Welcome back to May's Papers of the Month Podcast! Three more papers for you on three varied topics. We start off with the use of end tidal carbon dioxide in the content of prehospital head injuries.Taking a look at a paper delving a bit deeper into the utility of end tidal CO2 when compared with arterial CO2 measurements on arrival in ED, in patients having received a prehospital anaesthetic; how accurate is end tidal and what level should we be aiming for? Next we consider the importance of frailty in the outcomes of our older trauma patients and the ability of three different screening tools in identification of this cohort of high risk patients presenting to our hospitals. Finally we take a look at a treatment which some prehospital services have already employed and others are considering; the use of CPAP for patients presenting with acute respiratory distress. Does the evidence support its use? Once again we'd love to hear any thoughts or feedback either on the website or via twitter @TheResusRoom. Simon & Rob