Mechanical ventilation and resuscitation under water: Exploring one of the last undiscovered environments - A pilot study
DuCanto J, Lungwitz Y, Koch A, et al. Mechanical ventilation and resuscitation under water: Exploring one of the last undiscovered environments - A pilot study. Resuscitation. 2015 Aug;93:40-5.
INTRODUCTION: Airway management, mechanical ventilation and resuscitation can be performed almost everywhere - even in space - but not under water. The present study assessed the technical feasibility of resuscitation under water in a manikin model.
METHODS: Tracheal intubation was assessed in a hyperbaric chamber filled with water at 20m of depth using the Pentax AWS S100 video laryngoscope, the Fastrach™ intubating laryngeal mask and the Clarus optical stylet with guidance by a laryngeal mask airway (LMA) and without guidance. A closed suction system was used to remove water from the airways. A test lung was ventilated to a maximum depth of 50m with a modified Oxylator(®) EMX resuscitator with its expiratory port connected either to a demand valve or a diving regulator. Automated chest compressions were performed to a maximum depth of 50m using the air-driven LUCAS™ 1.
RESULTS: The mean cumulative time span for airway management until the activation of the ventilator was 36s for the Fastrach™, 57s for the Pentax AWS S100, 53s for the LMA-guided stylet and 43s for the stylet without LMA guidance. Complete suctioning of the water from the airways was not possible with the suction system used. The Oxylator(®) connected to the demand valve ventilated at 50m depth with a mean ventilation rate of 6.5min(-1) vs. 14.7min(-1) and minute volume of 4.5lmin(-1) vs. 7.6lmin(-1) compared to the surface. The rate of chest compression at 50m was 228min(-1) vs. 106min(-1) compared to surface. The depth of compressions decreased with increasing depth.
CONCLUSION: Airway management under water appears to be feasible in this manikin model. The suction system requires further modification. Mechanical ventilation at depth is possible but modifications of the Oxylator(®) are required to stabilize ventilation rate and administered minute volumes. The LUCAS™ 1 cannot be recommended at major depth.