Multicenter, triple-blind randomized placebo controlled trial of adjuvant nitrous oxide 50% in oxygen 50%: Efficacy for reducing pain and increasing satisfaction in patients treated for renal colic in the emergency department - Aguilar Mulet J; Álvarez Rodríguez V; Borobia Pérez A; Velayos Rubio R; Ochoa Mazarro M; del Arco Galán C (Emergencias: Revista De La Sociedad Española De Medicina De Urgencias Y Emergencias, 2016)