in atrial flutter. Sevoflurane was discontinued while the patient airway was maintaied with a mask. Dental procedure was cancelled and the patient was transferred to the intensive care unit (ICU) with a loading dose (50 mcg/kg over 60 min) followed by infusion of amiodarone (5 mcg/kg/min). The patient did not rquire intubation as he was spontaneonsly breathing upon transfer to the ICU. Transthoracic echocardiography showed a giant right atrium [Figure 1]b and severely dilated right ventricle with biventricular dysfunction and pulmonary valve regurgitation. Upon transfer to the ICU, he was in atrial flutter with a 2:1 conduction block with a ventricular rate of 115 bpm. Because of the high likelihood of prosthetic valve implantations, the boy still needed his dental restorations done before the proposed cardiac surgery. Despite amiodarone, the patient remained in atrial flutter and hence the plan was to cardiovert him after induction of anesthesia in the operating room. Induction was done with incremental midazolam and fentanyl (up to 50 mcg/kg and 4 mcg/kg, respectively) and intubated with rocuronim 0.6 mg/kg. An extracorporeal membrane oxygenator setup was available in case of hemodynamic collapse. Anesthesia was maintained with remifentanil infusion (0.1 mcg/kg/min) and isoflurane (0.5 MAC). The patient tolerated the procedure well and woke up with good response to commands. An extubation trial failed and he was tranferred to the ICU intubated. While in the ICU, the patient had two cardiac arrests requiring resuscitation. Two days later, it was decided that it was in the best interest of the patient to undergo cardiac surgery. The patient had endotracheal tube ETT in situ and was sedated with morphine and midazolam infusions prior to coming to the operating theater. He was on milrinone and amiodarone infusions. The patient was induced with midazolam (80 mcg/kg), fentanyl (30 mcg/kg) and rocuronium 1 mg/kg; anesthesia was maintained with low-dose isoflurane, fentanyl and rocuronim boluses. The cardiopulmonary bypass lasted 216 min, with an aortic cross-clamp time of 140 min. Surgery included implantation of a bioprosthetic pulmonary mosaic and a tricuspid mosaic valve along with a right atrial Cox-Maze procedure and atrial dimension reduction for atrial fibrillation. The initial transesophageal echocardiogram after bypass showed reduced biventricular function, which was treated with dopamine and epinephrine infusions. Significant bleeding required multiple blood products and one dose of factor VIIa. The patient was transferred to the ICU where he continued to have frequent bigeminy and bradyarrythmias. He was extubated on the fourth postoperative day and was discharged home on the twentieth postoperative day.{Figure 1}

The main therapeutic goal of PA/IVS focuses on establishing pulmonary blood flow, initially with alprostadil to keep ductus patent. Infants who have pulmonary valvotomy may develop significant pulmonary regurgitation, [3] leading to right ventricular dilatation, dysfunction and tricuspid annular dilatation with tricuspid regurgitation, carrying a high risk of developing significant hemodynamic instability. Maintaining sinus rhythm and atrioventricular synchrony is especially important in the presence of right ventricular failure. [4] Ventricular interdependence is an important concept in the management of right ventricular dysfunction as excessive volume loading may increase pericardial constraint and result in decreased left ventricular preload and cardiac output. [4] Inotropic or vasopressor support may also be required. Dobutamine or milrinone may be used to improve ventricular function. Because of lower pressure and flow velocity on the right side of the heart, the incidence of clot formations on mechanical valves is higher than on the left side. [5] However, bioprosthetic valves have a slower rate of degeneration if used on the right side of the heart and give the patient the freedom of not to be on chronic anticoagulation. [5] Cox-Maze procedure, as performed in our patient, involves mechanical destruction of cardiac tissue to produce scars that eliminate abnormal electrical conduction, and that can also help restore heart rate and rhythm control.

References

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3Buechel ER, Dave HH, Kellenberger CJ, Dodge-Khatami A, Pretre R, Berger F, et al. Remodelling of the right ventricle after early pulmonary valve replacement in children with repaired tetralogy of Fallot: Assessment by cardiovascular magnetic resonance. Eur heart J 2005;26:2721-7.
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5Scully HE, Armstrong CS. Tricuspid valve replacement: Fifteen years of experience with mechanical prostheses and bioprostheses. J Thorac Cardiovasc Surg 1995;109:1035-41.