Whilst not under the name of ERP, the first publication to consider a clinical pathway for bariatric surgery was published in 2001, with respect to 28 patients, 12 of whom were recruited to a multidisciplinary clinical pathway [6]. The pathway involved patient education materials, standardized preoperative and postoperative orders, including early ambulation and oral diet, together with standardized discharge instructions. In comparison to the 16 patients who underwent standard care, there was a reduction in hospital stay of 3 days, similar complication and readmission rates, and a greater than 15 % decrease in resource utilization costs. In 2005, McCarty et al. published results of 2000 consecutive patients having undergone outpatient laparoscopic gastric bypass [7]. Of the 1699 (84 %) discharged within 23 h, 34 (1.7 %) were readmitted within 30 days, with low overall early (38, 1.9 %) and late (86, 4.3 %) complication rates, and only 2 (0.1 %) deaths. In this publication, the authors very much focus upon the perioperative period, in terms of analgesia, antiemetics, and surgical technique.

Whilst both of these studies reflect the impact of standardization of clinical processes, neither describes their approach with regard to adoption by other centers. More recently, in 2013, Lemanu et al. published a randomized controlled trial of enhanced recovery versus standard care after laparoscopic sleeve gastrectomy [8]. Of their 116 patients, 40 patients underwent the ERP protocol, and were compared to two other groups, i.e., a control group of 38 patients, and a historical cohort of a further 38 patients. What is of interest here is that the authors specifically defined the preoperative, intraoperative, and postoperative aspects of their ERP protocol (Table 24.1), including a summary of their discharge criteria. Their work was preceded by an extensive review of the current literature of bariatric and major abdominal surgery [9]. With regard to the clinical outcomes, the ERP group had a reduced length of stay (from 2 days to 1 day), with similar complication and readmission rates.