First pass success of tracheal intubation using the C-MAC PM videolaryngoscope as first-line device in prehospital cardiac arrest compared with other emergencies: An observational study.

BACKGROUND: Successful airway management is a priority in the resuscitation of critically ill or traumatised patients. Several studies have demonstrated the importance of achieving maximum first pass success, particularly in prehospital advanced airway management.
OBJECTIVE: To compare success rates of emergency intubations between patients requiring cardiopulmonary resuscitation (CPR) for cardiac arrest (CPR group) and other emergencies (non-CPR group) using the C-MAC PM videolaryngoscope.
DESIGN: Ongoing analysis of prospective collected prehospital advanced airway management core variables.
SETTING: Single helicopter emergency medical service (HEMS) 'Christoph 22', Ulm Military Hospital, Germany, May 2009 to July 2018. PATIENTS: We included all 1006 HEMS patients on whom prehospital advanced airway management was performed by board-certified anaesthesiologists on call at HEMS 'Christoph 22'.
INTERVENTIONS: The C-MAC PM was used as the first-line device. The initial direct laryngoscopy was carried out using the C-MAC PM without the monitor in sight. After scoring the direct laryngoscopic view according to the Cormack and Lehane grade, the monitor was folded within the sight of the physician and tracheal intubation was performed using the videolaryngoscopic view without removing the blade. MAIN OUTCOME MEASURES: The primary outcome was successful airway management. Secondary outcomes were the patient's position during airway management, necessity for suction, direct and videolaryngoscopic view according to Cormack and Lehane grading, as well as number of attempts needed for successful intubation.
RESULTS: A patent airway was achieved in all patients including rescue techniques. There was a lower first pass success rate in the CPR group compared with the non-CPR group (84.4 vs. 91.4%, P = 0.01). In the CPR group, direct laryngoscopy resulted more often in a clinically unfavourable (Cormack and Lehane grade 3 or 4) glottic view (CPR vs. non-CPR-group 37.2 vs. 26.7%, P = 0.0071). Using videolaryngoscopy reduced the clinically unfavourable grading to Cormack and Lehane 1 or 2 (P < 0.0001). The odds of achieving first pass success were approximately 12-fold higher with a favourable glottic view than with an unfavourable glottic view (OR 12.6, CI, 6.70 to 23.65).
CONCLUSION: Airway management in an anaesthesiologist-staffed HEMS is associated with a high first pass success rate but even with skilled providers using the C-MAC PM videolaryngoscope routinely, patients who require CPR offer more difficulties for successful prehospital advanced airway management at the first attempt. TRIAL REGISTRATION: German Clinical trials register (drks.de) DRKS00020484.