All patients with severe Covid-19 admitted to the ICU of Razi Hospital in Rasht for period of March- June 2021 Age greater than or equal to 18 years Patients admitted with the following criteria: fever (oral temperature greater than 37.2 ° C), dry cough, severe tiredness or dyspnea At least one of the following criteria : positive PCR OR lung involvement on chest X-ray / CT scan Absolute lymphocyte count greater than or equal to 200 per cubic millimeter Absolute neutrophil count greater than or equal to 1000 per milliliter Cubic meters Hemoglobin above 8 grams per deciliter

All patients with severe Covid-19 admitted to the ICU of Razi Hospital in Rasht for period of March- June 2021 Age greater than or equal to 18 years Patients admitted with the following criteria: fever (oral temperature greater than 37.2 ° C), dry cough, severe tiredness or dyspnea At least one of the following criteria : positive PCR OR lung involvement on chest X-ray / CT scan Absolute lymphocyte count greater than or equal to 200 per cubic millimeter Absolute neutrophil count greater than or equal to 1000 per milliliter Cubic meters Hemoglobin above 8 grams per deciliter