Implementation of a pre-operative Very Low Calorie Diet weight loss program into the pre-operative model of care for obese general elective surgery patients

Abstract

Background: Overweight and obesity is considered an extensive burden of disease in Australia, with estimated direct costs for overweight and obesity of $21 billion annually. Obesity rates are on the rise, by 2025 it is predicted that three quarters of Australian adults will be overweight or obese. Obesity has long been perceived a risk factor for adverse post-surgical outcomes. It is suggested that people with obesity undergoing elective general surgery (non-bariatric) are at significantly higher risk of minor surgical complications such as wound infection, intra-operative blood loss and length of stay. Published studies demonstrate varied results with some reporting no association between obesity and risk of surgical complications. The available body of literature is limited by conflicting results, scarcity of studies, small sample sizes and variation in definitions of surgical outcomes. There is a variation among existing National and International guidelines on recommendations for weight loss strategies. The overall trend is that bariatric surgery is considered gold standard weight loss method whilst Very Low Calorie Diets (VLCDs) are considered the most effective short term non-surgical intervention. VLCDs are considered safe and effective and their use for pre-operative weight loss in bariatric surgery is commonly reported in the literature. However, there is a rarity of published studies reporting the use of VLCDs in pre elective general surgery patients. Failing to address the growing rates of obesity in the pre-operative general surgery population is neglecting the opportunity to potentially reduce risk of surgical complications and economic burden. Methods: A multi-phased program consisting of two phases including 50 patients with obesity awaiting elective general abdominal surgery excluding bariatrics surgery and 25 targeted National facilities involved in treating them. Phase I considered the feasibility and impact on patient related outcomes of nutrition intervention in pre-operative elective general abdominal surgery excluding bariatrics surgery including a randomised control trial. Phase I includes a cohort study nested in the larger RCT further exploring the impact of a pre-surgical VLCD program on patient’s health related quality of life. Ethics approvals for all phases were obtained. Phase IIa reports on patient related outcomes from a group-based lifestyle program compared with a VLCD program in pre-surgical patients. Phase IIb reported findings from a national audit investigating the use of pre-operative VLCDs in elective general surgery patients in Australian Hospitals and dietitian perceptions to the routine implementation of pre-operative VLCDs. Results: Findings from Phase I and II have resulted in novel models of pre-surgical nutrition care in general surgery patients. The collaboration and engagement with the wider multidisciplinary team and preoperative surgery network in a multiphase research intervention has demonstrated the feasibility and effectiveness on patient related outcomes of a pre-operative VLCD program in elective general abdominal surgery excluding bariatrics surgery patients. Demonstrated through a significantly greater weight loss, greater reduction in waist circumference, high clinic attendance rate and significant improvement in quality life, when compared with standard care. Phase IIa demonstrated greater weight loss, greater reduction in waist circumference and a significantly higher program completion rates in pre-surgical patients with obesity undertaking a VLCD program compared to a group-based lifestyle program. Phase IIb found a low uptake of the routine use of dietitian-led VLCDs in pre-general surgery patients with obesity around Australia. Discussion: This research was undertaken as part of routine clinical care allowing engagement with the multidisciplinary team along each stage of the study. Using a pragmatic approach has allowed the feasibility testing of implementing and evaluating the impact of a nutrition intervention in pre-operative mode of care. Results from Phase IIa and IIb, highlight the need for further research into the efficacy of VLCDs and pre-surgery patients which may have an influence of the uptake of routine use of VLCDs and ensure optimal weight loss interventions are used with this population. As a result of a successful RCT feasibility study (Phase I), changes to routine clinical practice and re-direction of health care resources were negotiated and implemented by the research team. These were implemented as a new dietitian led pre-operative VLCD clinic for patients with obesity awaiting elective general abdominal surgery excluding bariatrics surgery at The Prince Charles Hospital. Publications resulting from this study have contributed to filling gaps in the evidence and findings are considered pertinent to future nutrition care practices. The VLCD clinic is successfully embedded into preoperative general surgery model of care and as a result feasibility is currently being investigated across streams in orthopaedic surgery patients with obesity.