Blood lactate level in patients with severe COVID-19: Does it have any added value?

Abstract

Background: Increased blood lactate (BLac) concentration is common in critically ill patients. They are measured to estimate disease severity, predict morbidity and mortality. A level >2mmol/L is an outcome predictor in Septicaemia. COVID-19 mimics features of Sepsis with reports suggesting that BLac would be of added benefit in predicting survivorship in patients with COVID-19.

Aims: We set out to validate the role of BLac levels in our cohort of RT-PCR+ severe COVID-19 patients admitted to the respiratory support unit (RSU) of a district general hospital in United Kingdom (UK)

Methods: We carried out a retrospective analysis of all patients admitted to the RSU with features of severe COVID-19 as set out by the World Health Organisation (5). Data was collected for the 2 months of November and December 2020. We used Microsoft Excel for analysis and vassar stats for statistical evaluation

Results: 60 patients were admitted to RSU in the time period. 60% males (n=36) with a Mean age (SD) 69.5 (13.6) years

Mean (SD) BLac measured in all patients was 1.5 (0.42) mmol/L. 17% (n=10) patients had BLac between 2 mmol/L to 2.5 mmol/L, of which 2 patients have died. Blac level in patients with Age>65 years (n=38) was < 2.0 mmol/L; Mean (SD) 1.49 mmol/L (0.42). Overall, 9 patients died during this period with Mean (SD) BLac of survivors 1.51 mmol/L (0.4) v non-survivors 1.47 mmol/L (0.54) (p=0.4)

Conclusion: Analysis of our small cohort of severe COVID-19 patients’ show

1) Despite having features of Sepsis, Blac is below the critical threshold of 2mmol/L for majority of the patients

2) Blac >2mmol/L did not predict increased mortality and there was no significant difference in the Mean Blac between survivors and non survivors