Post Cardiac Surgery Blood Loss
When a child undergoes heart surgery, a heart lung machine is used to keep blood flowing while the child’s own heart is stopped. After surgery, a significant amount of the child’s own blood is left in this machine. In the case of small children, the relative amount of blood potentially lost to the child in this way is very large.
In older children, and those who have undergone less complicated surgery, this blood can all returned to the child. Giving the child back his or her own blood makes is less likely that the child will need a transfusion of donated blood.
However, in younger children, or in children who have undergone more complicated surgery, most or all of this blood is thrown away. This is because of worry that returning this blood may cause bleeding, and excessive bleeding is one of the most feared complications of heart surgery.
This project will explore a method whereby the red blood cells left in the heart lung machine can be returned to children without increasing the risk of bleeding. It will also carefully examine the exact causes of higher bleeding risk in children getting their own blood back so that in the future, all children can have their own blood returned at the end of surgery.
Cardiac Preload Indicators in Children
The assessment of intravascular volume status in children is a difficult task guided by minimal scientific evidence. Administration of intravenous fluid to hemodynamically unstable and anesthetised children is a common therapeutic intervention. Much evidence exists of the danger of indiscriminate intravenous fluid loading. Dynamic preload indicators have been demonstrated in adults to represent a good indicator of volume status, but little evidence exists in children.
We aim to compare the ability of static preload indicators (central venous pressure and pulmonary capillary wedge pressure) with less invasive dynamic indicators (pulse pressure variation, plethysmograph variation) to predict the cardiac output response to a fluid bolus. The ultimate aim of this study is to help improve the safety of fluid administration for sick children.