A significant decline in vitamin D status among children undergoing heart surgery was associated with the use of a machine that takes over heart function, according to research published in Anesthesiology. Cardiopulmonary bypass is a machine used to temporarily take over heart and lung function during heart surgery.
The prospective observational study was conducted at the Children’s Hospital of Eastern Ontario. The 58 participants had a mean age of 8.4 months and were scheduled for elective or semi-elective heart surgery.
Mean vitamin D status before surgery was 23 ng/ml, which decreased to 14 ng/ml following surgery, a 42% change. Forty-two percent of the infants had levels above 20 ng/ml before surgery. Following surgery 86% of infants had levels < 20 ng/ml. Four percent were severely deficient (<10 ng/ml) prior to surgery, although after surgery this increased to 27%. The authors report a 40% change in vitamin D levels during surgery.
Vitamin D levels remained fairly stable. One day following surgery 87% of infants had levels <20 ng/ml, with 24% considered severely deficient.
After collecting their data, the researchers compared vitamin D status decline between patients who didn’t receive cardiopulmonary bypass with a group who did. They report a significantly greater decrease in vitamin d status among the cardiopulmonary bypass group (p=0.01). The change in vitamin D status occurred when the cardiopulmonary bypass machine was initiated.
The authors also found that lower postoperative vitamin D status was associated with the need for fluids and catecholamines, “two established measures of cardiovascular and immune dysfunction.” Duration of intubation – used to assist with breathing during surgery – was also associated with lower vitamin D levels following surgery.
The authors want future research to focus on measuring changes in vitamin D status in children undergoing congenital heart disease surgery over a longer period of time.