Sodium Bicarbonate in Cardiac Surgery

NCT00334191 | Completed Phase 2

• 1 other identifier: H2005/02249
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

Many patients develop kidney failure after cardiac surgery. Although this kidney failure can usually be treated effectively, a longer stay in intensive care is often required. While many patients suffer no long term ill effects after developing post-operative kidney failure, some require long term kidney dialysis. We also know that patients who develop post-operative kidney failure are much more likely to die before they leave hospital. Why some people develop kidney failure after cardiac surgery is not known. However, doctors suspect that the process of cardiopulmonary bypass (where the functions of the heart and lungs are taken over by a machine during the operation, to allow the surgeon to operate) overactivates some of the same mechanisms the body uses to defend itself against severe infection. Many of the cell changes by which severe infection causes kidney failure also occur after cardiopulmonary bypass. One of the main overactive defence mechanisms is the release of highly toxic compounds derived from oxygen - a process called 'oxidative stress'. The investigators believe that sodium bicarbonate might reduce the oxidative stress, which occurs during cardiac surgery, and so prevent or decrease the kidney failure, which occurs in many patients. The investigators hope to give sodium bicarbonate (in similar doses to those used safely for treatment of acidosis) to patients during, and for 24 hours after cardiac surgery, and to compare the effects with patients who have not had sodium bicarbonate. The drug, or a placebo, will be given through the drip, which is present in all cardiac surgery patients. Whether a particular patient receives the drug or placebo will be decided at random, and neither the patient nor the investigators will know which has been given. We will measure kidney function before and after the operation using the standard blood tests. The investigators will also take four 20ml samples of blood, spaced before, during, and after the operation, from the arterial catheter routinely inserted in every patient. This blood would be used to measure oxidative stress, and also some of the proteins inside the blood cells, which are responsible for creating the toxic oxygen compounds. In this way we will discover not only the effect of sodium bicarbonate, but also the mechanism of that effect. Sodium bicarbonate is commonly used to treat metabolic acidosis in severe renal disease, circulatory insufficiency due to shock or severe dehydration and has been shown to be an effective drug in preventing contrast-induced nephropathy. Sodium bicarbonate is considered to be safe in the setting of intensive care treatment and is often used in the treatment of patients with metabolic acidosis without any discernible adverse clinical effects. This is a pilot study. If the drug proves effective in this context, further studies on a larger scale would be required to justify its general use. There will be no extra risk to a patient who participates in the study, and no discomfort other than that normally associated with cardiac surgery. Informed consent will be obtained from the patient prior to the operation by one of the investigators or the ICU research nurse. The clinical care of a patient who does not consent for any reason will not be affected.

Conditions

Cardiac Surgery and Cardiopulmonary Bypass

Keywords

Cardiac surgery,; Cardiopulmonary bypass,; Oxidative stress,; Acute renal dysfunction,; Sodium Bicarbonate

Outcome Measures

Primary Outcomes (1)

• Proportion of patients developing an increase in serum creatinine greater than 25% from baseline to peak level within first five postoperative days.

Secondary Outcomes (11)

• Proportion of patients developing an increase in serum creatinine greater than 50% from baseline to peak level within first five postoperative days.

• Relative change in serum creatinine,

• Urinary output,

• Use of renal replacement therapy (RRT),

• Acute renal dysfunction,

Interventions

Sodium Bicarbonate DRUG

Placebo DRUG

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age above 70 years
• Preexisting renal impairment (preoperative serum creatinine level \>120µmol/L
• New York Heart Association class III/IV or Moderate to poor left ventricular dysfunction
• Valve surgery or complex cardiac surgery
• Redo cardiac surgery
• Insulin-dependent diabetes mellitus

You may not qualify if:

• Age \<18 years
• Emergency cardiac surgery
• Planned off-pump cardiac surgery
• Enrolled in conflicting research study
• Known blood-borne infectious disease
• Chronic inflammatory disease on immunosuppression
• Chronic moderate to high dose corticosteroid therapy (\>10mg/d prednisone or equivalent)
• End stage renal disease (serum creatinine \>300µmol/L)
• Thiamine deficiency will be excluded on medical and dietary history.

Sponsors & Collaborators

• Austin Health: lead

Study Sites (1)

Austin Hospital

Melbourne, Victoria, 3084, Australia

Location

Related Publications (2)

• Haase M, Haase-Fielitz A, Bellomo R, Devarajan P, Story D, Matalanis G, Reade MC, Bagshaw SM, Seevanayagam N, Seevanayagam S, Doolan L, Buxton B, Dragun D. Sodium bicarbonate to prevent increases in serum creatinine after cardiac surgery: a pilot double-blind, randomized controlled trial. Crit Care Med. 2009 Jan;37(1):39-47. doi: 10.1097/CCM.0b013e318193216f.

  PMID: 19112278 DERIVED

• Haase M, Haase-Fielitz A, Ratnaike S, Reade MC, Bagshaw SM, Morgera S, Dragun D, Bellomo R. N-Acetylcysteine does not artifactually lower plasma creatinine concentration. Nephrol Dial Transplant. 2008 May;23(5):1581-7. doi: 10.1093/ndt/gfm818. Epub 2008 Jan 17.

  PMID: 18202091 DERIVED

MeSH Terms

Interventions

Sodium Bicarbonate

Intervention Hierarchy (Ancestors)

Bicarbonates; Carbonates; Carbonic Acid; Carbon Compounds, Inorganic; Inorganic Chemicals; Sodium Compounds

Study Officials

• Rinaldo Bellomo, MD, FRACP

  Austin Health

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV

Study Record Dates

• First Submitted: June 5, 2006
• First Posted: June 6, 2006
• Study Start: June 1, 2006
• Study Completion: June 1, 2006
• Last Updated: July 7, 2009

Record last verified: 2009-07

Locations

AU (1)