Improvement in glottic visualisation by using the C-MAC PM video laryngoscope as a first-line device for out-of-hospital emergency tracheal intubation: An observational study

BACKGROUNDOut-of-hospital tracheal intubation is associated with life-threatening complications. To date, no study has compared direct and video laryngoscopic views simultaneously in the same patients in an out-of-hospital setting. OBJECTIVESThe aim of this study was to determine the effect of C-MAC PM video laryngoscope on laryngeal view, compared with direct laryngoscopy, and to estimate possible consequences for patient safety. DESIGNAn observational, single-centre study. SETTINGHelicopter Emergency Medical Service (HEMS) ‘CHRISTOPH 22’, Ulm, Germany. PATIENTSTwo-hundrend and twenty-eight emergency patients undergoing airway management out of hospital. INTERVENTIONSLaryngoscopy and tracheal intubation using C-MAC PM video laryngoscope. For all intubations, the HEMS physician used CMAC PM as the first-line device and performed an initial direct laryngoscopy followed by a video laryngoscopy, without changing the laryngoscope blade. MAIN OUTCOME MEASURESThe difference in laryngeal view was recorded as well as the number of intubation attempts along with the success rate and difficulties in airway management. Improvement in glottic visualisation from Cormack and Lehane grade III/IV to I/II was rated as being clinically relevant. RESULTSDuring a 20-month study period, a total of 228 out-of-hospital emergency patients requiring tracheal intubation were included. The overall success rate in securing the airway was 100%. For 226 patients (99.1%), tracheal intubation was successful with two or fewer attempts. For comparison of direct and indirect laryngoscopic views, five patients were excluded because of the use of an indirect laryngoscope blade. Of 223 patients, 120 had a glottic view rated as Cormack and Lehane grade II to IV with direct laryngoscopy; in these patients, visualisation of the glottis was significantly improved with the C-MAC PM video laryngoscope (P