To the Editor:-End-tidal carbon dioxide monitoring is a standard used during general anesthesia and monitored anesthesia care. Nasal cannulas commonly are used to deliver supplemental oxygen and to sample carbon dioxide for the monitoring of respiratory rate and rhythm in patients undergoing sedation for surgical procedures. Monitoring endtidal carbon dioxide in patients with tracheal stomas may be difficult when using standard tracheal collar oxygen supplementation because no adaptation for the carbon dioxide sample line is readily available. We present a device for the monitoring of carbon dioxide in patients with tracheal stomas who are undergoing operative procedures that necessitate intravenous sedation.
Taking a standard tracheal collar, a 6-inch piece of corrugated oxygen tubing, a BODAI suction safe swively endotracheal suction connector (Sontek Medical, Hingham, MA), and an 8-French pediatric suction catheter, we fabricated a simple device to monitor carbon dioxide at the tracheal stoma (Figure 1). The pediatric suction catheter is placed through the BODAI suction device and threaded into the corrugated tubing until it rests at the skin edge of the tracheal stoma. The end-tidal carbon dioxide sample line is attached directly to the proximal end of the pediatric suction catheter, and end-tidal carbon dioxide is measured, producing a wave form that effectively monitors respiratory rate and rhythm. Supplemental oxygen is delivered to the patient by attaching the breathing circuit to the swivel arm of the BODAI suction connector. We found that increasing the flow of supplemental oxygen through the breathing circuit does not affect the carbon dioxide waveform, as long as the tip of the suction device rests at the skin edge of the tracheal stoma.
We found this device to be simple to prepare, nonirritating to the airway, and a reliable means to deliver supplemental oxygen and to monitoring end-tidal carbon dioxide in patients with tracheal stomas who require monitored anesthesia care.
Andrea R. Williams, M.D.; Courtney Shelbourne, D.M.D.; Mark Pinosky, M.D.
Department of Anesthesiology; Medical University of South Carolina; Charleston, South Carolina; Williand@musc.edu
(Accepted for publication April 24, 1998.)