Clinical trial NCT00522756: Preventing Acute Renal Failure After Cardiac Surgery in High Risk Patients Using Sodium Bicarbonate Therapy
Official title: Preventing Acute Renal Failure After Cardiac Surgery in High Risk Patients Using Sodium Bicarbonate Therapy (PARACHUTE) - Pilot Study
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE3
Conditions: Kidney Failure, Acute
Keywords: Kidney Failure, Acute
Cardiac Surgical Procedures
Sodium Bicarbonate
Sodium Chloride
Prevention and control
Lead sponsor: McGill University Health Centre/Research Institute of the McGill University Health Centre
Sponsor class: OTHER
First posted: 2007-08-30
Enrollment: 200
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The purpose of this study is to determine whether sodium bicarbonate is effective in reducing kidney injury that may occur during cardiac surgery.

Detailed description: Acute renal failure (ARF) is an important complication after cardiac surgery that has a prevalence ranging between 5 and 30%. In addition, the impact of chronic kidney disease (CKD) has been well correlated with poorer outcomes after cardiac surgery. These factors have been demonstrated to be associated with increased morbidity, mortality, as well as consuming limited health care resources.

Despite the identification of certain higher risk determinants such as emergency surgery, valvular surgery, preoperative creatinine level, diabetes, increasing age, obesity, and peripheral vascular disease, interventions to decrease postoperative ARF in these patients have been limited. Agents that have been successful in other settings, such as N-acetylcysteine and fenoldopam, have shown no difference in clinical outcomes of ARF when tested in randomized clinical trials in high-risk cardiac surgery patients. Although prophylactic hemodialysis has been shown to be effective for patients with underlying severe kidney disease, this is clearly a resource intensive therapy that may not be practical as a general prophylaxis strategy.

The use of sodium bicarbonate has shown efficacy in reducing the incidence of ARF due to contrast-induced nephropathy in those patients with moderate, stable renal dysfunction. The postulated mechanism of renal protection has been described through the prevention of free radical generation and damage. The generation of a higher renal proximal tubule pH with bicarbonate therapy may slow down the superoxide-generating Haber-Weiss reaction, limiting the formation of free radical oxidants. In addition, sodium bicarbonate may be directly scavenging reactive oxygen species generated from nitric oxide, at a physiologic pH.

If it is presumed that initiation and extension of ischemic renal injury occurs during cardiac surgery via oxidant injury, the use of sodium bicarbonate to disrupt this process could possibly be an effective therapeutic option to prevent ARF.

The objective of this study is to evaluate the renal protective effect of near-isotonic sodium bicarbonate as compared to sodium chloride when given as prophylaxis to patients with chronic kidney disease prior to non-emergent surgery involving the use of cardiopulmonary bypass.

Our hypothesis is that bicarbonate therapy may disrupt ischemia-induced, oxidant-mediated injury and this may prevent the propagation of renal damage. These events may be demonstrated clinically by a reduced incidence of ARF following surgery, decreased requirements for renal replacement therapy after surgery, and improved survival both perioperatively and in a longer-term follow up.

Eligibility criteria: Inclusion criteria:

* age greater than or equal to 18 years
* elective or urgent CABG +/- valve surgery, or elective or urgent isolated valve surgery
* exposure to cardiopulmonary bypass
* stable kidney disease: less than 25% change in serum creatinine during 3 months before surgery
* Estimated glomerular filtration rate, by Modification of Diet in Renal Disease (MDRD) equation, less than or equal to 60 ml/min/1.73m2

Exclusion criteria:

* emergency CABG, cardiac transplantation, or insertion of VAD
* planned off-pump surgery
* N-acetylcysteine given in last 72 hours prior to operation
* radiocontrast given in last 48 hours prior to operation
* acute renal failure (greater than 25% increase in serum creatinine from preadmission baseline)
* glomerular filtration rate less than 15 ml/min or chronic dialysis
* prior renal transplantation
* enrollment in another research study, with the exception of MUHC study SDR-05-033
* LV ejection fraction less than or equal to 20%

Primary outcomes:
measure: Increase in serum creatinine of 44 micromol/L or by 25% within the first 3 days after surgery.
timeFrame: 3 days
Secondary outcomes:
measure: Postoperative vasoactive medication, intra-aortic balloon pump, mechanical ventilation, reintubation, reoperation, myocardial infarction, stroke, infection, hypokalemia, dialysis, ICU and hospital length of stay and survival.
timeFrame: 3 weeks post operative period
Other outcomes:
Locations:
city: Montreal
country: Canada
facility: McGill University Health Centre - Royal Victoria Hospital
state: Quebec
Study officials:
affiliation: McGill University Health Centre/Research Institute of the McGill University Health Centre
name: Benoit de Varennes, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: McGill University Health Centre/Research Institute of the McGill University Health Centre
name: Ahsan Alam, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Merten GJ, Burgess WP, Gray LV, Holleman JH, Roush TS, Kowalchuk GJ, Bersin RM, Van Moore A, Simonton CA 3rd, Rittase RA, Norton HJ, Kennedy TP. Prevention of contrast-induced nephropathy with sodium bicarbonate: a randomized controlled trial. JAMA. 2004 May 19;291(19):2328-34. doi: 10.1001/jama.291.19.2328.