Many fluid and blood warming devices exist. Some use disposable aluminum (aluminium) coated plates in their cartridges; these may be coated or uncoated, the latter allowing the fluid to be in direct contact with the heated aluminum plate.
This study compared the two systems. They found that uncoated aluminium plates in an enFlow warmer can lead to a risk of administering potentially harmful concentrations of aluminium when balanced crystalloid solutions are used; by contrast, normal saline showed only small increases. The mechanism is unclear, but heat, low flow and longer infusion caused striking increases in Aluminum release.
Aluminum has been linked to neurological injury (especially in neonates), encephalopathy, osteomalacia, and renal injury.
Coating for aluminium within medical devices in direct contact with infusion fluids is recommended, but further studies on what implications these findings have for health and safety are needed.
Many hospitals have withdrawn the devices for now.