Reducing CO₂ Inhalation in Clinical Pulmonary Investigations

Abstract

Patient comfort during any scanning procedure always complements the quality of the scan being done. Many of our patients undergoing clinical pulmonary investigations were becoming progressively nervous; sometimes we were unable to complete the study. We later determined that this was caused by the rebreathing of expired CO₂ gas, which collected in a 12-in. flexible tube connecting the mouthpiece to the delivery arm of the machine. This problem was alleviated by affixing two one-way disposable valves to the mouthpiece in order to prevent backflow of expired CO₂ gas and at the same time allow fresh room air to be breathed. By eliminating the backflow of C0₂ and making it possible for the patient to breath easily in ample room air, we reduced the apprehension previously observed. As a result, complete and improved pulmonary function studies on our patients were produced.