A child undergoing surgery for an ASD would normally be expected to spend no more than ten days in hospital. This did not happen in Aric's case. Instead, he spent 52 days in the PICU, ultimately dying there. While his condition in the PICU was initially stable, by July 4 his condition was starting to deteriorate.

On Monday, July 4, (Aric's fourth day in the PICU) a PICU resident noted that Aric had had three episodes of pulmonary hypertension in the previous 48 hours. The right upper lobe of his lung had collapsed and he was slightly fluid overloaded. By Tuesday, the right upper lobe of his lung had re-expanded and his oxygen saturation level was 100 per cent. He showed varying degrees of heart block and needed the pacemaker to control his heart rhythm. During this period there were also problems in getting the pacemaker (or possibly the leads) to operate properly. On Wednesday, Aric continued to have problems with heart block. He also had low blood pressure, reduced blood flow to his tissues, a decrease in his oxygen saturation level and a drop in his urine output. In addition, he was suffering from a chemical imbalance. (He was in metabolic acidosis.)

From Thursday, July 7 to Wednesday, August 17, Aric's condition slowly deteriorated. He remained ventilated for his entire stay in the PICU. The major problems he had during this period were:

• Arrhythmias (abnormal heart rhythms): these required frequent manipulation of his pacemaker.
• Pulmonary hypertensive crises (high blood pressures in his pulmonary arteries): these required drug treatment (phenoxybenzamine), which did result in his condition becoming slightly more stable.
• Congestive heart failure, with pulmonary and peripheral edema (decreased heart function with fluid retention in the lungs and in the arms and legs), with worsening of the atrioventricular valve regurgitation: this was treated with large doses of diuretics.
• Episodes of sepsis (serious infections of the blood): these were treated with antibiotics.
• Pneumonia and respiratory distress syndrome (lung infections and decreased lung function): these meant that Aric needed to be ventilated by machine.

Giddins testified that it was expected that, since the repair had been successful, the high pressures in Aric's pulmonary arteries should have been reduced. However, this did not happen. Aric had ongoing problems with the vessels that carry blood to the lungs.

This was a very trying period for the Baumann family. For the entire time he was in the PICU, Aric had a tube down his trachea and was connected to a ventilator to assist his breathing. At one point in mid-July, the family was told that it looked as if Aric would only last another 48 hours. The distraught family arranged for baptism at that time. However, Aric rallied and survived for another month.

At the same time, the medical staff continued to search for the cause of Aric's deterioration. One of the people involved was Dr. Cameron Ward, a cardiologist who had started working with the Heart Centre in July. Ward suggested that there was a constriction of the pulmonary veins. This is also known as pulmonary vein stenosis. Over time, the pulmonary veins of patients suffering from this congenital disease become progressively narrow. It is not known what causes this process to start, nor do doctors know how to stop the process. Witnesses testified that while the condition is often fatal, there are instances of the condition arresting on its own. In some cases a patient might be left with one functioning lung and one non-functioning lung. The only definitive treatment was a full lung and heart transplant. However, this was rarely feasible with patients of Aric's age and size.

A cardiac catheterization was conducted on August 18. When compared with a catheterization conducted in May, the results indicated that Aric did indeed have pulmonary vein stenosis. Giddins testified that when he had examined the catheterization results in May he had not looked for signs of pulmonary vein stenosis; nor had he seen any. Following the diagnosis of pulmonary vein stenosis, he re-examined the May results and testified that he could see some signs of vein narrowing. However, this narrowing was much more extreme in the August catheterization.

Giddins testified that if he had diagnosed pulmonary vein stenosis in May, he would have still recommended proceeding with Aric's surgery. He said that the stenosis did not increase the surgical risk to the child. Furthermore, he said that he would not have recommended any change in Aric's post-operative care if he had known of the stenosis.

Odim testified that during the course of the operation, he could not see any sign of pulmonary vein stenosis. He also testified that, had he known of the stenosis, he would have still recommended proceeding with the operation.

Aric's pulmonary vein stenosis was extreme by the time the condition was diagnosed in August. Giddins, in consultation with Ward and Odim, concluded that the problem was not treatable. In a letter written to Simmonds after Aric's death, Odim wrote, "This was a rather unfortunate anatomic arrangement which was not entirely appreciated at the outset. The prognosis for this type of problem is very poor with the only option to date being a combined heart lung transplantation which in this age group continues to be an experimental venture." (Exhibit 2, page BAU 35)

Giddins, Dr. Fiona Fleming and Hawkins met with the family on August 20. It was explained to the Baumanns that a transplant was not possible in this situation and that there was no other treatment for Aric's condition apart from comfort care. The parents agreed to a recommendation to stop treatment once all of the family had been called together. Aric died in his grandmother's arms at 1134 hours on August 21, 1994.