A Comparison of the LMA Unique and LMA Supreme in Children

• Airway leak pressure [ Time Frame: after placement of the supraglottic airway device/ Participants will be followed 24 hours postoperatively ] [ Designated as safety issue: Yes ]
  Airway leak pressures will be measured by recording the circuit pressure at which equilibrium is reached when fresh gas flow is delivered at 3L/min when the pressure limiting valve is closed completely.
  
  

• Fiberoptic grade of laryngeal view [ Time Frame: After placement of the supraglottic device ] [ Designated as safety issue: No ]
  The laryngeal alignment through the devices will be graded using an established scoring system
  
  
• Adverse effects [ Time Frame: Participants will be followed 24 hours postoperatively ] [ Designated as safety issue: No ]
  complications such as oxygen desaturations, mucosal trauma, reflex activation of the airway, sore throat, dysphonia will be recorded
  
  
• Time to secure the airway [ Time Frame: after placement of the supraglottic airway device ] [ Designated as safety issue: No ]
  From picking up the airway device to bilateral chest expansion and presence of ETCO2
  
  
• Number of attempts to place the device [ Time Frame: at the beginning of anesthesia ] [ Designated as safety issue: No ]
  number of attempts needed for successful placement will be recorde (maximum of 3 attempts will be considered as a failure)
  
  
• Fiberoptic view through the gastric tube [ Time Frame: After placement of the LMA supreme ] [ Designated as safety issue: No ]
  The view through the gastric drain tube of the LMA supreme will be assessed and graded using an established scoring system
  
  
• Ease of gastric tube placement [ Time Frame: After placement of the LMA supreme ] [ Designated as safety issue: No ]
  The ease of gastric placement will be assessed using a subjective scale
  
  
• Gastric insufflation [ Time Frame: During leak pressure testing ] [ Designated as safety issue: No ]
  The presence of gastric insufflations will be assessed during leak pressure testing by using epigastric auscultation
  
  
• Quality of the airway [ Time Frame: During maintenance of anesthesia ] [ Designated as safety issue: No ]
  The quality of hands free anesthesia will be assessed during maintenance of anesthesia using a previously described scale
  
  

The LMA Supreme is a newer version of the current model, the laryngeal mask airway Unique. Both models are approved for use by the FDA, and are routinely used for airway management during general anesthesia. Three main features distinguish the laryngeal mask airway Supreme from the original LMA: i) a curved rigid airway tube, ii) provision for a gastric drain tube, and iii) a larger mask for improved fit and airway seal.

The aim of this randomized prospective study is to compare two types of the laryngeal mask airway: the laryngeal mask airway Unique and the laryngeal mask airway Supreme, in pediatric patients without the use of neuromuscular blockade. Based on the design features listed above, we hypothesize that the airway leak pressures with the LMA Supreme will be superior to the LMA Unique. Airway leak pressures will be measured by recording the circuit pressure at which equilibrium is reached. The ease of placement, fiberoptic grade of laryngeal view, feasibility of use, and complications (airway related, gastric insufflation, trauma) will also be assessed.