The effects of head flexion on airway seal, quality of ventilation and orogastric tube placement using the ProSeal™ laryngeal mask airway*

Summary This prospective self-controlled study was designed to evaluate the influences of head flexion on airway seal, quality of ventilation, and orogastric tube placement through the ProSeal™ laryngeal mask airway (ProSeal LMA™) in 80 anaesthetised, paralysed adult patients. After the ProSeal LMA was inserted and the cuff pressure was set at 5.9 kPa, ventilation quality, airway seal pressure, fibreoptic positions of the cuff and the drainage tube, orogastric tube placement and efficacy of intermittent positive pressure ventilation (IPPV) were assessed in two randomly selected positions: neutral and flexed position. When compared to the neutral head position, the head flexed significantly improved the airway seal pressure and the quality of ventilation of the ProSeal LMA (p   0.05). In conclusion, head flexion improves airway seal and ventilation quality of the ProSeal LMA. However, placement of an orogastric tube via the drainage tube is impaired in the flexed position compared to the neutral position. Fibreoptic scoring of the ProSeal cuff position is not an accurate test to assess the airway seal and ventilation function.