Abstract: SA-PO073

Serum Lactate Level Predicts Mortality among Patients with Metformin-Associated Lactic Acidosis Requiring Renal Replacement Therapy

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational

Authors

  • Kuo, Chin-Chi, China Medical University Hospital, Taichung City, Taiwan
  • Tsai, Ching-Wei, China Medical University Hospital, Taichung City, Taiwan

Group or Team Name

  • CHMU Kidney Research Group
Background

The risk factor for mortality and the best practice concerning timing, mode, and dose of renal replacement therapy (RRT) for patients with metformin-associated lactic acidosis (MALA) with renal failure remain undetermined.

Methods

We searched case reports and case series published in PubMed/Medline and EMBASE from inception to Sep 2014 and applied predetermined exclusion criteria. Case-level data including case's demographics and clinical information related to MALA were abstracted. Multiple logistic regression modeling was used to examine the predictors of mortality.

Results

A total of 253 unique cases were identified with cumulative mortality of 17.2%. Eighty-seven percent of patients had acute kidney injury. Serum lactate level was significantly higher in non-survivors (median 22.5 mmol/L) than in survivors (17.0 mmol/L, p-value <0.01) and so did the median blood metformin concentrations (58.5 vs. 43.9 mg/L, p-value=0.05). The survival advantage was not significantly different between the modalities of RRT. The adjusted odds ratio of mortality for every one mmol/L increase in serum lactate level was 1.09 (95% CI 1.02-1.17, p-value=0.01). The dose-response curve indicated a lactate threshold greater than 20 mmol/L was significantly associated with mortality.

Conclusion

Our study suggests that predialysis level of serum lactate level is an important marker of mortality in MALA patients requiring RRT with a linear dose-response relationship. To better evaluate the optimal prescription of RRT in MALA, we recommend fostering an international consortium to support prospective research and large-scale standardized case collection.

Odds ratio for MALA mortality by serum lactate level. Solid lines: adjusted odds ratios based on restricted quadratic splines for the serum lactate level, with knots at the 10th, 50th, and 90th percentiles. The shaded green region: upper and lower 95% CIs.