The impact of continuous haemofiltration during cardiopulmonary bypass on cardiac surgery patients with impaired renal function

INTERVENTION: Current information as of 26/03/10: Eligible patients will be randomised to one of the following groups: 1. Control group: ON‐pump high risk cardiac (coronary artery bypass graft (CABG) alone, valve surgery, CABG plus valve) surgery patients with GFR <50 ml/min without haemofiltration 2. Experimental group: ON‐pump high risk cardiac (coronary artery bypass graft (CABG) alone, valve surgery, CABG plus valve) patients with GFR <50 ml/min undergoing haemofiltration Study timetable: Start of recruitment: April 2010 ‐ Mar 2013 End of follow‐up: Apr 2013 Analysis and reporting: May 2013 ‐ Jul 2013 Final report: Sep 2013 Initial information at time of registration: Patients that fulfil inclusion and exclusion criteria will be asked to give consent for the study and will be randomised into the two study groups by a computer‐generated programme: 1. ON‐pump isolated CABG patients with GFR less than 60 ml/min without haemofiltration (control arm) 2. ON‐pump isolated CABG patients with GFR less than 60 ml/min undergoing haemofiltration CONDITION: Pre‐operative renal impairment/coronary heart disease/coronary heart interventions ; Urological and Genital Diseases PRIMARY OUTCOME: Current information as of 26/03/10:; Length of ICU stay for non‐dialysis patients with impaired kidney function (estimated glomerular filtration rate <50 ml/min); ; Initial information at time of registration:; Incidents of ICU stay greater than 3 days for patients with eGFR less than 60 ml/min. INCLUSION CRITERIA: Current information as of 26/03/10: 1. Consenting men and women aged at least 18 years old 2. High‐risk patients elective for on‐pump valve replacement, coronary artery bypass graft surgery (CABG) or combined CABG and valve procedures 3. Patients with impaired renal function established preoperative by an estimated glomerular filtration rate (eGFR) <50 ml/min Initial information at time of registration: 1. Male and female patients, at least 18 years old 2. Elective for on‐pump coronary artery bypass graft surgery (CABG) 3. Patients with impaired renal function established by pre‐operative estimated glomerular filtration rate (eGFR) less than 60 ml/min SECONDARY OUTCOME: Current information as of 26/03/10:; 1. Clinical Outcomes ; 1.1. Duration of Hospital stay; 1.2. Myocardial infarction ; 1.3. The mean eGFR/creatinine clearance values at hospital discharge; 2. Biomarkers Outcomes: ; 2.1. Plasma levels of protein nitration; 2.2. 8‐isoprostanes; 2.3. Malondialdehyde levels; 2.4. Plasma and erythrocyte reduced/oxidised glutathione (GSH/GSSG) ratio; 2.5. Urinary N‐acetyl‐D‐glucosamine (D‐NAG) excretion; 2.6. Highly sensitive C‐reactive protein (hsCRP); 2.7. Tumour necrosis factor alpha (TNF‐a); Measured at baseline, during CPB, 24 hours and 48 hours after the operation.; 3. Secondary Economic Outcomes: ; Resource utilisation and key costs indicators associated with each of the two pilot arms estimated up until hospital discharge. Specifically:; 3.1. ICU stay and hospital stay; 3.2. Postoperative renal replacement therapy; 3.3. Mechanical ventilation; 3.4. Medications; ; Initial information at time of registration:; 1. Clinical outcomes:; 1.1. Overall length of hospital stay ; 1.2. Need for renal support post‐operatively ; 1.3. Mechanical ventilation time ; 1.4. Length of tracheal intubation ; 1.5. Arrhythmias ; 1.6. The worst eGFR/creatinine clearance values during hospital stay ; 1.7. Myocardial infarction ; 2. Biomarker outcomes: ; Markers of oxidative stress and the systemic inflammatory response. ; 3. Cost outcomes: ; Resource utilisation and costs associated with the intra‐operative haemofiltration, care at the ICU and ward and adverse events (e.g., bleeding complications, sepsis), requirement for post‐operative haemofiltration will be measured. Since the number of operations performed in most cardiac centres depend on availability of ICU beds, the implications for the productivity of the ICU unit will be explored by simulating its activity and resource flows and outcomes, in terms of operations performed per unit time (e.g., a year).; ; Patients will be followed‐up for all secondary outcome measures until the time of hospital discharge.