The Frova intubating introducer was invented by the Italian anesthesiologist Dr. Giulio Frova, who practiced in Brescia until his retirement, and introduced into practice in 1996.
The catheter is available in two sizes, 8 and 14 Fr. It has length markings in centimeters on the side which start at 10 cm from the tip. The catheter contains a central lumen for oxygenation, which opens through two side holes at the blunt and closed tip. The tip of the catheter is bent in a way similar to the one of a gum-elastic bougie (see picture below), designed to facilitate passage through the glottis.
The Frova catheter is supplied with a stiffening cannula. Note that the 14 Fr catheter can also be purchased without the stiffening cannula while the 8 Fr cannot. The stiffening cannula is straight, very rigid, and cannot be bent other than through brute force.
'Stiffening cannula' is perhaps something of a euphenism. It has a considerable diameter, is not malleable, and is nothing like an ET tube stylet! It has weapon potential!
The Frova intubating introducer is also supplied with two Rapi-Fit adapters, trademarked by Cook Medical, which allow attachment of a Luer-lock or standard 15 mm breathing system connector. With the Rapi-Fit adapters, oxygenation is possible through the Frova catheter once it has been placed into the trachea and the stiffening cannula has been removed.
The Frova catheter is somewhat similar to the (gum-elastic) bougie, the main differences being the central lumen allowing for oxygenation and the stiffening cannula.
Close-up view of the tip of the Frova intubating introducer; note the closed blunt tip and side-hole openings to the central lumen
Length markings on the side of the Frova catheter starting at the 10 cm mark from the tip
Siffening cannula fully inserted (top) and slightly withdrawn (bottom)
Position of the stylet or 'stiffening cannula' when fully inserted into the Frova catheter
Side by side comparison of the tips of the Frova catheter and (gum-elastic) bougie
The indications for using the Frova catheter are pretty much the same as for the gum-elastic bougie, that is 'standard' orotracheal intubation with a conventional laryngoscope when visualization of the larynx in suboptimal, as in grade 2 or 3 Cormack-Lehane views. The Frova catheter has the added benefit of allowing oxygenation through a central lumen.
You should at least be able to see the epiglottis during laryngoscopy in order to use the Frova!
For oxygen delivery through the Frova catheter, remove the stiffening cannula after endotracheal positioning, and attach either the Luer-lock or the 15 mm Rapi-Fit connector. The Luer-lock connector can then be hooked up to a manual jet ventilator, whereas the 15 mm connector allows attachment of an anesthetic breathing system.
The stylet of the Frova catheter is very rigid, and although it does not extend all the way to the tube tip, you can cause serious damage to the airway with this device if you do not use it correctly. Most importantly, withdraw the stylet as soon as the tip of the Frova catheter passes through the vocal chords. The stylet should never pass through the vocal chords.
The part of the catheter containing the stylet has to be visible during laryngoscopy at all times!
More on the technique of intubation with the Frova catheter here.