Lower-Dose CRRT May Cut AKI Mortality
SAN DIEGO—Lower-dose continuous renal replacement therapy (CRRT) for critically ill patients with acute kidney injury (AKI) may boost their likelihood of survival, according to a new study.
Tomoko Fujii, MD, of the Department of Emergency and Critical Care Medicine, St. Marianna University, Kawasaki-city, Kanagawa, Japan, led a chart review of patients with AKI who were triaged in emergency departments at two hospitals and then transferred to the respective ICUs between January 2007 and July 2010. They included all those who received continuous veno-venous hemodiafiltration during their ICU stay. Data from nine patients who died in the hospital, either in the ICU or a non-ICU ward, were not available for calculation of the ICU survival rate.
There is ongoing controversy about the optimal CRRT dose: high dose (35-40 mL/kg/hr) or low dose (20-25 mL/kg/hr), according to the researchers.
The 131 patients in the study had an average age of 60 years and 66% were male. Of the 131 patients, 74 (56%) had sepsis. The average APACHE (Acute Physiology And Chronic Health Evaluation II) score was 26, the average blood urea nitrogen value at dialysis initiation was 39 mg/dL, and the average serum creatinine level at initiation was 2.4 mg/dL.
The median delivered dose of CRRT was 16 mL/kg/hr (interquartile range 14-19), which is lower than dose examined in many other studies. The ICU survival rate was 65% (79/122) and the hospital mortality rate was 42% (56/131). Of the 74 septic patients, 34 died in the hospital (45%). The median length of ICU stay was eight days (range 5-36 days) and the median hospital stay was 31 days (range 6-92). The study revealed a 95% renal recovery rate among those who survived their ICU stay. The mortality rates found in this study were lower than those reported in published studies of dialysis in the AKI population.
“As our study includes only patients from the emergency room, it is likely to be more reflective of actual clinical practice among patients with septic AKI. However, a larger prospective study with standardized protocols for CRRT would help clarify this,” noted Dr. Fujii, who presented study findings at the Society for Critical Care Medicine annual meeting.
Kirsten Johansen, MD, Professor of Medicine at the University of California in San Francisco and the Director of Dialysis at the San Francisco VA Medical Center, said it is difficult to determine the study's implications for American clinicians.
“Without a control group to rule out practice differences between here and Japan, such as timing of initiation of dialysis, how they handle ventilation, what sort of metabolic stability they achieved, etc., I would be very cautious in interpreting it,” Dr. Johansen said. “It is encouraging that it may be possible to go to lower-intensity dialysis, but it's hard to tell from this study whether that's the case.”