Efficacy of ventilation and ventilation adjuncts during in-water-resuscitation--a randomized cross-over trial.

ABSTRACT

INTRODUCTION: Drowning is a common cause of death in young adults. The 2010 guidelines of the European Resuscitation Council call for in-water-resuscitation (IWR). There has been controversy about IWR amongst emergency and diving physicians for decades. The aim of the present study was assessing the efficacy of IWR. METHODS: In this randomized cross-over trial, nineteen lifeguards performed a rescue manoeuvre over a 100 m distance in open water. All subjects performed the procedure four times in random order with no ventilation (NV) and transportation only, mouth-to-mouth ventilation (MMV), bag-mask-ventilation (BMV) and laryngeal tube ventilation (LTV). Tidal volumes, ventilation rate and minute-volumes were recorded using a modified Laerdal Resusci Anne manikin. Furthermore, water aspiration and number of submersions of the test mannequin were assessed, as well as the physical effort of the lifeguard rescuers.One lifeguard subject did not complete MMV due to exhaustion and was excluded from analysis. RESULTS: NV was the fastest rescue manoeuvre (advantage ∼40s). MMV and LTV were evaluated as efficient and relatively easy to perform by the lifeguards. While MMV (mean 199 ml) and BMV (mean 481 ml) were associated with a large amount of aspirated water, aspiration was significantly lower in LTV (mean 118 ml). The efficacy of ventilation was consistently good in LTV (Vt=447 ml), continuously poor in BMV (Vt=197) and declined substantially during MMV (Vt=1,019 ml initially and Vt=786 ml at the end). The physical effort of the lifeguards was remarkably higher when performing IWR 3.7 in NV, 6.7 in MMV, 6.4 in BMV and 4.8 in LTV as measured on the 0-10 visual analogue scale. CONCLUSION: IWR in open water is time consuming and physically demanding. The IWR training of lifeguards should put more emphasis on a reduction of aspiration. The use of ventilation adjuncts like the laryngeal tube might ease IWR, reduce aspiration of water and increase the efficacy of ventilation during IWR.