Continuous renal replacement therapy: does technique influence electrolyte and bicarbonate control?
OBJECTIVE
Different techniques of continuous renal replacement therapy (CRRT) might have different effects on electrolyte and acid-base control. The aim of this study was to determine whether continuous veno-venous hemodiafiltration (CVVHDF) or continuous veno-venous hemofiltration (CVVH) achieve better control of serum sodium, potassium and bicarbonate concentrations.


METHODS
Retrospective controlled study.


METHODS
Two tertiary intensive care units.


METHODS
Critically ill patients with acute renal failure (ARF) treated with CVVHDF (n=49) or CVVH (n=50).


METHODS
Retrieval of daily morning sodium and potassium values and arterial bicarbonate levels from computerized biochemical records before and after the initiation of CRRT for up to 2 weeks of treatment. Statistical comparison of findings.


RESULTS
Before treatment, abnormal (high or low) values were frequently observed for sodium (65.1% for CVVHDF vs. 80.0% for CVVH; NS), potassium (45.9% vs. 34.0%; NS), and bicarbonate (73.3% vs. 68.0%; NS). After treatment, however, CVVHDF was more likely to achieve serum sodium concentrations within the normal range (74.1% vs. 62.9%; p=0.0026). Both treatments decreased the mean serum potassium concentration over the first 48 h (p=0.0059 and p<0.0001, respectively), but there was no difference in terms of the normalization of serum potassium concentration during the entire treatment period (88.3% vs. 90.5%; NS). Both treatments increased the mean arterial bicarbonate concentration over the first 48 hours (p=0.011 and p<0.0001, respectively). However, CVVH was associated with a lower incidence of metabolic acidosis (13.8% for CVVH vs. 34.5% for CVVHDF; p<0.0001) and a higher incidence of metabolic alkalosis (38.9% vs. 1.1%; p<0.0001) during the entire treatment period.


CONCLUSIONS
CRRT strategies based on different techniques have a significantly different impact on sodium and bicarbonate control.
Morimatsu
H
H
Department of Intensive Care and Department of Medicine, Austin & Repatriation Medical Centre, Melbourne, Victoria, Australia.
Uchino
S
S
Bellomo
R
R
Ronco
C
C
D058186:Acute Kidney Injury / Q000097:blood* / Q000628:therapy*; D000328:Adult; D000368:Aged; D001639:Bicarbonates / Q000097:blood*; D002021:Buffers; D015331:Cohort Studies; D005260:Female; D017583:Hemodiafiltration / Q000009:adverse effects*; D006440:Hemofiltration / Q000009:adverse effects*; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D011188:Potassium / Q000097:blood; D012189:Retrospective Studies; D012964:Sodium / Q000097:blood; D014883:Water-Electrolyte Imbalance / Q000097:blood* / Q000209:etiology* / Q000517:prevention & control
D001639:Bicarbonates; D002021:Buffers; D012964:Sodium; D011188:Potassium