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The article discusses a recent study comparing the use of a stylet versus a bougie during hyperangulated videolaryngoscopy. The study found statistically significant results in favor of the bougie group, but the results were fragile, with just one patient in the bougie group potentially changing the outcome. The study's findings were also limited in generalizability due to underperformance of the stylet group compared to previous studies. The authors suggest that proper technique and equipment can make both stylets and bougies equally effective, but they recommend using bougies with a stable curve for better results. [Extracted from the article]

Proper placement of the tracheal tube requires confirmation, and the predominant method in addition to clinical signs is the presence of end-tidal carbon dioxide. Such is the importance of confirmation that novel methods may also have a place. We previously demonstrated using ex-vivo swine tissue a unique spectral reflectance characteristic of tracheal tissue that differs from oesophageal tissue. We hypothesised that this characteristic would be present in living swine tissue and human cadavers. Reflectance spectra in the range 500-650 nm were captured using a customised fibreoptic probe, compact spectrometer and white light source from both the trachea and the oesophagus in anesthetised living swine and in human cadavers. A tracheal detection algorithm using ratio comparisons of reflectance was developed. The existence of the unique tracheal characteristic in both in-vivo swine and cadaver models was confirmed (p < 0.0001 for all comparisons between tracheal and oesophageal tissue at all target wavelengths in both species). Furthermore, our proposed tracheal detection algorithm exhibited a 100% positive predictive value in both models. This has potential utility for incorporation into airway management devices. [ABSTRACT FROM AUTHOR]

The article presents author's views regarding two defective Optima CLX made by Timesco laryngoscope blades and its impact on child's airway. Topics include negative impact of blades on trachea which remain undetected during intubation; no action taken by Medicine and Healthcare products Regulatory Agency towards the case; and no complaint of injuries caused by laryngoscope blades was reported yet.

Guided intubation using a tracheal tube and semi-rigid introducer is associated with technical difficulties, failure and traumatic complications. We describe the development of a new system of guidewire-assisted tracheal intubation that may circumvent these problems. A reinforced silicone tracheal tube was modified with a guide channel built inside its wall, and a nitinol non-kinking guidewire was matched to this channel. Both anterograde and retrograde tracheal intubation were evaluated in a test rig, an airway manikin and then in preserved and fresh cadavers. There was minimal resistance to passage of the guidewire through the guide channel when the modified tube was in an anatomical configuration, in contrast to moderate resistance when an Airway Exchange Catheter was passed through a PVC tracheal tube. Intubation using the new equipment required increased force in the manikin and preserved cadavers, but minimal force in fresh cadavers. Resistance to tracheal tube advancement in preserved cadavers was overcome by withdrawal followed by 90° rotation, but this manoeuvre was not required in fresh cadavers. We suggest that the combination of the modified tracheal tube and matching guidewire may allow easy and reliable single-step guided tracheal intubation when used in patients. [ABSTRACT FROM AUTHOR]

Emergency catheter cricothyroidotomy often fails. Case reports have concentrated on kinking and displacement of the catheter as the major causes. We investigated catheter tip penetration of the trachea. Using insertion angles of 90°, 75°, 60°, 45° and 30° we advanced 14 G intravenous catheters into fresh isolated sheep tracheas during high pressure oxygen insufflation. At all angles, the catheter tip became blocked by pushing into the mucosa with submucosal gas injection on one or more attempts. Full thickness rupture with extratracheal gas also occurred on insertions at 90° and 60°. We then tested a Luer-mounted prototype wire stylet which remains in situ during insufflation. Using the same methodology, the stylet was able to be placed and prevented blockage at all angles of insertion. Mucosal trauma and submucosal gas injection occurred on insertions at 90° and 75°. Our results should guide further stylet design. [ABSTRACT FROM AUTHOR]

Use of a bougie is not without risk, and insertion too far may cause airway injury. We designed a new bougie with a 'traffic light' system to indicate depth of insertion. Forty anaesthetists were randomly assigned to insert either a conventional single-coloured bougie or a novel traffic light bougie. Depth of insertion was measured before and after railroading a tracheal tube. Participants were not informed as to the purpose of the colouring system. The median ( IQR [range]) insertion depth of the traffic light bougie was 22 (21-24 [19-27]) cm and for the conventional bougie was 28 (21-32 [20-35]) cm (p = 0.011). Median ( IQR [range]) insertion depth after railroading for the traffic light bougie was 25 (25-28 [21-34]) cm and for the conventional bougie was 30.5 (27-35 [23-40]) cm (p = 0.003). This simple colouring system appears to allow intuitive use and significantly reduced the depth of bougie insertion. This system could be also used with other airway exchange devices to improve safety. [ABSTRACT FROM AUTHOR]

Bougie impingement during tracheal intubation can increases the likelihood of prolonged intubation time, failed intubation and airway trauma. A flexible tip bougie may overcome this problem, which can occur when using a non-channelled, hyperangulated videolaryngoscope with a standard bougie. This randomised controlled study compared standard and flexible tip bougies using a non-channelled videolaryngoscope (C-MAC® D-blade) in 160 patients. The primary outcome measure was the modified intubation difficulty scale score. Secondary outcome measures were: laryngoscopy time; total tracheal intubation time; first attempt success rate; and postoperative sore throat verbal rating score. The median (IQR [range]) modified intubation difficulty scale scores for standard bougie and flexible tip bougie were 1 (0-2[0-5]) and 0 (0-1[0-3]), respectively (p = 0.001). There was no significant differences in laryngoscopy time, total tracheal intubation time, first attempt success rate and postoperative sore throat between the two groups. Both the flexible tip and standard bougies can be used with a high first attempt success rate for tracheal intubation using a C-MAC D-blade videolaryngoscope. The flexible tip bougie demonstrated a significantly better modified intubation difficulty scale score and lower incidence of bougie impingement., (© 2022 Association of Anaesthetists.)

We compared the work needed to retract a non-lubricated and a lubricated stylet from a tracheal tube over 24 h. Stylets were lubricated with sterile water, silicone fluid, lidocaine spray, lidocaine gel, MedPro® lubricating gel or Lacri-Lube®. The mean (SD) work in joules needed to retract the stylet by 5 cm from the tracheal tube was recorded immediately (time 0), at 5 and 30 min and at 1, 3 and 24 h. At time 0 lubrication with sterile water (0.53 (0.09); p = 0.001), silicone fluid (0.43 (0.10); p < 0.001), lidocaine gel (0.60 (0.15); p = 0.01) and MedPro gel (0.57 (0.07); p = 0.005), were better than no lubrication (0.94 (0.28)). Where a tracheal tube is pre-loaded with a stylet for use at an indeterminate time, silicone fluid was the best choice of lubricant as it performed consistently well up to 24 h. At 24 h only silicone fluid (0.49 (0.01)) outperformed no lubrication (0.77 (0.24); p = 0.04). [ABSTRACT FROM AUTHOR]

Modern ventilators provide capnography monitoring in patients with tracheal tubes, in compliance with national and international recommendations. This technology is often not used when patients' lungs are non-invasively ventilated; however, it should be accessed immediately following tracheal intubation to confirm tube placement. This study assessed the effect of ventilation interface design on the speed with which capnography can be activated by comparing the Dräger Evita 4 and Dräger V500 before and after a specific training episode. We configured the V500 to have a capnography activation button on the front screen in contrast to the Evita 4 which requires a sequence of actions to access capnography monitoring. We used a randomised crossover design, measuring time to monitoring activation, and repeated the study after 3 months. Survival analysis showed significantly quicker activation associated with ventilator choice (V500, p < 0.0001) and training (p = 0.0058). The training improved activation speed with both machines, though this was only significant for the Evita 4 (p = 0.0097). [ABSTRACT FROM AUTHOR]

We compared the Pentax Airway ScopeTM with the AirtraqTM optical laryngoscope in an infant manikin. Twenty-three anaesthetists randomly performed tracheal intubation: at rest, (a) with the Airway Scope and (b) with the Airtraq; and during chest compressions, (c) with the Airway Scope and (d) with the Airtraq. The success rate, modified Cormack and Lehane classification for glottic view, time taken to view the glottis, and time to place the tracheal tube were recorded. There was no difference in intubation success rate or quality of glottic view between the two devices. The median (IQR [range]) time taken to obtain a view of the glottis was 4.5 (3.7-6.4 [1.8-14.0]) s using the Airway Scope compared with 7.1 (5.5-9.6 [3.3-12.0]) s using the Airtraq (p = 0.001), and to successful placement of the tracheal tube was 8.3 (6.8-9.4 [3.7-20.7]) s using the Airway Scope compared with 11.2 (10.4-13.8 [4.9-23.7]) s using the Airtraq (p = 0.001). During chest compressions, the median (IQR [range]) time taken to view the glottis was 5.1 (4.0-7.2 [2.0-12.4]) s using the Airway Scope compared with 7.5 (5.0-13.2 [4.2-26.4]) s using the Airtraq (p = 0.006), and to successful placement of the tracheal tube was 9.5 (6.6-13.7 [4.5-16.2]) s using the Airway Scope compared with 11.7 (9.1-18.1 [6.2-37.4]) s using the Airtraq (p = 0.022). We conclude that both devices provided good quality views of the glottis and successful tracheal intubation in an infant manikin both at rest and during external chest compressions. Use of the Airway Scope resulted in a shorter time to view the glottis and perform successful tracheal intubation compared with the Airtraq. [ABSTRACT FROM AUTHOR]

Summary Tracheal extubation is a high-risk phase of anaesthesia. The majority of problems that occur during extubation and emergence are of a minor nature, but a small and significant number may result in injury or death. The need for a strategy incorporating extubation is mentioned in several international airway management guidelines, but the subject is not discussed in detail, and the emphasis has been on extubation of the patient with a difficult airway. The Difficult Airway Society has developed guidelines for the safe management of tracheal extubation in adult peri-operative practice. The guidelines discuss the problems arising during extubation and recovery and promote a strategic, stepwise approach to extubation. They emphasise the importance of planning and preparation, and include practical techniques for use in clinical practice and recommendations for post-extubation care. [ABSTRACT FROM AUTHOR]

Summary Tracheal tube cuffs are commonly inflated to pressures exceeding the recommended upper limit of 30 cmH2O. We evaluated whether a stethoscope-guided method of cuff inflation results in pressures within the recommended range. Patients were randomly assigned to receive one of two methods of cuff inflation. In the standard 'just seal' group, air was introduced into the tracheal cuff until the audible leak at the mouth disappeared. In the stethoscope-guided group, air was introduced into the cuff until a change from harsh to soft breath sounds occurred, whilst listening with a stethoscope bell placed over the thyroid cartilage. Twenty-five patients were recruited to each group. The median (IQR [range]) cuff pressure in the 'just seal' group was 34 (28-40 [18-49]) cmH2O, and in the stethoscope-guided group was 20 (20-26 [16-28]) cmH2O, p < 0.0001. The stethoscope-guided method of tracheal tube cuff inflation is a novel, simple technique that reliably results in acceptable tracheal cuff pressures. [ABSTRACT FROM AUTHOR]

Fifteen anaesthetists attempted to intubate the trachea of a manikin lying supine on the ground using the Airway Scope®, Airtraq® or Macintosh laryngoscope in three simulated conditions: (1) in room light; (2) in the dark and (3) in daylight. The main outcome measure was the time to ventilate the lungs after successful intubation; the secondary outcome was the success rate of ventilation within 30 s. In room light and in the dark, ventilation after successful tracheal intubation could always be achieved within 30 s for all three devices. There were no clinically meaningful differences in time to ventilate between the three devices. In daylight, time to ventilate the lungs for the Airway Scope was significantly longer than for the Macintosh blade (p < 0.0001; 95% CI for difference 27.5–65.0 s) and for the Airtraq (p < 0.0001; 95% CI for difference 29.2–67.6 s). Ventilation was always successful for the Macintosh and Airtraq laryngoscopes, but for the Airway Scope, only one of 15 participants could successfully ventilate the lungs (p < 0.0001). Therefore, the Airway Scope may have a role for tracheal intubation under room light or in darkness, but may not be so useful in daylight. In contrast, the Airtraq may have a role in both darkness and daylight. [ABSTRACT FROM AUTHOR]

Surgical Stress Index has been proposed for assessment of surgical stress and analgesia. It is a numeric index based on the normalised pulse beat interval and photoplethysmographic pulse wave amplitude. We determined the effect-site concentration of remifentanil for attenuation of Surgical Stress Index responses to intubation of the trachea. Thirty ASA 1–2 patients received either deep or normal anaesthesia and then target-controlled remifentanil. Burst suppression was maintained in the deep group and state entropy at 40–60 (scale 0–91) in the normal group. Mean (SD) effect-site concentrations of remifentanil attenuating responses in 50% of patients were 2.13 (0.25) ng.ml−1 and 3.05 (0.27) ng.ml−1 in deep and normal groups, respectively (p = 0.034). From probit analysis, EC50 and EC95 of remifentanil (95% CI) were 2.34 (1.97–2.71) ng.ml−1 and 3.19 (2.69–3.69) ng.ml−1 in deep group and 3.17 (2.67–3.67) ng.ml−1 and 3.79 (3.21–4.37) ng.ml−1 in the normal group, respectively. The values from probit analysis and up-and-down method did not differ significantly. [ABSTRACT FROM AUTHOR]

We present the use of the SensaScope™, an S-shaped rigid fibreoptic scope with a flexible distal end, in a series of 13 patients at high risk of, or known to have, a difficult intubation. Patients received conscious sedation with midazolam or fentanyl combined with a remifentanil infusion and topical lidocaine to the oral mucosa and to the trachea via a trans-cricoid injection. Spontaneous ventilation was maintained until confirmation of tracheal intubation. In all cases, tracheal intubation was achieved using the SensaScope. The median (IQR [range]) insertion time (measured from the time the facemask was taken away from the face until an end-expiratory CO2 reading was visible on the monitor) was 58 s (38–111 [28–300]s). In nine of the 13 cases, advancement of the SensaScope into the trachea was easy. Difficulties included a poor view associated with a bleeding diathesis and saliva, transient loss of spontaneous breathing, and difficulty in advancing the tracheal tube in a patient with unforeseen tracheal narrowing. A poor view in two patients was partially improved by a high continuous flow of oxygen. The SensaScope may be a valuable alternative to other rigid or flexible fibreoptic scopes for awake intubation of spontaneously breathing patients with a predicted difficult airway. [ABSTRACT FROM AUTHOR]

The C-MAC® videolaryngoscope is a novel intubation device that incorporates a camera system at the end of its blade, thereby facilitating obtaining a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. It retains the traditional Macintosh blade shape and can be used as a direct or indirect laryngoscope. We wished to determine the optimal stylet strategy for use with the C-MAC. Ten anaesthetists were allowed up to three attempts to intubate the trachea in one easy and three progressively more difficult laryngoscopy scenarios in a SimMan® manikin with four tracheal tube stylet strategies: no stylet; stylet; directional stylet (Parker Flex-It™); and hockey-stick stylet. The use of a stylet conferred no advantage in the easy laryngoscopy scenario. In the difficult scenarios, the directional and hockey-stick stylets performed best. In the most difficult scenario, the median (IQR [range]) duration of the successful intubation attempt was lowest with the hockey-stick stylet; 18 s (15–22 [12–43]) s, highest with the unstyletted tracheal tube; 60 s (60–60 [60, 60]) s and styletted tracheal tube 60 s (29–60 [18–60]) s, and intermediate with the directional stylet 21 s (15–60 [8–60]) s. The use of a stylet alone does not confer benefit in the setting of easy laryngoscopy. However, in more difficult laryngoscopy scenarios, the C-MAC videolaryngoscope performs best when used with a stylet that angulates the distal tracheal tube. The hockey-stick stylet configuration performed best in the scenarios tested. [ABSTRACT FROM AUTHOR]

We investigated the effect of temperature on single use and reuseable bougies. In a photographic study, three bougies (Portex® Venn reuseable (R), Portex single use (S) and Breathesafe™ single use (B)) were exposed to increasing temperatures and sequential photographs were taken of the bougies uncoiling from a preformed curve. Bougie type was associated with rate of uncoiling, type R maintaining its curve the longest but changing temperature did not affect this. In a randomised cross-over manikin study, 16 anaesthetists attempted to pass two bougies (Portex reuseable (R) and Portex single use (S)) at three temperatures (10, 20 and 30 °C) into the trachea of a manikin. Type R was significantly associated with higher success rate of tracheal placement compared to type S. Change of temperature was significant with success rate increasing with lower temperature. The odds of success at 10 °C was six times that at 30 °C (OR (95%) 6.7 (1.7, 25.7)). We concluded that both bougies performed best at 10 °C. [ABSTRACT FROM AUTHOR]

This study investigated the effects of smoking and gender on the haemodynamic response after tracheal intubation. Patients were assigned to one of four groups: female non-smokers, female smokers, male non-smokers and male smokers. After tracheal intubation, the highest mean (SD) increase in heart rate (30 (18) %) and rate–pressure product (40 (29) %) was seen in male smokers. The increases in heart rate and rate–pressure product in male smokers were significantly greater than those in female non-smokers, p < 0.05. The increase in rate–pressure product was significantly greater in male smokers than in male non-smokers, p = 0.022. [ABSTRACT FROM AUTHOR]

The article presents the new model of tracheal intubation and direct laryngoscopy which will assess the direct laryngoscopy into dynamic and static phases. The new model also aims to explain the extremes in normal patients, as well as the important components in a successful laryngoscopy. It is a clinically accurate model that recommends the best intubation strategy during difficulties.

A prospective observational study design was used to evaluate the clinical effectiveness of the Frova single-use tracheal tube introducer. Data were collected from 203 patients. Consultants and trainee anaesthetists completed 61 (30%) and 142 (70%) forms respectively, when the Frova introducer was used. It was successfully placed in the trachea in 194/203 (96%) of patients with two attempts at placement by the first clinician. The first clinician failed to either pass the Frova introducer or railroad the tube in six (3%) and 10 (5%) of the 203 patients respectively. The success rate by the first clinician was significantly influenced by the laryngeal view obtained (p < 0.0001). There was only one failure to place the Frova introducer in the trachea by either the first or second clinician. Airway trauma was detected in 11/203 (5%) patients. In six of these 11 patients blood was detected on tracheal suction; ‘distal hold up’ was elicited in five of these six. The Frova introducer has a high success rate for tracheal placement but has noteworthy potential to produce airway trauma. [ABSTRACT FROM AUTHOR]

Traditional teaching of laryngoscopy is difficult due to the trainer and trainee lacking a shared view. The Karl Storz BERCI DCI® Video Laryngoscope provides a video image for the trainer and a direct view identical to that of a standard laryngoscope for the trainee. Forty-nine novice subjects were randomly assigned to a control group ( n = 24) taught using a standard Macintosh laryngoscope or a study group ( n = 25) taught using the Video Laryngoscope. Following training all subjects were assessed using a standard laryngoscope. Under simulated difficult airway conditions the study group performed better in terms of number of attempts (p = 0.02), number of repositioning manoeuvres required (p = 0.046) and teeth trauma (p = 0.034). The study group were more confident of the success of their tube placement (p = 0.035), found it easier than the control group (p = 0.042) and had improved knowledge of airway anatomy (p = 0.011). We conclude that video laryngoscopy confers benefits in the teaching of tracheal intubation. [ABSTRACT FROM AUTHOR]

The article discusses the intubation training using Northwick Park drill. The Northwick Park drill uses the Macintosh method but instead of watching the tip of the bougie enter the trachea. Macintosh used a tube with a bevel rotated 90 degrees. Failed intubation in obstetrics provides a valuable yardstick of trainee performance.

In a randomised double blind prospective study, we tested the hypothesis that postoperative pain is lower in patients who receive an ProSeal LMA™ laryngeal mask airway compared with a tracheal tube. One hundred consecutive female patients (ASA I–II, 18–75 years) undergoing laparoscopic gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. Anaesthesia management was identical for both groups and included induction of anaesthesia using propofol/fentanyl, and maintenance with propofol/remifentanil, muscle relaxation with rocuronium, positive pressure ventilation, gastric tube insertion, dexamethasone/tropisetron for anti-emetic prophylaxis, and diclofenac for pain prophylaxis. All types of postoperative pain were treated using intravenous patient-controlled analgesia (PCA) morphine. Patients and postoperative staff were unaware of the airway device used. Data were collected by a single blinded observer. We found that pain scores were lower for the ProSeal LMA at 2 h and 6 h but not at 24 h. Morphine requirements were lower for the ProSeal LMA by 30.4%, 30.6% and 23.3% at 2, 6 and 24 h, respectively. Nausea was less common with the ProSeal LMA than with the tracheal tube at 2 h and 6 h but not at 24 h. There were no differences in the frequency of vomiting, sore throat, dysphonia or dysphagia. We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery. [ABSTRACT FROM AUTHOR]

We compared the Airway Scope® with a gum elastic bougie and fibreoptic bronchoscope in a manikin with a simulated Cormack and Lehane Grade 3 laryngoscopic view. Twenty-seven anaesthetists intubated the trachea of the manikin with these devices and the time required for intubation was measured. They were then asked to rate the subjective difficulty of intubation (1 = very easy; 5 = very difficult). Mean (SD) intubation times were 16.6 (11.2) s with the Airway Scope, 29.4 (10.9) s with the gum elastic bougie (p < 0.0001), and 30.6 (20.0) s with the fibreoptic bronchoscope (p < 0.0001). The median (range) difficulty was 2 (1–4) with the Airway Scope, 3 (2–4) with the gum elastic bougie (p < 0.001), and 2 (1–5) with the fibreoptic bronchoscope (p = 0.014). In Cormack and Lehane grade 3 laryngoscopic views, the Airway Scope may enable faster and easier tracheal intubation than does a Macintosh laryngoscope with a gum elastic bougie or a fibreoptic bronchoscope. [ABSTRACT FROM AUTHOR]

We conducted a randomised study in 70 patients to assess the effect of orientation of a standard polyvinyl chloride tracheal tube on the ease of railroading the tube during awake fiberoptic orotracheal intubation. Conventional orientation of the tube (with the bevel of the tube directed to the patient's left) was compared with orientation of the tube with the bevel facing posteriorly. The success rate of intubation at the first attempt was higher with the bevel oriented posteriorly (35/35; 100%) than with the conventional orientation (21/35; 60%; p = 0.0001), and the intubating time was shorter (median (range) 7 (5–11) s and 11 (5–60) s, respectively; p = 0.0001). We recommend that the tracheal tube should be aligned in this manner when railroading it over the fibrescope during awake fibreoptic orotracheal intubation. [ABSTRACT FROM AUTHOR]

This study examines the incidence and site of tracheal tube impingement during nasotracheal fibreoptic intubation, and the efficacy of anticlockwise tube rotation to overcome the problem. Forty-three patients underwent fibreoptic-assisted nasotracheal intubation using a preformed nasal tube, and a second fibrescope was used to observe any obstruction to passage of the tracheal tube. Impingement occurred in 10 cases, with the most common site being the right arytenoid cartilage. Rotation resulted in successful intubation in all 10 cases, but proximal rotation did not always result in an equal degree of rotation at the tube tip. We conclude that the site of impingement for nasotracheal intubation with preformed nasal tubes is located at the posterior structures of the laryngeal inlet and that anticlockwise rotation is a simple and effective solution. [ABSTRACT FROM AUTHOR]

Airway manikins have traditionally been used for teaching mask ventilation and tracheal intubation. There is an increasing need to use manikins for training in procedures such as insertion of the laryngeal mask airway. We have assessed four new airway training manikins (latest versions of the Airway Trainer™ (Laerdal, Norway), Airway Management Trainer™(Ambu, UK), ‘Bill 1’™(VBM, Germany) and Airsim™(Trucorp, Ireland)) as simulators for insertion of the LMA Classic™ laryngeal mask airway. Twenty volunteer anaesthetists inserted a size-4 laryngeal mask airway five times into each of the four manikins, in random order. Each insertion was assessed using objective and subjective tests. Subjective assessment varied widely but overall assessment indicated that the Airway Management Trainer was the poorest simulator for insertion of the laryngeal mask airway. The ‘Bill 1’ and Airsim manikins performed best as simulators for insertion of the laryngeal mask airway, although realistic ventilation with ‘Bill 1’ was not possible. [ABSTRACT FROM AUTHOR]

An endobronchial tube (Macintosh-Leatherdale) was used to secure the airway for a tracheal resection and end-to-end anastomosis. This lung separation device enabled insertion of both a fibreoptic bronchoscope and a tube exchange catheter. These were required after the trachea was transected and re-anastomosis proved surgically difficult. The airway exchange catheter allowed for jet ventilation and later a tube change when an emergency occurred. Options and management issues for tracheal surgery and lung separators are discussed. A case is made for a re-evaluation of endobronchial tubes both as a useful conduit for modern airway instruments and as an alternative to small double-lumen tubes for the increasing population of obese patients weighing > 100 kg, requiring thoracic surgery. [ABSTRACT FROM AUTHOR]

Airway manikins have traditionally been used for teaching mask ventilation and tracheal intubation. There is an increasing need to use manikins for training in procedures such as insertion of the laryngeal mask airway. We have assessed four new airway training manikins (latest versions of the Airway Trainer™ (Laerdal, Norway), Airway Management Trainer™(Ambu, UK), ‘Bill 1’™(VBM, Germany) and Airsim™(Trucorp, Ireland)) as simulators for insertion of the LMA Classic™ laryngeal mask airway. Twenty volunteer anaesthetists inserted a size-4 laryngeal mask airway five times into each of the four manikins, in random order. Each insertion was assessed using objective and subjective tests. Subjective assessment varied widely but overall assessment indicated that the Airway Management Trainer was the poorest simulator for insertion of the laryngeal mask airway. The ‘Bill 1’ and Airsim manikins performed best as simulators for insertion of the laryngeal mask airway, although realistic ventilation with ‘Bill 1’ was not possible. [ABSTRACT FROM AUTHOR]

High-volume, low-pressure tracheal cuffs of disposable double lumen tubes may offer limited protection to the dependent lung if fluid leaks through folds in the inflated cuffs. This study was undertaken to determine the incidence of fluid leakage past the tracheal cuff and whether gel lubrication reduces the incidence. Fifty-five patients were randomly assigned to receive a double lumen tube with or without gel lubrication. The dependent lung was intubated. With the patient in the lateral position, methylthionium chloride was administered above the tracheal cuff via a pre-attached catheter. Fibreoptic bronchoscopy was performed to determine if dye had passed the tracheal cuff. Three patients were excluded. Dye leakage was seen in 12/27 and 3/25 patients in the unlubricated and lubricated group, respectively (p = 0.014). Gel lubrication significantly reduces fluid leakage past the tracheal cuff of a double lumen tube and should be considered for all thoracic surgical patients requiring one-lung ventilation. [ABSTRACT FROM AUTHOR]

The single tapered dilator kit is the most commonly used percutaneous tracheostomy set in the UK. The Cook Blue Rhino™ and the Portex Ultraperc™ were compared in the laboratory on mannequin and porcine airway models. The following data were collected: the subjective ease of dilating the trachea and inserting the tracheostomy tube; the time taken and the anterior–posterior compression during dilatation and tube insertion; the incidence and extent of posterior tracheal wall damage. During dilatation, the Blue Rhino™ caused less mean percentage anterior–posterior compression (34.8% vs. 51.5%, p = 0.0014). There was no difference in subjective ease or time for dilatation in either mannequin or porcine airway models. During insertion of the tracheostomy tube, the Ultraperc™ was subjectively easier in the porcine airway model ( p = 0.001); had a shorter median insertion time in both the mannequin (3 s vs. 7.2 s, p = 0.0006) and the porcine airway model (4.3 s vs. 8.5 s, p = 0.0005); the mean percentage anterior–posterior compression caused was less in the mannequin (51.5% vs. 76%, p = 0.0008). The overall incidence of posterior wall damage was 65% with 25% having deep lacerations. There was no difference in the incidence of damage between the two sets. The Ultraperc™ therefore has advantages during tracheostomy tube insertion that are statistically and clinically significant. The advantages are probably due to the presence of the tracheostomy tube introducer. [ABSTRACT FROM AUTHOR]

The single tapered dilator kit is the most commonly used percutaneous tracheostomy set in the UK. The Cook Blue Rhino™ and the Portex Ultraperc™ were compared in the laboratory on mannequin and porcine airway models. The following data were collected: the subjective ease of dilating the trachea and inserting the tracheostomy tube; the time taken and the anterior–posterior compression during dilatation and tube insertion; the incidence and extent of posterior tracheal wall damage. During dilatation, the Blue Rhino™ caused less mean percentage anterior–posterior compression (34.8% vs. 51.5%, p = 0.0014). There was no difference in subjective ease or time for dilatation in either mannequin or porcine airway models. During insertion of the tracheostomy tube, the Ultraperc™ was subjectively easier in the porcine airway model ( p = 0.001); had a shorter median insertion time in both the mannequin (3 s vs. 7.2 s, p = 0.0006) and the porcine airway model (4.3 s vs. 8.5 s, p = 0.0005); the mean percentage anterior–posterior compression caused was less in the mannequin (51.5% vs. 76%, p = 0.0008). The overall incidence of posterior wall damage was 65% with 25% having deep lacerations. There was no difference in the incidence of damage between the two sets. The Ultraperc™ therefore has advantages during tracheostomy tube insertion that are statistically and clinically significant. The advantages are probably due to the presence of the tracheostomy tube introducer. [ABSTRACT FROM AUTHOR]

In the South-West Thames region of the United Kingdom, during a 5-year period from 1999 to 2003, there were 20 failed tracheal intubations occurring in 4768 obstetric general anaesthetics (incidence 1 : 238). In half of the 16 cases for which the patient's notes could be examined there was a failure to follow an accepted protocol for failed tracheal intubation. [ABSTRACT FROM AUTHOR]

We compared times to intubate the trachea orally and success rates using two fibreoptically assisted techniques in 42 healthy patients with normal airways using (a) a 6.0-mm nasal RAE tracheal tube passed through a classic laryngeal mask airway (CLMA group) or (b) a 6.0-mm nasal RAE tracheal tube passed through a new disposable Portex Soft Seal laryngeal mask airway (PLMA group). The mean (SD) total intubation times were 82 (14) and 80 (17) s, respectively (p= 0.55). The success rates for intubation at the first attempt were similar (17/21 in the CLMA vs. 16/21 in the PLMA group; p = 0.50). We conclude that there is no clinically significant difference between the times to intubate the trachea or success rates using these two devices, but there may be other more subtle measures which might influence the choice of device in clinical practice. Finally, in the course of this study we developed a grading scale to describe the laryngeal views obtained when using a fibrescope passed through supraglottic airway devices. [ABSTRACT FROM AUTHOR]

Changes in the tracheal tube tip to carina distance were measured by radiographic screening following various head postures in 45 children undergoing cardiac catheterisation under general anaesthesia who were intubated via nasal and oral routes. Extension of the head moved the tracheal tube away from the carina and flexion moved it towards the carina in both routes. Endobronchial intubation was noted during neck flexion in a significant proportion of children intubated orally but none occurred during nasal intubation. Extension produced greater upward movement of the tracheal tube tip in the oral route than the nasal route. In contrast, flexion produced greater downward movement in the nasal route in some patients. The direction of movement with lateral rotation and use of a shoulder roll was inconsistent. [ABSTRACT FROM AUTHOR]

In this study we developed a model lung to compare the effectiveness of ventilation using four different cricothyrotomy devices. The Ravussin 13G cannula (VBM Medical), the Quicktrach cannula 4 mm ID (VBM Medical), the Melker cannula 6 mm ID (Cook) and a cuffed tracheal tube 6 mm ID were used in turn to ventilate the model lung through a cricothyrotomy over a range of upper airway resistances. The 6 mm cuffed tracheal tube provided consistently good ventilation independent of upper airway resistance . The 6 mm ID Melker device provided at least reasonable and at best very good ventilation, whatever the patency of the upper airway. The Ravussin cannula could ventilate well with the jet ventilator with low upper airway resistance but could not ventilate at all with complete upper airway obstruction . The Quicktrach performed poorly with low upper airway resistance but well with increased upper airway resistance. With its easier insertion, fewer complications compared to a surgical cricothyrotomy, and the ability to use it with a standard anaesthetic circuit, the authors feel that the 6 mm Melker canula is the technique of choice for emergency trans-tracheal ventilation. [ABSTRACT FROM AUTHOR]

Tracheal airway pressures were measured via a transduced fibrescope during transtracheal jet ventilation in 10 patients. Ravussin transtracheal jet ventilation catheters were inserted under local anaesthesia. Following induction of general anaesthesia, tracheal airway pressures were measured at three anatomical levels during fibreoptic intubation. Overall pressure changes during transtracheal jet ventilation were small with the maximal pressure increase (13 mmHg) measured at the carina. [ABSTRACT FROM AUTHOR]

In a randomised cross-over study, 50 anaesthetists attempted to place a multiple-use bougie in the trachea of a manikin, when holding it at either 20 cm or 30 cm from the tip. A grade 3 laryngoscopic view was simulated. The anaesthetists were blinded to success (tracheal placement) or failure (oesophageal placement). The success rates when held at 20 and 30 cm distance from the tip were 68 and 62%, respectively ( p = 0.55). In a separate experiment, multiple and single-use bougies were held at four different positions and pressed onto a disc attached to a force transducer. The peak force exerted by the single-use bougies was two to three times greater than that which could be exerted by the multiple-use bougies ( p < 0.0001). Holding the bougie at either 20 or 30 cm distance from the tip is unlikely to influence bougie placement. The single-use bougie is much more likely to cause trauma to tissue during placement, particularly if held close to the tip. [ABSTRACT FROM AUTHOR]

Tracheal intubating conditions were assessed in 112 children after induction of anaesthesia with propofol and remifentanil 1.0, 2.0 or 3.0 µg.kg−1. Subjects in a control group were given propofol and mivacurium 0.2 mg.kg−1. Haemodynamic and respiratory parameters were recorded. Plasma catecholamine levels were measured in a subgroup of 40 children. Intubating conditions were acceptable in 14/28 (50%), 18/26 (69%) and 22/27 (82%) in those subjects given remifentanil 1.0, 2.0 or 3.0 µg.kg−1, respectively, and in 27/28 (96%) of the control group. Intubating conditions in subjects given remifentanil 3.0 µg.kg−1 were better than in those given remifentanil 1.0 µg.kg−1 ( p < 0.05). There were no significant differences in intubating conditions between those given remifentanil 3.0 µg.kg−1 and the control group. Systolic blood pressure and heart rate increased in response to tracheal intubation in subjects given remifentanil 1.0 µg.kg−1 and in the control group ( p < 0.05). Time to resumption of spontaneous respiration was prolonged in subjects given remifentanil 3.0 µg.kg−1 ( p < 0.001). In conclusion, remifentanil 2 µg.kg−1 provides acceptable intubating conditions and haemodynamic stability without prolonging the return of spontaneous respiration. [ABSTRACT FROM AUTHOR]

Summary We conducted a review of routine anaesthetic audit data collected between April 1995 and December 2001 at Northampton General Hospital. A total of 97 904 anaesthetics were given. The average monthly rate of tracheal intubation fell during the study period from ∼450 per month to ∼280 per month. This was largely at the expense of tracheal tubes used during normal working hours, which fell by 40% (from ∼390 per month to ∼230 per month). Use outside normal working hours did not change. Of those cases managed in normal working hours with a tracheal tube, the decline in use over time was most obvious in patients of ASA physical status 1–2, and whose surgery was classified as elective or scheduled. The proportion of cases classified as ASA 3–5 or whose surgery was urgent or emergency increased (from 15.5% to 22.3%, and from 7.5% to 15.5%, respectively.) There was considerable variation across surgical specialities, with the greatest decline in tracheal intubation in head and neck surgery. These changes in practice have implications for the teaching of airway management skills. [ABSTRACT FROM AUTHOR]

Summary Thirty anaesthetists attempted to place a derived ‘optimal’ curve bougie or a straight bougie in the trachea of a manikin, in a randomised cross-over study. A Grade 3 Cormack and Lehane laryngoscopic view was simulated. The anaesthetists were blinded to success (tracheal placement) or failure (oesophageal placement). The success rates with the curved and straight bougies were 83 and 7%, respectively, giving a difference (95% confidence interval) of 77% (54–87%) between the two bougies (p < 0.0001). On a separate occasion, under identical laboratory conditions, 30 anaesthetists attempted to place a straight coudé (angled)-tipped bougie or a straight straight-tipped bougie in the trachea of a manikin. The success rates with the coudé- and straight-tipped bougies were 43 and 0%, respectively, giving a difference (95% confidence interval) of 43% (21–61%) between the two bougies (p < 0.001). These results suggest that bougies used to facilitate difficult intubation should be curved and have a coudé tip. [ABSTRACT FROM AUTHOR]

Summary We studied the reasons for difficulty with tracheal intubation over a fibrescope, and whether cricoid pressure facilitated intubation, in 50 patients. After induction of anaesthesia and neuromuscular blockade in 10 patients (phase 1), we attempted to clarify the reasons for difficulty in advancing a tracheal tube over an orally-inserted fibrescope, by observing through another fibrescope that was inserted nasally into the pharynx. In the next 40 patients (phase 2), we studied the effect of cricoid pressure on the success rate of tracheal intubation over the fibrescope. After a fibrescope (with a tracheal tube over it) had been inserted orally into the trachea, patients were randomly allocated to receive either criocoid pressure or sham pressure, and the success rate of intubation within 60 s was assessed. In phase 1, the tube was advanced into the trachea without difficulty in three of 10 patients. In the remaining seven patients, the tube impacted on the epiglottis in one patient and on the arytenoid cartilage in another two patients, and the tube migrated into the hypopharynx in the remaining four patients. In phase 2, tracheal intubation was successful within 60 s in seven of 21 patients (33%) without cricoid pressure, compared with 12 of 19 patients (63%) when cricoid pressure was applied (95% CI for difference 2–59%; p = 0.04). We conclude that cricoid pressure facilitates fibrescope-aided tracheal intubation. [ABSTRACT FROM AUTHOR]