Sustained low efficiency dialysis in the continuous mode (C-SLED): dialysis efficacy, clinical outcomes, and survival predictors in critically ill cancer patients

Abstract

Background and objectives: Oliguric, hypotensive patients who require large amounts of fluids may benefit from sustained low-efficiency dialysis performed continuously (C-SLED). C-SLED through higher clearance may improve survival, or through greater nutritional loss may worsen survival. No studies have assessed survival on C-SLED. The objective was to examine patient outcomes and survival predictors on C-SLED.

Design, setting, participants, & measurements: The data of 199 consecutive cancer patients treated with C-SLED were analyzed. The median duration of C-SLED was 50 h. With 48 h of C-SLED, the blood urea nitrogen (BUN) and serum creatinine levels had decreased by 80% and 73%, respectively. The mean arterial pressure (MAP) was maintained despite higher ultrafiltration and reduced vasopressor use. The 30-d mortality rate was 65%. Despite excellent dialysis, the sequential organ failure assessment (SOFA) score remained predictive of mortality. In the univariate model, higher SOFA scores and lower values for MAP, blood pH, and serum albumin and creatinine levels were associated with higher mortality. Administration of total parenteral nutrition (TPN) was, however, associated with lower mortality.

Results: In the multivariate model, the higher SOFA score and lower blood pH, MAP and C-SLED duration were associated with higher mortality. In a subset analysis of 129 patients who received C-SLED for at least 48 h, those with higher BUN levels, which were associated with higher TPN infusion, had a lower mortality risk.

Conclusion: This first detailed report on C-SLED indicates that C-SLED can be effective and suggests a link between nutrition and survival.

Figure 1.

Sequential organ failure assessment (SOFA) scores (mean ± 95% confidence interval) in 199 patients.

Figure 2.

Frequency distribution of continuous sustained low-efficiency dialysis (C-SLED) duration in 199 patients.

Figure 3.

Box plots (median with interquartiles) for key biochemical measurements obtained during the first 48 h of continuous sustained low-efficiency dialysis (C-SLED). Error bars indicate confidence intervals. *P < 0.05 versus 0 h.

Figure 4.

Probability of 30-d survival in 199 patients treated with continuous sustained low-efficiency dialysis (C-SLED) as a function of sequential organ failure assessment (SOFA) score tertiles.

Figure 5.

Cumulative mortality risk in patients with 48-h blood urea nitrogen (BUN) levels of ≥8 mg/dl or <8 mg/dl. The lower limit of normal value for BUN is 8 mg/dl. This graph is based on the multivariate Cox regression model of a subset of 129 patients who received continuous sustained low-efficiency dialysis (C-SLED) for at least 48 h (Table 5).