Abstract: Clinical studies on adult ventilated patients demonstrate that bacterial contamination of the condensate occurs in ventilator circuits. The purpose of this research is to find out if this is also true of the condensate in the Continuous Positive Airway Pressure (CPAP) circuit. It aims to determine whether there is bacterial contamination in the humidifier reservoir of the CPAP system when the condensate is drained back into the humidifier reservoir without disconnecting the circuit, or when the inspiratory tubing is disconnected to drain out the condensate.