Phlebotomy-induced blood loss in critically ill children is common, contributes to anemia, and may be avoidable. We aimed to identify factors associated with phlebotomy-induced blood loss.
Prospective observational study, single-center tertiary children's hospital.
Pediatric intensive care unit.
A total of 63 patients admitted to the pediatric intensive care unit for >48 hrs from 2004 to 2005.
Phlebotomy resulted in a mean blood volume loss of 2.5 ± 1.4 mL per draw, 7.1 ± 5.3 mL per day, and 34 ± 37 mL per pediatric intensive care unit stay, of which 1.4 ± 1.1 mL per draw, 3.8 ± 3.6 mL per day, and 23 ± 31 mL per pediatric intensive care unit stay were discarded as excess. This excess represents 210% ± 174% of the volume requested by the laboratory and a 110% overdraw. Blood drawn from central venous catheters had significantly greater overdraw volumes, 254% ± 112%, compared to those of arterial, 168% ± 44%, and peripheral intravenous catheters, 143% ± 39%, p < .001. Blood draws sent for one test had an associated overdraw of 278% ± 81%, compared to draws sent for two, 168% ± 48%, three 173% ± 4%, and four or greater tests 55% ± 5%, p < .001. Patients <10 kg had significantly greater mean volumes of blood loss/kg/day compared to patients ≥10 kg, p < .001.
Blood drawn in excess of phlebotomy requirements exceeds the blood volume loss drawn for phlebotomy by two fold. Using indwelling catheters for phlebotomy often requires a discard volume to be drawn before obtaining the laboratory sample. Consolidating phlebotomy tests and using a closed system may decrease the amount of blood overdrawn and minimize overall phlebotomy-induced blood loss.
From the Department of Anesthesia and Perioperative Medicine (SLV), Division of Critical Care Medicine, Children's Hospital Boston, Boston, MA; and University of Massachusetts Medical Center (SB), Worcester, MA.
Supported, in part, by the Frederick Lovejoy Resident Research Award, Children's Hospital Boston, and the Agency for Healthcare Research and Quality Grant T32 HS000063 (SLV).
Dr. Bateman was a Johnson and Johnson consultant for the original data collection of the parent study but was not a consultant for this study. He did not receive financial support for this study. Dr. Valentine has not disclosed any potential conflicts of interest.
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