MEASUREMENT OF END-EXPIRATORY PRESSURE DURING TRANSTRACHEAL HIGH FREQUENCY JET VENTILATION FOR LARYNGOSCOPY

摘要: An anaesthetic technique using high frequency jet ventilation has been proposed for direct laryngoscopy, but this may expose the patients to risk of barotrauma. In order assess risk, we have measured end-expiratory airway pressure (EEP) through injector two three-way solenoid valves mounted in series. At end insufflation first valve was switched off and apparatus deadspace connected atmosphere a large exit port during an adjustable time (decompression time). Then second injection line transducer, allowing measurement EEP injector. The accuracy tested against directly trachea (Pt) lung model. Provided that decompression long enough (70 ms) small (6 ml), difference between Pt less than 1 cm H2O frequencies up 5 Hz. A clinical evaluation performed 64 under general anaesthesia before laryngoscopy. correlated with pulmonary volume above apnoeic FRC inferred from abdominal thoracic displacements. Hz, correlations these variables were satisfactory (r greater 0.88), suggesting is good indicator overdistension.