Fasting before live kidney donation, effect on donor wellbeing and postoperative recovery

Rationale: Enhanced Recovery After Surgery (ERAS) reduces both hospital stay and complication rates. Part of the ERAS protocol consists of early postoperative mobilization and ad libitum diet. No clear recommendation of a preoperative diet has been made. Further research should be conducted to improve the recovery time and lessen postoperative fatigue, one of the main postoperative effectors on donor quality of life (QoL). Caloric restriction (CR) is associated with extended life span, lower risk of age associated diseases, improved fitness and increased resistance to acute stress. CR represents a non-invasive, non-expensive method of mitigating the effects of acute surgery-induced stress. Short-term CR increases expression of cytoprotective genes, increases immunomodulation via increased anti-inflammatory cytokine production and also decreases the expression of pro-inflammatory markers. Live kidney donors are an excellent population to further investigate the potential beneficial effect of DR. To investigate whether the beneficial effect of preoperative fasting reduces the postoperative fatigue after live kidney donation, a large randomized clinical trial is needed. This research is needed since postoperative fatigue is one of the main effectors on donor quality of life.

Objective: to determine whether nutritional preconditioning by 2,5 days of fasting reduces postoperative fatigue score, 4 weeks after live kidney donation.

Study design: multicenter randomized controlled trial

Study population: patients and donors opting for living kidney donation and transplantation at Erasmus University Medical Center in Rotterdam and University Medical Center Groningen.

Intervention: a control group receiving current standard of care and an intervention group fasting for 2,5 days with a low dose laxative for 3 days.

Main study parameters/endpoints: Postoperative fatigue, 4 weeks after live kidney donation. Secondary endpoints include f.i. effect of preoperative fasting on postoperative hospital admission time, the feasibility of the fasting diet & adherence to the fasting diet, renal function of the donor and the transplanted patient, the use of urinary extracellular vesicles in renal transplantation and the immune-modulating effect of fasting.

We aim to investigate whether a preoperative fasting diet reduced postoperative fatigue at 4 weeks after living donor nephrectomy in adult patients

12 weeks and 3 days before surgery and 3 days, 4 and 12 weeks after surgery

Subjects in the intervention group will start a preoperative fasting regime from 60 hours before surgery. Fasting is defined as very few to no caloric intake. Subjects are free to drink unlimited water, tea and coffee to maintain a sufficient fluid balance. In addition, they are allowed a daily dose of 100 grams of vegetables (cucumber, baby carrots and baby tomatoes). To prevent the loss of electrolytes they are allowed 4 bouillons a day. After surgery, they can resume their usual diet at own discretion. During the fasting period, subjects will use 1 dose of Macrogol 3350 daily, to reduce a common side-effect of fasting: constipation. Macrogol will be used the same way it has been approved for and used in daily practice.