Kurt Ruetzler

Performance and skill retention of intubation by paramedics using seven different airway devices—A manikin study

INTRODUCTION Endotracheal intubation (ETI) is the most widespread method for emergency airway management. Several studies reported that ETI requires considerable skill and experience and if performed incorrectly, may result in serious adverse events. Unrecognized tube misplacement or oesophageal intubation is associated with high prehospital morbidity. This study investigates the usability of supraglottic airway devices compared to ETI and the skill retention of 41 previously inexperienced paramedics following training using a manikin model. METHODS 41 paramedics participated in this study. None had prior experience in airway management, apart from bag-valve ventilation. After a standardised audio-visual lecture lasting 45min, the paramedics participated in a practical demonstration using the advanced patient simulator SimMan(®) (Laerdal Medical, Stavanger, Norway). Afterwards, paramedics were instructed to perform airway-management using seven different techniques to secure the airway (ETI, Laryngeal mask unique [LMA], Proseal, Laryngeal tube disposable [LT-D(®)], I-Gel(®), Combitube(®), and EasyTube(®)) following a randomized sequence. Participants underwent reassessment after 3 months without any further training or practice in airway-management. RESULTS During the initial training session, ETI was successfully performed in 78% of cases, while 3 months later the success rate was 58%. For the supraglottic airway devices, five out of six were successfully used by all paramedics at both time points, the exception being Proseal(®). Our data show successful skill retention (success rate: 100%) after 3 months for five out of six supraglottic airway devices. Time to ventilation (T3) was significantly less for LMA, LT-D(®) and I-Gel(®) at all time points compared to ETI. CONCLUSION ETI performed by inexperienced paramedics is associated with a low success rate. In contrast, supraglottic airway devices like LMA, LT-D(®), I-Gel(®), Combitube(®) and EasyTube(®) are fast, safe and easy-to-use. Within the limitations of a manikin-study, this study suggests that inexperienced medical staff might benefit from using supraglottic airway devices for emergency airway management.

Randomized clinical trial comparing double-lumen tube and EZ-Blocker® for single-lung ventilation

BACKGROUND In several clinical situations, lung separation and single-lung ventilation (SLV) is essential. In these cases, the double-lumen tube (DLT) is the most widely used device. Bronchial blocker such as Univent or Arndt Blocker serves as an alternative. The EZ-Blocker(®) (EZ; AnaesthetIQ B.V., Rotterdam, The Netherlands) is a new device promising to exceed clinical performance of DLT. The aim of this study was to assess the clinical performance of EZ in comparison with conventional left-sided DLT. METHODS Forty adult patients undergoing elective thoracic surgery requiring thoracotomy and SLV were included in this study. The patients were randomly assigned to one of two groups: EZ (combined with conventional 7.5 or 8.5 mm single-lumen tube) or DLT (37 or 39 Fr left-sided DLT). Time for intubation procedure and time to verification of the correct position of EZ or DLT using fibreoptic bronchoscopy (FOB) were recorded. After surgery, a thoracic surgeon rated the quality of collapse of the lung (1-3 on a three-level scale). RESULTS Time for intubation using DLT 85.5 (54.8) s was significantly faster (P<0.001) than using EZ 192 (89.7) s, whereas time for bronchoscopy was not significantly different (P=0.556). Conditions of surgery were rated equally [DLT 1.3 (0.6) vs EZ 1.4 (0.6), P=0.681]. CONCLUSIONS Although time for intubation was longer with the EZ, the device proved to be an efficient and easy-to-use device. The EZ is a valuable alternative device to conventional DLT. Verification of the correct position of the EZ by FOB seems to be obligatory. This study was registered at http://www.clinicaltrials.gov (identifier: NCT01171560).

Hands-off time during insertion of six airway devices during cardiopulmonary resuscitation: A randomised manikin trial

INTRODUCTION Cardiopulmonary resuscitation (CPR) guidelines recommend limiting interruptions of chest compressions because prolonged hands-off (i.e., non-compression) time compromises tissue perfusion. 2010 European Resuscitation Council guidelines suggest that chest compressions should be paused less than 10 s during airway device insertion. METHODS With approval of the local ethics committee of the Medical University of Vienna and written informed consent, we recruited 40 voluntary emergency medical technicians, none of whom had advanced airway management experience. After a standardised audio-visual lecture and practical demonstration, technicians performed airway management with each six airway devices (endotracheal tube, Combitube, EasyTube, laryngeal tube, Laryngeal Mask Airway, and I-Gel) during on-going chest compressions in a randomised sequence on a Resusci Anne Advanced Simulator. Data were analysed using a mixed-effects model accounting for the repeated measurements and pair-wise comparisons among the airway devices. RESULTS The hands-off time associated with airway management using an endotracheal tube (including all intubation attempts) was 48 s (95% confidence interval: 43-53). The hands-off time for airway management using a laryngeal tube was 8.4 (3.4-16.4) s, Combitube 10.0 (4.9-15.1) s, EasyTube 11.4 (6.4-16.4) s, LMA 13.3 (8.2-18.3) s and for I-Gel 15.9 (10.8-20.9) s. Hands-off time was significantly longer with the conventional endotracheal tube than with any of the other airway systems. Only a third of the technicians successfully inserted an endotracheal tube whereas all of them successfully positioned each supraglottic device. CONCLUSION Supraglottic devices appear to be a reasonable emergency airway management strategy, even for inexperienced personnel.

Incidence of difficult airway situations during prehospital airway management by emergency physicians—A retrospective analysis of 692 consecutive patients ,

INTRODUCTION In the prehospital setting, advanced airway management is challenging as it is frequently affected by facial trauma, pharyngeal obstruction or limited access to the patient and/or the patients airway. Therefore, incidence of prehospital difficult airway management is likely to be higher compared to the in-hospital setting and success rates of advanced airway management range between 80 and 99%. METHODS 3961 patients treated by an emergency physician in Zurich, Switzerland were included in this retrospective analysis in order to determine the incidence of a difficult airway along with potential circumstantial risk factors like gender, necessity of CPR, NACA score, GCS, use and type of muscle relaxant and use of hypnotic drugs. RESULTS 692 patients underwent advanced prehospital airway management. Seven patients were excluded due to incomplete or incongruent documentation, resulting in 685 patients included in the statistical analysis. Difficult intubation was recorded in 22 patients, representing an incidence of a difficult airway of 3.2%. Of these 22 patients, 15 patients were intubated successfully, whereas seven patients (1%) had to be ventilated with a bag valve mask during the whole procedure. CONCLUSION In this physician-led service one out of five prehospital patients requires airway management. Incidence of advanced prehospital difficult airway management is 3.2% and eventual success rate is 99%, if performed by trained emergency physicians. A total of 1% of all prehospital intubation attempts failed and alternative airway device was necessary.

C-MAC videolaryngoscope compared with direct laryngoscopy for rapid sequence intubation in an emergency department: A randomised clinical trial.

BACKGROUND Airway management in the emergency room can be challenging when patients suffer from life-threatening conditions. Mental stress, ignorance of the patients medical history, potential cervical injury or immobilisation and the presence of vomit and/or blood may also contribute to a difficult airway. Videolaryngoscopes have been introduced into clinical practice to visualise the airway and ultimately increase the success rate of airway management. OBJECTIVE The aim of this study was to test the hypothesis that the C-MAC videolaryngoscope improves first-attempt intubation success rate compared with direct laryngoscopy in patients undergoing emergency rapid sequence intubation in the emergency room setting. DESIGN A randomised clinical trial. SETTING Emergency Department of the University Hospital, Zurich, Switzerland. PATIENTS With approval of the local ethics committee, we prospectively enrolled 150 patients between 18 and 99 years of age requiring emergency rapid sequence intubation in the emergency room of the University Hospital Zurich. Patients were randomised (1 : 1) to undergo tracheal intubation using the C-MAC videolaryngoscope or by direct laryngoscopy. INTERVENTIONS Owing to ethical considerations, patients who had sustained maxillo-facial trauma, immobilised cervical spine, known difficult airway or ongoing cardiopulmonary resuscitation were excluded from our study. All intubations were performed by one of three very experienced anaesthesia consultants. MAIN OUTCOME MEASURES First-attempt success rate served as our primary outcome parameter. Secondary outcome parameters were time to intubation; total number of intubation attempts; Cormack and Lehane score; inadvertent oesophageal intubation; ease of intubation; complications including violations of the teeth, injury/bleeding of the larynx/pharynx and aspiration/regurgitation of gastric contents; necessity of using further alternative airway devices for successful intubation; maximum decrease of oxygen saturation and technical problems with the device. RESULTS A total of 150 patients were enrolled, but three patients had to be excluded from the analysis, resulting in 74 patients in the C-MAC videolaryngoscopy group and 73 patients in the direct laryngoscopy group. Tracheal intubation was achieved successfully at the first attempt in 73 of 74 patients in the C-MAC group and all patients in the direct laryngoscopy group (P = 1.0). Time to intubation was similar (32 ± 11 vs. 31 ± 9 s, P = 0.51) in both groups. Visualisation of the vocal cords, represented as the Cormack and Lehane score, was significantly better using the C-MAC videolaryngoscope (P < 0.001). CONCLUSION Our study demonstrates that visualisation of the vocal cords was improved by using the C-MAC videolaryngoscope compared with direct laryngoscopy. Better visualisation did not improve first-attempt success rate, which in turn was probably based on the high level of experience of the participating anaesthesia consultants. TRIAL REGISTRATION Clinicaltrials.gov identifier NCT02297113.

Evaluation of advanced airway management in absolutely inexperienced hands: a randomized manikin trial.

Aims Endotracheal intubation (ETI) and basic ventilation techniques (i.e. mouth-to-mouth/nose, bag-valve-mask ventilation) require skills and training. As an alternative, supraglottic airway devices (SAD) are efficient and technically easy to insert. We therefore evaluated the time to ventilation, success rate, and skill retention for various airway management approaches by medical laypersons using a manikin model. Methods Fifty medical laypersons with no previous experience whatsoever in airway management or resuscitation were enrolled. All participants received a 1-h-long theoretical lecture and a practical demonstration of mouth-to-mouth ventilation, ETI, and six SAD. Afterwards, the laypersons performed mouth-to-mouth ventilation and used each of the seven airway-management systems on an advanced patient simulator (SimMan) in a random sequence. All participants were re-evaluated 3 months later without any further practical or theoretical demonstration. Results The success rates for ETI were 74% during the first evaluation and 64% during the second, whereas the success rate for all six SAD was 100% during all application attempts. The success rate for mouth-to-mouth ventilation was 86% initially and 84% 3 months later. The time to adequate mouth-to-mouth ventilation was 15±13 s initially and 16±7 s subsequently. ETI required 53±21 s during the initial evaluation and 44±16 s 3 months later. Conclusion A variety of SAD all proved to reliably secure airways quickly, even in the hands of complete novices. The SAD were much more effective than ETI, which often failed, and were even superior to mouth-to-mouth ventilation. SAD may thus be an appropriate first-line approach to field ventilation.

A Randomized, Double-Blind Comparison of Licorice Versus Sugar-Water Gargle for Prevention of Postoperative Sore Throat and Postextubation Coughing

BACKGROUND:One small study suggests that gargling with licorice before induction of anesthesia reduces the risk of postoperative sore throat. Double-lumen tubes are large and thus especially likely to provoke sore throats. We therefore tested the hypothesis that preoperative gargling with licorice solution prevents postoperative sore throat and postextubation coughing in patients intubated with double-lumen tubes. METHODS:We enrolled 236 patients having elective thoracic surgery who required intubation with a double-lumen endotracheal tube. Patients were randomly assigned to gargle 5 minutes before induction of anesthesia for 1 minute with: (1) Extractum Liquiritiae Fluidum (licorice 0.5 g); or (2) Sirupus Simplex (sugar 5 g); each diluted in 30 mL water. Sore throat and postextubation coughing were evaluated 30 minutes, 90 minutes, and 4 hours after arrival in the postanesthesia care unit, and the first postoperative morning using an 11-point Likert scale by an investigator blinded to treatment. RESULTS:The incidence of postoperative sore throat was significantly reduced in patients who gargled with licorice rather than sugar-water: 19% and 36% at 30 minutes, 10% and 35% at 1.5 hours, and 21% and 45% at 4 hours, respectively. The corresponding estimated treatment effects (relative risks) were 0.54 (95% CI, 0.30–0.99, licorice versus sugar-water; P = 0.005), 0.31 (0.14–0.68) (P < 0.001), and 0.48 (0.28–0.83) (P < 0.001). CONCLUSION:Licorice gargling halved the incidence of sore throat. Preinduction gargling with licorice appears to be a simple way to prevent a common and bothersome complication.

Evaluation of airway management associated hands-off time during cardiopulmonary resuscitation: a randomised manikin follow-up study

IntroductionAirway management is an important component of cardiopulmonary resuscitation (CPR). Recent guidelines recommend keeping any interruptions of chest compressions as short as possible and not lasting more than 10 seconds. Endotracheal intubation seems to be the ideal method for establishing a secure airway by experienced providers, but emergency medical technicians (EMT) often lack training and practice. For the EMTs supraglottic devices might serve as alternatives.Methods40 EMTs were trained in a 1-hour standardised audio-visual lesson to handle six different airway devices including endotracheal intubation, Combitube, EasyTube, I-Gel, Laryngeal Mask Airway and Laryngeal tube. EMTs performances were evaluated immediately after a brief practical demonstration, as well as after 1 and 3 months without any practice in between, in a randomised order. Hands-off time was pair-wise compared between airway devices using a repeated-measures mixed-effects model.ResultsOverall mean hands-off time was significantly (p<0.01) lower for Laryngeal tube (6.1s; confidence interval 5.2-6.9s), Combitube (7.9s; 95% CI 6.9-9.0s), EasyTube (8.8s; CI 7.3-10.3s), LMA (10.2s; CI 8.6-11.7s), and I-Gel (11.9s; CI 10.2-13.7s) compared to endotracheal intubation (39.4s; CI 34.0-44.9s). Hands-off time was within the recommended limit of 10s for Combitube, EasyTube and Laryngeal tube after 1 month and for all supraglottic devices after 3 months without any training, but far beyond recommended limits in all three evaluations for endotracheal intubation.ConclusionUsing supraglottic airway devices, EMTs achieved a hands-off time within the recommended time limit of 10s, even after three months without any training or practice. Supraglottic airway devices are recommended tools for EMTs with lack of experience in advanced airway management.

Evaluation of six different airway devices regarding regurgitation and pulmonary aspiration during cardio-pulmonary resuscitation (CPR) – A human cadaver pilot study

BACKGROUND Chest compressions and ventilation are lifesaving tasks during cardio-pulmonary resuscitation (CPR). Besides oxygenation, endotracheal intubation (ETI) during CPR is performed to avoid aspiration of gastric contents. If intubation is difficult or impossible, supraglottic airway devices are utilized. We tested six different airway devices regarding their potential to protect against regurgitation and aspiration during CPR in a randomized experimental human cadaver study. METHODS Five-hundred ml of 0.01% methylene-blue-solution were instilled into the stomach of 30 adult human cadavers via an oro-gastric tube. The cadavers were then randomly assigned to one of six groups, resulting in 5 cadavers in each group. Airway management was performed with either bag-valve ventilation, Laryngeal Tube, EasyTube, Laryngeal Mask (Classic), I-Gel, or ETI. Thereafter 5min of CPR were performed according to the 2010 Guidelines of the European Resuscitation Council. Pulmonary aspiration was defined as the presence of methylene-blue-solution below the vocal cords or the ETI cuff as assessed by fiber-optic bronchoscopy. RESULTS Thirty cadavers were included (14 females, 16 males). Aspiration was detected in three out of five cadavers receiving bag-valve ventilation and in two out of five intubated with LMA or I-Gel. In cadavers intubated with the LT, aspiration occurred in one out of five cases. No aspiration could be detected in cadavers intubated with ETI and EasyTube. CONCLUSION This study provides experimental evidence that, during CPR, ETI offers superior protection against regurgitation and pulmonary aspiration of gastric contents than supraglottic airway devices or bag-valve ventilation.

Forced-air and a novel patient-warming system (vitalHEAT vH2) comparably maintain normothermia during open abdominal surgery

BACKGROUND:The vitalHEAT vH2 (Dynatherm Medical, Inc., Fremont, California) system transfers heat through a single extremity using a combination of conductive heat (circulating warm water within soft fluid pads) with mild vacuum, which improves both vasodilation and contact between the heating element and the skin surface. We tested the hypothesis that core temperatures were not >0.5°C lower in patients warmed with the vitalHEAT system than with forced air. METHODS:Patients having general anesthesia for open abdominal surgery were randomly assigned to the circulating-water sleeve on 1 arm (n = 37) or an upper-body forced-air warming cover (n = 34). Patients were eligible to participate when body mass index was 20 to 36 kg/m2, age was 18 to 75 years, and ASA physical status was 1 to 3. Intraoperative distal esophageal (core) temperatures were recorded. Repeated-measures analysis and 1-tailed t tests were used to assess noninferiority of vitalHEAT to forced air using a noninferiority &dgr; of −0.5°C. RESULTS:Demographic and morphometric characteristics were similar, as were surgical details. Preoperative core temperatures were similar in each group. Intraoperative core temperatures were also similar with each warming system and were significantly noninferior during the first four hours of surgery. The observed difference in means was never more than about 0.2°C. After 4 hours of surgery, the average temperature was 36.3°C ± 0.6°C (mean ± SD) with the circulating-water sleeve (n = 18) and 36.4°C ± 0.5°C with forced air (n = 20), for a difference (95% confidence interval) of −0.21°C (−0.47, 0.06). CONCLUSIONS:The 2 systems thus apparently transfer comparable amounts of heat. Both appear suitable for maintaining normothermia even during large and long operations.