Ninety-seven percent (n = 29) of all participants were unable to ventilate within the recommended tidal volume for the simulated patient when using the conventional 1600 ml bag – a potentially catastrophic outcome for cardiac arrest patients in the field. A similar result was found with minute volumes, with the level of suboptimal ventilation reducing from 93% in participants using the 1600 ml bag to 70% (n = 21) in participants using the smaller 1000 Inhibitors,research,lifescience,medical ml bag (p = 0.045). Doerges and colleagues were one of the first to query the difficulty in reaching new
ventilation targets with current capacity adult bags. Their study found that ventilation using an adult capacity bag via an advanced airway usually resulted in tidal volumes as high as 1000 ml and often over-shooting the recommended 400–600 ml by the ERC[16] Mean minute volumes of almost 20 litres were also noted with the use of a large bag. When compared Inhibitors,research,lifescience,medical to a paediatric 700 ml bag, they found that they were able to reduce tidal volumes to a mean of 389 ml ± 113 and therefore significantly reducing the incidence Inhibitors,research,lifescience,medical of hyperventilation[16] A follow-up study showed that a medium sized adult bag (1100 ml) could provide a mean tidal volume of 623 ml ± 26 when used in conjunction with an intubating LMA[17] This produced a statistically significant difference when compared to
the use of a conventional 1500 ml bag (741 ml ± 33). Other authors have demonstrated similar difficulties in achieving guideline consistent ventilations during CPR, with some minute volumes peaking at 21.3 litres[15] In accordance with manufacturer specifications, the smaller 1000 ml capacity bag produces a maximum functional output of 750 ml – a characteristic Inhibitors,research,lifescience,medical that is likely to completely eliminate the incidence of overzealous volumes in excess of 1000 ml. With research suggesting that current capacity bags are likely to result in hyperventilation, we can also demonstrate an Inhibitors,research,lifescience,medical association to life-threatening secondary
complications such as gastric insufflation, regurgitation, aspiration and barotrauma[18] While the effects of hypoxia and hypocapnia have proven to reduce the survivability of patients with severe head injury, the effect of suboptimal ventilation on outcomes for cardiac arrest patients are Doramapimod supplier nowbeginning to demonstrate similar outcomes for swine models in cardiac Thiamine-diphosphate kinase arrest[19] It is now becoming more evident that “larger tidal volumes and ventilation rates can be associated with complications, whereas the detrimental effects observed with smaller tidal volumes appear to be acceptable.”[4] The results from this study have provided teaching staff with evidence to assist them in improving student ventilation during clinical simulation sessions. The findings from this study also highlight the need to investigate the ventilation ability of practicing Victorian paramedics.