Ventilation of a model lung using various cricothyrotomy devices.

In this study we developed a model lung to compare the effectiveness of ventilation using four different cricothyrotomy devices. The Ravussin 13G cannula (VBM Medical), the Quicktrach cannula 4 mm ID (VBM Medical), the Melker cannula 6 mm ID (Cook) and a cuffed tracheal tube 6 mm ID were used in turn to ventilate the model lung through a cricothyrotomy over a range of upper airway resistances. The 6 mm cuffed tracheal tube provided consistently good ventilation independent of upper airway resistance. The 6 mm ID Melker device provided at least reasonable and at best very good ventilation, whatever the patency of the upper airway. The Ravussin cannula could ventilate well with the jet ventilator with low upper airway resistance but could not ventilate at all with complete upper airway obstruction. The Quicktrach performed poorly with low upper airway resistance but well with increased upper airway resistance. With its easier insertion, fewer complications compared to a surgical cricothyrotomy, and the ability to use it with a standard anaesthetic circuit, the authors feel that the 6 mm Melker canula is the technique of choice for emergency trans-tracheal ventilation.