Ventilation during laryngoscopy in chronic obstructive lung disease

Many patients requiring direct examination of the upper airway and gastrointestinal tract under general anesthesia have chronic obstructive lung disease, yet virtually no work has been done to assess the adequacy of their ventilation during laryngoscopy and in the early postoperative period. This study demonstrates that, using the Carden tube, their blood gases are well maintained even when areas outside the endolarynx, such as the upper esophagus, are examined. The Carden tube is shown to be easy to insert and remove as well as permitting a superior view of the larynx. Also, this study pinpoints the period of maximum danger of respiratory failure as occurring postoperatively in the recovery room. This should be independent of the method of ventilation employed at surgery and indicates the need for cocainization of the vocal cords before extubation, as well as careful, early postoperative monitoring. The problems of ventilation during direct examination of the upper airway and gastrointestinal tract are discussed and alternative methods evaluated.