Can Delivery Dialysis Dose Affect Survival of Acute Kidney Injury Patients?

Intensity of dialysis dose in acute kidney injury (AKI) might benefit critically ill patients. The aim of this study was to evaluate the effect of intermittent hemodialysis (IHD) dose on mortality in patients with AKI. Methods: Prospective observational study was performed on AKI patients treated with IHD. The delivered dialysis dose per session was calculated based on single-pool Kt/V urea. Patients were allocated in two groups according to the weekly delivered median Kt/V: higher intensity dialysis dose (HID: Kt/V higher than median) and lower intensity dialysis dose (LID: Kt/V lower than median). Thereafter, AKI patients were divided according to the presence or absence of sepsis and urine output. Clinical and lab characteristics and survival of AKI patients were compared. Results: A total of 121 AKI patients were evaluated. Forty-two patients did not present with sepsis and 45 did not present with oliguria. Mortality rate after 30 days was lower in the HID group without sepsis (14.3% x 47.6%; p = 0.045) and without oliguria (31.8% x 69.5%; p = 0.025). Survival curves also showed that the HID group had higher survival rate when compared with the LID group in non-septic and non-oliguric patients (p = 0.007 and p = 0.003, respectively). Conclusion: Higher dialysis doses can be associated with better survival of less seriously ill AKI patients.

Effluent volume and dialysis dose in CRRT: time for reappraisal

The results of several studies assessing dialysis dose have dampened the enthusiasm of clinicians for considering dialysis dose as a modifiable factor influencing outcomes in patients with acute kidney injury. Powerful evidence from two large, multicenter trials indicates that increasing the dialysis dose, measured as hourly effluent volume, has no benefit in continuous renal replacement therapy (CRRT). However, some important operational characteristics that affect delivered dose were not evaluated. Effluent volume does not correspond to the actual delivered dose, as a decline in filter efficacy reduces solute removal during therapy. We believe that providing accurate parameters of delivered dose could improve the delivery of a prescribed dose and refine the assessment of the effect of dose on outcomes in critically ill patients treated with CRRT.

High volume peritoneal dialysis for acute renal failure

Background. Peritoneal dialysis (PD) is still widely used for acute renal failure (ARF) in developing countries despite concerns about its inadequacy. Continuous PD has been evaluated in ARF by analyzing the resolution of metabolic abnormality and normalization of plasma pH, bicarbonate, and potassium.Methodology: A prospective study was performed on 30 ARF patients who were assigned to high-dose continuous PD (Kt/V = 0.65 per session) via a flexible catheter (Tenckhoff) and automated PD with a cycler. Fluid removal, pH and metabolic control, protein Loss, and patient outcome were evaluated.Results: Patients received 236 continuous PD sessions; 76% were admitted to ICUs. APACHE II score was 32.2 +/- 8.65. BUN concentrations stabilized after 3 sessions, creatinine after 4, and bicarbonate and pH after 2. Fluid removal was 2.1 +/- 0.62 L/day. Creatinine and urea clearances were 15.8 +/- 4.16 and 17.3 +/- 5.01 mL/minute respectively. Normalized creatinine clearance and urea Kt/V values were 110.6 +/- 22.5 L/week/1.73 m(2) body surface area and 3.8 +/- 0.6 respectively. Solute reduction index was 41% +/- 6.5% per session. Serum albumin values remained stable in spite of considerable protein tosses (median 21.7 g/day, interquartile range 9.1 - 29.8 g/day). Regarding ARF outcome, 23% of patients presented renal function recovery, 13% remained on dialysis after 30 days of follow-up, and 57% died.Conclusion: High-dose continuous PD by flexible catheter and cycler was an effective treatment for ARF. It provided high solute removal, allowing appropriate metabolic and pH control, and adequate dialysis dose and fluid removal. Continuous PD can therefore be considered an alternative to other forms of renal replacement therapy in ARF.

Peritoneal dialysis in acute renal failure

The definition of adequate dialysis in acute renal failure (ARF) is complex and involves the time of referral to dialysis, dose, and dialytic method. Nephrologist experience with a specific procedure and the availability of different dialysis modalities play an important role in these choices. There is no consensus in literature on the best method or ideal dialysis dose in ARF. Peritoneal dialysis (PD) is used less and less in ARF patients, and is being replaced by continuous venovenous therapies. However, it should not be discarded as a worthless therapeutic option for ARF patients. PD offers several advantages over hemodialysis, such as its technical simplicity, excellent cardiovascular tolerance, absence of an extracorporeal circuit, lack of bleeding risk, and low risk of hydro-electrolyte imbalance. PD also has some limitations, though: it needs an intact peritoneal cavity, carries risks of peritoneal infection and protein losses, and has an overall lower effectiveness. Because daily solute clearance is lower with PD than with daily HD, there have been concerns that PD cannot control uremia in ARF patients. Controversies exist concerning its use in patients with severe hypercatabolism; in these cases, daily hemodialysis or continuous venovenous therapy have been preferred. There is little literature on PD in ARF patients, and what exists does not address fundamental parameters such as adequate quantification of dialysis and patient catabolism. Given these limitations, there is a pressing need to re-evaluate the adequacy of PD in ARF using accepted standards. Therefore, new studies should be undertaken to resolve these problems. Copyright © Informa Healthcare.

Different prescribed doses of high-volume peritoneal dialysis and outcome of patients with acute kidney injury.

The optimal dialysis dose for the treatment of acute kidney injury (AKI) is controversial. No studies have directly examined the effects of peritoneal dialysis (PD) dose on outcomes in AKI. From January 2005 to January 2007, we randomly assigned critically ill patients with AKI to receive higher- or lower-intensity PD therapy (prescribed Kt/Vof 0.8 and 0.5 per session respectively). The main outcome measure was death within 30 days. Of the 61 enrolled patients, 30 were randomly assigned to higher-intensity therapy, and 31, to a lower-intensity PD dose. The two study groups had similar baseline characteristics and received treatment for 6.1 days and 5.7 days respectively (p = 0.42). At 30 days after randomization, 17 deaths had occurred in the higher-intensity group (55%), and 16 deaths, in the lower-intensity group (53%, p = 0.83). There was a significant difference between the groups in the PD dose prescribed compared with the dose delivered (higher-intensity group: 0.8 vs. 0.59, p = 0.04; lower-intensity group: 0.5 vs. 0.49, p = 0.89). The groups had similar metabolic control after 4 PD sessions (blood urea nitrogen: 69.3 +/- 14.4 mg/dL and 60.3 +/- 11.1 mg/dL respectively, p = 0. 71). In critically ill patients with AKI, an intensive PD dose did not lower the mortality or improve the recovery of kidney function or metabolic control. The PD dose is limited by dialysate flow and membrane permeability, and clearance per exchange can decrease if a shorter dwell time is applied.

A randomized clinical trial of high volume peritoneal dialysis versus extended daily hemodialysis for acute kidney injury patients

Background: Acute kidney injury (AKI) requiring dialysis in critically ill patients is associated with an in-hospital mortality rate of 50-80 %. Extended daily hemodialysis (EHD) and high volume peritoneal dialysis (HVPD) have emerged as alternative modalities. Methods: A double-center, randomized, controlled trial was conducted comparing EHD versus HVPD for the treatment for AKI in the intensive care unit (ICU). Four hundred and seven patients were randomized and 143 patients were analyzed. Principal outcome measure was hospital mortality, and secondary end points were recovery of renal function and metabolic and fluid control. Results: There was no difference between the two groups in relation to median ICU stay [11 (5.7-20) vs. 9 (5.7-19)], recovery of kidney function (26.9 vs. 29.6 %, p = 0.11), need for chronic dialysis (9.7 vs. 6.5 %, p = 0.23), and hospital mortality (63.4 vs. 63.9 %, p = 0.94). The groups were different in metabolic and fluid control. Blood urea nitrogen (BUN), creatinine, and bicarbonate levels were stabilized faster in EHD group than in HVPD group. Delivered Kt/V and ultrafiltration were higher in EHD group. Despite randomization, there were significant differences between the groups in some covariates, including age, pre-dialysis BUN, and creatinine levels, biased in favor of the EHD. Using logistic regression to adjust for the imbalances in group assignment, the odds of death associated with HVPD was 1.4 (95 % CI 0.7-2.4, p = 0.19). A detailed investigation of the randomization process failed to explain the marked differences in patient assignment. Conclusions: Despite faster metabolic control and higher dialysis dose and ultrafiltration with EHD, this study provides no evidence of a survival benefit of EHD compared with HVPD. The limitations of this study were that the results were not presented according to the intention to treat and it did not control other supportive management strategies as nutrition support and timing of dialysis initiation that might influence outcomes in AKI. © 2012 Springer Science+Business Media Dordrecht.

Hemodiálise prolongada na lesão renal aguda associada a sepse: sobrevida dos pacientes de acordo com o momento da indicação e a dose de diálise recebida

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Prevention of Intradialytic Hypotension in Patients with Acute Kidney Injury Submitted to Sustained Low-Efficiency Dialysis

Objectives: This study evaluated the effects of a protocol aiming to reduce hypotension in acute kidney injury (AKI) patients submitted to sustained low-efficiency dialysis (SLED). Methods: Patients were randomly assigned to two SLED prescriptions-control group, dialysate temperature was 37.0 degrees C with a fixed sodium concentration [138 mEq/L] and ultrafiltration (UF) rate; and profiling group, dialysate temperature was 35.5 degrees C with a variable sodium concentration [150-138 mEq/L] and UF rate. Results: Sixty-two SLED sessions were evaluated (34 in profiling and 28 in control). Patients (n = 31) were similar in terms of gender, age, and Sequential Organ Failure Assessment (SOFA) score. Dialysis time, dialysis dose, and post-dialysis serum sodium were similar in both groups. The profiling group had significantly less hypotension episodes (23% vs. 57% in control, p = 0.009) and achieved higher UF volume (2.23 +/- 1.25 L vs. 1.59 +/- 1.03 L in control, p = 0.04) when compared with control group. Conclusions: SLED protocol with modulation of dialysate temperature, sodium, and UF profiling showed similar efficacy but less intradialytic hypotension when compared with a standard SLED prescription.

Toward the optimal dose metric in continuous renal replacement therapy

Purpose: There is no consensus on the optimal method to measure delivered dialysis dose in patients with acute kidney injury (AKI). The use of direct dialysate-side quantification of dose in preference to the use of formal blood-based urea kinetic modeling and simplified blood urea nitrogen (BUN) methods has been recommended for dose assessment in critically-ill patients with AKI. We evaluate six different blood-side and dialysate-side methods for dose quantification. Methods: We examined data from 52 critically-ill patients with AKI requiring dialysis. All patients were treated with pre-dilution CWHDF and regional citrate anticoagulation. Delivered dose was calculated using blood-side and dialysis-side kinetics. Filter function was assessed during the entire course of therapy by calculating BUN to dialysis fluid urea nitrogen (FUN) ratios q/12 hours. Results: Median daily treatment time was 1,413 min (1,260-1,440). The median observed effluent volume per treatment was 2,355 mL/h (2,060-2,863) (p<0.001). Urea mass removal rate was 13.0 +/- 7.6 mg/min. Both EKR (r(2)=0.250; p<0.001) and K-D (r(2)=0.409; p<0.001) showed a good correlation with actual solute removal. EKR and K-D presented a decline in their values that was related to the decrease in filter function assessed by the FUN/BUN ratio. Conclusions: Effluent rate (ml/kg/h) can only empirically provide an estimated of dose in CRRT. For clinical practice, we recommend that the delivered dose should be measured and expressed as K-D. EKR also constitutes a good method for dose comparisons over time and across modalities.

Treatment of acute renal failure in the intensive care unit: lower costs by intermittent dialysis than continuous venovenous hemodiafiltration

Intermittent and continuous renal replacement therapies (RRTs) are available for the treatment of acute renal failure (ARF) in the intensive care unit (ICU). Although at present there are no adequately powered survival studies, available data suggest that both methods are equal with respect to patient outcome. Therefore, cost comparison between techniques is important for selecting the modality. Expenditures were prospectively assessed as a secondary end point during a controlled, randomized trial comparing intermittent hemodialysis (IHD) with continuous venovenous hemodiafiltration (CVVHDF). The outcome of the primary end points of this trial, that is, ICU and in-hospital mortality, has been previously published. One hundred twenty-five patients from a Swiss university hospital ICU were randomized either to CVVHDF or IHD. Out of these, 42 (CVVHDF) and 34 (IHD) were available for cost analysis. Patients' characteristics, delivered dialysis dose, duration of stay in the ICU or hospital, mortality rates, and recovery of renal function were not different between the two groups. Detailed 24-h time and material consumption protocols were available for 369 (CVVHDF) and 195 (IHD) treatment days. The mean daily duration of CVVHDF was 19.5 +/- 3.2 h/day, resulting in total expenditures of Euro 436 +/- 21 (21% for human resources and 79% for technical devices). For IHD (mean 3.0 +/- 0.4 h/treatment), the costs were lower (Euro 268 +/- 26), with a larger proportion for human resources (45%). Nursing time spent for CVVHDF was 113 +/- 50 min, and 198 +/- 63 min per IHD treatment. Total costs for RRT in ICU patients with ARF were lower when treated with IHD than with CVVHDF, and have to be taken into account for the selection of the method of RRT in ARF on the ICU.

Efecto de ajuste del flujo dializante (Qd) sobre la eficacia en hemodialisis a pacientes de bajo peso

Introducción: Las guías KDOQI del 2006 utilizan patrón de adecuación de diálisis el Kt/V, donde V es volumen de distribución de la úrea, pacientes de bajo peso tienen menor agua corporal total, menor V, que podrían reducir el requerimiento de Qd sin afectar la eficiencia de la diálisis. Objetivo: Evaluar el efecto sobre la adecuación de hemodiálisis que produce la reducción del Qd en pacientes con peso menor o igual a 60 kg . Metodología: Se incluyeron pacientes con Enfermedad Renal crónica en hemodiálisis de forma regular con peso menor o igual a 60 Kg de la unidad renal, para evaluar dos períodos I y II, se continuaron los parámetros de la terapia, con descenso del Qd para el segundo período . Las variables fueron recolectadas de forma directa por los investigadores de la historia clínica . Los valores así obtenidos serían comparados mediante prueba t para variables relacionadas o pareadas, y significancia estadística de la prueba inferior a 0,05. Resultados: Se incluyeron 61 pacientes, el 60.7% sexo femenino, promedio de edad 57,3 años (DE 14,8). Edad promedio de los hombres 60,1 (DE 13,9) y de las mujeres fue de 55,9 (DE 15,4). No se encontraron diferencias estadísticamente significativas para las variables Kt/V y Hb, con descenso significativo del P. (p 0.015) Conclusiones: Este estudio demuestra que se logra una adecuada terapia con Qd inferiores a los estándares tradicionales, con 400ml /min en pacientes de bajo peso, siempre y cuando se mantengan los demás parámetros de suplencia renal.

Effect of fractional urea clearance on survival of hemodialysis patients in relation to gender

Many studies have demonstrated the relationship between dialysis dose and survival. Global mortality is similar among men and women; however, the influence of dialysis dose in the survival could be more intensive between women. Therefore, we conduct an observational study to evaluate the gender-related impact of single pool Kt/V (spKt/V) on the survival of patients submitted to hemodialysis in a university hospital. We found that survival was lower in groups with spKt/V smaller than 1.2 than in those with Kt/V between 1.2 and 1.4. Among female patients, spKt/V smaller than 1.2 had a more adverse effect in survival than among men with a comparable Kt/V. Otherwise, among women, the dialysis dose had an impact in survival even with Kt/V greater than 1.4. Thus, fractional urea clearance more heavily influenced the survival of females than males in hemodialysis patients.

Efeitos da redução no conteúdo de sódio da dieta sobre o volume de água corporal e marcadores inflamatórios em pacientes com insuficiência renal crônica em tratamento hemodialítico

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Efeitos de diferentes doses de hemodiálise convencional diária na sobrevida de pacientes com injúria renal aguda

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da mortalidade e recuperação renal de pacientes com insuficiência renal aguda submetidos à diálise com diferentes níveis de uréia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)