Scottish Airway Group Annual Meeting 2017 Report
Rajib Ahmed, ST7 Anaesthesia, West of Scotland
The seventh Annual Meeting of the Scottish Airway Group saw a change of venue to the Royal College of Surgeons in Edinburgh. On 10th March 2017, 189 delegates and 23 faculty attended this increasingly popular and important fixture on the Scottish anaesthesia community’s calendar.
The organising committee headed by Dr Simon Crawley of Dundee did a great job of putting together the meeting. A range of speakers from throughout the UK provided a varied programme which entertained as well as educated the assembly.
After the delegates were welcomed by Dr Crawley, proceedings were kicked off by Dr Alistair Baxter of the Royal Hospital for Sick Children Edinburgh. In a thought provoking talk, Dr Baxter shared his opinions on some relatively recent areas of practice. First to be scrutinised was the iGel LMA, which Dr Baxter had noted to allow entrainment of air and subsequent lightening of anaesthesia. He surmised that this could be due to the gastric port being located over the larynx. This was also a problem experienced by some members of the audience. There followed a question mark over the efficacy of all 2nd-generation supraglottic airway devices in paediatrics and a note of caution over their efficacy in adult practice, an opinion contrary to other sources advocating the use of 2nd-generation devices as first line over older devices.
Next up to be scrutinized was laryngoscopy blade use in paediatrics and the message was that MacIntosh and Miller blades can both be acceptably used as both will provide a view down to one month of age. Dr Baxter endorsed the use of the McGrath Mac in paediatrics for several reasons (which are equally applicable arguments for its use in adult practice): we are familiar with the shape of the MacIntosh blade so there is no learning curve with its use; teaching is enhanced as the teacher can see the view obtained; they are relatively low-cost and at RHSCE one is located in every theatre.
Also advocated for in paediatrics were TIVA use in airway surgery, micro-cuffed endotracheal tubes and the use of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) – a BJA paper was published earlier this year which demonstrated increased safe apnoea times (although not as long as adults). On the subject of Front of Neck Access (FONA), Dr Baxter felt that this should remain the remit of our surgical colleagues. He finished by urging involvement with and support from those interested in National Procurement, in order to ensure that we retain sufficient influence in securing adequate quality of equipment.
There followed an entertaining account of the development of an educational programme in tracheostomy care for ICU staff. Dr Rosie Baruah of Edinburgh and her team had identified major gaps in knowledge of tracheostomy care amongst nursing staff. She recounted the origins of Trachy Tracey and her journey to becoming an indispensible training manikin, along with a range of other teaching tools, to address this shortfall using the PRISM framework. These included bedside teaching for nurses, doctors, CSWs, physios and SALTs (in particular to address the lack of study leave for nursing staff), posters (in places where people would notice and read them such as next to the blood gas machine and in the toilets) and bedspace signs/ boxes. Monitoring of improvement was by quality improvement principles and the use of run charts.
The first session was wrapped up by Dr Andrew Dalton of Dundee with a very interesting talk on awake videolaryngoscopy and whether it has a place in our practice. Dr Dalton started by showing a dramatic video of awake videolaryngoscopy on a patient. He then quoted the NAP4 finding that highlighted 18 cases where awake fibreoptic intubation (AFOI) was not carried out but should have been considered. The likely reasons for this are numerous: service pressures, lack of training and lack of confidence. Attitudes like “just get on with it, most predicted difficult airways are fine” may still be worryingly prevalent. There is evidence that another often quoted concern, that patients find AFOI distressing, is overstated.
The problems with AFOI are well known, with passage of the endotracheal tube (ETT) being blind and a risk of bleeding from friable tumour or impingement of the ETT. According to Dr Dalton, awake videolaryngoscopy confers the advantages of being suitable for use in supraglottic, glottic and infraglottic disease including marked narrowing, predicted difficult mask ventilation, blood/secretions which could limit FOI, stridor, friable airways and assessing airways in ICU. Videolaryngoscopes are also portable and easy to clean and store. They are not suitable if mouth opening is less than 15mm, the patient has a fixed flexion neck deformity or vallecula pathology.
The question of which videolaryngoscope to use does not have a definitive answer but an indirect 60 angulation is best. Fibreoptic skills remain essential and anaesthetists should be able to use both alongside each other.
The late morning session commenced with an update on the SAG National Trainee Audit by Dr Yvonne Bramma, a trainee from the West of Scotland. This was an examination of neuromuscular blockade (NMB) and peripheral nerve stimulator (PNS) use throughout Scotland. PNS were used during emergence in 75% of cases, during maintenance in 44%, induction in 10% and not at all in 19%. Underdosing was also noted to frequently occur with neostigmine. Recommendations made included: an increased use of quantitative PNS, increased use of double-burst stimulation and post-tetanic count if using qualitative PNS, monitor blockade during maintenance, use the ulnar nerve and adjust dose of reversal agent for weight.
The trainee oral presentations followed on. The winner was a cadaveric study of the correlation of skinfold thickness to distance to the cricothyroid membrane. Second place was a targeted approach for adoption of the 2015 DAS Guidelines via a variety of education methods. Third prize was won for a case series of THRIVE (transnasal humidified rapid-insufflation ventilatory exchange) to achieve a tubeless field in upper airway surgery.
The final morning presentation was by Mr Peter Inglis, head of research and development at Aircraft Medical. He gave a fascinating account of the evolution of the McGrath Mac, from the Mk. 1 to the videolaryngoscope (VL) produced in 2010 that we know today. It was a great insight into the design and engineering considerations involved in producing the McGrath Mac, such as the need to balance the handle offset to reduce obstruction and the need to reduce twisting forces caused by too great an offset. Meticulous attention has been paid to all details such as electronics, the orientation of the screen, how to make the disposable plastic blade rigid like steel without increasing its bulk. The company was successful in its ultimate aim of creating the world’s first fully portable VL and the first single use VL blade. They were also successful in introducing a piece of kit which we use routinely and therefore reach for with confidence when confronted with a difficult airway. And by the way, if you ever wondered why the tip of the blade has a little bulge, even this detail is intentional; called a “blobble” it allows the blade to “surf” over the tongue – without it, the tongue ripples over the tip, causing it to stick. Aircraft Medical was acquired by Medtronic in 2015 and the McGrath Mac used in 5.9 million cases.
After a delicious buffet lunch, which allowed time to catch up with friends and colleagues and further peruse the posters, the first afternoon session focused on training and human factors. Dr Rob McCahon of Nottingham talked about the impact of decision making – poor judgement was implicated in 63% of cases in NAP 4. This is thought to be in large part due to a lack of education and training. For our ODP colleagues this is further exacerbated by training opportunities often being unpaid and restricted due to service pressures. In Nottingham they have an on-site operating theatre training room where they cover topics such as the DAS Intubation Guidelines, familiarisation with the difficult airway trolley, failed direct laryngoscopy drills and front-of-neck access. They also run a ten week programme for consultants and trainees based around local needs. Dr McCahon raised the issue of possible mandatory difficult airway training, which requires departmental motivation and interest.
Following on from this were the recollections of two airway fellows. Dr Karen Pearson of the East of Scotland and Dr Cara Marshall of the West of Scotland both achieved much during their advanced airway rotations and their accounts of their experiences should inspire anybody considering advanced airway training.
Dr Evie Fioratou, a lecturer in social and behavioural science from Dundee, then spoke about human factors and systems thinking. System 1 is automatic and fast while system 2 slow and effortful. In difficult airway management (DAM), system 1 thinking can lead to errors. Our thinking is affected by the overall system in which we work, therefore the situation in which we work can lead to cognitive errors. Dr Fioratou described a Systems Engineering Initiative for Patient Safety (SEIPS) model in DAM, which can lead to the development of solutions such as the Airway Rescue Trolley, which would have been of use in cases such as that of Elaine Bromiley.
The final session saw Dr Andy Higgs of Warrington discuss the forthcoming ICU guidelines. NAP 4 identified ICU and ED as settings that suffered from an increased incidence of airway related complications. This is for a variety of reasons such as deranged physiology, precipitating pathology, environmental factors, but a key factor that we can change is lack of planning. Difficult intubation in the ICU can be predicted using the MACOCHA score – where 3 predicts difficult intubation. Dr Higgs recommends a strategy for management consisting of preoxygenation with Optiflow and or CPAP and laryngoscopy using a VL at first attempt. There should be a maximum of two attempts at laryngoscopy with one further attempt by a more competent anaesthetist. Plans B and C should follow the DAS guidelines and rescue with plan D should consist of scalpel, bougie and ETT as per DAS guidelines. To reduce errors due to human factors, plans should be rehearsed.
The final session was a keenly contested debate: “pre-oxygenation is a key part of anaesthesia for all”. Speaking in favour of the motion was Dr Gordon Bathgate of Inverness who stated the physiological reason for pre-oxygenation i.e. denitrogenation of the FRC. He then addressed the counter-arguments to pre-oxygenation: oxygen toxicity is not relevant for a short period of pre-oxygenation as the effects of a high FiO2 are incremental. There may be a mild change in systemic vascular resistance but the main argument of atelectasis can be offset by a quick recruitment maneouvre of 40cmH2O for 8 seconds, then minimizing FiO2. The main argument was that we should pre-oxygenate everyone as we are poor at predicting difficult airways.
Up against Dr Bathgate, and speaking against the motion was Dr S McLeod of Dundee. He cited the damage caused by reactive oxygen species and free radicals. Atelectasis leads to hypoxia and pulmonary complications and furthermore, is not reversed by PEEP unless a recruitment maneouvre is carried out first. We should anticipate a prolonged apnoea time and certain situations such as difficult extubation and be mindful of states of increased oxygen utilisation such as sepsis and pregnancy.
After presentation of poster prizes, a thoroughly enjoyable day was wrapped up by Dr Crawley. Future dates for your diary are the SAG Annual Meeting to be held in Glasgow on the 2nd of March 2018, and the DAS Annual Scientific Meeting on 28-30th November 2018 at the Edinburgh International Conference Centre.