Background & Objectives: Percutaneous trans-tracheal and subglottic cannulation jet ventilation techniques are well established in current practice(1,2,3). However, when oxygenation via either route is not possible eg abnormal tracheal anatomy, hand-held high frequency jet ventilation (HFJV) using a Venturi needle trans-stomally is a recognised, safe technique in short, non-laser supra-glottic procedures(4). Percutaneous tracheostomy techniques have been studied(4). However, there are no studies clarifying the optimum angle for hand-held jet ventilation needle position to obtain appropriate tidal volumes. Aim:We evaluated the optimal maximal tidal volume obtained at three pre-determined angles of manual trans-stomal HFJV. Materials & Methods: A benchtop manikin study was performed to assess the maximal tidal volume obtained using a Venturi Jet ventilation needle manually held at 3 pre-determined angles; 45, 60 and 75 degrees measured using a digital protractor from the trans-stomal site. An 8mm standard Portex tracheostomy stoma was created. HFJV was delivered (constant pressure = 2 bar; frequency = 100min-1) via the needle attached to an automated Jet ventilator equipped with airway pressure monitoring and automatic gas cut-off. The needle was manually held at a constant distance of 2cm and tidal volume measured with spirometry attached to a 2 litre manual ventilation bag. Results: A one-way ANOVA was calculated for the observed tidal volumes at each angle, detecting a statistically significant difference between groups [F(2.15) 8.21 p=0.0390]. Correlation coefficients(R) were calculated between groups showing a positive association between all angles: the greatest between 75 vs 60 degrees R=0.75, with 65 vs 45 degrees R= 0.63 following, and finally and 75 vs 45 degrees R=0.47. Median and interquartile ranges were plotted (Fig.1) showing an increase in tidal volumes with increase in angle.Conclusion: This study demonstrated a statistically significant difference in observed tidal volumes when only changing the angle of Venturi needle HFJV application. A positive correlation between all angles showed larger tidal volumes were obtained at steeper angles with volumes increasing over time at a constant angle. This has clinical relevance in post-laryngectomy patients undergoing short, supra-glottic procedures in maintaining adequate oxygenation for their duration. Limitations include a small data set. Future work should focus on evaluation in the clinical setting using a variety of angles, jet ventilation needles and patient groups.