General information and imaging examinations
Fifteen patients were all diagnosed as COVID-19 as detected of SARS-CoV-2 virus nucleic acid by RT-PCR. All patients had lived, traveled to Wuhan city or had contacted with others came back from Wuhan. Among the fifteen patients, three were severe or critically-ill patients (20.0%). Case 01 was a 83 years old man who had basic diseases including hypertension, chronic obstructive pulmonary disease (COPD) and tuberculous pleurisy. He returned to Guiyang from Wuhan by air on Jan. 21st and was admitted on Feb. 7th after showing the initial symptoms of fever and fatigue. The patient was cured and discharged on Feb 24th. Case 02 was a 61-year-old woman with type 2 diabetes and hypertension. She was admitted with cough, fever and diarrhea as the initial symptom after contacting her sister who returned to Guiyang from Wuhan on Jan. 23rd. The patient was cured and discharged on Feb 24th. Case 03 was a 33-year-old man without basic disease. He came to Guiyang from Wuhan on Jan. 15th by air and was admitted with cough, fever, asthenia, body ache, shortness of breath and dyspnea as the initial symptom on Jan. 21st. He was admitted to a county-level hospital on Jan. 22nd. Due to the aggravation of dyspnea and the decrease of oxygenation, the patient was transferred to the Affiliated Hospital of Guizhou Medical University on Jan. 31st for further treatment. The patient died on Feb. 5th, due to respiratory failure and septic shock. Imaging examinations of all 3 cases showed typical features of viral pneumonia. CT scan of Case 01 and Case 02 were obtained on 2nd day and 14th day post admission, Case 03 only had a bedside chest radiograph (Fig. 1).
Treatment Regimen
All patients were given mask oxygen inhalation and ventilator to assist breathing immediately after admission to improve the situation of hypoxia. Abidol hydrochloride tablets, interferon alfa-2b, ribavirin, Lianhuaqingwen combined with lopinavir plus ritonavir or chloroquine phosphate were given as antiviral therapy. Thymalfasin and γ-immunoglobulin were administered to enhance immunity. Methylprednisolone and Xuebijing was intravenously dripped based on disease severity to suppress cytokine storm according to the the fifth edition guidelines for new coronavirus pneumonia. Meanwhile, empirical antibiotic agents were applied to prevent secondary bacterial and fungal infections. Case 03 was given adjusted dose of heparin to maintain activated clotting time (ACT) of whole blood at about 200 s because the use of extracorporeal membrane oxygenation (ECMO). In addition, on 3rd day of admission, low doses of norepinephrine was intermittently used to maintain circulatory stability, and therapeutic plasma exchange was performed twice to remove inflammatory factors caused by cytokine storm. On the 5th day of admission, ultrasound showed massive hemorrhage in the left chest of the patient. Thus heparin were stopped and leukocyte-removing red blood cells, fresh frozen plasma, cryoprecipitated coagulation factors, platelets and recombinant activated factor VIIa were given to improve coagulation status.
Sofa Scores And Sepsis
A SOFA score of 2 or above identified a 2- to 25-fold increased risk of death compared with a SOFA score less than 2 [15]. All the three patients met the criteria of sepsis with SOFA scores over or equal to 2. Case 01 and Case 02 were two severe cases of COVID-19. The number of days in hospital for Case 01 is 17 days, among which 12 days had a SOFA score greater than or equal to 2 points (70.5%). The number of days in hospital for Case 02 was 25 days, of which 18 days had a SOFA score greater than or equal to 2 points (72.0%). Case 03 was a critical-ill case of COVID-19, his daily SOFA score was all above or equal to 5. During the last four days post admission, the SOFA score had increased to 9 (Fig. 2) and septic shock was diagnosed because of persisting hypotension requiring vasopressors to maintain MAP > 65 mmHg and having a serum lactate level > 2 mmol/L despite adequate volume resuscitation. The patient began to use ECMO to provide extracorporeal respiration on the first day of admission. From the 3rd to 5th day post admission, 0.1 ug/kg noradrenaline was given to maintain blood pressure. The concentration of lactate in peripheral blood was 3.0 mmol/L. On the 6th day post admission, the PaO2/FiO2 was lower than 100 mmHg even when treated with ventilator. 3.0ug/kg noradrenaline was given while the MAP was still lower than 65 mmHg, the patient eventually died of septic shock and MODS.
Multiple Organ Dysfunction Scores
Marshall MOD score above or equal to 4 represented marked functional dysfunction and an mortality rate of more than equal to 50% [16]. Data were collected daily to calculate three patients’ MOD score. Among the 17-admission-days of Case 01, the MOD scores did not exceed 2. On the 5th and 6th days post admission, the MOD score was 2 (1 score for bilirubin and 1 score for creatinine) (Fig. 3). From the 11th to 19th days post admission, the MOD score of Case 02 was 4 (3 score for PaO2/FiO2 and 1 score for bilirubin). When the patient was discharged on 25th day post admission, the MOD score was reduced to 0 (Fig. 3). Case 03 was a critical-ill case of COVID-19, the MOD score of the fist two days post admission was 5 (3 score for PaO2/FiO2 and 1 score for creatinine). From the 3rd to 5th days post admission, the MOD score increased to 7 (3 score for PaO2/FiO2, 1 score for creatinine and 2 scores for CNS Glasgow Coma Scale). At 12:40 pm on 5th day post admission of Case 03, the patient had a sudden increase of heart rate, decrease of blood pressure, progressive decrease of hemoglobin. After dilatation and transfusion, 0.3ug/kg noradrenaline was given. Bedside ultrasound indicated that there was a large amount of blood in the left thorax. Diagnostic puncture drew out red non coagulation, immediately stopped ECMO heparinization treatment and pressurized blood transfusion. Coagulation test showed that thrombin time (TT) and activated partial thromboplastin time (APTT) were significantly prolonged (TT: 240 s, APTT: 206.3 s). At 1:30am on the 6th day post admission, the blood pressure and heart rate decreased gradually. After rescue, chest compression and intravenous injection of noradrenaline, unfortunately, the patient died on the 6th day post admission (16 days after initial symptoms) with coagulation, respiratory, circulatory and renal dysfunction.
Analysis Of Immune Cell Populations
Patients who died of COVID-19 had significantly reduced lung immune cells and reduced peripheral blood lymphocytes. Meanwhile, lymphocytes are over-activated because of the increase in highly pro-inflammatory CCR4 + CCR6 + Th17 cells [5]. The number of peripheral blood lymphocytes was significantly lower in severe patients when admitted to the hospital than mild patients. The T cells and CD4 + T cell subsets of severe patients continued to decrease compared to mild patients [17]. Consistent with these studies, the percentage of peripheral blood T lymphocytes all decreased in three patients post admission. For Case 01 and Case 02, the percentage of CD3 + T lymphocyte was 64.24% and 55.8% for the 7th day post admission, a slightly lower than normal reference range (65%-75%). The percentage of CD3 + CD8 + suppressor T cells was 27.58% and 14.78% (normal reference range 20%-30%), that of CD3 + CD4 + helper T cells was 27.58% and 47.65% (normal reference range 35%-55%). The percentage of CD3 + T lymphocyte of Case 03 was significantly decreased to 35.68% on the first day of admission. The percentage of suppressor T cells and helper T cells were 18.48% and 16.91% on the first day of admission, much lower than normal reference range. However, the percentage of B cells all increased to 19.30%, 26.35% and 29.66% for three patients (normal reference range 5.9%-19.2%).