Investigation on success of ventilation with a laryngeal mask or facemask by medical students unexperienced in airway management - a teaching evaluation from manikin training to patient

Ventilation of the patient's lungs is an elementary skill of medical practice. Especially in the treatment of critically ill patients. Tracheal tube placement is a complex skill and unsuccessful in an unacceptably high percentage when performed by unskilled providers. If tracheal tube placemant fails, international guidelines recommend ventilation by facemask or, as an alternative, insertion of a supraglottic airway device. There is growing evidence and scientific consensus that supraglottic airway devices should be used as a first measure by personnel unexperienced with tracheal intubation as manikin trials have shown that placement of supraglottic airway devices is easy even for unexperienced users. However, there is an ongoing discussion to what extend manikin based studies can be transferred to real patients. Therefore this study compares the facemask and the LMA-Supreme(TM) laryngeal mask with regard to how well airway skills were transferred from manikin to patient by medical students during their anaesthesia rotation. The students were required to ventilate the lungs of a manikin using a facemask and then position a LMA-Supreme(TM) and ventilate the lungs. This process was then repeated on anaesthetised patients with identical respirator settings. Sixty-three students participated in the manikin study. The success rate for ventlating the lungs was 100% for both devices, but the mean (SD) time to achieve successful ventilation was 27.8 (24.4) s with the facemask compared with 38.6 (22.0) s with the LMA-Supreme(TM) (p = 0.008). Fifty-one of the students progressed to the second part of the study. In anaesthetised patients, the success rate for ventilating the lungs was lower for the facemask, 27/41 (66%) compared to the LMA-Supreme(TM) 37/41 (90%, p = 0.006). For 26 students who succeeded with both devices, the tidal volume was lower using the facemask, 431 (192) ml compared with the LMA-Supreme 751 (221) ml (p = 0.001), but the time to successful ventilation did not differ, 60.0 (26.2) s vs 57.3 (26.6) s (p = 0.71). Therefore, manikin training alone is of limited value for education of medical students, as well as the results of manikin-based studies regarding single airway skills or the performance of distinct airway devices are of limited value. Based on the findings of this study, supraglottic airway devices, such as the LMA-Supreme(TM), might be a more appropriate option for novices in airway management as compared to facemask ventilation and future guidelines should take this into account.2015-10-2