The difficult airway with recommendations for management – Part 1 – Difficult tracheal intubation encountered in an unconscious/induced patient

Abstract

BackgroundPreviously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered. MethodsNineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.ConclusionsThe clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.

Radiologic indicators for prediction of difficult laryngoscopy in patients with cervical spondylosis

“…Many national airway guidelines underline the importance of a thorough and skilled airway assessment of all patients before undergoing anaesthesia 11, 12. The modified Mallampati test (MMT) is the most popular test for screening difficult laryngoscopy, but there is controversy regarding its accuracy.…”

Obstructing pathology of the upper airway in a post-NAP4 world: time to wake up to its optimal management

“…Second, for both emergency and elective surgical patients with a tenuous airway-as losing the airway is always possible during intubation attempts-full equipment and personnel should be present for all the primary and alternative intubation and CICO plans so as to facilitate smooth and rapid transitions if needed. 19 If an emergency cricothyrotomy is a backup plan, the location of the cricothyroid membrane (CTM) should be determined and marked beforehand, recognizing that existing studies indicate poor success at identification of the CTM by palpation alone. [20][21][22] Thus, if time permits, ultrasound should be used to locate the CTM.…”

Airway management: judgment and communication more than gadgets

“…The authors do not recommend a specific device or method of insertion. In the first article, 2 Fig. 1 Plan B calls for an ''alternative device'' or a ''different operator''.…”

“…This compromise is illustrated in the recommendation that a stylet be used with direct laryngoscopy if intubation is initially unsuccessful. 2 The use of a stylet involves extra manipulations; thus, it is more complicated, and traumatic lesions are more likely with this approach than with performing an intubation without a stylet. Even so, stylet use is associated with a higher success rate; therefore, it makes sense to try direct laryngoscopy first without a stylet and to reserve stylet use for more difficult cases.…”

“…7 The previous recommendations included enthusiastic discussion of specific airway tools, such as the Combitube TM and the lighted stylets, which turned out to have a very limited future. 1 This time, the authors of the revised recommendations 2,3 are to be congratulated for refraining to endorse any particular type of equipment. All the devices available today might be replaced in the future by improved technology.…”