Search

We have previously shown that remote ischemic preconditioning reduces acute kidney injury (acute kidney injury) in high-risk patients undergoing cardiopulmonary bypass and that the protective effect is confined to patients who exhibit an increased urinary tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 in response to remote ischemic preconditioning. The purpose of this study was to determine the optimal intensity of remote ischemic preconditioning to induce required [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] changes and further explore mechanisms of remote ischemic preconditioning.Observational and randomized controlled, double-blind clinical trial.University Hospital of Muenster, Germany.High-risk patients undergoing cardiac surgery as defined by the Cleveland Clinic Foundation Score.In the interventional part, patients were randomized to receive either one of four different remote ischemic preconditioning doses (3 × 5 min, 3 × 7 min, 3 × 10 min remote ischemic preconditioning, or 3 × 5 min remote ischemic preconditioning + 2 × 10 min remote ischemic preconditioning in nonresponders) or sham-remote ischemic preconditioning (control).The primary endpoint of the interventional part was change in urinary [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] between pre- and postintervention. To examine secondary objectives including acute kidney injury incidence, we included an observational cohort. A total of 180 patients were included in the trial (n = 80 observational and n = 100 randomized controlled part [20 patients/group]). The mean age was 69.3 years (10.5 yr), 119 were men (66.1%). Absolute changes in [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] were significantly higher in all remote ischemic preconditioning groups when compared with controls (p0.01). Although we did not observe a dose-response relationship on absolute changes in [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] across the four different remote ischemic preconditioning groups, in the 15 patients failing to respond to the lowest dose, nine (60%) responded to a subsequent treatment at a higher intensity. Compared with controls, fewer patients receiving remote ischemic preconditioning developed acute kidney injury within 72 hours after surgery as defined by both Kidney Disease: Improving Global Outcomes criteria (30/80 [37.5%] vs 61/100 [61.0%]; p = 0.003).All doses of remote ischemic preconditioning significantly increased [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] and significantly decreased acute kidney injury compared with controls. High-dose remote ischemic preconditioning could stimulate [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] increases in patients refractory to low-dose remote ischemic preconditioning.

Supplemental Digital Content is available in the text., OBJECTIVES: To describe study design considerations and to simulate a trial of biomarker-guided sepsis management aimed to reduce acute kidney injury (acute kidney injury). Tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7, urinary biomarkers of cell-cycle arrest, and indicators of kidney stress can detect acute kidney injury before clinical manifestations. We sought to determine the event rates for acute kidney injury as a function of serial measurements of urinary (tissue inhibitor of metalloproteinases-2)•(insulin-like growth factor-binding protein 7) in patients at risk of sepsis-associated acute kidney injury, so that an escalating series of kidney-sparing sepsis bundles based on international guidelines could be applied. DESIGN: We described the study protocol of “Limiting acute kidney injury Progression In Sepsis,” a phase 4, multicenter, adaptive, randomized controlled trial. We performed simulations to estimate the rates for the trial’s primary endpoint using patient-level data from two previous studies (Sapphire and Protocolized Care for Early Septic Shock). SETTING: Academic and community ICUs. PATIENTS: Critically ill patients with sepsis or septic shock, without evidence of stage 2/3 acute kidney injury at enrollment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Our primary endpoint is progression of two or more stages of acute kidney injury, death, or dialysis within 72 hours after enrollment. In the Sapphire simulation, 45 of 203 patients (22%) with sepsis met the endpoint. In Protocolized Care for Early Septic Shock, 144 of 607 patients (24%) with septic shock met the endpoint. In both simulations, (tissue inhibitor of metalloproteinases-2)•(insulin-like growth factor-binding protein 7) patterns, suggested by Limiting acute kidney injury Progression In Sepsis protocol, stratified the risk for the endpoint from 6% (three negative tests) to 41% (for patients eligible for the highest level of kidney-sparing sepsis bundle) in Sapphire, and 14% (two negative tests) to 46% (for the highest level of kidney-sparing sepsis bundle) in Protocolized Care for Early Septic Shock. CONCLUSIONS: Findings of our Limiting acute kidney injury Progression In Sepsis trial simulation confirmed that (tissue inhibitor of metalloproteinases-2)•(insulin-like growth factor-binding protein 7) could identify patients with different rates of progression to moderate/severe acute kidney injury, death, or dialysis in 72 hours. The Limiting acute kidney injury Progression In Sepsis protocol algorithm is therefore feasible in terms of identifying suitably high-risk individuals for kidney-sparing sepsis bundle.

Acute kidney injury is a common complication in critically ill patients and is associated with increased morbidity and mortality. Sepsis, major surgery, and nephrotoxic drugs are the most common causes of acute kidney injury. There is currently no effective strategy available to prevent or treat acute kidney injury. Therefore, novel treatment regimens are required to decrease acute kidney injury prevalence and to improve clinical outcomes. Remote ischemic preconditioning, triggered by brief episodes of ischemia and reperfusion applied in distant tissues or organs before the injury of the target organ, attempts to invoke adaptive responses that protect against acute kidney injury. We sought to evaluate the clinical evidence for remote ischemic preconditioning as a potential strategy to protect the kidney and to review the underlying mechanisms in light of recent studies.We searched PubMed for studies reporting the effect of remote ischemic preconditioning on kidney function in surgical patients (search terms: "remote ischemic preconditioning," "kidney function," and "surgery"). We also reviewed bibliographies of relevant articles to identify additional citations.Published studies, consisting of randomized controlled trials, are reviewed.The authors used consensus to summarize the evidence behind the use of remote ischemic preconditioning.In addition, the authors suggest patient populations and clinical scenarios in which remote ischemic preconditioning might be best applied.Several experimental and clinical studies have shown tissue-protective effects of remote ischemic preconditioning in various target organs, including the kidneys. Remote ischemic preconditioning may offer a novel, noninvasive, and inexpensive treatment strategy for decreasing acute kidney injury prevalence in high-risk patients. Although many new studies have further advanced our knowledge in this area, the appropriate intensity of remote ischemic preconditioning, its mechanisms of action, and the role of biomarkers for patient selection and monitoring are still unknown.