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Correspondence

Comparison of tracheal intubation by the Mackintosh laryngoscope and AirTraq during chest compression: a mannequin study

Gaszynski, Tomasz M

Author Information
European Journal of Anaesthesiology: March 2011 - Volume 28 - Issue 3 - p 225-226
doi: 10.1097/EJA.0b013e3283423472

Editor,

It is strongly advised by the European Resuscitation Council not to interrupt chest compressions for prolonged instrumental airway management in order to maximise coronary and cerebral perfusion pressure.1 Only a very short pause in chest compressions is allowed for fast endotracheal intubation. Skilled operators should even try to secure the airway without interruption in chest compressions.1 In previous reports it was shown that chest compressions prolonged the time needed for successful endotracheal intubation.2 The most common method of definite securing of the airway is still endotracheal intubation using a standard Mackintosh blade (McL). Unfortunately, this requires skills and skill maintenance training, especially in case of occasional users.3,4 The advised way of securing airway for those not well trained in endotracheal intubation rescuers is using supraglottic airway devices (SADs) such as the laryngeal mask airway.1 However, the best method to prevent possible aspiration of gastric content to the bronchus is endotracheal intubation. In emergency settings, all patients should be treated as full stomach patients. Chest compressions may increase the risk of regurgitation and aspiration during cardiopulmonary resuscitation (CPR). Therefore, endotracheal intubation should be performed in such cases. AirTraq (Prodol Meditec S.A., Vizcaya, Spain) is a new device for endotracheal intubation that has a very good learning curve and good skill maintenance and can be used instead of standard laryngoscope.5

We hypothesised that AirTraq may provide shorter intubation time and/or higher intubation success rate during uninterrupted chest compressions. In the studies reported here, we compared the performance of AirTraq and standard laryngoscope with McL in terms of the ease of airway management during chest compressions on a mannequin.

The protocol study was approved by Medical University of Lodz Ethics Committee (Protocol Number: RNN/607/10/KB; Chair person: Professor P. Polakowski; 12 October 2010). Forty-two final-year students of emergency medicine for paramedics took part in the study. They had only a little experience in endotracheal intubation on mannequin models. All participants had a standard 20 min training in the use of AirTraq. The simulated CPR scenario was endotracheal intubation using a standard laryngoscope with McL and endotracheal intubation using AirTraq. Airway management was performed without interruption of chest compressions on mannequin Ambu MegaCode Man (Ambu, Ballerup, Denmark) with a normal airway (no difficult airway simulation) lying on the ground. The time from insertion of the device into the mouth of the mannequin to achieving successful ventilation confirmed by volumeter on the mannequin during self-inflating bag ventilation was recorded. The size 3 blade of the McL or the standard AirTraq adult size was used in all cases in a randomised fashion. For each insertion, all airway devices and the mannequin's airway were well lubricated in accordance with the manufacturers' instructions. The internal diameter of the tracheal tube was 7.5 mm. The mannequin was placed on the floor, and all trials were performed at the same level. One student continued chest compressions, whereas the other one performed airway management. The frequency of chest compressions was 100 min−1, and a clock was used to keep it constant. The chest compression deepness of 4–5 cm was confirmed by electronic measurement by the Ambu MegaCode Man mannequin system. The statistical analysis was performed using Microsoft Excel.

The success ratio was the same for AirTraq and McL (76.2%) – 10 participants failed to intubate the mannequin using AirTraq and 10 using McL (in most cases not the same persons). The mean time from insertion of the studied devices into the mouth of the manniquin to achievement of correct ventilation was 22.9 s SD 12.5 vs. 21.8 s SD 13.3 in the AirTraq and McL groups, respectively. There were no significant differences between the two groups (P > 0.05).

In order to secure a patient's airway during cardiopulmonary resuscitation, the European Resuscitation Council recommends a tracheal intubation. This gold standard is a procedure which requires a highly qualified and experienced operator, who may not be present during the first minute of the emergency. An alternative to tracheal intubation is the use of a SAD which seems to be more convenient and easier for new users. However, endotracheal intubation is still the best method of securing airway, especially in resuscitated patients with a potentially full stomach. If tracheal intubation can be performed during uninterrupted chest compressions, this will sustain circulation during the intubation procedure and may lead to successful resuscitation. In Poland, like in many other countries in the world, the basic ambulance team consists of paramedics, not medical doctors (anaesthesiologists) as was the case a few years ago. Although paramedics are well trained in emergency airway management, they may have lesser skills to intubate patients than anaesthesiologists, so it is justified to offer them adequate equipment for endotracheal intubation designed for the difficult airway as is the AirTraq. In our study, the time needed and the success rate for successful endotracheal intubation were similar for McL and AirTraq, different from the results of other researchers. Koyama et al.6 performed a study comparing three types of laryngoscope on a mannequin to determine whether they enabled tracheal intubation while the mannequin's chest was rhythmically compressed. Thirty-five persons with little or no experience in intubation served as examinees. The laryngoscopes used were a conventional Macintosh laryngoscope, a new video laryngoscope, Pentax-AWS (Pentax, Tokyo, Japan), and an optic laryngoscope, AirTraq. Pentax-AWS is a device similar in construction and way of operating to AirTraq, but it may be easer to use in difficult settings because it has a displayer – the operator does not have to approach very close to the patient's face. During chest compression on the mannequin by an assistant, the examinee attempted to perform intubation. The success rates with the Pentax-AWS were significantly higher than those with the McL or AirTraq. The success ratios for AirTraq and McL were similar to our results (80 and 75%), but time needed for endotracheal tube placement during CPR using AirTraq was shorter than in our study (16 vs. 21.8 s). The reason for that may be the difference in experience with using AirTraq in our group compared with that of Koyama et al. Our paramedics had only 20 min' standard AirTraq training, but they had much more training on endotracheal intubation during their studies. Maybe longer training on AirTraq or similar devices (Pentax AWS) would result in a higher success ratio and could be a good alternative to standard McL use in CPR in an out-hospital setting.

On the basis of the results of our observation, we conclude that AirTraq is not a superior device for endotracheal intubation during CPR compared with a standard laryngoscope with McL after standard short training.

Acknowledgement

The author received no financial support from any company producing the devices evaluated here.

References

1 Hazinski MF, Nadkarni VM, Hickey RW, et al. Major changes in the 2005 AHA Guidelines for CPR and ECC: reaching the tipping point for change. Circulation 2005; 112:206–211.
2 Gatward JJ, Thomas MJ, Nolan JP, Cook TM. Effect of chest compressions on the time taken to insert airway devices in a manikin. Br J Anaesth 2008; 100:351–356.
3 Katz SH, Falk JL. Misplaced endotracheal tubes by paramedics in an urban emergency medical services system. Ann Emerg Med 2001; 37:32–37.
4 Jones JH, Murphy MP, Dickson RL, et al. Emergency physician-verified out-of-hospital intubation: miss rates by paramedics. Acad Emerg Med 2004; 11:707–709.
5 Maharaj CH, Costello J, Higgins BD, et al. Retention of tracheal intubation skills by novice personnel: a comparison of the Airtraq and Macintosh laryngoscopes. Anaesthesia 2007; 62:272–278.
6 Koyama J, Iwashita T, Okamoto K. Comparison of three types of laryngoscope for tracheal intubation during rhythmic chest compressions: a manikin study. Resuscitation 2010; 81:1172–1174.
© 2011 European Society of Anaesthesiology