Early metabolic acidosis in critically ill patients: a binational multicentre study

Katsunori Mochizuki; Tomoko Fujii; Eldho Paul; Matthew Anstey; David V Pilcher; Rinaldo Bellomo

doi:10.51893/2021.1.OA6

Early metabolic acidosis in critically ill patients: a binational multicentre study

Crit Care Resusc. 2023 Oct 18;23(1):67-75. doi: 10.51893/2021.1.OA6. eCollection 2021 Mar.

Authors

Katsunori Mochizuki^{1

2}, Tomoko Fujii^{1

3}, Eldho Paul¹, Matthew Anstey^{4

5}, David V Pilcher^{1

6

7}, Rinaldo Bellomo^{1

8

9

10}

Affiliations

¹ Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia.
² Department of Emergency and Critical Care Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
³ Intensive Care Unit, Jikei University Hospital, Tokyo, Japan.
⁴ Intensive Care, Sir Charles Gairdner Hospital, Perth, WA, Australia.
⁵ School of Medicine, University of Western Australia, Perth, WA, Australia.
⁶ Department of Intensive Care, The Alfred, Melbourne, VIC, Australia.
⁷ Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation, Melbourne, VIC, Australia.
⁸ Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia.
⁹ Department of Intensive Care, Royal Melbourne Hospital, Melbourne, VIC, Australia.
¹⁰ Centre for Integrated Critical Care, Department of Medicine, the University of Melbourne, Melbourne, VIC, Australia.

Abstract

Objective: We aimed to measure the incidence, prevalence, characteristics and outcomes of intensive care unit (ICU) patients with early (first 24 hours) metabolic acidosis (MA) according to two different levels of severity with a focus on recent data. Design: We retrospectively applied two diagnostic criteria to our analysis based on literature for early MA: i) severe MA criteria (pH ≤ 7.20 and Paco₂ ≤ 45 mmHg and HCO₃^- ≤ 20 mmol/L with total Sequential Organ Failure Assessment [SOFA] score ≥ 4 or lactate ≥ 2 mmol/L), and ii) moderate MA criteria (pH < 7.30 and base excess < -4 mmol/L and Paco₂ ≤ 45 mmHg). Setting: ICUs in the Australian and New Zealand Intensive Care Society Adult Patient Database program. Participants: Adult patients registered to the database from 2008 to 2018. Main outcome measures: Incidence, prevalence, and hospital mortality of patients with MA by the two criteria. Results: We screened 1 076 087 patients. Given the Australian and New Zealand population during the study period, we estimated the incidence of severe MA at 39.5 per million per year versus 349.2-411.5 per million per year for moderate MA. In the most recent 2 years, we observed early severe MA in 1.5% (1350/87 110) of patients compared with 8.4% (20 679/244 740) for moderate MA. Overall, hospital mortality for patients with early severe MA was 48.3% (652/1350) compared with 21.5% (4444/20 679) for moderate MA. Conclusions: Early severe MA is uncommon in Australian and New Zealand ICUs and carries a very high mortality. Moderate MA is over seven-fold more common and still carries a high mortality.