Intubation Tips, Part 2
Hopefully, you have already read about NO DESAT and the importance of pre-oxygenation before intubation in Intubation Tips, Part 1. We want to share some more tips that optimize the safety and success of this high-risk procedure.
In a great intubation lecture by Dr. Levitan, he covers a wide variety of airway topics. It will change the way you perform airway management, and your patients will benefit.
His discussion of video laryngoscopy is invaluable for those who like to use the glidescope or other video intubation devices. He demonstrates that these devices are superb at visualizing the vocal cords, but not very good for tube delivery, which is the ultimate goal of the procedure. Dr. Levitan has some useful tips focused on passing the tube with video laryngoscopy. Most important is to avoid being too close, which gives you a great picture but limited perspective, crowds out the tube, and leads to a more difficult approach angle. His advice is to identify the cords, and then place them towards the top of the screen and back out a bit, which allows a better view of the approaching tube and more space to deliver it into the trachea.
Positioning is very important in the pre-oxygenation phase, as well as during the intubation procedure. It is ideal to keep the patient sitting up as long as possible, as this optimizes lung expansion. Although there are a variety of suggestions for optimal head placement during intubation, Dr. Levitan and others make a very strong argument for the ear to sternal notch position. This position leaves the head neutral in terms of angle, face flat to the ceiling, but raises the head so that the ear is at the level of the sternal notch. You can watch the remarkable images in his lecture. The video demonstrates the laryngeal view with direct laryngoscopy in various head positions. Ramping of obese patients, which is the creation of a gradual incline of the torso and head, is beneficial in minimizing obstruction from redundant soft tissue, and moderating the fact that obese patients desaturate very quickly when lying flat.
Another important consideration in optimizing the safety of intubation concerns the use of positive pressure ventilation during Rapid Sequence Intubation. Positive pressure ventilation increases the risk of gastric regurgitation and aspiration. Ideally, if the patient is properly pre-oxygenated and has adequate physiologic reserve, you would not give any positive pressure ventilations throughout the intubation procedure. After pre-oxygenation, the patient would be induced, paralyzed, and intubated without the need for any ventilation. However, if a patient is difficult to pre-oxygenate or has limited reserve, assisted ventilations may be required, but should be kept to the minimum needed to maintain oxygen saturation levels greater than 90%.
Last but not least, abandon the use of Cricoid Pressure (Sellick’s maneuver) during intubation. Dr. Levitan’s video also shows how this maneuver hampers the ability to intubate, and a lot of other research demonstrates that it does not serve its intended purpose of preventing aspiration. Bimanual cricoid manipulation, where the intubator moves the larynx into view is a popular technique, and has merits, but having another person blindly push downward on the larynx makes the intubation more difficult and doesn’t prevent regurgitation.
As previously discussed, pre-oxygenation and nasal oxygenation should become a routine part of the intubation procedure. These techniques maximize the time you have to place the tube before desaturation occurs, or needing to bag the patient, which increases the aspiration risk. Optimally positioning your patient will give you the best opportunity for success. Although many of us intubate regularly and feel very comfortable with the procedure, we need to remember that controlling the airway is high stakes, and we should do everything we can to limit the risks of complications, and maximize our likelihood of success.