A respiratory gas measurement system is described. In one embodiment, the respiratory gas measurement system includes a chamber and an adhesive pad. The chamber is configured to collect a respiratory gas. The adhesive pad includes a substrate. At least a portion of a first surface of the substrate is covered with adhesive. The adhesive on the first surface of the substrate attaches the adhesive pad to a first surface of the chamber. The adhesive pad enables the chamber to attach to a surface of another nasal cannula.