Blood warming: current applications and techniques.

Area of Science:

• Transfusion Medicine
• Biomedical Engineering

Background:

• Blood storage requires refrigeration, but rapid transfusion methods risk hypothermia.
• Reconciling blood preservation with patient safety during resuscitation necessitates active blood warming.

Purpose of the Study:

• To evaluate the necessity and risks of active blood warming in transfusion medicine.
• To assess current blood warmer technologies and standards in relation to modern transfusion practices.

Main Methods:

• Review of current practices in blood storage and transfusion.
• Analysis of the physiological effects of transfusing cold blood.
• Evaluation of available blood warming devices and their limitations.

Main Results:

• Active blood warming is crucial for rapid transfusions to prevent hypothermia.
• Stored red blood cells (RBC) tolerate temperatures slightly above normal body temperature without harm.
• Many current in-line blood warmers are inadequate for rapid transfusion systems.
• Countercurrent warmers and saline admixture are effective for rapid, massive transfusions.

Conclusions:

• Blood warming is essential for rapid resuscitation but carries its own risks.
• Current upper temperature limits for blood warmers may be overly conservative.
• Reconsideration of blood warmer standards is warranted, particularly for RBC safety.
• Elective transfusions at conventional rates rarely require blood warming.