Effect of Remote Ischemic Preconditioning on the Incidence of Acute Kidney Injury in Patients Undergoing Coronary Artery Bypass Graft Surgery
Condition: Acute Kidney Injury; Coronary Artery Bypass; Ischemic Preconditioning
MeSH terms: Acute Kidney Injury; Ischemia; Wounds and Injuries
Study type: Interventional

Summary: 
      Background:

      Acute kidney injury (AKI) following coronary artery bypass graft (CABG) surgery is a major
      complication occurring in 1% to 53% of patients (depending on how it is defined) with the
      pooled rate of 18.2% and unfortunately 2.1% of them require renal replacement therapy.
      Cardiopulmonary bypass (CPB)-associated AKI increases mortality 2-4 fold regardless of AKI
      definition. It is also associated with increased risk of postoperative stroke, acute
      myocardial infarction, cardiac tamponade, heart failure, and lengthened intensive care unit
      and hospital stays. Even minor elevations of postoperative serum creatinine (SCr) have been
      associated with a significant increase in 30-day mortality, from a 3-fold increase risk for a
      small elevation of up to 0.5 mg/dL from baseline to an 18-fold increase risk of death with a
      SCr rise greater than 0.5 mg/dL.

      The pathogenesis of CPB-associated AKI is complicated and includes hemodynamic, inflammatory
      and other mechanisms that interact at a cellular level. To date, despite several clinical
      trials of pharmacologic interventions, none of them have demonstrated conclusively efficacy
      in the prevention of AKI after cardiac surgery.

      Remote ischemic preconditioning (RIPC) is a phenomenon in which brief ischemia of one organ
      or tissue, provokes a protective effect that can reduce the mass of infarction caused by
      vessel occlusion and reperfusion. In CABG surgery, cardiomyocyte injury caused by myocardial
      protection failure is predominantly responsible for adverse outcomes. RIPC was shown to
      reduce troponin release 24 h postoperatively in children undergoing corrective surgery for
      congenital heart disease. Other studies demonstrated that RIPC using brief ischemia and
      reperfusion of the upper limb reduces myocardial injury in adult patients undergoing CABG
      surgery.

      Due to the similarities between the mechanisms of ischemia-reperfusion injury produced by
      RIPC and those proposed for AKI after CPB, we decided to test the hypothesis that RIPC
      prevents AKI in patients undergoing CABG surgery.

      Methods:

      180 patients who fulfill all inclusion and exclusion criteria will be divided into case and
      control groups (90 patients in the case and 90 patients in the control group).

      Patients in the treatment group will receive three sequential sphygmomanometer cuff
      inflations on their right upper arm after induction of anesthesia in the operating room. The
      cuff will be inflated by the OR nurse up to 200 mmHg for five minutes each occasion, with
      five minutes deflation in between inflations. Following this pre-conditioning phase, surgery
      will be started. The entire pre-conditioning phase will last 30 minutes.

      Patients in the control group will have the sphygmomanometer cuff placed on their right upper
      arm, but the cuff will not be inflated. Similar to patients in the treatment group, patients
      in the control group will undergo the same 30 minute delay before starting surgery.

      Complete blood count (CBC), SCr, liver function test (LFT), will be checked before surgery.

      After surgery, SCr will be checked daily. If AKI occurs, it will be managed and dialysis will
      be done if the patient requires it. All patients will undergo electrocardiogram and LFT after
      CABG surgery during hospital course.
    


Intervention name(s): Remote Ischemic Preconditioning (RIPC); sham-RIPC
Intervention type(s): Procedure; Procedure
Intervention description(s): Remote ischemic preconditioning (RIPC) is a phenomenon in which brief ischemia of one organ or tissue, provokes a protective effect that can reduce the mass of infarction caused by vessel occlusion and reperfusion.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: remote ischemic preconditioning; transient limb ischemia; acute kidney injury; coronary artery bypass graft surgery