Macintosh is a curved blade whose tip is inserted into the vallecula (the space between the base of the tongue and the pharyngeal surface of the epiglottis). Most adults require a Macintosh number 3 or 4 blade.
Miller is a straight blade that is passed so that the tip of the blade lies beneath the laryngeal surface of the epiglottis. The epiglottis is then lifted to expose the vocal cords. Most adults require a Miller number 3 blade.
Preparation of Equipment -Inspect endotracheal tubes
adult male 8 mm to 9 mm tube
adult female 7 mm to 8 mm tube
Tube length- extend from the lower incisor to a point midway between the cricoid cartilage and Louis's angle (the sternal angle) on the patient
inflate the cuff and apply positive pressure ventilation while the assistant auscultates
secure the endotracheal tube in position
Curved Blade Technique The curved blade technique is essentially similar. The only difference being when the epiglottis is in view, advance the tip of the laryngoscope blade into the vallecula, formed by the base of the tongue and the epiglottis; lift upward and forward.