Additional file 1: of The NAPRESSIM trial: the use of low-dose, prophylactic naloxone infusion to prevent respiratory depression with intrathecally administered morphine in elective hepatobiliary surgery: a study protocol and statistical analysis plan for a randomised controlled trial CosgraveDavid GalliganMarie SoukhinEra McMullanVictoria McGuinnessSiobhan PuttappaAnand ConlonNiamh BoylanJohn HussainRabia DoranPeter NicholAlistair 2017 SPIRIT 2013 Checklist: recommended items to address in a clinical trial protocol and related documents*. (DOC 122 kb)