A randomised crossover comparison of manikin ventilation through Soft Seal®, i‐gel™ and AuraOnce™ supraglottic airway devices by surf lifeguards

Forty surf lifeguards attempted to ventilate a manikin through one out of three supraglottic airways inserted in random order: the Portex^® Soft Seal^®; the Intersurgical^® i‐gel?; and the Ambu^® AuraOnce?. We recorded the time to ventilate and the proportion of inflations that were successful, without and then with concurrent chest compressions. The mean (SD) time to ventilate with the Soft Seal, i‐gel and AuraOnce was 35.2 (7.2)s, 15.6 (3.3)s and 35.1 (8.5) s, respectively, p < 0.0001. Concurrent chest compression prolonged the time to ventilate by 5.0 (1.3–8.1)%, p = 0.0072. The rate of successful ventilations through the Soft Seal (100%) was more than through the AuraOnce (92%), p < 0.0001, neither of which was different from the i‐gel (97%). The mean (SD) tidal volumes through the Soft Seal, i‐gel and AuraOnce were 0.65 (0.14) l, 0.50 (0.16) l and 0.39 (0.19) l, respectively. Most lifeguards (85%) preferred the i‐gel. Ventilation through supraglottic airway devices may be considered for resuscitation by surf lifeguards.     

A randomised crossover trial comparing a single‐use polyvinyl chloride laryngeal mask airway with a single‐use silicone laryngeal mask airway

We compared insertion rates of single‐use polyvinyl chloride laryngeal mask airways (LMAs) vs single‐use silicone LMAs in 72 anaesthetised patients. Both airways were produced by Flexicare Medical. Laryngeal mask airway insertion was successful on the first attempt in 68/72 (94%) polyvinyl chloride LMAs vs 64/72 (89%) silicone LMAs (p = 0.39). Overall insertion rates were 72/72 (100%) for the polyvinyl chloride LMAs and 71/72 (99%) for the silicone LMAs (p = 1.0). Mean (SD) insertion times were similar for polyvinyl chloride and silicone LMAs: 24.3 (5.1)s vs 24.8 (7.8)s (p = 0.64). Laryngeal mask airway position, as assessed using a fibrescope, was not different (p = 0.077). The median (IQR [range]) leak pressure was 16 (12–20 [6–30]) cmH₂O for the polyvinyl LMA and 18 (13–22 [6–30]) cmH₂O or the silicone LMA (p = 0.037). In conclusion, we did not find any important differences between polyvinyl chloride and silicone laryngeal mask airways.     

A randomised crossover trial comparing the i‐gel supraglottic airway and classic laryngeal mask airway*

In a randomised cross‐over study, we compared the performance of the single use i‐gel supraglottic airway and reusable classic laryngeal mask airway (cLMA^TM) in 50 healthy anaesthetised patients who were breathing spontaneously. Primary outcome was successful insertion at first attempt. Secondary outcomes included overall insertion success rate, ease of insertion, leak pressure and fibreoptic position. Success rate for insertion at the first attempt was significantly different (54% with i‐gel vs 86% with cLMA; p = 0.001). Overall success after two attempts (when the anaesthetist was allowed to change the size of the device) improved to 84% with i‐gel vs 92% with cLMA; p = 0.22. In 14 patients, the i‐gel when used first needed to be replaced with a larger size. Leak pressure was higher for the i‐gel (median [IQR] 20 [14–24] cm H₂O than the cLMA 17 [12–22] cm H₂O; p = 0.023). The fibreoptic view through the device was significantly better with the i‐gel than the cLMA, which was statistically significant (p = 0.03). We conclude that, with its current sizing recommendations, the i‐gel is not an acceptable alternative to cLMA. However because of the significantly improved success rate after a larger sized i‐gel was used, we recommend the manufacturer to review the sizing guidelines to improve the success rate.     

A comparison of the i‐gel™ and the PRO‐Breathe® laryngeal mask during pressure support ventilation in children

Many studies comparing the i‐gel^? with laryngeal masks include patients in whom laryngeal mask cuff inflation pressures are higher than recommended, or involve the use of neuromuscular blocking drugs and positive pressure ventilation. We compared the i‐gel with the PRO‐Breathe^® laryngeal mask in anaesthetised, spontaneously breathing children. Two hundred patients aged up to 16 years were randomly allocated to either the i‐gel or the PRO‐Breathe laryngeal mask. The PRO‐Breathe was inflated to an intracuff pressure of 40 cmH₂O. All patients received pressure support of 10 cmH₂O and positive end‐expiratory pressure of 5 cmH₂O. Successful insertion at the first attempt was 82% for the i‐gel compared with 93% for the PRO‐Breathe (p = 0.019). Leakage volume was significantly higher with i‐gel sizes 1.5 (p = 0.015), 2 (p = 0.375), 2.5 (p = 0.021) and 3 (p = 0.003) compared with the equivalent‐sized PRO‐Breathe device. Device dislodgement following successful initial placement was more frequent with the i‐gel (5%) compared with the PRO‐Breathe laryngeal mask (0%). We conclude that the PRO‐Breathe laryngeal mask is superior to the i‐gel in terms of leakage volume and device dislodgement.     

A comparison of fibreoptic‐guided tracheal intubation through the Ambu®Aura‐i™, the intubating laryngeal mask airway and the i‐gel™: a manikin study

We compared the Aura‐i ^? , intubating laryngeal mask airway and i‐gel ^? as conduits for fibreoptic‐guided tracheal intubation in a manikin. Thirty anaesthetists each performed two tracheal intubations through each device, a total of 180 intubations. The median (IQR [range]) time to complete the first intubation was 40 (31–50 [15–162]) s, 37 (34–48 [25–75]) s and 28 (22–35 [14–59]) s for the Aura‐i, intubating laryngeal mask airway and i‐gel, respectively. Tracheal intubation through the i‐gel was the quickest (p < 0.01). Resistance to railroading of the tracheal tube over the fibrescope was significantly greater through the Aura‐i compared with the intubating laryngeal mask airway and the i‐gel (p = 0.001). There were no failures to intubate through the intubating laryngeal mask airway or the i‐gel but six intubation attempts through the Aura‐i were unsuccessful, in five owing to a railroading failure and in one owing to accidental oesophageal intubation. We conclude that the Aura‐i does not perform as well as the intubating laryngeal mask airway or the i‐gel as an adjunct for performing fibreoptic‐guided tracheal intubation.     

Risk factors for overactive bladder in the elderly population: A community‐based study with face‐to‐face interview

Objectives: The aim of this study was to measure the prevalence of and risk factors for overactive bladder (OAB) in the elderly. Methods: A cross‐sectional study of elderly subjects was conducted by analyzing data from a community‐based Comprehensive Geriatric Assessment on people aged 70 years or older. Trained interviewers performed face‐to‐face interviews for the assessment of urological symptoms. OAB definition was based on urgency and eight or more episodes of urination per day. The subjects completed a self‐administered questionnaire including lifestyle evaluation, Geriatric Depression Scale, Mini‐Mental Status Examination and medical history. Brachial‐ankle pulse wave velocity was recorded to assess atherosclerotic disease. The analysis included 833 subjects, after the exclusion of 115 subjects who provided insufficient information. Results: Based on the definition of OAB, 153 subjects (18.4%) were identified as having OAB. Univariate analysis showed a significant association between OAB and depressive symptoms. Multivariate analysis showed that the risk of having OAB was significantly higher in subjects with depressive symptoms, current drinkers, and overweight subjects with odds ratios of 2.37 (1.60–3.52, 95% confidence interval), 1.65 (1.04–2.62), and 1.51 (1.02–2.24), respectively. Conclusions: This is the first report to show an association between OAB and depressive symptoms and alcohol intake in an epidemiological study of elderly people. The reasons for these correlations remain unclear, but should be the foci of future OAB studies.     

A randomised crossover comparison of patient-controlled sedation and patient-maintained sedation using propofol

This randomised, crossover study compared patient-controlled sedation using boluses of propofol and patient-maintained sedation using a target-controlled infusion of propofol. Twenty-three patients aged 18-35 years having surgical removal of bilateral third molar teeth under local anaesthesia during two separate visits were studied. In the majority of patients, both techniques provided moderate sedation, good operating conditions, stable physiological parameters and a high degree of patient satisfaction. Two patients became over-sedated during patient-controlled sedation. The time taken for titration to adequate sedation was longer with patient-maintained sedation than with patient-controlled sedation [mean (SD) = 8.6 (3.7) min vs. 5.7 (3.1) min, p < 0.005]. The mean overall propofol consumption was similar with both techniques. The majority of patients preferred patient-maintained sedation to patient-controlled sedation, p < 0.05.     

A comparison of the Miller laryngoscope versus the prototype neonatal offset‐blade laryngoscope in a manikin

Laryngoscope blades used to intubate newborn babies are relatively bulky and frequently exert high pressure on the upper jaw. We tested a prototype neonatal offset‐blade laryngoscope (NOBL) developed to overcome these limitations. Our aims were to compare the pressure on the upper jaw exerted by a size 0 Miller laryngoscope and the NOBL on a neonatal manikin, as well as the time taken to intubate the trachea and the area of view of the larynx. Twenty healthcare professionals with more than five years of experience in neonatal intensive care took part; the findings were assessed using pressure‐sensitive film and photographs. High‐pressure indentation occurred in 17 (85%) attempts using the Miller versus 1 (5%) using the NOBL (p = 0.0001). The median (IQR [range]) pressure exerted with the Miller laryngoscope was 455 (350–526 [75–650]) kPa vs 80 (0–133 [0–195]) kPa with the NOBL (p < 0.0001). The area of pressure exerted with the Miller laryngoscope was 68 (32–82 [0–110]) mm² vs 8 (0–23 [0–40]) mm² with the NOBL (p < 0.0001). The time to intubate was 8.3 (7.3–10.1[4–19]) s for the Miller and 8.0 (5.6–9.6 [4–13.5]) s for the NOBL (p < 0.0001). The area of view blocked by the Miller laryngoscope was 38% of the oral orifice versus 12% with the NOBL. We conclude that the NOBL significantly reduced undesired pressure on the upper jaw during tracheal intubation and improved the view of the larynx compared with a conventional laryngoscope.     

Comparison of fibrescope guided intubation via the classic laryngeal mask airway and i‐gel in a manikin*

We compared the classic laryngeal mask airway and i‐gel as adjuncts to fibrescope guided intubation in a manikin. Two methods of intubation were compared with each device: the tracheal tube directly over the fibrescope; and the tracheal tube over an Aintree Intubation Catheter. Thirty‐two anaesthetists took part in this randomised crossover study. Each anaesthetist performed two intubations with each method via each device. The mean (SD) time for the first intubation using the tracheal tube over the fibrescope was 43 (24) s with the classic laryngeal mask airway and 22 (9) s with the i‐gel (95% CI for the difference 12–30 s, p < 0.0001). The mean (SD) times for the first intubation when using the Aintree Intubation Catheter was 46 (24) s with the classic laryngeal mask airway and 37 (9) s with the i‐gel (95% CI for the difference 5–12 s, p < 0.0001). We recorded five (5/64, 8%) oesophageal intubations when using the classic laryngeal mask airway and none when using the i‐gel. The participants rated the ease of railroading of the tracheal tube and railroading the Aintree Intubation Catheter over the fibrescope to be significantly easier (p < 0.0001 and p = 0.002 respectively) when using the i‐gel than when using the classic laryngeal mask airway. Furthermore, 30/32 (94%) of anaesthetists reported preference for the i‐gel over the classic laryngeal mask airway for fibrescope guided tracheal intubation when managing a difficult airway. We conclude that the i‐gel is likely to be a more appropriate conduit than the classic laryngeal mask airway for fibrescope guided intubation irrespective of the intubation method used.     

A comparison of the Glidescope® and Karl Storz DCI® videolaryngoscopes in a paediatric manikin*

A new paediatric Glidescope^® (Cobalt GVL^® Stat) has recently become available. This varies in design from the Karl Storz DCI^® videolaryngoscope, as it possesses a short curved disposable blade compared with the narrower straighter blade of the Storz^®. We compared the time taken for tracheal intubation under normal and difficult intubation conditions in a paediatric manikin. A total of 32 anaesthetists completed four intubations in a random order, with each participant blinded to the airway condition. We hypothesised there would be no difference between the devices. The results showed no difference in tracheal intubation time between the Glidescope and the Storz videolaryngoscope. The mean (SD) times under normal conditions were 18.8 (5.2) s vs 19.9 (6.1) s, (p = 0.16), respectively. Under difficult conditions the times were 22.6 (10.5) vs 27.0 (14.2) s, (p = 0.13), respectively. There were no differences in the visual analogue scores for field of view, ease of use, willingness to use in an emergency, and overall satisfaction.     

Tracheal intubation with restricted access: a randomised comparison of the Pentax-Airway Scope and Macintosh laryngoscope in a manikin

Ten anaesthetists assessed the ease of tracheal intubation (time to see the glottis, to intubate the trachea and to ventilate), using the Pentax Airway Scope and Macintosh laryngoscope in a manikin, in three simulated circumstances of restricted laryngoscopy: (1) the patient lying supine on the ground; (2) the patient lying supine on the ground with the head close to a wall; (3) the patient confined to a car driver's seat. For the Pentax Airway Scope, intubation was successful (within 2 min) in all three circumstances. For the Macintosh laryngoscope, intubation was successful in all cases in circumstance (1), eight in circumstance (2), and five in circumstance (3). In circumstances (2) and (3), the Pentax Airway Scope needed significantly shorter time to see the vocal cords (median [95% confidence interval] for difference: 4.5 [0.5–9.5] s in circumstance (2), and 12.5 [7.0–32.5] s in circumstance (3)), shorter time to intubate (median [95% confidence interval] for difference: 21.0 [5.5–38.5] s in circumstance (2), and 40.5 [17.5–64.0] s in circumstance (3)), and shorter time to ventilate the lungs (median [95% confidence interval] for difference: 18. 3 [4.5–36.0] s in circumstance (2), and 47.5 [16.0–84.5] s in circumstance (3)). These results indicate that, in situations where access to the patient's head is restricted, the Pentax Airway Scope is more effective than the Macintosh laryngoscope.     

A comparison of the laryngeal tube and bag-valve mask ventilation by emergency medical technicians: a feasibility study in anesthetized patients

Airway management is of major importance in emergency care. The basic technique for all health care providers is bag-valve mask (BVM) ventilation, which requires skill and may be difficult to perform. Endotracheal intubation, which is the advanced method for securing the airway, is a demanding technique that has been shown to be associated with infrequent success, even when used by experienced paramedical personnel. Therefore, alternative airway devices have been sought. The use of the laryngeal tube (LT) by experienced anesthesia personnel had been studied in anesthetized patients and manikins in emergency medical training. We decided to evaluate the ability of inexperienced firefighter-emergency medical technician students (fire-EMT) to insert the LT or perform BVM in anesthetized patients. Thirty fire-EMTs randomly inserted the LT (n = 15) and performed 1 min of ventilation or used the BVM (n = 15). We found that all students successfully (100%) inserted the LT. Those who inserted the LT on the first attempt (73%) required 48.2 +/- 14.7 s for the insertion. Both the LT and BVM provided adequate oxygenation and ventilation. In this study, we found that inexperienced fire-EMT students inserted LT and performed 1-min ventilation with a reasonable success rate and insertion time in anesthetized patients.     

A randomised, crossover comparison between the CobraPLA and the LMA Classic in paralysed patients

We performed a randomised, crossover study in 38 anaesthetised and paralysed patients to compare the performance of the CobraPLA and the LMA Classic during controlled ventilation. The median (IQR [range]) airway leak pressure was 23.0 (20-24 [12-30]) cmH(2)O for the CobraPLA and 15.0 (12-19 [8-30]) cmH(2)O for the LMA Classic (p < 0.001). The median (IQR [range]) insertion time was 15.0 (11-26 [9-31]) s for the CobraPLA and 22.5 (20-25 [15-50]) s for the LMA Classic (p < 0.001). There was no significant difference between the two devices for the number of insertion and reposition attempts, the anatomical position scored by fibreoptic bronchoscopy or the peak and plateau airway pressures. There were no adverse events during anaesthesia. The CobraPLA provides a better airway leak pressure and takes less time to insert than the LMA Classic in paralysed patients. Our data show that the CobraPLA can be used to secure a patent airway during controlled ventilation in selected patients.     

Tracheal intubation in daylight and in the dark: a randomised comparison of the Airway Scope®, Airtraq®, and Macintosh laryngoscope in a manikin

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.     

A comparison of bonfils fiberscope‐assisted laryngoscopy and standard direct laryngoscopy in simulated difficult pediatric intubation: a manikin study

Introduction: Difficult airway management in children is challenging. One alternative device to the gold standard of direct laryngoscopy is the STORZ Bonfils fiberscope (Karl Storz Endoscopy, Tuttlingen, Germany), a rigid fiberoptic stylette‐like scope with a curved tip. Although results in adults have been encouraging, reports regarding its use in children have been conflicting. We compared the effectiveness of a standard laryngoscope to the Bonfils fiberscope in a simulated difficult infant airway. Methods: Ten pediatric anesthesiologists were recruited for this study and asked to perform three sets of tasks. For the first task, each participant intubated an unaltered manikin (SimBaby ^TM, Laerdal, Puchheim, Germany) five times using a styletted 3.5 endotracheal tube (ETT) and a Miller 1 blade (group DL‐Normal). For the second task, a difficult airway configuration simulating a Cormack‐Lehane grade 3B view was created by fixing a Miller‐1 blade into position in the manikin using a laboratory stand. Each participant then intubated the manikin five times with a styletted 3.5 ETT using conventional technique but without touching the laryngoscope (group DL‐Difficult). In the third task, the manikin was kept in the same difficult airway configuration, and each participant intubated the manikin five times using a 3.5‐mm ETT mounted on the Bonfils fiberscope as an adjunct to direct laryngoscopy with the Miller‐1 blade (group BF‐Difficult). Primary outcomes were time to intubate and success rate. Results: A total of 150 intubations were performed. Correct ETT placement was achieved in 100% of attempts in group DL‐Normal, 90% of attempts in group DL‐Difficult and 98% of attempts in BF‐Difficult. Time to intubate averaged 14 s (interquartile range 12–16) in group DL‐Normal; 12 s (10–15) in group DL‐Difficult; and 11 s (10–18) in group BF‐Difficult. The percentage of glottic opening seen (POGO score) was 70% (70–80) in group DL‐Normal; 0% (0–0) in group DL‐Difficult; and 100% (100–100) in group BF‐Difficult. Discussion: The Bonfils fiberscope‐assisted laryngoscopy was easier to use and provided a better view of the larynx than simple direct laryngoscopy in the simulated difficult pediatric airway, but intubation success rate and time to intubate were not improved. Further studies of the Bonfils fibrescope as a pediatric airway adjunct are needed.