Why are cold iv fluids bad?

Answer 1

Blood is 98.6 F or 37 degrees C. Ideally IV fluids should be the same temperature when given to a patient. Measures are often taken to maintain fluids at the appropriate temperature prior to use. Fluids may be kept in a heated cabinet, on a hot plate type of device or in a portable pack that maintains the temperature at or close to 98.6. In a relatively healthy adult patient, administering a liter of IV fluid that is at ambient temperature will not cause any ill effect. Occasionally patients will notice the cold feeling of the fluid at the IV site.

Healthy patients can easily compensate for the effect of the cold fluid. However, the smaller the patient and the colder the fluid the greater the risk of inducing hypothermia. Administration of cold IV fluids is not best medical practice but some providers may not be equipped with iv fluid warming devices or may be working with devices that have failed and must balance the risk of administering the cold fluid with the risk of withholding fluid from a patient who may need it. Obviously administering cold fluid to a patient whose primary issue is hypothermia would be harmful.

Trauma patients experiencing bleeding can also be harmed because coagulation depends on enzymes that have evolved to function best at normal body temperature. Bleeding may be exacerbated by administration of cold fluid both because of dilutional coagulopathy, but also because clotting enzymes are slow beneath 34`C.

Cold IV fluids also flow directly to the heart, and because the conduction system is closer to the chambers of the heart than the outside, the conduction system may become cooled down before the myocardium is, therefore decreasing the rate of conduction more than the muscles. This could precipitate VFib.

However this risk must be balanced with need to maintain a blood pressure high enough to provide blood flow to the brain and vital organs. Best to keep the fluids warm so as not to have to do this risk benefit analysis.

Fluids as high as 65`C have been found safe when used through a central venous catheter. The AHA recommends 44`C as safe infusion temperature. One must also compensate for the heat lost via the administration set while en-route to the patient.