Does regional block improve outcome after surgery?

Seventy-five years have elapsed since the first claim that the use of local anaesthetics improved surgical outcome. Despite extensive research, the literature provides contradictory views of the role of regional block in improving outcome. This paper attempts to reconcile these contradictions by examining biological hypotheses underlying the research question and reviewing relevant epidemiological clinical research methodology. The paper concludes with recommendations to prospective investigators for strategies in design, planning and execution of randomised trials to assess the efficacy of regional block in determining outcome after surgery.