Validity of low-intensity continuous renal replacement therapy*.
OBJECTIVE
To study the hospital mortality of patients with severe acute kidney injury treated with low-intensity continuous renal replacement therapy.


METHODS
Multicenter retrospective observational study (Japanese Society for Physicians and Trainees in Intensive Care), combined with previously conducted multinational prospective observational study (Beginning and Ending Supportive Therapy).


METHODS
Fourteen Japanese ICUs in 12 tertiary hospitals (Japanese Society for Physicians and Trainees in Intensive Care) and 54 ICUs in 23 countries (Beginning and Ending Supportive Therapy).


METHODS
Consecutive adult patients with severe acute kidney injury requiring continuous renal replacement therapy admitted to the participating ICUs in 2010 (Japanese Society for Physicians and Trainees in Intensive Care, n = 343) and 2001 (Beginning and Ending Supportive Therapy Beginning and Ending Supportive Therapy, n = 1,006).


METHODS
None.


RESULTS
Patient characteristics, variables at continuous renal replacement therapy initiation, continuous renal replacement therapy settings, and outcomes (ICU and hospital mortality and renal replacement therapy requirement at hospital discharge) were collected. Continuous renal replacement therapy intensity was arbitrarily classified into seven subclasses: less than 10, 10-15, 15-20, 20-25, 25-30, 30-35, and more than 35 mL/kg/hr. Multivariable logistic regression analysis was conducted to investigate risk factors for hospital mortality. The continuous renal replacement therapy dose in the Japanese Society for Physicians and Trainees in Intensive Care database was less than half of the Beginning and Ending Supportive Therapy database (800 mL/hr vs 2,000 mL/hr, p < 0.001). Even after adjusting for the body weight and dilution factor, continuous renal replacement therapy intensity was statistically different (14.3 mL/kg/hr vs 20.4 mL/kg/hr, p < 0.001). Patients in the Japanese Society for Physicians and Trainees in Intensive Care database had a lower ICU mortality (46.1% vs 55.3%, p = 0.003) and hospital mortality (58.6% vs 64.2%, p = 0.070) compared with patients in the Beginning and Ending Supportive Therapy database. In multivariable regression analysis after combining the two databases, no continuous renal replacement therapy intensity subclasses were found to be statistically different from the reference intensity (20-25 mL/kg/hr). Several sensitivity analyses (patients with sepsis, patients from Western countries in the Beginning and Ending Supportive Therapy database) confirmed no intensity-outcome relationship.


CONCLUSIONS
Continuous renal replacement therapy at a mean intensity of 14.3 mL/kg/hr did not have worse outcome compared with 20-25 mL/kg/hr of continuous renal replacement therapy, currently considered the standard intensity. However, our study is insufficient to support the use of low-intensity continuous renal replacement therapy, and more studies are needed to confirm our findings.
1Intensive Care Unit, Department of Anesthesiology, Jikei University School of Medicine, Tokyo, Japan. 2Department of Internal Medicine, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan. 3Division of Intensive Care Medicine, Hyogo College of Medicine, Hyogo, Japan. 4Intensive Care Unit, Department of Anesthesiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan. 5Department of Emergency and Critical Care, Showa University Fujigaoka Hospital, Kanagawa, Japan. 6Department of Emergency Medicine, Asahi General Hospital, Chiba, Japan. 7Department of Nephrology and Hypertension, St. Marianna University School of Medicine, Kanagawa, Japan. 8Intensive Care Unit, Department of Emergency and Critical Care Medicine, Japanese Red Cross Musashino Hospital, Tokyo, Japan. 9Intensive Care Unit, Osaka University Hospital, Osaka, Japan. 10Division of Intensive Care, University Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan. 11Department of Emergency, Kanto Rosai Hospital, Kanagawa, Japan.
Shigehiko
S
Uchino
Noriyoshi
N
Toki
Kenta
K
Takeda
Tetsu
T
Ohnuma
Yoshitomo
Y
Namba
Shinshu
S
Katayama
Hiroo
H
Kawarazaki
Hideto
H
Yasuda
Junichi
J
Izawa
Makiko
M
Uji
Natsuko
N
Tokuhira
Isao
I
Nagata
D018806:APACHE; D058186:Acute Kidney Injury / Q000401:mortality / Q000628:therapy*; D000368:Aged; D005260:Female; D006440:Hemofiltration / Q000379:methods* / Q000401:mortality; D017052:Hospital Mortality; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D062606:Tertiary Care Centers