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Notes: Conditions for insertion of a laryngeal mask airway in 90 unpremedicated adult patients were assessed in a randomised, single-blinded trial. Each patient received fentanyl 1 μg.kg-1 and thiopentone 5 mg.kg-1, and this was preceded either by lignocaine 0.5mg.kg-1intravenously (group 1), lignocaine 1.5mg.kg-1 intravenously (group 2) or 40mg of topical lignocaine spray to the posterior pharyngeal wall (group 3). Conditions for laryngeal mask airway insertion were recorded. The group receiving topical lignocaine had a lower incidence of laryngospasm (p 〈 0.05), required fewer attempts for successful insertion of the laryngeal mask (p 〈 0.05) and coughed or gagged less frequently than either group receiving lignocaine intravenously (p 〉 0.05). Overall, the conditions for laryngeal mask airway insertion were better in the topical group (p 〈 0.05). There were no significant differences in haemodynamic response and apnoea between the three groups. Topical lignocaine spray prior to thiopentone provides conditions for insertion of a laryngeal mask that are superior to those provided by lignocaine and thiopentone intravenously.

Notes: We assessed conditions for insertion of a laryngeal mask airway in 90 unpremedicated adult patients who received either thiopentone 5mg.kg-1 preceded by 40 mg of topical lignocaine spray to the posterior pharyngeal wall or propofol 2.5 mg.kg-1 alone in a randomised, single-blinded trial. All patients received fentanyl 1 μg.kg-1. Gagging, coughing and laryngospasm following laryngeal mask insertion were graded and haemodynamic data and apnoea times were recorded. There were no significant differences between the two groups with regard to the incidence of gagging, coughing and laryngospasm, but the apnoea time was significantly less in the thiopentone group (p 〈 0.005). The decrease in systolic and diastolic blood pressure, following induction and the insertion of a laryngeal mask with propofol was significantly greater than following thiopentone (p 〈 0.05—systolic, p 〈 0.01—diastolic). We conclude that thiopentone preceded by topical lignocaine spray provides conditions for insertion of a laryngeal mask equal to those of propofol, with more haemodynamic stability and a shorter period of apnoea.

Notes: We were interested in recent correspondence relating to reflux of gastric contents into the drain tube of the Pro-Seal laryngeal mask airway (Dalgleish & Dolgner. Anaesthesia 2001; 56: 1010). As part of a trial comparing performance of the Pro-Seal with the classic laryngeal mask airway we inserted a gastric tube into the drain tube of 30 Pro-Seal laryngeal mask airways in elective surgery patients. All patients were starved for 6 h for solids and 3 h for fluids. In all cases, fibre-optic examination of the drain tube and the oesophagus below was undertaken before passage of the gastric tube. On no occasion was gastric content seen in the drain tube or in the upper oesophagus. Gastric fluid was aspirated in 29 of 30 cases with a median volume of 22 ml and a range of 0–85 ml. In none of the cases was there any suggestion of clinical regurgitation or aspiration.In a recent case in our intensive care unit, a Pro-Seal was being used to allow endoscopic guidance during a percutaneous tracheostomy. The patient had been nasogastrically fed and the stomach was aspirated before the procedure. During dilation of the trachea, some nasogastric feed was vented a considerable distance out of the drain tube. Since the endoscope was at the glottic opening during this episode of regurgitation, it was possible to confirm, under direct vision, that there was no laryngeal or tracheal soiling.Large studies and meta-analysis has suggested that the incidence of aspiration of gastric contents when using a classic laryngeal mask airway is approximately 0.05–0.009% [1, 2]. A recent editorial on mechanical ventilation via the laryngeal mask airway rather speculatively suggested that aspiration of gastric contents might occur in up to 360 patients per year in the UK [3] and implied that such practice could not be considered entirely safe. The choice of whether to use a laryngeal mask airway when artificially ventilating a patient varies considerably in UK practice [4].If elective cases may have significant volumes of gastric fluid, and there is some doubt as to whether ventilation via the classic laryngeal mask airway is safe, then the Pro-Seal is likely to be a valuable addition to the airway armamentarium. Laryngeal seal pressure is increased by approximately 50% [5] and the drain tube allows easy and reliable access to the stomach [5]. In addition, the drain tube might be expected to vent gas leaking into the oesophagus reducing gastric dilation, although this is untested. Should regurgitation occur, the drain tube may allow venting of regurgitated material and its appearance in the drain tube may act as an early warning.However, these potential advantages have not been rigorously examined and it is therefore too early to be sure of the role of the Pro-Seal in anaesthetic practice. What evidence is there that the Pro-Seal allows a greater margin of safety in the event of regurgitation? At present there is little; we are aware of three cases in which regurgitated matter has appeared in the drain tube without laryngeal or tracheal soiling (A. Brain, Personal communication). Drs Dalgleish and Dolgner's report brings the total to four, but is the first to be published. In addition, a study in cadavers [6] supports the contention. A study, at present only presented at a meeting, of the use of the Pro-Seal for laparoscopic cholecystectomy showed no more gastric distension than with a tracheal tube (Maltby JR, Beriault MT, Watson NC, Liepert DJ, Fick GH. Laparoscopic cholecystectomy: LMA-Proseal vs. tracheal intubation. Poster presentation. Canadian Anaesthesiologist's Congress 2001, Halifax, Canada).If we wait for a controlled study between the two devices to give us the answer, it will be a long wait. If the incidence of aspiration during anaesthesia while ventilating through the classic laryngeal mask is 1 in 11 000 cases, as has recently been suggested [3] and this␣number can be halved by using the Pro-Seal, this would reduce the number of such cases in the UK by 180 per year. Conducting a trial to detect such a reduction, however, would require approximately 1.3 million patients in each group.

Notes: We performed a national postal survey exploring anaesthetists' practice in rapid sequence induction. All respondents used pre-oxygenation, although the technique employed, and its reliability, varied. Thiopental and succinylcholine, given after waiting for signs of loss of consciousness, were the most widely used drugs for rapid sequence induction. Propofol and rocuronium were used by more than a third of respondents, and most respondents (75%) also routinely administered an opioid. Cricoid pressure was used universally but the practice of its application varied widely. The commonest aids used if intubation was difficult were the gum elastic bougie, the long laryngoscope blade and the laryngeal mask. After failed intubation, approximately half of respondents would maintain the supine position. Failure to intubate at rapid sequence intubation had been seen by 45% of respondents but harm was uncommon. In contrast, 28% had seen regurgitation, which frequently led to considerable harm and to three deaths. In spite of this, practice of a failed intubation drill was uncommon (15%) and anaesthetic assistants were rarely known to practice application of cricoid pressure. Consultants were less likely than trainees to use rocuronium as a muscle relaxant, and more likely to choose morphine if administering an opioid. They were less likely to practice a failed intubation drill. Other aspects of practice varied little between grades. This survey suggests that many anaesthetists do not follow best practice when performing a rapid sequence induction.

Notes: We studied 20 anaesthetic assistants applying simulated cricoid pressure with the left or right hand in random order. Simulated cricoid pressure was continued for up to 5 min with one hand and then, after resting, with the other hand. Applied pressure was measured at intervals and the subjects were blind to the results. Nineteen assistants were right-handed and all routinely applied cricoid pressure with their right hand. Mean (SD) force applied during simulated ‘awake’ cricoid pressure was 13.8 (5.7) N with either left or right hand, and during ‘anaesthetised’ cricoid pressure it was initially 25.1 (8.2) N and 24.7 (8.8) N with left or right hand, respectively. Mean force was maintained above 20 N and below 30 N throughout the study period with either hand. Force applied with the left hand was significantly lower than with the right hand but the difference was clinically insignificant (0.4 N). Inadequate or excessive force was more frequently associated with use of the left hand (p 〈 0.0001). Cricoid pressure was released before 5 min in three cases, two left-handed and one right-handed. Our results demonstrate that anaesthetic assistants apply a lower force than is classically taught and are able to maintain the force with either hand for a sustained period. Application with the left hand is justified where clinically indicated but may have a lower margin for error than when applied with the right hand.