A simple modification of pediatric and adult Macintosh laryngoscopes for oxygen insufflation.

Sir,

We propose a simple method for pharyngeal oxygen insufflation during paediatric and adult Macintosh laryngoscopy [Figure 1]. A 06 FG size suction catheter is fixed to the laryngoscope blade in the angle between the tongue and the web using paper tape, [Figure 2] with the side hole near the tip exposed, and the tip midway between tip of the bulb and the tip of the laryngoscope blade [Figure 3]. The proximal end of the catheter is connected to the tubing of an oxygen source (e.g., auxiliary oxygen flowmeter of the anaesthesia machine), and a flow of 2-6 L/minute[1] oxygen can be used. The catheter can also be connected to a suction source for a short while to suction out oropharyngeal secretions if the need arises. This can be used for all sizes of Macintosh blades, from 0 to 5.

Figure 1

Modified Macintosh blade

Figure 2

Angle between the web and tongue of the blade

Figure 3

Tip of the catheter

Many methods have been employed for oxygen insufflation during laryngoscopy using Miller blades for pediatric patients. Taped feeding tubes,[2] feeding tubes threaded through drilled holes on the blade,[1] soldered metallic hollow tubes or channels,[34] and others have been used. The use of disposable suction catheters over soldered metallic channels has the advantage of ease in cleaning and sterilizing the blade. A possible disadvantage is that the adhesive tape can loosen;[2] in our experience, this can be prevented by carefully applying the tape and firmly securing the catheter. This is a simple, cost-effective alternative to the commercially available oxygen-insufflating laryngoscopes in institutions where such equipment is not available. Pharyngeal insufflation of oxygen has been shown to delay the onset of desaturation and hypoxemia during apnea.[5] Such a laryngoscope will be extremely useful in paediatric patients[6] and adult patients at risk for desaturation and hypoxemia,[78] such as in obesity, pregnancy, critically ill patients, and others.