Comparison of superimposed high-frequency jet ventilation with conventional jet ventilation for laryngeal surgery

摘要

Background: New ventilators have simplified the use of supraglottic superimposed high-frequency jet ventilation (SHFJV SG), but it has not been systematically compared with other modes of jet ventilation (JV) in humans. We sought to investigate whether SHFJV SG would provide more effective ventilation compared with single-frequency JV techniques. Methods: A total of 16 patients undergoing minor laryngeal surgery under general anaesthesia were included. In each patient, four different JV techniques were applied in random order for 10-min periods: SHFJV SG, supraglottic normal frequency (NFJV SG), supraglottic high frequency (HFJV SG), and infraglottic high-frequency jet ventilation (HFJV IG).Chest wall volume variations were continuously measured with opto-electronic plethysmography (OEP), intratracheal pressure was recorded and blood gases were measured. Results: Chest wall volumes were normalized to NFJV SG end-expiratory level. The increase in end-expiratory chest wall volume (EEV CW) was 239 (196) ml during SHFJV SG (P0.05 compared with NFJV SG). EEV CW was 148 (145) and 44 (106) ml during HFJV SG and HFJV IG, respectively (P0.05 compared with SHFJV SG). Tidal volume (V T) during SHFJV SG was 269 (149) ml. V T was 229 (169) ml (P=1.00 compared with SHFJV SG), 145 (50) ml (P0.05), and 110 (33) ml (P0.01) during NFJV SG, HFJV SG, and HFJV IG, respectively.Intratracheal pressures corresponded well to changes in both EEV CW and V T. All JV modes resulted in adequate oxygenation. However,Pa co2 was lowest during HFJV SG [4.3 (1.3) kPa; P0.01 compared with SHFJV SG]. Conclusions: HFJV SG was associated with increased EEV CW and V T compared with the three other investigated JV modes. All four modes provided adequate ventilation and oxygenation, and thus can be used for uncomplicated laryngeal surgery in healthy patients with limited airway obstruction.