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

Abstract

Background: New ventilators have simplified the use of supraglottic superimposed high-frequency jet ventilation (SHFJVSG), but it has not been systematically compared with other modes of jet ventilation (JV) in humans. We sought to investigate whether SHFJVSG 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: SHFJVSG, supraglottic normal frequency (NFJVSG), 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 NFJVSG end-expiratory level. The increase in end-expiratory chest wall volume (EEVCW) was 239 (196) ml during SHFJVSG (P<0.05 compared with NFJVSG). EEVCW was 148 (145) and 44 (106) ml during HFJVSG and HFJVIG, respectively (P<0.05 compared with SHFJVSG). Tidal volume (VT) during SHFJVSG was 269 (149) ml. VT was 229 (169) ml (P=1.00 compared with SHFJVSG), 145 (50) ml (P<0.05), and 110 (33) ml (P<0.01) during NFJVSG, HFJVSG, and HFJV IG, respectively.Intratracheal pressures corresponded well to changes in both EEVCW and VT. All JV modes resulted in adequate oxygenation. However,Paco2 was lowest during HFJV SG [4.3 (1.3) kPa; P<0.01 compared with SHFJVSG]. Conclusions: HFJVSG was associated with increased EEVCW and VT 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. © 2012 The Author. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved.