Investigation of Inspiratory Circuit Condensation due to Room Temperature in a Heated Humidifier during Mechanical Ventilation

Heating and humidification control during mechanical ventilation is impor-tant. Water condensation can occur due to insufficient humidification. Condensation in the breathing circuit can cause various adverse events. In this study, we investigated whether the occurrence of tubing condensation in the breathing circuit could be affected by room temperature using a simulated respiratory circuit with a humidifier. The room temperature was set at 23˚C, 25˚C, and 27˚C, and mechanical ventilation was performed for 8 h. The inspired gas was appropriately heated and humidified according to the manu-facturer’s instructions. The weight of the circuit was measured every 2 h at room temperature to estimate the amount of condensation. During the mechanical ventilation, condensation continued to increase at a room temperature of 23˚C, but only for the first 2 h at 25˚C, and did not occur at 27˚C. The room temperature of the indoor environment was one of the factors generat-ing water condensation in the breathing circuit with a humidifier even when a heater wire in the breathing circuit was appropriately operated.