Long-term risk of mortality and acute kidney injury during hospitalization after major surgery.

OBJECTIVE: To determine the relationship between long-term mortality and acute kidney injury (AKI) during hospitalization after major surgery. SUMMARY BACKGROUND DATA: AKI is associated with a risk of short-term mortality that is proportional to its severity; however the long-term survival of patients with AKI is poorly studied. METHODS: This is a retrospective cohort study of 10,518 patients with no history of chronic kidney disease who were discharged after a major surgery between 1992 and 2002. AKI was defined by the RIFLE (Risk, Injury, Failure, Loss, and End-stage Kidney) classification, which requires at least a 50% increase in serum creatinine (sCr) and stratifies patients into 3 severity stages: risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed using a risk-adjusted Cox proportional hazards regression model. RESULTS: In the risk-adjusted model, survival was worse among patients with AKI and was proportional to its severity with an adjusted hazard ratio of 1.18 (95% confidence interval [CI], 1.08-1.29) for the RIFLE-Risk class and 1.57 (95% CI, 1.40-1.75) for the RIFLE-Failure class, compared with patients without AKI (P < 0.001). Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.20 (95% CI, 1.10-1.31) compared with patients without AKI (P < 0.001). CONCLUSIONS: In a large single-center cohort of patients discharged after major surgery, AKI with even small changes in sCr level during hospitalization was associated with an independent long-term risk of death.

Acute kidney injury is associated with increased long-term mortality after cardiothoracic surgery.

BACKGROUND: Long-term survival after acute kidney injury (AKI) is poorly studied. We report the relationship between long-term mortality and AKI with small changes in serum creatinine during hospitalization after various cardiothoracic surgery procedures. METHODS AND RESULTS: This was a retrospective study of 2973 patients with no history of chronic kidney disease who were discharged from the hospital after cardiothoracic surgery between 1992 and 2002. AKI was defined by the RIFLE classification (Risk, Injury, Failure, Loss, and End stage), which requires at least a 50% increase in serum creatinine and stratifies patients into 3 grades of AKI: Risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed with a risk-adjusted Cox proportional hazards regression model. Survival was worse among patients with AKI and was proportional to its severity, with an adjusted hazard ratio of 1.23 (95% CI 1.06 to 1.42) for the least severe RIFLE risk class and 2.14 (95% CI 1.73 to 2.66) for the RIFLE failure class compared with patients without AKI. Survival was worse among all subgroups of cardiothoracic surgery with AKI except for valve surgery. Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.28 (95% CI 1.11 to 1.48) compared with patients without AKI. CONCLUSIONS: The risk of death associated with AKI after cardiothoracic surgery remains high for 10 years regardless of other risk factors, even for those patients with complete renal recovery. Improved renal protection and closer postdischarge follow-up of renal function may be warranted.

Interactive web simulation for propofol and fospropofol, a new propofol prodrug.

Using pharmacokinetic and pharmacodynamic data published in the scientific literature, we have developed interactive on-line simulations to model administration of propofol and fospropofol, a new water-soluble prodrug formulation of propofol. The prodrug formulation of fospropofol leads to a delayed onset to peak concentrations of propofol. A comparison simulation that overlays administration of fospropofol and propofol allows clinicians to understand the differences of administering fospropofol and traditional propofol. The simulations have the added advantage of allowing for differences among patients documented in test studies and the use of different models.

Exit of catheter lock solutions from double lumen acute haemodialysis catheters--an in vitro study.

BACKGROUND: Double lumen dialysis catheters are routinely heparin or citrate 'locked' to maintain patency. Heparin lock-related bleeding episodes and antibiotic lock-related toxicity have been reported. The aim of this study is to quantify the amount of leak during 'lock' procedures and to compare leakage for different double lumen dialysis catheters. METHODS: In an experimental, in vitro study at a University research laboratory, five different double lumen dialysis catheters were tested using three different lock volumes. RESULTS: Using the catheter flush volume, leak ratios for Flexxicon II 15 cm and 20 cm catheters were greater than that seen in the Arrow 16 cm catheter (P < 0.05). Using 20% less than the catheter flush volume, the Flexxicon II 20 cm catheter had greater leak than the Duo-flow 15 and 20 cm catheters and Arrow 16 cm catheter (P < 0.05). The Flexxicon II 15 cm catheter had greater leak than the Duo-flow 15 cm and Duo-flow 20 cm catheters with 20% less locking volume (P < 0.05). Using 20% greater than the catheter flush volume, the Duo-flow 20 cm catheter had significantly less leak ratio than the Flexxicon II 20 cm catheter (P < 0.05). There were no other significant differences in leak ratios between the catheters. CONCLUSION: All double lumen dialysis catheters we tested have a substantial amount of leak even when the catheter 'lock' volumes were used, and leak ratio increases significantly with 20% overfill. There is a leak even when using 20% less 'lock' volume. The amount of leak can be clinically important and may explain the reports of bleeding episodes after heparin lock and antibiotic toxicity after antibiotic and anticoagulant combination lock. Some devices have lower leak ratios than others, likely related to catheter design.