Background: Intraosseous (IO) access is often indicated for administration of drugs and fluids in emergencies when venous access is challenging. There is no consensus regarding whether and which laboratory analyses may be performed on IO aspirates, and research on hemodynamically unstable subjects is limited.
Methods: Twelve anesthetized pigs were sampled from IO, venous, and arterial accesses during stable circulation and after hemorrhage corresponding to 20% and 40% of the blood volume. Samples were analyzed for blood gases and acid-base status, electrolytes, hematocrit, creatinine, glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (γ-GT), alkaline phosphatase (ALP), and creatine kinase (CK). Results: Average differences of blood gases and acid-base parameters, sodium, creatinine, hematocrit, ALT, and γ-GT and between IO and venous samples were small at baseline and after hemorrhage while differences for lactate and glucose increased with hypovolemia. Both IO-arterial and venoarterial differences in acid-base parameters increased with hypovolemia. Dispersions of differences were often large.
Conclusions: Average levels of blood gases, acid base parameters, hematocrit, CK, AST, γ-GT, creatinine, and ALT, but not lactate and glucose, were similar in IO and venous samples in hypovolemia. However, precision was limited, indicating that IO test results should be confirmed when other vascular access is established, and that analysis of IO samples should be limited to acute situations and not used for detailed diagnostics in this setting.