Context: Intraosseous (IO) blood is frequently used to establish a blood chemistry profile in critically ill patients. Questions remain regarding the reliability of IO blood for laboratory analysis and established criteria regarding the amount of marrow/blood to waste before taking an IO sample are not available.
Objectives: To evaluate IO-derived blood for routine laboratory blood tests needed in the care of critically ill patients and to determine the amount of marrow/blood to waste before drawing blood from the IO space for laboratory analysis.
Design: Blood samples were drawn from peripheral veins of 10 volunteers. Within 5 minutes, 2 IO blood samples were obtained; one following 2 mL of waste and another following 6 mL of waste. Samples were analyzed for complete blood count and chemistry profile. Values were analyzed using Pearson correlation coefficients. Levels of significance were determined using the t distribution. Mean values for the draws were calculated and compared, with the intravenous blood sample serving as a control for the IO samples.
Results: There was a significant correlation between intravenous and IO samples for red blood cell counts and hemoglobin and hematocrit levels but not for white blood cell counts and platelet counts. There was a significant correlation between intravenous and IO samples for glucose, blood urea nitrogen, creatinine, chloride, total protein, and albumin concentrations but not for sodium, potassium, CO(2), and calcium levels.
Conclusions: When venous blood cannot be accessed, IO blood aspirate may serve as a reliable alternate, especially for hemoglobin and hematocrit levels and most analytes in a basic blood chemistry profile. Exceptions are CO(2) levels and platelet counts, which may be lower, and white blood cell counts, which may appear elevated.