RCT of 60 patients undergoing primary THA, randomized to active normothermia (~36.6°C) vs mild hypothermia (~35°C). The study tested whether a ~1.5°C core temperature difference causes measurable increases in blood loss and transfusion requirements. All patients received standardized anesthesia, haemodilution, and cell salvage.
A patient drifting to 35°C on your THA table will lose roughly 500 mL more blood and is approximately seven times more likely to need an allogeneic transfusion than a patient kept at 36.6°C. Forced-air warming blankets and warmed IV fluids from the start of the case are the intervention this paper validated. These are not comfort measures — they are blood conservation.
Critically, a normal PT/PTT does not rule out hypothermic coagulopathy. Standard coagulation tests run at 37°C will look reassuring even when your patient's clotting machinery is functionally impaired at their actual tissue temperature.
Temperature management must extend into the recovery room. Because most THA blood loss is postoperative, allowing the patient to cool after leaving the OR defeats the purpose of intraoperative warming.
RCT of 60 patients undergoing primary THA, randomized to active normothermia (~36.6°C) vs mild hypothermia (~35°C). The study tested whether a ~1.5°C core temperature difference causes measurable increases in blood loss and transfusion requirements. All patients received standardized anesthesia, haemodilution, and cell salvage.
A patient drifting to 35°C on your THA table will lose roughly 500 mL more blood and is approximately seven times more likely to need an allogeneic transfusion than a patient kept at 36.6°C. Forced-air warming blankets and warmed IV fluids from the start of the case are the intervention this paper validated. These are not comfort measures — they are blood conservation.
Critically, a normal PT/PTT does not rule out hypothermic coagulopathy. Standard coagulation tests run at 37°C will look reassuring even when your patient's clotting machinery is functionally impaired at their actual tissue temperature.
Temperature management must extend into the recovery room. Because most THA blood loss is postoperative, allowing the patient to cool after leaving the OR defeats the purpose of intraoperative warming.