Clinical outcomes of Indigenous Australians and New Zealand Māori with metabolic acidosis and acidaemia

Ary Serpa Neto; Tomoko Fujii; James Moore; Paul J Young; Sandra Peake; Michael Bailey; Carol Hodgson; Alisa M Higgins; Emily J See; Paul Secombe; Vanessa Russ; Lewis Campbell; Meredith Young; Mikihiro Maeda; David Pilcher; Jamie Cooper; Andrew Udy

doi:10.51893/2022.1.OA2

Clinical outcomes of Indigenous Australians and New Zealand Māori with metabolic acidosis and acidaemia

Crit Care Resusc. 2023 Oct 18;24(1):14-19. doi: 10.51893/2022.1.OA2. eCollection 2022 Mar 7.

Authors

Ary Serpa Neto^{1

2

3

4}, Tomoko Fujii^{1

5}, James Moore^{6

7}, Paul J Young^{1

2

6

7}, Sandra Peake^{1

8

9}, Michael Bailey¹, Carol Hodgson¹, Alisa M Higgins¹, Emily J See^{2

10}, Paul Secombe^{1

11

12

13}, Vanessa Russ¹⁴, Lewis Campbell^{12

15

16}, Meredith Young¹⁷, Mikihiro Maeda¹⁸, David Pilcher^{13

17}, Jamie Cooper^{1

17}, Andrew Udy^{1

17}

Affiliations

¹ Australian and New Zealand Intensive Care Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia.
² Department of Critical Care, Melbourne Medical School, University of Melbourne, Austin Hospital, Melbourne, VIC, Australia.
³ Data Analytics Research and Evaluation Centre, Austin Hospital, Melbourne, VIC, Australia.
⁴ Department of Critical Care Medicine, Hospital Israelita Albert Einstein, São Paulo, Brazil.
⁵ Intensive Care Unit, Jikei University School of Medicine, Tokyo, Japan.
⁶ Intensive Care Unit, Wellington Hospital, Wellington, New Zealand.
⁷ Medical Research Institute of New Zealand, Wellington, New Zealand.
⁸ Department of Intensive Care Medicine, Queen Elizabeth Hospital, Adelaide, SA, Australia.
⁹ Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia.
¹⁰ Department of Intensive Care Medicine, Austin Hospital, Melbourne, VIC, Australia.
¹¹ Intensive Care Unit Alice Springs Hospital, Alice Springs, NT, Australia.
¹² School of Medicine, Flinders University, Adelaide, SA, Australia.
¹³ Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation, Melbourne, VIC, Australia.
¹⁴ Indigenous Data Network, University of Melbourne, Melbourne, VIC, Australia.
¹⁵ Intensive Care Unit, Royal Darwin Hospital, Darwin, NT, Australia.
¹⁶ Menzies School of Health Research, Darwin, NT, Australia.
¹⁷ Department of Intensive Care and Hyperbaric Medicine, Alfred Hospital, Melbourne, VIC, Australia.
¹⁸ Department of Pharmacy, St Marianna University School of Medicine Hospital, Kawasaki, Japan.

Abstract

Objective: To assess the incidence and impact of metabolic acidosis in Indigenous and non-Indigenous patients Design: Retrospective study. Setting: Adult intensive care units (ICUs) from Australia and New Zealand. Participants: Patients aged 16 years or older admitted to an Australian or New Zealand ICU in one of 195 contributing ICUs between January 2019 and December 2020 who had metabolic acidosis, defined as pH < 7.30, base excess (BE) < -4 mEq/L and PaCO₂ ≤ 45 mmHg. Main outcome measures: The primary outcome was the prevalence of metabolic acidosis. Secondary outcomes included ICU length of stay, hospital length of stay, receipt of renal replacement therapy (RRT), major adverse kidney events at 30 days (MAKE30), and hospital mortality. Results: Overall, 248 563 patients underwent analysis, with 11 537 (4.6%) in the Indigenous group and 237 026 (95.4%) in the non-Indigenous group. The prevalence of metabolic acidosis was higher in Indigenous patients (9.3% v 6.1%; P < 0.001). Indigenous patients with metabolic acidosis received RRT more often (28.2% v 22.0%; P < 0.001), but hospital mortality was similar between the groups (25.8% in Indigenous v 25.8% in non-Indigenous; P = 0.971). Conclusions: Critically ill Indigenous ICU patients are more likely to have a metabolic acidosis in the first 24 hours of their ICU admission, and more often received RRT during their ICU admission compared with non-Indigenous patients. However, hospital mortality was similar between the groups.