Data regarding blood drawing sites in patients receiving intravenous fluids.

Intravenous fluids were infused into the forearms of 18 volunteers. Baseline hematologic and serum biochemical profiles were obtained from each volunteer prior to starting the IV. After the intravenous fluids had infused for 30 minutes, blood was drawn from the opposite arm, and above and below the IV in the same arm. The intravenous fluids were then stopped, and after waiting two minutes, another blood sample was drawn from the IV needle. The deviation from the baseline value was determined for each analyte by sampling site for each volunteer and the mean deviation was calculated for each analyte from each sample site. Drawing blood from above the infusing IV line resulted in a dilutional effect for most of the analytes. Most analytes were not affected when blood was drawn from the other sites. Serum glucose and phosphorus had mean deviations greater than two standard deviations from the baseline, regardless of where they were drawn. Serum glucose was the only analyte with values higher than the baseline values. We recommend that serum biochemical and hematologic profiles not be drawn above an infusing IV, but should be drawn from the opposite arm or below the IV while it is infusing or out of the IV needle after the intravenous fluids have been stopped for two minutes.