Asian Hematology Research Journal

Introduction: SARS-CoV-2 infection can cause manifestations in multiple systems in the body. Haematological system can also be affected by both SARS-CoV-2 infection and critical illness. There have been studies that show thrombocytopaenia is connected with SARS-CoV-2 infection.  The data on its prevalence and outcome on critically ill COVID-19 patients are scarce. Some studies have shown that thrombocytopaenia is associated with worsening of respiratory   parameters and unfavourable outcome of the critically ill patients. Identifying the presence of thrombocytopaenia and its consequences is important to manage critically ill COVID-19 patients.

Aims: To identify the prevalence and consequences of thrombocytopaenia, the presence of other causes of thrombocytopaenia and association of thrombocytopenia with the outcome in critically ill COVID-19 patients.

Study Design: A retrospective clinical analysis.

Study Set Up: This was done in COVID designated Intensive care unit and High dependency unit in Base Hospital- Teldeniya, Sri Lanka.

Methodology: A retrospective study was done at COVID designated intensive care unit- Base Hospital, Teldeniya, Sri Lanka. All patients with positive SARS-CoV-2 testing who later develops pneumonia with oxygen dependency and requiring ICU or HDU care were included in the study. Data was collected from patient records for the duration from 1^st of January 2021 to 30^th of June 2021. Their demographic data, data related to platelet counts, complications, outcome and other causes leading to thrombocytopaenia were collected. Thrombocytopaenia was categorised as mild (platelet count 100-150×10⁹/L), Moderate (50-100×10⁹/L) and severe (less than 50×10⁹/L).

Results: Total of 189 patients were admitted to either ICU or HDU requiring oxygen therapy due to COVID pneumonia during the study period. The mean age was 60.59 years with SD of 14.9. Age range was 16 to 94 years.  63 patients (33.33%) had thrombocytopenia with 8 (12.69%), 19 (30.15%) and 36 (57.14%) had severe, moderate and mild thrombocytopenia respectively. 28 (44.4%) of the patients had low platelets at the time of admission. 31.7% of the patients had another cause that could contribute for thrombocytopenia. In thombocytapanic patients, there were significantly elevated levels of C-reactive protein and serum creatinine. Twenty (31.7%) of the patients with thrombocytopenia died. This accounted for 48.7% of all critical care deaths. When compared to patients with a normal platelet count, the proportion of deaths in patients with thrombocytopenia was found to be significant. (p=0.045).

Conclusions: In critically ill patients, thrombocytopenia can occur due to a variety of causes. According to our findings, at least one-third of critically ill patients with COVID-19 infection develop thrombocytopenia at some point during their illness. This group has a high mortality rate. It is critical to understand the progression of the illness as well as the outcome in order to plan discharge and follow-up for these patients.