Patient hematology during hospitalization for viral pneumonia caused by SARS-CoV-2 and non-SARS-CoV-2 agents: a retrospective study

Haematological predictors of poor outcome among COVID-19 patients admitted to an intensive care unit of a tertiary hospital in South Africa

BACKGROUND

Studies from Asia, Europe and the USA indicate that widely available haematological parameters could be used to determine the clinical severity of Coronavirus disease 2019 (COVID-19) and predict management outcome. There is limited data from Africa on their usefulness in patients admitted to Intensive Care Units (ICUs). We performed an evaluation of baseline haematological parameters as prognostic biomarkers in ICU COVID-19 patients.

METHODS

Demographic, clinical and laboratory data were collected prospectively on patients with confirmed COVID-19, admitted to the adult ICU in a tertiary hospital in Cape Town, South Africa, between March 2020 and February 2021. Robust Poisson regression methods and receiver operating characteristic (ROC) curves were used to explore the association of haematological parameters with COVID-19 severity and mortality.

RESULTS

A total of 490 patients (median age 54.1 years) were included, of whom 237 (48%) were female. The median duration of ICU stay was 6 days and 309/490 (63%) patients died. Raised neutrophil count and neutrophil/lymphocyte ratio (NLR) were associated with worse outcome. Independent risk factors associated with mortality were age (ARR 1.01, 95%CI 1.0-1.02; p = 0.002); female sex (ARR 1.23, 95%CI 1.05-1.42; p = 0.008) and D-dimer levels (ARR 1.01, 95%CI 1.002-1.03; p = 0.016).

CONCLUSIONS

Our study showed that raised neutrophil count, NLR and D-dimer at the time of ICU admission were associated with higher mortality. Contrary to what has previously been reported, our study revealed females admitted to the ICU had a higher risk of mortality.

Hematological findings in adult patients with SARS CoV‐2 infection at Tygerberg Hospital Cape Town South Africa

Background

Coronavirus disease 2019 (COVID‐19) is associated with hematological abnormalities of variable severity. The full blood count (FBC) and leukocyte differential count (DIFF) could facilitate the prediction of disease severity and outcome in COVID‐19. This study aimed to assess the hematological parameters in early severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and their correlation with disease outcome.

Methods

A retrospective cross‐sectional descriptive study was performed. Adults with a FBC and positive SARS‐CoV‐2 polymerase chain reaction results between March 1, and June 31, 2020 were reviewed. Basic hematological parameters (FBC, DIFF) and human immunodeficiency virus (HIV) status were recorded. Outcome measures were admission to a general ward or intensive care unit (ICU), recovery or death.

Results

Six hundred and eighty‐five cases median age 51 years, were analyzed. Forty‐four percent were males and fourteen percent were HIV‐positive with no association between death and/or ICU admission (p = 0.522 and p = 0.830, respectively). Leucocytosis was predictive of ICU admission (odds ratio [OR]: 2.4, confidence interval [CI]: 1.77–3.8186) and neutrophilia, of both mortality (OR: 1.5, CI: 1.0440–2.0899) and ICU admission (OR: 4, CI: 2.5933–6.475). Median lymphocyte count was decreased and d‐dimer raised, showing no significant association with outcome. Raised neutrophil‐to‐lymphocyte‐ratio (NLR) was associated with increased odds of mortality (OR: 2.5, CI: 1.3556–3.2503) and ICU admission (OR: 4.8, CI: 2.4307–9.5430) as was monocyte‐to‐lymphocyte‐ratio (MLR) (OR: 2, CI: 1.3132–2.9064) and (OR: 2.3, CI: 1.0608–1.9935), respectively. Hospital admission and older age were significantly associated with mortality (p = 0.0008 and p < 0.0001), respectively.

Conclusion

Evidence‐based interpretation of routine laboratory parameters, readily available in resource‐constrained settings, may identify patients at increased risk of mortality. The FBC, DIFF, NLR, and MLR should form part of the early COVID‐19 investigation.