This was a laboratory experimental study. We measured temperature at the end of the infusion line tubes (ILT). A 500 ml saline bag at 4 °C was administered at 15 and 30 ml/min, with and without cold packs applied to the cold fluid bag or to the ILT. Cold fluid temperature was integrated in a linear mixed model. Then we performed a mathematical modelization of the thermal transfer across the ILT.
The linear mixed model showed that the mean temperature of the cold fluid was 1 °C higher (CI 95%: [0.8–1.2]) with an outflow rate of 15 versus 30 ml/min (P < 0.001). Similarly, the mean temperature of the cold fluid was 0.7 °C higher (CI 95%: [0.53–0.9]) without cold pack versus with cold packs (P < 0.001). Mathematical modelization of the thermal transfer across the ILT suggested that the cold fluid warming could be reduced by a shorter and a wider ILT. As expected, use of CP has also a noticeable influence on warning reduction. The combination of multiple parameters working against the rewarming of the solution should enable the infusion of a solute with retained caloric properties.
By limiting this “ILT effect,” the volume required for inducing mild therapeutic hypothermia could be reduced, leading to a safer and a more efficient treatment.