The effects of preoperative volume replacement in diabetic patients undergoing coronary artery bypass grafting surgery: Protocol for a randomised controlled trial (VeRDiCT trial)

Background: Diabetes mellitus is a major risk factor for prolonged hospital stay, renal failure and mortality in patients having coronary artery bypass grafting (CABG). Complications pose a serious threat to patients and prolong intensive care and hospital stay. Low glomerular filtration rate due to existing renal impairment or volume depletion may exacerbate acute renal impairment/failure in these patients. Preoperative volume replacement therapy (VRT) is reported to increase the glomerular filtration rate and we hypothesise that it will reduce renal impairment and related complications in diabetic patients.

Objective: The objective of this study is to establish the efficacy of preoperative VRT in reducing postoperative complications in diabetic patients undergoing CABG surgery. Time to “fit for discharge”, incidence of post-operative renal failure, cardiac injury, inflammation, and other health outcomes will be investigated.

Methods: In this open parallel group randomised controlled trial 170 diabetic patients undergoing elective or urgent CABG surgery will receive 1 ml/kg/hr of Hartmann’s solution for 12 consecutive hours prior to surgery versus routine care. The primary outcome will be time until participants are ‘fit for discharge’ defined as presence of normal temperature, pulse and respiration, normal oxygen saturation on air, normal bowel function and physically mobility. Secondary outcomes will include incidence of renal failure, markers of renal function, inflammation, and cardiac damage, operative morbidity, intensive care stay, patient-assessed outcome including the Coronary Revascularisation Outcome Questionnaire (CROQ), and use of hospital resources.

Results: Recruitment started in July 2010. Enrolment for the study was completed in July 2014. Data analysis commenced in December 2016. Study results will be submitted for publication in the spring of 2017.

Conclusions: VRT is a relatively easy treatment to administer in patients at risk of renal failure undergoing surgical procedures. This experimental protocol will increase scientific and clinical knowledge of VRT in diabetic patients undergoing elective or urgent CABG surgery. Findings supporting the efficacy of this intervention could be easily implemented in the healthcare system.

Trial registration: ISRCTN02159606