Comparison of C-MAC Videolaryngoscopy-guided Proseal Laryngeal Mask Airway Placement vs Conventional Blind Technique: a Prospective Randomized Study

Airway management is one of the cornerstones for modern anaesthesia and is vital for all patients undergoing general anaesthesia. Supraglottic airway devices (SADs) are increasingly used for managing airways.

The ProSeal laryngeal mask airway (PLMA) (Laryngeal Mask Company, San Diego, CA, USA) is a supraglottic airway device with a larger cuff than the Classic laryngeal mask airway to produce a better seal. The PLMA is also equipped with a drainage tube to permit insertion of a gastric tube and evacuation of gastric content. The presence of the drainage tube reduces the risk of aspiration, which is the major concern of the Classic laryngeal mask airway, especially when the device is used with positive pressure ventilation. While a dedicated introducer (commonly known as an ''introducer tool'') is recommended by the manufacturer to facilitate insertion of the PLMA, difficulties can still be encountered during insertion. The PLMA insertion success rate at first attempt has been reported as 82-87%, which is lower than the insertion success rate of the Classic laryngeal mask airway.

Malpositioning of the PLMA is common in clinical practice because its soft cuff can fold over onto itself. Malpositioning of the device can result in severe leaks and even obstruction of the airway, with potentially negative outcomes for the patient. Although the incidence of complications(e.g. airway trauma, obstruction, regurgitation, gastric distension with mechanical ventilation) is likely to be higher with an incorrectly placed SAD, clinical airway obstruction can result from other causes, such as laryngospasm and transient closure of the glottis.

Many methods have been proposed to facilitate insertion of PLMAs, including insertion of a gastric tube,a suction catheter, or a gum elastic bougie into the drainage tube. These techniques help to prevent the PLMA soft cuff from folding over and help to decrease the incidence of malpositioning.

This prospective study that will investigated the usefulness of the C-MAC videolaryngoscopy for inserting a PLMA in anesthetized non-paralyzed patients and compared it with the index finger.