Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults.

These guidelines provide a strategy to manage unanticipated difficulty with tracheal intubation. They are founded on published evidence. Where evidence is lacking, they have been directed by feedback from members of the Difficult Airway Society and based on expert opinion. These guidelines have been informed by advances in the understanding of crisis management; they emphasize the recognition and declaration of difficulty during airway management. A simplified, single algorithm now covers unanticipated difficulties in both routine intubation and rapid sequence induction. Planning for failed intubation should form part of the pre-induction briefing, particularly for urgent surgery. Emphasis is placed on assessment, preparation, positioning, preoxygenation, maintenance of oxygenation, and minimizing trauma from airway interventions. It is recommended that the number of airway interventions are limited, and blind techniques using a bougie or through supraglottic airway devices have been superseded by video- or fibre-optically guided intubation. If tracheal intubation fails, supraglottic airway devices are recommended to provide a route for oxygenation while reviewing how to proceed. Second-generation devices have advantages and are recommended. When both tracheal intubation and supraglottic airway device insertion have failed, waking the patient is the default option. If at this stage, face-mask oxygenation is impossible in the presence of muscle relaxation, cricothyroidotomy should follow immediately. Scalpel cricothyroidotomy is recommended as the preferred rescue technique and should be practised by all anaesthetists. The plans outlined are designed to be simple and easy to follow. They should be regularly rehearsed and made familiar to the whole theatre team.

National census of airway management techniques used for anaesthesia in the UK: first phase of the Fourth National Audit Project at the Royal College of Anaesthetists.

BACKGROUND: The first stage of the Royal College of Anaesthetists Fourth National Audit Project (NAP4) (to determine the incidence of major complications of airway management in the UK) required a national census of airway management techniques currently in use. METHODS: A network of local reporters (LRs) was established, with a link to each of the 309 National Health Service hospitals believed to undertake surgery. LRs were requested to report the primary airway management technique used for all general anaesthetics performed in their hospital during a specified 2 week period. Individual unit's data for the survey period were extrapolated using a multiplier of 25 to provide an estimated annual usage. RESULTS: Data were received from all 309 hospitals. The number of general anaesthetics reported in the 2 weeks was 114,904 giving an estimate of 2.9 million annually. Eighty-nine per cent of returns were reported by the LR to be 'accurate' or 'a close estimate' (an error of <10%). The primary airway management device for general anaesthesia was a supraglottic airway in 64,623 (56.2%), a tracheal tube in 44,114 (38.4%), and a facemask in 6167 (5.3%). CONCLUSIONS: The second stage of NAP4 is designed to register and collect details of each major airway complication from the same hospitals over a 12 month period. The individual case reports will produce the numerator to calculate the incidence of airway complications associated with general anaesthesia in the UK. The results of the census presented here will provide the denominator.

Complications of awake fibreoptic intubation without sedation in 200 healthy anaesthetists attending a training course.

BACKGROUND: Two hundred anaesthetists underwent airway endoscopy and attempted awake fibreoptic intubation (FOI) on a training course. Complications were recorded and each subject's response to the procedure was assessed. METHODS: Topical airway local anaesthesia was produced with up to 9 mg kg(-1) of lidocaine, sedation was not used. Complications during and after the procedure were noted. Later, the subjects completed an anonymous questionnaire about anxiety, pain, coughing, and side-effects of lidocaine. RESULTS: More than 1300 endoscopies were performed, 180 delegates were intubated, 175 by the nasal route and five orally. Intubation was abandoned in 20 (10%) subjects. Nasal bleeding occurred in 20 (10%) subjects. Symptoms that could be attributed to lidocaine were reported by 71 (36%) subjects. Afterwards, two (1%) subjects experienced rigors and one developed a lower respiratory tract infection. CONCLUSIONS: Nasendoscopy and FOI under local anaesthesia are associated with complications, notably those of infection and airway trauma. Side-effects potentially attributable to lidocaine administration were commonly reported.

Combined nebulization and spray-as-you-go topical local anaesthesia of the airway.

BACKGROUND: Twenty-five anaesthetists underwent awake fibreoptic intubation using a combination of nebulization and topical local anaesthesia. Plasma lidocaine concentrations were measured and the quality of the local anaesthesia was assessed. METHODS: After i.v. glycopyrrolate 3 microg kg(-1) and intranasal xylometolazone 0.1%, lidocaine 4% 200 mg was administered by nebulizer. Supplementary lidocaine to a maximum total of 9 mg kg(-1) was applied directly and via a fibreoptic endoscope. Nasotracheal intubation was performed once the vocal cords became unreactive. Heart rate, non-invasive blood pressure and oxygen saturation were recorded at 5-min intervals. Blood sampling commenced with a baseline sample and continued at 10 min intervals until 60 min after final administration of local anaesthetic. Subjects graded levels of anxiety, pain and coughing using written and visual analogue scales. RESULTS: Conditions for fibreoptic endoscopy and intubation were good. Seventeen received the maximum lidocaine dose of 9 mg kg(-1). The average dose used was 8.8 mg kg(-1). All plasma lidocaine concentrations assayed were below 5 mg litre(-1). Four volunteers reported feeling lightheaded after the procedure, despite normal blood pressure. Of these, two had the highest plasma lidocaine concentrations recorded: 3.5 and 4.5 mg litre(-1). Twenty-two of the 25 subjects found endoscopy and intubation acceptable, three found it enjoyable and no subject rated it as distressing. CONCLUSIONS: This method of airway anaesthesia was acceptable to this small group of unsedated subjects. It produced good conditions for fibreoptic intubation. A maximum calculated lidocaine dose of 9 mg kg(-1) did not produce toxic plasma concentrations of lidocaine.

Training course in local anaesthesia of the airway and fibreoptic intubation using course delegates as subjects.

BACKGROUND: We describe a practical method of training anaesthetists in the technique of awake fibreoptic intubation. This is performed on a training course using the delegates as subjects. METHODS: The first 15 subjects underwent cardiovascular monitoring during airway fibreoptic endoscopy performed by other course members. They were subsequently interrogated by use of a questionnaire. RESULTS: Evidence from questionnaires suggests this method of instruction is acceptable in this self-selected group of individuals. Gagging was the commonest unpleasant side-effect of airway endoscopy, although only one delegate rated this as uncomfortable. Fifty-four per cent of subjects found the procedure slightly painful; 46% reported no pain at all. Overall, the procedure was rated as acceptable by 85% of subjects and enjoyable by 15% of subjects. No delegate found endoscopy or intubation distressing. Cardiovascular monitoring revealed pulse rate and arterial pressure changes of less than 25% of baseline values. Paraesthesia developed in one individual and nasal bleeding in two cases, neither of which was clinically significant and did not interfere with endoscopy. CONCLUSIONS: The use of course delegates as subjects for training was acceptable to anaesthetists and is associated with a low level of discomfort and morbidity.

Pupillary signs during cardiac surgery. Their use in the prediction of major cerebral deficit following cardiopulmonary bypass.

Pupil sizes and reactions to light were studied in 100 patients who had cardiopulmonary bypass. Behaviour of the pupils was observed at six stages during the operation. Most patients (71) had pupils of equal size and similar reaction to light at all times. Twenty-three patients developed unequal pupils at some stage, while six had equal pupils throughout but exhibited differing reaction to light. Major cerebral deficit was significantly more common after operation in patients who developed inequality in pupil size than those who did not (p less than 0.05). No relationship was seen between dissimilar pupil reaction to light and the development of neurological complications. The clinical estimation of pupil size may help to identify those patients who may exhibit postoperative major neurological dysfunction.

Dopamine produces forearm vasodilatation following alpha-adrenoceptor blockade by an action on vascular dopamine (DA1) receptors in man.

The purpose of this study was to investigate the receptor type mediating dopamine-induced forearm vasodilatation following alpha-adrenoceptor blockade. Forearm blood flow (FBF) was measured using venous occlusion plethysmography in normal volunteers. Intra-arterial (i.a.) dopamine alone produced variable and small changes in FBF. However, following alpha-adrenoceptor blockade with phenoxybenzamine, dopamine infusion resulted in forearm vasodilatation in the infused arm. This effect was not antagonized by the beta-adrenoceptor antagonist propranolol, but was antagonized by the vascular dopamine receptor antagonist, sulpiride, the (d) enantiomer being more active than the (l). It is concluded that i.a. dopamine induces forearm vasodilatation following alpha-adrenoceptor blockade by an action on vascular dopamine (DA1) receptors similar to those described in the renal and mesenteric vasculature of other species.

Beta-adrenoceptor blockade and suxamethonium-induced rise in plasma potassium.

The effects of beta-adrenergic blockade on the suxamethonium-induced rise in arterial plasma potassium were studied in patients who presented for open heart surgery. No potentiation of the immediate rise in plasma potassium was observed.