Authors: Horowitz R et al., Ann Emerg Med 2014 Jan 17;
Injecting agitated saline into a femoral venous line while sonographically imaging the heart confirms the line’s location.
Accidental placement of a femoral venous catheter into the artery can cause limb ischemia, especially in children, who have small femoral arteries. Investigators assessed ability of the FLUSH (Flush the Line and UltraSound the Heart) test to distinguish arterial from venous placement of femoral lines in a cardiac catheterization lab. In each of 51 children who required both arterial and venous femoral lines as standard care, three vascular flushes with agitated saline were performed while the right atrium was monitored with subxiphoid ultrasound. A positive FLUSH was defined as opacification of the right atrium (due to air bubbles).
No arterial lines had a positive FLUSH test result. Ten percent of venous FLUSH results were negative. The FLUSH test was 100% sensitive and 90% specific for detecting arterial placement.
Pending validation in a larger, more diverse sample, the FLUSH test could become standard practice for confirming venous placement of femoral lines, similar to end-tidal CO2 (ETCO2) monitoring for confirming tracheal placement of endotracheal tubes. Like color change in an ETCO2 detector after several bag ventilations, a positive FLUSH result would be an indicator of correct placement. Negative FLUSH results would indicate greater than 90% likelihood of arterial placement.