Portal de Periódicos da CAPES

Airway alerts

2005; Wiley; Volume: 60; Issue: 5 Linguagem: Inglês

10.1111/j.1365-2044.2005.04202.x

1365-2044

D. R. Ball, P. Jefferson,

Anesthesia and Sedative Agents

We agree with Chandradeva and Ghosh that an episode of difficult airway management should be communicated effectively [1]. They and others [2, 3] suggest that a Cormack and Lehane grade 3 view on direct laryngoscopy qualifies as ‘difficult’ as well as the much rarer grade 4 view. It is important that these two grades are not considered a single group. It is generally agreed that the clinical management of a grade 4 views presents a ‘much more formidable challenge’ (original author's emphasis), but management of grade 3 views is ‘usually straightforward’[4]. If an airway alert is to be reported in a patient with a grade 3 view we feel that the following points be considered. Firstly, it is not that rare for patients to have a grade 3 view. The Australian Incident Monitoring Study reported an incidence of 4%[5] as did a recent UK study [3]. If 4% of our patients (whose tracheas are intubated) qualify for an alert scheme, there are risks of reporting fatigue as well as the logistical challenges of efficient alerting. Secondly, there is variation in the degree of difficulty encountered when managing a grade 3 view. Cook has divided the grade into 3a and 3b, with the latter associated with more difficulty [6]. We suggest that this division is clinically useful and is worth recording. Thirdly, external laryngeal manipulation can alter the laryngoscopic view, reducing the incidence of a grade 3 view [7]. The use of this manoeuvre is also worth reporting. Lastly, the view seen on laryngoscopy can change with the experience of the anaesthetist. In a prospective study the incidence of grade 3 and 4 views was 1.3 and 0.3%, respectively [8]. In four cases where the initial grading was 4, the view was subsequently converted to a grade 3 by a second anaesthetist, who generally used a greater lifting force (‘traction’) during direct laryngoscopy. In another study the overall incidence of difficult intubation was reduced from 3.1% to 1.2% when a senior anaesthetist managed the case [5]. It is important to agree on the definitions of the degree of difficulty. The ASA Task Force on the Management of the Difficult Airway defined such difficulty as ‘the clinical situation in which a conventionally trained anesthesiologist experiences difficulty with mask ventilation, difficulty with tracheal intubation, or both’[9]. When this Task Force reported, conventional training was considered to be 2 years in a US residency programme, which roughly compared to 6 years training in the UK. Before a patient with a grade 3 view is reported as ‘difficult’ (in reasonably objective terms) and before a comprehensive airway alert be distributed in the format adopted by the Difficult Airway Society, we suggest that the cases of patients with grade 3 views be discussed at a Departmental level (at a Morbidity and Mortality meeting, for instance). Most departments have a named individual with an interest in difficult airway management (75% of UK departments in 2001 [10]). We suggest that this person is well placed to co-ordinate the issues over the raising an airway alert.