Study objective: To demonstrate the utility of a new blood-conserving arterial line system in reducing blood loss associated with blood drawing in the critical care setting.
Design: Prospective, randomized, crossover comparison between two arterial line systems.
Setting: Medical intensive care unit (ICU); tertiary care teaching institution.
Patients: Thirty-one patients who required invasive arterial blood pressure monitoring throughout their ICU course.
Interventions: For ICU days 1 to 2, patients were randomized to receive either a conventional arterial line system or a new blood-conserving arterial line system. On ICU days 3 to 7, patients with a conventional arterial line were crossed over to the blood-conserving arterial line, and vice versa. Laboratory blood volumes, mixed discard volumes, and blood discard volumes were then recorded to document how much blood loss is associated with each aspect of the blood sampling process.
Results: The mean total volume of blood sent to the laboratory for testing was 257.4 ml. As a result of "clearing the line" over the 7-day period, patients with the conventional arterial line system lost a mean volume of 340.2 ml of blood mixed with heparinized saline solution more than patients with the blood-conserving arterial line. In terms of the blood component of the blood-heparinized saline solution mixture, use of the conventional arterial line was associated with an average of 156.8 ml more blood discarded than with the blood-conserving arterial line.
Conclusion: The new blood-conserving arterial line system provides a simple and effective method for reducing blood loss related to diagnostic sampling in the critical care setting.