Laryngeal Mask Airway,Hai Yu Department of Anesthesiology West China Hospital Sichuan University,Introduction,The LMA was invented by Dr. Archie Brain at the London Hospital, Whitechapel in 1981 UK(1988) , US (1991) The LMA consists of two parts: The mask The tube The LMA has proven to be very effective in the management of airway crisis,Introduction continued,The LMA design: Provides an “oval seal around the laryngeal inlet” once the LMA is inserted and the cuff inflated. Once inserted, it lies at the crossroads of the digestive and respiratory tracts.,Indications for the use of the LMA,Situations involving a difficult mask fit. May be used as a back-up device where endotracheal intubation is not successful. May be used as a “second-last-ditch” airway where a surgical airway is the only remaining option.,Contraindications of the LMA,Greater than 14 to 16 weeks pregnant Patients with multiple or massive injury Massive thoracic injury Massive maxillofacial trauma Patients at risk of aspiration NOTE: Not all contraindications are absolute,Side-Effects of the LMA,Throat soreness Dryness of the throat and/or mucosa Side effects due to improper placement vary based on the nature of the placement,Equipment for LMA Insertion,Body Substance Isolation equipment Appropriate size LMA Syringe with appropriate volume for LMA cuff inflation Water soluble lubricant Ventilation equipment Stethoscope Tape or other device(s) to secure LMA,Preparation of the LMA for Insertion,Step 1: Size selection Step 2: Examination of the LMA Step 3: Check deflation and inflation of the cuff Step 4: Lubrication of the LMA Step 5: Position the Airway,Step 1: Size Selection,Verify that the size of the LMA is correct for the patient Recommended Size guidelines: Size 1: under 5 kg Size 1.5: 5 to 10 kg Size 2: 10 to 20 kg Size 2.5: 20 to 30 kg Size 3: 30 kg to small adult Size 4: adult Size 5: Large adult/poor seal with size 4,Step 2: Examination of the LMA,Visually inspect the LMA cuff for tears or other abnormalities Inspect the tube to ensure that it is free of blockage or loose particles Deflate the cuff to ensure that it will maintain a vacuum Inflate the cuff to ensure that it does not leak,TEST: VISUAL INSPECTION,Step 3: Deflation and Inflation of the LMA,Step 1: Leakage Deflate the cuff so that the cuff walls are tightly flattened against each other. Do not use the LMA airway if the cuff walls reinflate immediately and spontaneously, even if only slightly. Inflate the cuff with air from a complete vacuum as shown in the table below. Test Cuff Inflation Volumes: Size 1: 6 ml Size 1.5: 10 ml Size 2: 15 ml Size 2.5: 21 ml Size 3: 30 ml Size 4: 45 ml Size 5: 60 ml Size 6: 75 ml,Step 2: Herniation,Step 4: Lubrication of the LMA,Use a water soluble lubricant to lubricate the LMA Only lubricate the LMA just prior to insertion Lubricate the back of the mask thoroughly Important Notice: Avoid excessive amounts of lubricant on the anterior surface of the cuff in the bowl of the mask. Inhalation of the lubricant following placement may result in coughing or obstruction. Lubrication of the mask should avoid the use of local anesthetics in order to preserve protective reflexes against aspiration.,Step 5: Positioning of the Airway,Extend the head and flex the neck Avoid LMA fold over: Assistant pulls the lower jaw downwards. Visualize the posterior oral airway. Ensure that the LMA is not folding over in the oral cavity as it is inserted.,LMA Insertion Technique,LMA Insertion Step 1,Grasp the LMA by the tube, holding it like a pen as near as possible to the mask end. Place the tip of the LMA against the inner surface of the patients upper teeth,LMA Insertion Step 2,Under direct vision: Press the mask tip upwards against the hard palate to flatten it out. Using the index finger, keep pressing upwards as you advance the mask into the pharynx to ensure the tip remains flattened and avoids the tongue.,LMA Insertion Step 3,Keep the neck flexed and head extended: Press the mask into the posterior pharyngeal wall using the index finger.,LMA Insertion Step 4,Continue pushing with your index finger. Guide the mask downward into position.,LMA Insertion Step 5,Grasp the tube firmly with the other hand then withdraw your index finger from the pharynx. Press gently downward with your other hand to ensure the mask is fully inserted.,LMA Insertion Step 6,Inflate the mask with the recommended volume of air. Do not over-inflate the LMA. Do not touch the LMA tube while it is being inflated unless the position is obviously unstable. Normally the mask should be allowed to rise up slightly out of the hypopharynx as it is inflated to find its correct position.,Verify Placement of the LMA,Connect the LMA to a Bag-Valve Mask device or low pressure ventilator Ventilate the patient while confirming equal breath sounds over both lungs in all fields and the absence of ventilatory sounds over the epigastrium,Securing the