Paediatric Anaesthesia 1997
7: 255–258
Case report
Repair of ventricular septal defect in a child with severe pulmonary hypertension—response to inhaled nitric oxide NUALA CREGG
MB, FFARCSI
AND WILLIAM CASEY
MB, FFARCSI
Department of Anaesthesia, Children’s Research Centre, Our Lady’s Hospital for Sick Children, Crumlin, Dublin 12, Ireland
Summary Nitric oxide (NO), was administered successfully, to a child with severe pulmonary hypertension, following surgical repair of a large ventricular septal defect. Inhalation of NO, 20–25 parts per million (ppm) was continued for 24 h, resulting in mean pulmonary artery pressure (PAP) of 25 mmHg and permitting a reduction in both ventilatory and inotropic support. Weaning of NO was commenced. At 5 ppm, administration was discontinued. An immediate and dramatic increase in PAP occurred. A similar pattern resulted on further attempts, demonstrating the extreme sensitivity of the pulmonary vasculature to the effects of inhaled low dose NO and the selectivity of the response. Keywords: ventricular septal defect; pulmonary hypertension; nitric oxide
Introduction Right ventricular failure from pulmonary hypertension is a common cause of morbidity and mortality following surgical repair of congenital heart disease with left to right shunt. Hyperventilation-induced alkalosis and pharmacological therapy to decrease pulmonary vascular resistance is limited by lack of selectivity, resulting in both pulmonary and systemic vasodilation and profound systemic hypotension. Nitric oxide (NO) has recently been identified as a physiological vasodilator, released by the endothelial cell. NO administration by inhalation results in
Correspondence to: Nuala Cregg, Department of Anaesthesia, Toronto Hospital, 200 Elizabeth Street, Toronto, Ontario M5G 2C4, Canada. 1997 Blackwell Science Ltd
selective pulmonary vasodilation. We report a case of a child with severe pulmonary hypertension following surgical repair of a large ventricular septal defect (VSD). Inhalation of NO, 20–25 ppm, for 24 h, resulted in a dramatic decrease in pulmonary artery pressure and permitted a reduction in ventilatory and inotropic support.
Case report A three-year-old boy, 11.6 kg, was admitted for correction of a large VSD, with severe preoperative pulmonary hypertension. Preoperative cardiac catheterization revealed a large outlet VSD, high pulmonary vascular resistance (PVR), pulmonary artery pressure (PAP) 97/39 (66) mmHg and systemic arterial pressure 110/56 (81) mmHg. 255
N. CREGG & W. CASEY
70 PAP MAP (mmHg) (mmHg)
Premedication was with phenoperidine 0.35 mg, droperidol 0.15 mg, atropine 0.1 mg i.m. Anaesthesia was induced with sodium thiopentone 50 mg i.v. and maintained with pancuronium, morphine, isoflurane. Induction and maintenance of anaesthesia were uneventful. Left atrial (LA) and pulmonary artery (PA) lines were inserted and revealed mean pressures of 6 and 56 mmHg, respectively. Right atriotomy and ventriculotomy were performed. A large outlet VSD was seen and haemopatch was used to close the ventricular defect. Immediately post cardiopulmonary bypass (CPB), the child developed severe pulmonary hypertension. He was hyperventilated, respiratory rate of 60 min−1. Fio2 of 0.8–1.0 was required to ensure adequate oxygenation. Paralysis and sedation were achieved using vecuronium and morphine infusions. Dopamine 10 lg kg−1·min−1 and adrenaline 0.25 lg kg−1·min−1 were administered continuously to maintain mean systemic arterial pressure (MAP) >60 mmHg. Nitric oxide, a selective pulmonary vasodilator, approved by the National Drugs Advisory Board (NDAB) and the Hospital Ethics Committee for use in the treatment of pulmonary hypertension, was administered post CPB at 25 ppm. Improvement was immediate, with a fall of the mean PAP from 56 to 29 mmHg. NO was administered for 24 h, permitting a reduction in both ventilatory and inotropic support. After 24 h weaning of NO was commenced. NO was reduced by 5 ppm at hourly intervals, and was tolerated well. At this stage Fio2 was 0.5 and ventilation was to normocarbia and inotropic support had been reduced steadily. When the dose of NO had been reduced to 5 ppm, NO was discontinued. An immediate and dramatic increase in PAP resulted, mean PAP rising from 26 to 40 mmHg, within 5 min. Two further attempts to discontinue NO resulted in similar responses. On reintroducing NO there was an immediate fall in mean PAP, within minutes, at doses
7: 255–258
Case report
Repair of ventricular septal defect in a child with severe pulmonary hypertension—response to inhaled nitric oxide NUALA CREGG
MB, FFARCSI
AND WILLIAM CASEY
MB, FFARCSI
Department of Anaesthesia, Children’s Research Centre, Our Lady’s Hospital for Sick Children, Crumlin, Dublin 12, Ireland
Summary Nitric oxide (NO), was administered successfully, to a child with severe pulmonary hypertension, following surgical repair of a large ventricular septal defect. Inhalation of NO, 20–25 parts per million (ppm) was continued for 24 h, resulting in mean pulmonary artery pressure (PAP) of 25 mmHg and permitting a reduction in both ventilatory and inotropic support. Weaning of NO was commenced. At 5 ppm, administration was discontinued. An immediate and dramatic increase in PAP occurred. A similar pattern resulted on further attempts, demonstrating the extreme sensitivity of the pulmonary vasculature to the effects of inhaled low dose NO and the selectivity of the response. Keywords: ventricular septal defect; pulmonary hypertension; nitric oxide
Introduction Right ventricular failure from pulmonary hypertension is a common cause of morbidity and mortality following surgical repair of congenital heart disease with left to right shunt. Hyperventilation-induced alkalosis and pharmacological therapy to decrease pulmonary vascular resistance is limited by lack of selectivity, resulting in both pulmonary and systemic vasodilation and profound systemic hypotension. Nitric oxide (NO) has recently been identified as a physiological vasodilator, released by the endothelial cell. NO administration by inhalation results in
Correspondence to: Nuala Cregg, Department of Anaesthesia, Toronto Hospital, 200 Elizabeth Street, Toronto, Ontario M5G 2C4, Canada. 1997 Blackwell Science Ltd
selective pulmonary vasodilation. We report a case of a child with severe pulmonary hypertension following surgical repair of a large ventricular septal defect (VSD). Inhalation of NO, 20–25 ppm, for 24 h, resulted in a dramatic decrease in pulmonary artery pressure and permitted a reduction in ventilatory and inotropic support.
Case report A three-year-old boy, 11.6 kg, was admitted for correction of a large VSD, with severe preoperative pulmonary hypertension. Preoperative cardiac catheterization revealed a large outlet VSD, high pulmonary vascular resistance (PVR), pulmonary artery pressure (PAP) 97/39 (66) mmHg and systemic arterial pressure 110/56 (81) mmHg. 255
N. CREGG & W. CASEY
70 PAP MAP (mmHg) (mmHg)
Premedication was with phenoperidine 0.35 mg, droperidol 0.15 mg, atropine 0.1 mg i.m. Anaesthesia was induced with sodium thiopentone 50 mg i.v. and maintained with pancuronium, morphine, isoflurane. Induction and maintenance of anaesthesia were uneventful. Left atrial (LA) and pulmonary artery (PA) lines were inserted and revealed mean pressures of 6 and 56 mmHg, respectively. Right atriotomy and ventriculotomy were performed. A large outlet VSD was seen and haemopatch was used to close the ventricular defect. Immediately post cardiopulmonary bypass (CPB), the child developed severe pulmonary hypertension. He was hyperventilated, respiratory rate of 60 min−1. Fio2 of 0.8–1.0 was required to ensure adequate oxygenation. Paralysis and sedation were achieved using vecuronium and morphine infusions. Dopamine 10 lg kg−1·min−1 and adrenaline 0.25 lg kg−1·min−1 were administered continuously to maintain mean systemic arterial pressure (MAP) >60 mmHg. Nitric oxide, a selective pulmonary vasodilator, approved by the National Drugs Advisory Board (NDAB) and the Hospital Ethics Committee for use in the treatment of pulmonary hypertension, was administered post CPB at 25 ppm. Improvement was immediate, with a fall of the mean PAP from 56 to 29 mmHg. NO was administered for 24 h, permitting a reduction in both ventilatory and inotropic support. After 24 h weaning of NO was commenced. NO was reduced by 5 ppm at hourly intervals, and was tolerated well. At this stage Fio2 was 0.5 and ventilation was to normocarbia and inotropic support had been reduced steadily. When the dose of NO had been reduced to 5 ppm, NO was discontinued. An immediate and dramatic increase in PAP resulted, mean PAP rising from 26 to 40 mmHg, within 5 min. Two further attempts to discontinue NO resulted in similar responses. On reintroducing NO there was an immediate fall in mean PAP, within minutes, at doses
