Randomised controlled trial of analgesia for the management of acute severe pain from traumatic injury: study protocol for the paramedic analgesia comparing ketamine and morphine i... by Michelet, F, Smyth, M, Lall, R, Noordali, H, Starr, K, Berridge, L, Yeung, J, Fuller, G, Petrou, S, Walker, A, Mark, J, Canaway, A, Khan, K, Perkins, GD