Relation of Tracheal Cuff Pressure to Tracheal Morbidity after Extubation. Combes et al. (page 1120)
Even after short-duration anesthesia, laryngotracheal morbidity is common after tracheal intubation. Although the exact cause of postintubation airway symptoms is not known, mucosal damage at the cuff level is believed to be key. Such lesions have been linked to use of nitrous oxide, which diffuses into the tracheal tube cuff and exerts increased cuff pressure. Filling the tracheal tube with saline instead of air can help to maintain low intracuff pressure, thus decreasing the incidence of postoperative laryngotracheal discomfort and injury. Accordingly, Combes et al. randomly allocated 50 patients scheduled for surgical procedures of 90 min or more during general anesthesia to one of two groups. The endotracheal cuff in group A patients was inflated with air, and the endotracheal cuff in group S patients was inflated with saline. In both groups, the cuff was initially inflated to achieve a cuff pressure of 20–30 cm H2O. At the time of extubation, an observer blinded to group assignment performed fiberoptic examinations of patients’ tracheas, noting any evidence of mucosal ulcerations. Patients were queried about any laryngopharyngeal discomfort when discharged from the postanesthesia care unit and at 24 h after surgery.
Cuff pressure increased steadily throughout the procedure in group A but remained stable in group S. Incidence of sore throat was lower in group S than in group A patients. Group A patients had a higher incidence of and more severe tracheal mucosal lesions than patients in group S. Incidence of dysphagia and hoarseness was similar for the two groups in the postanesthesia care unit and 24 h after surgery. The authors were able to demonstrate a correlation between tracheal mucosal lesions and sore throat. Although the symptoms were generally moderate, incidence of sore throat could be minimized by monitoring cuff pressure throughout the course of anesthesia.