Acute kidney injury based on KDIGO (Kidney Disease Improving Global Outcomes) criteria in patients with elevated baseline serum creatinine undergoing cardiac surgery

Introduction

Preoperatively elevated serum creatinine (SCr) is considered an independent risk factor for morbidity and mortality after cardiac surgery. The aim of this study was to apply the Kidney Disease Improving Global Outcomes classification for acute kidney injury in a population of patients with preoperatively elevated serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery) and to evaluate the acute worsening of renal function as a predictor of 30-day mortality.

Methods

This was a single-center retrospective study that included patients from the Postoperative Cardiac Surgery Intensive Care Unit of the Hospital de Base, São José do Rio Preto Medical School. Demographics, type of surgery, laboratory data and pre, peri and postoperative data were obtained from a prospectively collected database. From January 2003 to June 2013, 2,878 patients underwent cardiac surgery, either coronary artery bypass grafting or cardiac valve surgery, at the Hospital de Base of São José do Rio Preto Medical School. Out of those, 918 showed elevated preoperative serum creatinine, with SCr > 1.30 mg/dL for men and > 1.00 mg/dL for women. Five hundred and forty nine patients (60%) undergoing coronary artery bypass grafting and 369 patients (40%) undergoing cardiac valve surgery. A Multivariate Cox Proportional Hazard Model (stepwise) was used to assess the relationship between AKI and mortality at 30 days.

Results

Out of the 918 patients studied, 391 (43%) had postoperative AKI: 318 (35%) had Kidney Disease Improving Global Outcomes stage 1, 27 (2.9%) had Kidney Disease Improving Global Outcomes stage 2, and 46 (5.0%) had Kidney Disease Improving Global Outcomes stage 3. Patients in every stage of acute kidney injury showed progressive increase in EuroSCORE values, 30-day mortality ratescardiopulmonary bypass duration, and intensive care length of stay. Among patients classified as Kidney Disease Improving Global Outcomes stage 3, 76% required dialysis with a 30-day mortality of 66%. The Cox proportional hazards model showed that the hazard ratio for 30-day mortality was 4.8 for Kidney Disease Improving Global Outcomes stage 1 patients, 13.5 for Kidney Disease Improving Global Outcomes stage 2 patients, and 20.8 for Kidney Disease Improving Global Outcomes stage 3 patients (P<0.001 for all). Subgroup analyses (coronary artery bypass grafting and cardiac valve surgery) had similar results.

Conclusion

In this population, acute kidney injury based on the Kidney Disease Improving Global Outcomes criteria was a powerful predictor of 30-day mortality in patients with elevated preoperative serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery).     

The effects of prework functional screening on lowering an employer's injury rate, medical costs, and lost work days

STUDY DESIGN: The data in this study were gathered retrospectively after the progress of program development in terms of employee outcomes within an organization. This design characterizes a retrospective longitudinal study. OBJECTIVE: To determine whether prework functional screens are effective in lowering the incidence of work-related back sprains or strains, related medical costs, and lost work days within an organization. SUMMARY OF BACKGROUND: Musculoskeletal injuries are considered the leading cause of disability for people during their working years. Back injuries are the most common reason for workers' decreased work capacity and reduced leisure time. The increased rate of injury and escalating workers' compensation costs are are a major force motivating companies to implement a tool that can be effective in lowering back sprain or strain injuries and containing their workers' compensation costs. The U.S. Department of Health and Human Services reports a major objective of increasing the number of companies offering back injury prevention programs by the year 2000. METHODS: The study follows the effects realized when a medical center institutes close case management, early return to work policies, and prework functional screens in three stages over the course of 10.5 years. RESULTS: The severity of back sprains or strains, related medical costs, and lost work days were significantly lower with the use of prework functional screens on all new employees hired into physically laborious jobs. CONCLUSIONS: This study offers employers a proven effective tool that can be used to help lower the severity of on-the-job back sprains or strains, resulting medical costs, and lost work days in their organization.