Carbon Dioxide Sensitive Indicator: A Newly Developed Device to Detect Location of Intubated Endotracheal Tube

One of the major problems associated with the use of endotracheal tube is to ensure that the patient end of the tube is correctly located in the trachea and not in the oesophagus. A device based on color change when exposed to expiratory and inspiratory carbon dioxide gas has been developed which contains pH sensitive dye. The indicator comprised of 1) an aqueous solution of colorless compound i.e. a base, which provides an alkaline solution (for example: Calcium hydroxide, Barium hydroxide, Sodium carbonate, Potassium hydroxide); 2) a hydroscopic, high boiling, transparent, colorless, water-miscible liquid (such as Glycerol, Propylene, Diethylene glycol); 3) a chromogenic pH sensitive indicator which changes color in response to changes in pH of the solution. Such indicator can be of low cost and can provide clear indication that tube has been correctly inserted. If the indicator fails to change the color, clinician realizes immediately that the tube has not been correctly inserted.