EO technique provides better mask seal than the EC clamp technique during single handed mask holding by novices in anaesthetised and paralysed patients

Abstract

Background and Aims: Bag mask ventilation (BMV) allows for oxygenation and ventilation of patients until a definitive airway is secured and when definitive airway is difficult/impossible. This study hypothesised that the EO (thumb and index finger form a O shape around the mask) technique of mask holding provides better mask seal with the novices compared to the classic EC clamp technique (thumb and index finger form a C shape around the mask). Methods: Sixty patients participated in this double blinded, prospective, crossover study. The patients were randomly allocated to either EC or EO group. After adequate anaesthesia and neuromuscular blockade, a novice (experience of less than five attempts at BMV) held the mask with preferred hand with the allotted technique, while the ventilator provided five breaths at set pressure control of 15 cm H2O with one second each for inspiration and expiration. After recording the exhaled tidal volume (primary objective) for each breath for five consecutive breaths, the study was repeated with the other technique. Secondary outcome variables were minute ventilation, audible mask and epigastric leak. Results: The tidal volume and minute ventilation were significantly better with EO technique compared with the EC technique (P = 0.001, a tidal volume difference of 46 mL and P = 0.001, a minute volume difference of 0.51 L). Conclusion: The EO technique provides better mask seal (superior tidal volumes) than the conventional EC technique during single-handed mask holding performed by novices in the absence of other factors contributing to difficulty in mask ventilation.

Keywords

• Bag mask ventilation
• EC clamp technique
• EO technique