Forced Diuresis Versus Observation in Resolving Renal Failure After Haemofiltration in Critically Ill Patients

Introduction: Virtually all intensive care (IC) patients with prolonged IC stay have multiple organ dysfunction syndrome. Frequently renal failure is present. The resolution of renal failure is often relatively late. After cessation of hemofiltration, oliguria may be present, at least for some time. Increasing diuresis by diuretics will probably increase clearance. As a result, intensive care stay and outcome may improve. However, diuretics might also be harmful as it is when applied in developing renal failure. Aim of the study: To study whether the stimulation of diuresis by furosemide when hemofiltration is stopped enhances renal recovery and secondary shortens the length of IC-stay. Setting: IC-patients treated at the Medical Centre Leeuwarden with MODS and renal failure are included when hemofiltration is stopped. The ICU is mixed medical and surgical, 16 beds with full time intensivists responsible for hemofiltration. Study design: Prospective randomised placebo controlled single centre trial. Methods: Inclusion criteria. Patients with mechanical ventilation in whom hemofiltration is stopped. Written informed consent must be obtained. Excluded are patients with pre-existent serum creatinin of 150 umol/l or clearance less than 30 ml/min. Patients admitted with renal failure as the primary admission diagnosis in case acute renal failure is due to glomerulonephritis. Creatinin clearance is measured in a 4 hour period directly after cessation of hemofiltration. The patient is then randomised for furosemide or sodium chloride. Furosemide is administered at 0.5 mg/kg/hour. Dehydration is prevented by infusing the patient the volume of their diuresis. Daily creatinin clearance is calculated. Primary endpoints: 1. Recovery of renal function (clearance more than 30 ml/min) 2. Stable or declining serum creatinin in case of persistent clearance less than 30 ml/min 3. Need for re-start of renal replacement therapy (metabolic acidosis, hyperkalaemia, fluid overload, uremia or uremic complications) Secondary endpoints: Length of stay ICU, mortality. Poweranalysis: 36 patients per group for alpha 0.05 and beta 0.8 and 30% faster recovery of renal failure for the intervention group. Statistical analysis: Student t for normally distributed variables, otherwise non-parametric tests. Kaplan Meier and Cox regression for time to recovery of renal function.