RESUMEN
Acute kidney injury (AKI) requiring dialysis is becoming more common. Several types of renal replacement therapies have been used, including continuous, intermittent, and prolonged intermittent renal replacement therapy (PIRRT). There is no clear difference between those therapies in terms of patient survival. The aim of this study was to describe a form of PIRRT (shift continuous veno-venous hemodialysis [CVVHD]) and the results of this technique in a population of patients with AKI requiring dialysis in a tertiary care center. We studied 302 patients with AKI requiring dialysis over a 3-year period. All patients were treated in the intensive care unit. There were 1709 treatments in the study. Shift CVVHD was done for 8 h daily using NxStage machines, with a bicarbonate base dialysate at a rate of 5 L/h. Demographics and laboratory data were obtained from the electronic medical record. Dialysis data were obtained from the dialysis run sheets. Patient mortality was 51.3%.The dialysis time was close to 8 h and the blood flow was 310 (± 43) mL/min. The mean arterial pressure was stable before and after the dialysis. The total ultrafiltration averaged 2934 mL per treatment; the ultrafiltration rate was 4.1 (± 3.1) mL/kg/h, and the ultrafiltration per hour was 359 (± 257.8) mL/h. The average dialysate potassium used was 2.9 mEq/L. The dose of dialysis was 57 (± 19) mL/kg/h. The urea reduction ratio was 48% (± 15%), the standardized KT/V (a measure of dialysis dose obtained by urea kinetic modeling) was 3.5 (± 0.9), and the equivalent renal urea clearance (EKR) was 9.8 (± 4.1) mL/min. The method produced a consistent reduction in the levels of blood urea nitrogen, creatinine, potassium, and phosphorous. The delivered dose of dialysis was stable during the observation period. In conclusion, shift CVVHD is effective in treating patients with AKI requiring dialysis and has a survival similar to that of continuous therapies with less intensive use of resources.
RESUMEN
Data on long-term follow up after acute kidney injury (AKI) requiring dialysis are scarce. The aim of this study was to describe and identify factors associated with survival, recovery of kidney function at discharge, and long-term follow up of renal function in AKI patients requiring dialysis. All AKI patients requiring dialysis during calendar year 2000-2011 treated with conventional hemodialysis and daily shift continuous venovenous hemodialysis (8-hour 40 L dialysate) were included. The data were mean and SD. The results were: 65.8% male; 33.9% diabetic; 75% dipstick positive proteinuria on admission; 72.5% medical AKI; and 27.6% surgical AKI of those (14.2%) who had postcardiovascular surgery. At discharge mortality by cause of AKI: medical 25%, surgical 29.8%; and at the end of study: medical 35.3%, surgical 43.6%. Two-hundred thirty-four patients were discharged alive (mortality 26%). Forty-two died after discharge; 50% in the first 156 days post discharge. Mortality at the end of study was 37.8%. Follow-up (F/U) (1-86 m). At discharge, 200 recovered from kidney function (63.2%), and of those who died in the hospital 80.5% did not recover from kidney function (died dialysis dependent). Baseline serum creatinine was 1.33 mg/dL (0.64), estimated glomerular filtration rate (eGFR) 63.4 mL/minute (29.3), peak creatinine 6.3 mg/dL (2.9), and peak blood urea nitrogen 88.1 mg/dL (39.9). At discharge, serum creatinine was 3.1 mg/dL (2.1) and eGFR was 31.6 mL/minute (27.4); at 6 months, creatinine was 1.66 mg/dL (1.1) and eGFR was 60.8(36); at all F/U times, the creatinine was higher and eGFR was lower than the baseline values (P < 0.05). Of the nonsurvivors, the only significant difference was a lower albumin at baseline (2.9 vs. 3.1 g/dL) (P < 0.05) and lower peak creatinine (5.5 vs. 6.8 mg/dL) (P < 0.05). The mean survival time was 45.4 months. The survival of the patients who recovered from kidney function at discharge was longer than the ones who did not recover (59.7 vs. 16 m, P < 0.05). By Cox regression, the factors significant for survival were peak creatinine and status at discharge. During follow up (data up to 54 months), the percentage of patients with eGFR < 60 mL/minute decreased from 90.9% at discharge to 63.6% at 24 months, then increased to 81.8% at 30 months and longer. The percentage of patients with eGFR < 30 mL/minute decreased from 45.4% at discharge to 18.2% at 24 months to increase at a later date (27-36%). The percentage of patients with eGFR < 15 mL/minute decreased from 45.45% at discharge to 18% until 24 months of follow up (to increase to 27.7% at later dates). AKI requiring dialysis has a significant effect on GFR with almost 80% of the survivors having chronic kidney disease stage 3 or worse. Furthermore, progression was observed on the long-term follow up. Factors affecting the survival included peak creatinine and status of recovery of kidney function at discharge.