Since the beginning of the outbreak of COVID-19, several studies have emerged on clinical, laboratory, and radiological presentation of patients, followed by summarization of the criteria of mild, moderate, and severe cases.[3, 5, 6]
The current study focused on patients with severe COVID-19 who were admitted to critical care unit, aiming to identify their clinical, and laboratory data, in addition to identify risk factors associated with mortality. The mean age of patients in the present study was 61.14± 13.4, fever and cough were the most frequent clinical presentations(69.9% and 84.5% respectively);while diarrhea was the least one(7.8%), also a large percentage of patients had comorbidities. Several studies came in agreement with these results; they documented that severe COVID-19 disease was associated with older age (more and equal to 51 years), and was more encountered in patients with underlying co-morbidities (hypertension, diabetes, and cardiopulmonary conditions).[13, 14]Other studies highlighted that older groups were more likely to have severe symptoms, and that the presence of co-morbodieties increased the likelihood of developing a poor outcome.[14, 15] In correlation with the current study,several studies documented that fever and cough were the most frequent presentations, and that gastrointestinal symptoms were the least. They related this to the variation in tropism of the virus, they also related fever to the development of a cytokine storm, initiation of inflammation and overstimulation of the immune response.[16- 20] In addition, these studies reported that afebrile illness was more frequent in COVID-19 presentation compared to other corona viruses, and also influenza virus;the finding that may lead to missed cases of COVID -19. [16-19] As regard the radiological pattern of the disease in this study, bilateral affection was observed in 68% of cases with ground glass opacity (GGO) representing the most common finding. In agreement with this finding, a recent study on the radiological presentation of the novel corona virus confirmed that the most common presentation is bilateral, peripheral, ground glass opacity.[21] Laboratory data of the studied patients revealed that increased NLR, CRP, D-dimer levels, serum ferritin and PLR were significantly higher in dead patients compared to living personnel (as our patients were of the severe form and were in cytokine storm). Longer ICU stay, lower lymphocyte count , and lower PaO2/FIO2 ratio were encountered in patients who did not survive. In agreement with our results, several studies reported that raised inflammatory markers (CRP, serum ferritin), higher levels of D- dimer and lymphopenia were observed in severe disease group. [13, 22] These studies also documented that older age, high CRP, presence of comorbidities, and lymphopenia by univariate regression analysis correlated with severe disease and poorer outcome, but after adjusting these variables to multivariate regression analysis lymphopenia was not included[13, 22], which was similar to the present study.A P. Yang, et al[22] stated that NLR is a blood marker that independently predicts prognosis, and also predicts the progression of COVID related pneumonia, and that a NLR value ≥3.3 was associated with disease progression and the need for ICU. They said "large number of reactive oxygen species released from neutrophils resulting in damage of the DNA of the cell, with subsequent viral liberation from the cell. It is observed that under-expression of vascular endothelial growth factor (VEGF) leads to inhibition of damage of tissue and organs; unfortunately COVID -19 infection is found to be associated with increased neutrophil release of these inflammatory markers [24, 25]. In addition , COVID-19 virus produces systemic inflammation that inhibit cellular immunity, with reduced CD4 and increased CD8T lymphocyte.[26] Guisado-Vasco et al[27] stated that factors associated with increased risk of mortality in COVID-19 patients include older age, lower PaO2/FIO2, and increased D-dimer levels,which was also noticed in the current study.
High mortality, which reached up78.6% in this study, may reflect late presentation of the patients with progression of disease to critical levels. This observation reflects poor awareness of population about the severity of the disease, and timing at which the patient must don not hesitate and resist hospital admission. In addition to the fact that our hospital is a tertiary hospital received complicated cases from other smaller hospitals after several trials of treatment.