Creatinine- and Cystatin C-Based Incidence of Chronic Kidney Disease and Acute Kidney Disease in AKI Survivors.

BACKGROUND: Renal dysfunction after acute kidney injury (AKI) is common, potentially modifiable, but poorly understood. Acute kidney disease (AKD) describes renal dysfunction 7 to 90 days after AKI and is determined by percentage change in creatinine from baseline. Chronic kidney disease (CKD) is defined as the estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m2 persisting for more than 90 days. We compared CKD incidence using both creatinine- and cystatin C-based GFR with AKD incidence at 90 days in AKI survivors. METHODS: A prospective cohort study was conducted in a Swedish intensive care unit (ICU) between 2008 and 2010. We included AKI patients alive at 90 days. We excluded patients <18 and >100 years, death before follow-up, CKD prior to admission, and follow-up before 60 days or beyond 270 days. Creatinine and cystatin C were measured at 90 days and converted to eGFR (mL/min/1.73 m2). RESULTS: We included 274 patients. At 90-day follow-up, the median creatinine eGFR (MDRD) was 81.6 (IQR 58.6-106.8) and median cystatin C eGFR was 51.5 (IQR 35.8-70.7). The incidence of CKD (eGFR < 60) was 25.8% based on creatinine but 63.7% using cystatin C estimates. AKD was present in 47 patients (18.9%). Age, discharge cystatin C, creatinine at discharge, and female gender predicted creatinine-defined CKD at follow-up. Age, discharge cystatin C, CRRT on ICU, and diabetes were associated with cystatin C-based CKD. CONCLUSIONS: In AKI survivors followed up at 3 months, CKD criteria were met in a quarter of patients using creatinine and in two-thirds using cystatin C eGFR. Less than one-fifth of patients fulfilled AKD criteria. The application of AKD criteria may underestimate renal dysfunction in AKI survivors.

A comparison of two emergency medical dispatch protocols with respect to accuracy.

BACKGROUND: Emergency medical dispatching should be as accurate as possible in order to ensure patient safety and optimize the use of ambulance resources. This study aimed to compare the accuracy, measured as priority level, between two Swedish dispatch protocols - the three-graded priority protocol Medical Index and a newly developed prototype, the four-graded priority protocol, RETTS-A. METHODS: A simulation study was carried out at the Emergency Medical Communication Centre (EMCC) in Stockholm, Sweden, between October and March 2016. Fifty-three voluntary telecommunicators working at SOS Alarm were recruited nationally. Each telecommunicator handled 26 emergency medical calls, simulated by experienced standard patients. Manuscripts for the scenarios were based on recorded real-life calls, representing the six most common complaints. A cross-over design with 13 + 13 calls was used. Priority level and medical condition for each scenario was set through expert consensus and used as gold standard in the study. RESULTS: A total of 1293 calls were included in the analysis. For priority level, n = 349 (54.0%) of the calls were assessed correctly with Medical Index and n = 309 (48.0%) with RETTS-A (p = 0.012). Sensitivity for the highest priority level was 82.6% (95% confidence interval: 76.6-87.3%) in the Medical Index and 54.0% (44.3-63.4%) in RETTS-A. Overtriage was 37.9% (34.2-41.7%) in the Medical Index and 28.6% (25.2-32.2%) in RETTS-A. The corresponding proportion of undertriage was 6.3% (4.7-8.5%) and 23.4% (20.3-26.9%) respectively. CONCLUSION: In this simulation study we demonstrate that Medical Index had a higher accuracy for priority level and less undertriage than the new prototype RETTS-A. The overall accuracy of both protocols is to be considered as low. Overtriage challenges resource utilization while undertriage threatens patient safety. The results suggest that in order to improve patient safety both protocols need revisions in order to guarantee safe emergency medical dispatching.

Dialysis modality and correction of uremic metabolic acidosis: relationship with all-cause and cause-specific mortality.

BACKGROUND AND OBJECTIVES: Uremic metabolic acidosis is only partially corrected in many hemodialysis patients, and low serum bicarbonate predicts higher death risk. This study determined the comparative efficacy of peritoneal dialysis in correcting uremic metabolic acidosis and the association of serum bicarbonate and death risk with the two therapies. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data were obtained from 121,351 prevalent ESRD patients (peritoneal dialysis, 10,400; hemodialysis, 110,951) treated in DaVita facilities between July 1, 2001 and June 30, 2006, with follow-up through June of 2007. RESULTS: Serum bicarbonate was <22 mEq/L in 25% and 40% of peritoneal dialysis and hemodialysis patients, respectively. Thus, peritoneal dialysis patients were substantially less likely to have lower serum bicarbonate (adjusted odds ratio<20 mEq/L, 0.45 [0.42, 0.49]; <22 mEq/L, 0.41 [0.39, 0.43]). Time-averaged serum bicarbonate<19 mEq/L was associated with an 18% and 25% higher risk for all-cause and cardiovascular mortality, respectively, in prevalent peritoneal dialysis patients (reference group: serum bicarbonate between 24 and <25 mEq/L). In analyses using the entire cohort of peritoneal dialysis and hemodialysis patients, the adjusted risk for all-cause mortality was higher in most subgroups with serum bicarbonate<22 mEq/L, irrespective of dialysis modality. CONCLUSIONS: The measured bicarbonate is significantly higher in peritoneal dialysis patients, suggesting that the therapy provides a more complete correction of metabolic acidosis than intermittent hemodialysis. Survival data suggest maintaining serum bicarbonate>22 mEq/L for all ESRD patients, irrespective of dialysis modality.

Serum potassium and cause-specific mortality in a large peritoneal dialysis cohort.

BACKGROUND AND OBJECTIVES: Unlike hemodialysis (HD), peritoneal dialysis (PD) is a continuous therapy and does not induce myocardial stunning. Yet, the death risk in HD and PD patients is similar. This study tested the hypothesis that serum potassium abnormalities contribute more to the death risk in PD patients than in HD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data from patients treated in DaVita facilities between July 1, 2001 and June 30, 2006 (n=10,468 PD patients; n=111,651 HD patients) were used to determine association of serum potassium with mortality. RESULTS: PD patients were significantly more likely to have serum potassium < 4 mEq/L, with an adjusted odds ratio of 3.30 (95% confidence interval [95% CI], 3.05, 3.56). There was a U-shaped relationship between time-averaged serum potassium and all-cause and cardiovascular mortality of PD patients, with adjusted hazards ratios of 1.51 for all-cause mortality for potassium < 3.5 mEq/L (95% CI, 1.29, 1.76) and 1.52 for potassium ≥ 5.5 mEq/L (95% CI, 1.32, 1.75). The population-attributable risks for all-cause mortality for serum potassium < 4.0 and ≥ 5.5 mEq/L were 3.6% and 1.9%, respectively, in PD patients, and 0.8% and 1.5%, respectively, in HD patients. CONCLUSIONS: Abnormalities in serum potassium contribute disproportionately to the high death risk in PD patients. This may, in part, account for the equivalent cardiac risk seen with the two therapies.