The surgical airway
What could be more dramatic than being unable to intubate a patient, the pulse oximetry reading plummeting, a desperate turn to the BVM resuscitator not able to do anything about arresting the slide, the hypoxic bradycardia and worse only moments away?
Rarely the paramedic will be confronted with the feared cannot intubate – cannot ventilate (or oxygenate) scenario. Maybe there has been an unsuccessful intubation attempt or maybe it decided too difficult before even pulling out the laryngoscope. Think about this even as the patient is being initially assessed. Those with a difficult airway are more likely to end up in this bad place (Marshall 2016). Whichever, no airway equals death. When no other option exists, the only option for upper airway patency is the emergency surgical or percutaneous cricothyroidotomy. If there is another option that works, stick with that.
Tracheotomies are a surgical procedure through the lower anterior neck and are, by comparison, common. The emergency cricothyroidotomy accesses the tiny membrane between thyroid and cricoid cartilage (Melchiors et al. 2016). This is tiny with at most about 10mm space possible (Ince and Melachuri. 2017). Why would you aim here?
Compared to any other front of neck site, this one is usually readily locatable, relatively light on for fat covering and, importantly, free of the major blood vessels, cricothyroid muscles and thyroid gland that run laterally and inferiorly. Relatively easy then to find and safe to access.
Suddenly confronted with the failed upper airway that no other option or ventilation method can overcome, immediately declare to your team the surgical airway is happening. Get everyone working for the same cause. Critically, don’t delay. Anxiety will be stratospheric yet delay is common and potentially fatal (Heymans et al. 2016; Ince and Melachuri. 2017; Kristenson et al. 2015; Melchiors et al. 2016).
There are a number of ‘front of neck access’ methods available for this crisis with none necessarily better than any other (Asai. 2016; Frerk et al. 2015; Kristensen et al. 2015; Marshall. 2016; Mallari et al. 2016). Essentially though, options are surgical or percutaneous.
Arguably the biggest statement of the obvious is that the person performing the skill may be vastly experienced as a paramedic, they will almost certainly be inexperienced at this skill. This will be a moment when regular training will pay dividends.
Given this, surgical methods are favoured since they are usually faster to perform and frequently more successful (Asai. 2016; Chrisman et al. 2016; Frerk et al. 2015; Heymans et al. 2016; Kristensen et al. 2015; Pracy et al 2016). All require some incision through the cricothyroid membrane then place a tube into the trachea through the wound.
Firstly, extend the patient’s neck to expose the target site. Replace the sniffing position with head tilted back and shoulders propped slightly with padding (Frerk et al. 2015; Ince and Melachuri. 2017; Patel and Meyer. 2014). Then sit either in the intubation position or beside the patient, dominant hand next to the patient. Even if seemingly futile, have a colleague continue to try to ventilate the patient (Frerk et al. 2015).
Locate the incision site. Patients with short, fat, oedematous, burnt or traumatised necks will likely proved troublesome (Kristensen et al. 2015). Run a finger up from the suprasternal notch until the cricoid cartilage is reached. The membrane is just the other side of that, right in the anterior midpoint. Alternatively, grasp the larynx between thumb and second finger with first finger feeling down to the membrane. Mark the site with a pen (Ince and Melachuri. 2017; Patel and Meyer. 2014).
If you cannot feel the membrane, cut a vertical incision down the larynx and cricoid cartilage to allow a finger to probe for the site (Frerk et al. 2015; Heymans et al. 2016; Patel and Meyer. 2014). Ignore any bleeding that might occur.
Fair to say swabbing might not be a high priority here. Perhaps swab the neck during the early stage of resuscitation.
For surgical cricothyroidotomy, with a size 10 scalpel, plunge the blade directly into the marked site, perpendicular to the trachea. To enlarge the wound, remove the blade and reinsert with the cutting edge facing the other way (Ince and Melachuri. 2017).
With the wound now opened up, insert a bougie tip in. With it angled toward the lungs, push it in several centimetres into the trachea. Confident in place, hopefully just above the carina, feed a 5 or 6mm ETT over it until the cuff is also in the trachea (Melchiors et al. 2016). You don’t have to push that far in; you’re already below the cords and close to a bronchus. Remove the bougie and tie the tube in place.
There are basically two percutaneous options. The Seldinger method inserts a needle first, a guide wire through that followed by a dilator or cannula over that. Alternatively, a needle can be simply inserted and the cannula left within. These tend to kink/occlude and, unless using a large Quicktrach II kit, are very narrow diameter prompting the different Jet ventilation method. The larger needles are difficult to push in and prone to failure (Asai. 2016; Frerk et al. 2015; Kristensen et al. 2015; Marshall 2016; Ince and Melachuri. 2017).
Ventilation should be possible through a BVM attached to the standard 15mm attachment. The cuff can be inflated allowing EtCO2 monitoring and normal ventilation methods.
So high five, job done.
There must be some pitfalls. Of course. Firstly, don’t try this on kids. Besides needing a much smaller device, permanent injury to the larynx is possible, the surgical method not even really an option (Patel and Meyer. 2014; Melchiors et al. 2016).
If you use a needle approach, the tiny opening only lets air out slowly. If the upper airway is totally obstructed, it is possible to cause gas retention and pulmonary barotrauma (Patel and Meyer. 2004).
Asai, T., 2016. Surgical cricothyrotomy, rather than percutaneous cricothyrotomy, in “cannot intubate, cannot oxygenate” situation. Anesthesiology: The Journal of the American Society of Anesthesiologists, 125(2), pp.269-271.
Chrisman, L., King, W., Wimble, K., Cartwright, S., Mohammed, K.B. and Patel, B., 2016. Surgicric 2: A comparative bench study with two established emergency cricothyroidotomy techniques in a porcine model. British journal of anaesthesia, 117(2), pp.236-242.
Frerk, C., Mitchell, V.S., McNarry, A.F., Mendonca, C., Bhagrath, R., Patel, A., O’Sullivan, E.P., Woodall, N.M. and Ahmad, I., 2015. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. British journal of anaesthesia, 115(6), pp.827-848
Heymans, F., Feigl, G., Graber, S., Courvoisier, D.S., Weber, K.M. and Dulguerov, P., 2016. Emergency Cricothyrotomy Performed by Surgical Airway–naive Medical PersonnelA Randomized Crossover Study in Cadavers Comparing Three Commonly Used Techniques. Anesthesiology: The Journal of the American Society of Anesthesiologists, 125(2), pp.295-303.
Ince, M. and Melachuri, V.K., 2017. Emergency front of neck access. Indian Journal of Respiratory Care, 6(2), p.793.
Kristensen, M.S., Teoh, W.H.L. and Baker, P.A., 2015. Percutaneous emergency airway access; prevention, preparation, technique and training.
Marshall, S.D., 2016. Evidence is important: safety considerations for emergency catheter cricothyroidotomy. Academic Emergency Medicine, 23(9), pp.1074-1076.
Mallari, C.A., Ross, E.E. and Vieux, E.E., 2016. Emergency airway: cricothyroidotomy. In Interventional Critical Care (pp. 59-65). Springer, Cham
Melchiors, J., Todsen, T., Konge, L., Charabi, B. and von Buchwald, C., 2016. Cricothyroidotomy–The emergency surgical airway. Head Neck, 38(7), pp.1129-1131.
Patel, S.A. and Meyer, T.K., 2014. Surgical airway. International journal of critical illness and injury science, 4(1), p.71
Pracy, J.P., Brennan, L., Cook, T.M., Hartle, A.J., Marks, R.J., McGrath, B.A., Narula, A. and Patel, A., 2016. Surgical intervention during a Can’t intubate Can’t Oxygenate (CICO) Event: Emergency Front-of-neck Airway (FONA)?. British journal of anaesthesia, 117(4), pp.426-428.