SESSION TITLE: Critical Care Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Pulmonary arteriovenous malformations (PAVM) are a rare cause of hypoxemia in the neonatal period. They are caused by abnormal communications between pulmonary arteries and pulmonary veins, which are most commonly congenital. Without gas exchange it produces hypoxemia to a varying degree.
CASE PRESENTATION: A baby girl born at 38 weeks of gestation weighing 2500 g, with Apgar score 9 at 1 min, presented with cyanosis at three days of age. She was evaluated and admitted to a Level 3 maternity hospital, where her oxygen saturation was found to be 80-90%. Infection and cardiac malformation were ruled out. As her condition did not improve despite assisted ventilation, systemic and inhaled corticosteroids, and inhaled bronchodilator, she was referred to our hospital at 20 days of age for further evaluation and management. The clinical picture on admission: T37.3°C, weight 2400 g, generalized cyanosis, on conventional mechanical ventilation, oxygen saturation 75% with FiO2 1.0, normal pulmonary auscultation, heart rate 146 beats/min, blood pressure 95/74 mmHg, otherwise normal clinical exam. On admission to our unit, she was on conventional mechanical ventilation, and we started empirically inhaled nitric oxide (NO) with little improvement. For cardiac support, she received dopamine, dobutamine, and furosemide, and for preventing infection she received antibiotherapy. Laboratory results: normal CBC, CRP 8.8 mg/l, blood gas: metabolic acidosis. Chest x-rays showed a normal cardiothoracic ratio, reduced pulmonary transparency in the left parahilar region and an area of increased opacity in the median third of the left lung, considered to be atelectasis. The suspicion of PAVM was raised by echocardiography and proved by “bubble test” and Angio CT. She underwent surgery on the 28th day of life. The surgical procedure - left pneumonectomy - was required by the inability of reconstruction of the left pulmonary fissure. When the left pulmonary artery was ligated, the oxygen saturation increased quickly from 80% to 100%. On the 14th day after the surgery, it was possible to stop the NO and the Milrinone. However, the following days, her pulmonary hypertension worsened again, and she required resumption of NO and initiation of Sildenafil. Echocardiography showed severe right ventricular dysfunction with ejection fraction 25-30%, pulmonary valve insufficiency Gr II, tricuspid insufficiency Gr II, and pulmonary artery dilatation. She required higher doses of NO, dopamine, dobutamine, and milrinone, and epinephrine was started by continuous infusion. The clinical status worsened constantly, she developed severe lactic acidosis, which was unresponsive to treatment, and she died on the 48th day of life (20 days after the surgery).
DISCUSSION: In neonates, clinical manifestations of the pulmonary arteriovenous malformations from the first days of life are rare. More commonly, these lesions are not diagnosed until the third or fourth decade, when the right-to-left shunt increases and causes symptoms . Our patient had a complete type of PAVM and the predominant symptom was severe hypoxemia, requiring ventilation to maintain oxygen saturation. Left lower lobectomy proved unfeasible and the surgeon was compelled to extirpate the whole lung. Pneumectomy in a neonate could associate compression of the trachea and bronchus by the major vessels and pulmonary hypertension.
CONCLUSIONS: This case illustrates a large pulmonary vascular malformation as a rare cause of hypoxemia and respiratory distress in the newborn. The diagnosis was established using echocardiography, chest x-ray, and confirmed by angioCT. Surgical removal of the AVM and of the left lung, plus hypoxia lead to severe pulmonary hypertension. Lung conserving resection would be the best choice when a lung malformation should be removed.
Reference #1:  Mitchell R O,Austin E H. Pulmonary arteriovenous malformation in the neonate. J Pediatr Surg 1993;12:1536 -8
Reference #2: -www.hopkinsradiology.org/HHT/Patients/UNDERSTANDING%2520AGITATED%2520SALINE%2520ECHO%2520TEST.pdf (accessed 1 March 2012).
DISCLOSURE: The following authors have nothing to disclose: Catalin Cirstoveanu
No Product/Research Disclosure Information