Tohoku J. Exp. Med., 2014 August, 233(4)

Classical Indications Are Useful for Initiating Continuous Renal Replacement Therapy in Critically Ill Patients

JEONGHWAN LEE,¹ JANG-HEE CHO,² BYUNG HA CHUNG,³ JUNG TAK PARK,⁴ JUNG PYO LEE,⁵ JAE HYUN CHANG,⁶ DONG KI KIM⁷ and SEJOONG KIM⁸

¹Department of Internal Medicine, Hallym University Hangang Sacred Heart Hospital, Seoul, Korea
²Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
³Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
⁴Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
⁵Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
⁶Department of Internal Medicine, Gachon University of Medicine and Science, Incheon, Korea
⁷Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
⁸Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea

The optimal timing for initiating continuous renal replacement therapy (CRRT) remains controversial, and it is not obvious which parameters should be considered during this process. We investigated the predictive value of physiological parameters among critically ill patients receiving CRRT due to acute kidney injury (AKI). A total of 496 patients who started CRRT were prospectively enrolled. The following physiological parameters were significantly associated with mortality even after multivariate adjustments: level of pH [hazard ratio (95% CI): 7.15 < pH ≤ 7.20, 1.971 (1.319-2.946); pH ≤ 7.15, 2.315 (1.586-3.380); reference > 7.25, P-for-trend < 0.001]; bicarbonate level (HCO₃⁻) [≤ 14 mmol/L, 2.010 (1.542-2.620); reference > 18 mmol/L, P-for-trend < 0.001]; phosphorus level [> 7 mmol/L, 1.736 (1.313-2.296); reference ≤ 5 mmol/L, P-for-trend < 0.001]; and urine output < 0.3 ml/kg/hr [1.509 (1.191-1.912); reference > 0.3 ml/kg/hour]. Weight gain over 2 kg was associated with mortality exclusively according to univariate analysis [1.516 (1.215-1.892)]. The diagnostic value of the composite of these factors (pH, bicarbonate level, phosphorus level, urine output, weight gain, and potassium levels) [area under the curve (AUC) 0.701, 95% CI 0.644-0.759] was comparable to or higher than the blood urea nitrogen level (AUC 0.571, 95% CI 0.511-0.630), serum creatinine level (AUC 0.462, 95% CI 0.399-0.525), eGFR (AUC 0.541, 95% CI 0.478-0.605), and AKI Network stage (AUC 0.627, 95% CI 0.561-0.692). In conclusion, the physiological parameters are useful in predicting post-AKI mortality and should be considered when initiating CRRT in critically ill patients with AKI.

keywords —— acute kidney injury; continuous renal replacement therapy; indication; mortality; renal replacement therapy

© 2014 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2014, 233, 233-241

Correspondence: Sejoong Kim, M.D., Ph.D., Division of Nephrology, Department of Internal Medicine, Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam 463-707, Republic of Korea.

e-mail: sejoong2@snu.ac.kr