Effectiveness of sodium bicarbonate infusion on mortality in septic patients with metabolic acidosis
Although sodium bicarbonate (SB) solution has been widely used in clinical practice, its effect on mortality when administered to a large population of patients with acidosis is not known. The study aimed to investigate the effectiveness of SB infusion in septic patients with metabolic acidosis.
Septic patients with metabolic acidosis were identified from the Medical Information Mart for Intensive Care (MIMIC)-III database. Propensity score (PS) was used to account for the baseline differences in the probability to receive SB or not. The marginal structural Cox model (MSCM) was employed to adjust for both baseline and time-varying confounding factors.
A total of 1718 septic patients with metabolic acidosis were enrolled in the study, including 500 in the SB group and 1218 in the non-SB group. Both pH [7.16 (standard deviation (SD): 0.10) vs. 7.22 (SD: 0.07); p < 0.001] and bicarbonate concentration (BC) [11.84 (SD: 3.63) vs. 14.88 (SD: 3.36) mmol/l; p < 0.001] were significantly lower in the SB than that in the non-SB group. While there was no significant mortality effect in the overall population [hazard ratio (HR): 1.04; 95% CI 0.86–1.26; p = 0.67], SB was observed to be beneficial in patients with acute kidney injury (AKI) stage 2 or 3 and pH < 7.2 (HR 0.74; 95% CI 0.51–0.86; p = 0.021). Similar results were replicated with the MSCM.
Our study observed that SB infusion was not associated with improved outcome in septic patients with metabolic acidosis, but it was associated with improved survival in septic patients with AKI stage 2 or 3 and severe acidosis. The results need to be verified in randomized controlled trials.
KeywordsSodium bicarbonate Critical care Sepsis Mortality Marginal structural Cox Model
Z.Z. received funding from The public welfare research project of Zhejiang province (LGF18H150005) and Scientific research project of Zhejiang Education Commission (Y201737841).
Compliance with ethical standards
Conflicts of interest
There is no conflict of interest.
- 2.Zhang Z, Ni H, Qian Z (2015) Effectiveness of treatment based on PiCCO parameters in critically ill patients with septic shock and/or acute respiratory distress syndrome: a randomized controlled trial. Intensive Care Med 41:444–451. https://doi.org/10.1007/s00134-014-3638-4 CrossRefPubMedGoogle Scholar
- 4.Khwannimit B (2007) A comparison of three organ dysfunction scores: MODS, SOFA and LOD for predicting ICU mortality in critically ill patients. J Med Assoc Thail 90:1074–1081Google Scholar
- 13.Jaber S, Paugam C, Futier E et al (2018) Sodium bicarbonate therapy for patients with severe metabolic acidaemia in the intensive care unit (BICAR-ICU): a multicentre, open-label, randomised controlled, phase 3 trial. Lancet 392:31–40. https://doi.org/10.1016/s0140-6736(18)31080-8 CrossRefPubMedGoogle Scholar
- 19.Zhang Z (2016) Missing data imputation: focusing on single imputation. Ann Transl Med 4:9. https://doi.org/10.3978/j.issn.2305-5839.2015.12.38 CrossRefPubMedPubMedCentralGoogle Scholar
- 24.Dupuis C, Garrouste-Orgeas M, Bailly S et al (2017) Effect of transfusion on mortality and other adverse events among critically ill septic patients: an observational study using a marginal structural cox model. Crit Care Med 45:1972–1980. https://doi.org/10.1097/ccm.0000000000002688 CrossRefPubMedGoogle Scholar
- 25.de Keyser CE, Leening MJG, Romio SA et al (2014) Comparing a marginal structural model with a cox proportional hazard model to estimate the effect of time-dependent drug use in observational studies: statin use for primary prevention of cardiovascular disease as an example from the Rotterdam Study. Eur J Epidemiol 29:841–850. https://doi.org/10.1007/s10654-014-9951-y CrossRefPubMedGoogle Scholar
- 27.Ahn S, Kim Y-J, Sohn CH et al (2018) Sodium bicarbonate on severe metabolic acidosis during prolonged cardiopulmonary resuscitation: a double-blind, randomized, placebo-controlled pilot study. J Thorac Dis 10:2295–2302. https://doi.org/10.21037/jtd.2018.03.124 CrossRefPubMedPubMedCentralGoogle Scholar