Too much tolerance for hyperoxemia in mechanically ventilated patients with SARS-CoV-2 pneumonia? Report from an Italian intensive care unit.

Background: In COVID-19 patients requiring mechanical ventilation, the administration of high oxygen (O2) doses for prolonged time periods may be necessary. Although life-saving in most cases, O2 may exert deleterious effects if administered in excessive concentrations. We aimed to describe the prevalence of hyperoxemia and excessive O2 administration in mechanically ventilated patients with SARS-CoV-2 pneumonia and determine whether hyperoxemia is associated with mortality in the Intensive Care Unit (ICU) or the onset of ventilator-associated pneumonia (VAP). Materials and methods: Retrospective single-center study on adult patients with SARS-CoV-2 pneumonia requiring invasive mechanical ventilation for ≥48 h. Patients undergoing extracorporeal respiratory support were excluded. We calculated the excess O2 administered based on the ideal arterial O2 tension (PaO2) target of 55-80 mmHg. We defined hyperoxemia as PaO2 > 100 mmHg and hyperoxia + hyperoxemia as an inspired O2 fraction (FiO2) > 60% + PaO2 > 100 mmHg. Risk factors for ICU-mortality and VAP were assessed through multivariate analyses. Results: One hundred thirty-four patients were included. For each day of mechanical ventilation, each patient received a median excess O2 of 1,121 [829-1,449] L. Hyperoxemia was found in 38 [27-55]% of arterial blood gases, hyperoxia + hyperoxemia in 11 [5-18]% of cases. The FiO2 was not reduced in 69 [62-76]% of cases of hyperoxemia. Adjustments were made more frequently with higher PaO2 or initial FiO2 levels. ICU-mortality was 32%. VAP was diagnosed in 48.5% of patients. Hyperoxemia (OR 1.300 95% CI [1.097-1.542]), time of exposure to hyperoxemia (OR 2.758 [1.406-5.411]), hyperoxia + hyperoxemia (OR 1.144 [1.008-1.298]), and daily excess O2 (OR 1.003 [1.001-1.005]) were associated with higher risk for ICU-mortality, independently of age, Sequential Organ failure Assessment score at ICU-admission and mean PaO2/FiO2. Hyperoxemia (OR 1.033 [1.006-1.061]), time of exposure to hyperoxemia (OR 1.108 [1.018-1.206]), hyperoxia + hyperoxemia (OR 1.038 [1.003-1.075]), and daily excess O2 (OR 1.001 [1.000-1.001]) were identified as risk factors for VAP, independently of body mass index, blood transfusions, days of neuromuscular blocking agents (before VAP), prolonged prone positioning and mean PaO2/FiO2 before VAP. Conclusion: Excess O2 administration and hyperoxemia were common in mechanically ventilated patients with SARS-CoV-2 pneumonia. The exposure to hyperoxemia may be associated with ICU-mortality and greater risk for VAP.

Too much tolerance for hyperoxemia in mechanically ventilated patients with SARS-CoV-2 pneumonia? Report from an Italian intensive care unit

Background In COVID-19 patients requiring mechanical ventilation, the administration of high oxygen (O2) doses for prolonged time periods may be necessary. Although life-saving in most cases, O2 may exert deleterious effects if administered in excessive concentrations. We aimed to describe the prevalence of hyperoxemia and excessive O2 administration in mechanically ventilated patients with SARS-CoV-2 pneumonia and determine whether hyperoxemia is associated with mortality in the Intensive Care Unit (ICU) or the onset of ventilator-associated pneumonia (VAP). Materials and methods Retrospective single-center study on adult patients with SARS-CoV-2 pneumonia requiring invasive mechanical ventilation for ≥48 h. Patients undergoing extracorporeal respiratory support were excluded. We calculated the excess O2 administered based on the ideal arterial O2 tension (PaO2) target of 55–80 mmHg. We defined hyperoxemia as PaO2 > 100 mmHg and hyperoxia + hyperoxemia as an inspired O2 fraction (FiO2) > 60% + PaO2 > 100 mmHg. Risk factors for ICU-mortality and VAP were assessed through multivariate analyses. Results One hundred thirty-four patients were included. For each day of mechanical ventilation, each patient received a median excess O2 of 1,121 [829–1,449] L. Hyperoxemia was found in 38 [27–55]% of arterial blood gases, hyperoxia + hyperoxemia in 11 [5–18]% of cases. The FiO2 was not reduced in 69 [62–76]% of cases of hyperoxemia. Adjustments were made more frequently with higher PaO2 or initial FiO2 levels. ICU-mortality was 32%. VAP was diagnosed in 48.5% of patients. Hyperoxemia (OR 1.300 95% CI [1.097–1.542]), time of exposure to hyperoxemia (OR 2.758 [1.406–5.411]), hyperoxia + hyperoxemia (OR 1.144 [1.008–1.298]), and daily excess O2 (OR 1.003 [1.001–1.005]) were associated with higher risk for ICU-mortality, independently of age, Sequential Organ failure Assessment score at ICU-admission and mean PaO2/FiO2. Hyperoxemia (OR 1.033 [1.006–1.061]), time of exposure to hyperoxemia (OR 1.108 [1.018–1.206]), hyperoxia + hyperoxemia (OR 1.038 [1.003–1.075]), and daily excess O2 (OR 1.001 [1.000–1.001]) were identified as risk factors for VAP, independently of body mass index, blood transfusions, days of neuromuscular blocking agents (before VAP), prolonged prone positioning and mean PaO2/FiO2 before VAP. Conclusion Excess O2 administration and hyperoxemia were common in mechanically ventilated patients with SARS-CoV-2 pneumonia. The exposure to hyperoxemia may be associated with ICU-mortality and greater risk for VAP.

Antibiotic Treatment of Acinetobacter baumannii Superinfection in Patients With SARS-CoV-2 Infection Admitted to Intensive Care Unit: An Observational Retrospective Study.

Introduction: In COVID-19 patients on mechanical ventilation, VAP from Acinetobacter baumannii remains a crucial risk factor for death. Antibiotic resistance represents an important problem in treating this infection. This study aims to describe the evolution of the superinfection from PDR Acinetobacter baumannii in patients with acute respiratory failure from SARS-CoV-2 infection admitted to ICU and compare the impact of two different antibiotic strategies on microbiological negativization. Methods: Single-center observational retrospective study, including patients admitted to our ICU from March 2020 to May 2021 for acute respiratory failure from SARS-CoV-2 infection who developed PDR Acinetobacter baumannii superinfection. Clinical data at ICU admission were collected, as well as the timing of isolation of Acinetobacter baumannii, its resistance profile, the site of infection, and the antibiotic therapy. Results: Of the 32 patients enrolled, 10 patients (31.2%) were treated with the combination of high-dose ampicillin/sulbactam, high-dose tigecycline, intravenous and inhaled colistin (Protocol), the other 22 (68.8%) were treated with the combination of two antibiotics (Control). Of the 10 patients in the Protocol group, 8 patients (80%) received also fosfomycin. All patients (100%) in the Protocol group had microbiological negativization, while in the Control group microbiological negativization was observed in 8 (36.4%) patients, p < 0.01. Conclusion: Our report shows microbiological negativization in all patients treated with the combination therapy of nebulized and intravenous colistin, high-dose tigecycline, and high-dose ampicillin/sulbactam. This combination of antibiotics seems to be a useful alternative when other treatments are not available or fail.

Effect of Whey Proteins on Malnutrition and Extubating Time of Critically Ill COVID-19 Patients.

The novel SARS-CoV-2 virus has led to a severe pandemic, starting from early 2020. Intensive care (ICU) management of the COVID-19 disease is difficult with high morbidity and mortality. Early nutritional support, especially with whey protein, seems to be crucial in this medical case. Thus, we aimed to assess the effects of an adequate nutritional protocol rich in whey protein on nutritional and inflammatory status, extubating time, and mortality of critically ill COVID-19 patients (CICP). METHODS: A prospective single-center exploratory observational study was undertaken on 32 consecutive CICP admitted to the ICU of Santa Maria Hospital, Terni, Italy, and treated with whey protein-enriched formula. Patients' demographics, nutritional status, indexes of inflammation, daily pre-albumin serum levels, duration of mechanical ventilation, and mortality were recorded. RESULTS: Thirty-two patients were enrolled. Ninety-five percent of them showed a gradual reduction in C-reactive protein (CRP) values and increase in pre-albumin levels after the whey protein-enriched formula. Prealbumin levels were not correlated with a better nutritional status but with a shorter extubating time and better survival. CONCLUSIONS: An adequate administration of whey protein during COVID-19 patients' ICU stays can provide fast achievement of protein targets, reducing the duration of mechanical ventilation, and improving inflammatory status and ICU survival. Further prospective and large-scale, controlled studies are needed to confirm these results.

Machine learning using the extreme gradient boosting (XGBoost) algorithm predicts 5-day delta of SOFA score at ICU admission in COVID-19 patients.

Background: Accurate risk stratification of critically ill patients with coronavirus disease 2019 (COVID-19) is essential for optimizing resource allocation, delivering targeted interventions, and maximizing patient survival probability. Machine learning (ML) techniques are attracting increased interest for the development of prediction models as they excel in the analysis of complex signals in data-rich environments such as critical care. Methods: We retrieved data on patients with COVID-19 admitted to an intensive care unit (ICU) between March and October 2020 from the RIsk Stratification in COVID-19 patients in the Intensive Care Unit (RISC-19-ICU) registry. We applied the Extreme Gradient Boosting (XGBoost) algorithm to the data to predict as a binary outcome the increase or decrease in patients' Sequential Organ Failure Assessment (SOFA) score on day 5 after ICU admission. The model was iteratively cross-validated in different subsets of the study cohort. Results: The final study population consisted of 675 patients. The XGBoost model correctly predicted a decrease in SOFA score in 320/385 (83%) critically ill COVID-19 patients, and an increase in the score in 210/290 (72%) patients. The area under the mean receiver operating characteristic curve for XGBoost was significantly higher than that for the logistic regression model (0.86 vs. 0.69, P < 0.01 [paired t-test with 95% confidence interval]). Conclusions: The XGBoost model predicted the change in SOFA score in critically ill COVID-19 patients admitted to the ICU and can guide clinical decision support systems (CDSSs) aimed at optimizing available resources.

Rationale for Polyclonal Intravenous Immunoglobulin Adjunctive Therapy in COVID-19 Patients: Report of a Structured Multidisciplinary Consensus.

INTRODUCTION: Adjunctive therapy with polyclonal intravenous immunoglobins (IVIg) is currently used for preventing or managing infections and sepsis, especially in immunocompromised patients. The pathobiology of COVID-19 and the mechanisms of action of Ig led to the consideration of this adjunctive therapy, including in patients with respiratory failure due to the SARS-CoV-2 infection. This manuscript reports the rationale, the available data and the results of a structured consensus on intravenous Ig therapy in patients with severe COVID-19. METHODS: A panel of multidisciplinary experts defined the clinical phenotypes of COVID-19 patients with severe respiratory failure and, after literature review, voted for the agreement on the rationale and the potential role of IVIg therapy for each phenotype. Due to the scarce evidence available, a modified RAND/UCLA appropriateness method was used. RESULTS: Three different phenotypes of COVID-19 patients with severe respiratory failure were identified: patients with an abrupt and dysregulated hyperinflammatory response (early phase), patients with suspected immune paralysis (late phase) and patients with sepsis due to a hospital-acquired superinfection (sepsis by bacterial superinfection). The rationale for intravenous Ig therapy in the early phase was considered uncertain whereas the panelists considered its use in the late phase and patients with sepsis/septic shock by bacterial superinfection appropriate. CONCLUSION: As with other immunotherapies, IVIg adjunctive therapy may have a potential role in the management of COVID-19 patients. The ongoing trials will clarify the appropriate target population and the true effectiveness.

Adjunctive IgM-enriched immunoglobulin therapy with a personalised dose based on serum IgM-titres versus standard dose in the treatment of septic shock: a randomised controlled trial (IgM-fat trial).

INTRODUCTION: In patients with septic shock, low levels of circulating immunoglobulins are common and their kinetics appear to be related to clinical outcome. The pivotal role of immunoglobulins in the host immune response to infection suggests that additional therapy with polyclonal intravenous immunoglobulins may be a promising option in patients with septic shock. Immunoglobulin preparations enriched with the IgM component have largely been used in sepsis, mostly at standard dosages (250 mg/kg per day), regardless of clinical severity and without any dose adjustment based on immunoglobulin serum titres or other biomarkers. We hypothesised that a personalised dose of IgM enriched preparation based on patient IgM titres and aimed to achieve a specific threshold of IgM titre is more effective in decreasing mortality than a standard dose. METHODS AND ANALYSIS: The study is designed as a multicentre, interventional, randomised, single-blinded, prospective, investigator sponsored, two-armed study. Patients with septic shock and IgM titres <60 mg/dL will be randomly assigned to an IgM titre-based treatment or a standard treatment group in a ratio of 1:1. The study will involve 12 Italian intensive care units and 356 patients will be enrolled. Patients assigned to the IgM titre-based treatment will receive a personalised daily dose based on an IgM serum titre aimed at achieving serum titres above 100 mg/dL up to discontinuation of vasoactive drugs or day 7 after enrolment. Patients assigned to the IgM standard treatment group will receive IgM enriched preparation daily for three consecutive days at the standard dose of 250 mg/kg. The primary endpoint will be all-cause mortality at 28 days. ETHICS AND DISSEMINATION: The study protocol was approved by the ethics committees of the coordinating centre (Comitato Etico dell'Area Vasta Emilia Nord) and collaborating centres. The results of the trial will be published within 12 months from the end of the study and the steering committee has the right to present them at public symposia and conferences. TRIAL REGISTRATION DETAILS: The trial protocol and information documents have received a favourable opinion from the Area Vasta Emilia Nord Ethical Committee on 12 September 2019. The trial protocol has been registered on EudraCT (2018-001613-33) on 18 April 2018 and on ClinicalTrials.gov (NCT04182737) on 2 December 2019.

Sublingual microcirculation in patients with SARS-CoV-2 undergoing veno-venous extracorporeal membrane oxygenation.

Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO) is a rescue treatment for severe acute respiratory failure refractory to conventional ventilation. We examined the alterations of sublingual microcirculation in patients with SARS-CoV-2 during VV-ECMO treatment and assessed the relationship between microvascular parameters and ventilation, hemodynamics, and laboratory tests. Nine patients were included in the study and the following microcirculatory parameters were estimated: TVD 16.81 (14.46-18.6) mm/mm2; PVD 15.3 (14.09-17.96) mm/mm2; PPV 94.85% (93.82%-97.79%); MFI 2.5 (2.5-2.92); HI 0.4 (0.18-0.4). TVD and PVD were inversely related to D-dimer levels (rho = -0.667, p = 0.05 and rho = -0.733, p = 0.025 respectively), aspartate aminotransferase (AST) (rho = -0.886, p = 0.019 and rho = -0.886, p = 0.019 respectively) and alanine aminotransferase (ALT) (rho = -0.829, p = 0.042 and rho = -0.829, p = 0.042 respectively). Our results showed an altered sublingual microcirculation in patients receiving VV-ECMO for severe SARS-CoV-2 and suggest a potential contribution of endothelia dysfunction to determine microvascular alteration.

Multi-centre, three arm, randomized controlled trial on the use of methylprednisolone and unfractionated heparin in critically ill ventilated patients with pneumonia from SARS-CoV-2 infection: A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: To assess the hypothesis that an adjunctive therapy with methylprednisolone and unfractionated heparin (UFH) or with methylprednisolone and low molecular weight heparin (LMWH) are more effective in reducing any-cause mortality in critically-ill ventilated patients with pneumonia from SARS-CoV-2 infection compared to LMWH alone. TRIAL DESIGN: The study is designed as a multi-centre, interventional, parallel group, superiority, randomized, investigator sponsored, three arms study. Patients, who satisfy all inclusion criteria and no exclusion criteria, will be randomly assigned to one of the three treatment groups in a ratio 1:1:1. PARTICIPANTS: Inpatients will be recruited from 8 Italian Academic and non-Academic Intensive Care Units INCLUSION CRITERIA (ALL REQUIRED): 1. Positive SARS-CoV-2 diagnostic (on pharyngeal swab of deep airways material) 2. Positive pressure ventilation (either non-invasive or invasive) from > 24 hours 3. Invasive mechanical ventilation from < 96 hours 4. PaO2/FiO2 ratio lower than 150 mmHg 5. D-dimer level > 6 times the upper limit of normal reference range 6. C-reactive Protein > 6-fold upper the limit of normal reference range EXCLUSION CRITERIA: 1. Age < 18 years 2. On-going treatment with anticoagulant drugs 3. Platelet count < 100.000/mm3 4. History of heparin-induced thrombocytopenia 5. Allergy to sodium enoxaparin or other LMWH, UFH or methylprednisolone 6. Active bleeding or on-going clinical condition deemed at high risk of bleeding contraindicating anticoagulant treatment 7. Recent (in the last 1 month prior to randomization) brain, spinal or ophthalmic surgery 8. Chronic assumption or oral corticosteroids 9. Pregnancy or breastfeeding or positive pregnancy test. In childbearing age women, before inclusion, a pregnancy test will be performed if not available 10. Clinical decision to withhold life-sustaining treatment or "too sick to benefit" 11. Presence of other severe diseases impairing life expectancy (e.g. patients are not expected to survive 28 days given their pre-existing medical condition) 12. Lack or withdrawal of informed consent INTERVENTION AND COMPARATOR: • LMWH group: patients in this group will be administered enoxaparin at standard prophylactic dosage. • LMWH + steroid group: patients in this group will receive enoxaparin at standard prophylactic dosage and methylprednisolone. • UFH + steroid group: patients in this group will receive UFH at therapeutic dosages and methylprednisolone. UFH will be administered intravenously in UFH + steroid group at therapeutic doses. The infusion will be started at an infusion rate of 18 UI/kg/hour and then modified to obtain aPTT Ratio in between the range of 1.5-2.0. aPTT will be periodically checked at intervals no longer than 12 hours. The treatment with UFH will be administered up to ICU discharge. After ICU discharge anticoagulant therapy may be interrupted or switched to prophylaxis with LMWH in the destination ward up to clinical judgement of the attending physician. Enoxaparin will be administered in both LMWH group and LMWH + steroid group at standard prophylactic dose (i.e., 4000 UI once day, increased to 6000 UI once day for patients weighting more than 90 kg). The treatment will be administered subcutaneously once a day up to ICU discharge. After ICU discharge it may be continued or interrupted in the destination ward up to clinical judgement of the attending physician. Methylprednisolone will be administered in both LMWH + steroid group and UHF + steroid group intravenously with an initial bolus of 0,5 mg/kg followed by administration of 0,5 mg/kg 4 times daily for 7 days, 0,5 mg/kg 3 times daily from day 8 to day 10, 0,5 mg/kg 2 times daily at days 11 and 12 and 0,5 mg/kg once daily at days 13 and 14. MAIN OUTCOMES: Primary Efficacy Endpoint: All-cause mortality at day 28 Secondary Efficacy Endpoints: - Ventilation free days (VFDs) at day 28, defined as the total number of days that patient is alive and free of ventilation (either invasive or non-invasive) between randomization and day 28 (censored at hospital discharge). - Need of rescue administration of high-dose steroids or immune-modulatory drugs; - Occurrence of switch from non-invasive to invasive mechanical ventilation during ICU stay; - Delay from start of non-invasive ventilation to switch to invasive ventilation; - All-cause mortality at ICU discharge and hospital discharge; - ICU free days (IFDs) at day 28, defined as the total number of days between ICU discharge and day 28. - Occurrence of new infections from randomization to day 28; including infections by Candida, Aspergillus, Adenovirus, Herpes Virus e Cytomegalovirus - Occurrence of new organ dysfunction and grade of dysfunction during ICU stay. - Objectively confirmed venous thromboembolism, stroke or myocardial infarction; Safety endpoints: - Occurrence of major bleeding, defined as transfusion of 2 or more units of packed red blood cells in a day, bleeding that occurs in at least one of the following critical sites [intracranial, intra-spinal, intraocular (within the corpus of the eye; thus, a conjunctival bleed is not an intraocular bleed), pericardial, intra-articular, intramuscular with compartment syndrome, or retroperitoneal], bleeding that necessitates surgical intervention and bleeding that is fatal (defined as a bleeding event that was the primary cause of death or contributed directly to death); - Occurrence of clinically relevant non-major bleeding, defined ad acute clinically overt bleeding that does not meet the criteria for major and consists of any bleeding compromising hemodynamic; spontaneous hematoma larger than 25 cm2, intramuscular hematoma documented by ultrasonography, haematuria that was macroscopic and was spontaneous or lasted for more than 24 hours after invasive procedures; haemoptysis, hematemesis or spontaneous rectal bleeding requiring endoscopy or other medical intervention or any other bleeding requiring temporary cessation of a study drug. RANDOMIZATION: A block randomisation will be used with variable block sizes (block size 4-6-8), stratified by 3 factors: Centre, BMI (<30/≥30) and Age (<75/≥75). Central randomisation will be performed using a secure, web-based, randomisation system with an allocation ratio of 1:1:1. The allocation sequence will be generated by the study statistician using computer generated random numbers. BLINDING (MASKING): Participants to the study will be blinded to group assignment. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): The target sample size is based on the hypothesis that the combined use of UHF and steroid versus the LMWH group will significantly reduce the risk of death at day 28. The overall sample size in this study is expected to be 210 with a randomization 1:1:1 and seventy patients in each group. Assuming an alpha of 2.5% (two tailed) and mortality rate in LMWH group of 50%, as indicated from initial studies of ICU patients, the study will have an 80% power to detect at least a 25 % absolute reduction in the risk of death between: a) LMHW + steroid group and LMWH group or b) UHF + steroid group and LMWH group. The study has not been sized to assess the difference between LMHW + steroid group and UHF + steroid group, therefore the results obtained from this comparison will need to be interpreted with caution and will need further adequately sized studies confirm the effect. On the basis of a conservative estimation, that 8 participating sites admit an average of 3 eligible patients per month per centre (24 patients/month). Assuming that 80 % of eligible patients are enrolled, recruitment of 210 participants will be completed in approximately 10 months. TRIAL STATUS: Protocol version 1.1 of April 26th, 2020. Recruitment start (expected): September 1st, 2020 Recruitment finish (expected): June 30th, 2021 TRIAL REGISTRATION: EudraCT number 2020-001921-30 , registered on April 15th, 2020 AIFA approval on May 4th, 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

SARS-CoV-2 infection in kidney transplant recipients: Experience of the italian marche region.

BACKGROUND: Infection related to Coronavirus-19 (CoV-2) is pandemic affecting more than 4 million people in 187 countries worldwide. By May 10, 2020, it caused more than 280 000 deaths all over the world. Preliminary data reported a high prevalence of CoV-2 infection and mortality due to severe acute respiratory syndrome related CoV-2 (SARS-CoV-2) in kidney-transplanted patients (KTRs). Nevertheless, the outcomes and the best treatments for SARS-CoV-2-affected KTRs remain unclear. METHODS: In this report, we describe the clinical data, the treatments, and the outcomes of 5 KTRs with SARS-CoV-2 admitted to our hospital in Ancona, Marche region, Italy, from March 17 to present. Due to the severity of SARS-CoV-2, immunosuppression with calcineurin inhibitors, antimetabolites, and mTOR-inhibitors were stopped at the admission. All KTRs were treated with low-dose steroids. 4/5 KTRs were treated with hydroxychloroquine. All KTRs received tocilizumab up to one dose. RESULTS: Overall, the incidence of SARS-CoV-2 in KTRs in the Marche region was 0.85%. 3/5 were admitted in ICU and intubated. One developed AKI with the need of CRRT with Cytosorb. At present, two patients died, two patients were discharged, and one is still inpatient in ICU. CONCLUSIONS: The critical evaluation of all cases suggests that the timing of the administration of tocilizumab, an interleukin-6 receptor antagonist, could be associated with a better efficacy when administered in concomitance to the drop of the oxygen saturation. Thus, in SARS-CoV-2-affected KTRs, a close biochemical and clinical monitoring should be set up to allow physicians to hit the virus in the right moment such as a sudden reduction of the oxygen saturation and/or a significant increase in the laboratory values such as D-dimer.

Clinical characteristics of 2019 novel coronavirus pneumonia and risk factors for severe cases: a meta-analysis involving 5,729 patients (preprint)

Objective: 2019 novel coronavirus (2019-nCov) has become a global health emergency. However, the clinical presentations are not well characterized. The study aimed to describe clinical characteristics of 2019-nCov pneumonia with meta-analytic approach, and to identify risk factors for developing severe cases.Methods: The electronic databases of PubMed, Google Scholar and MedRxiv were searched from December 2019 to February 2020. Records were included if they reported clinical characteristics of 2019-nCov pneumonia. Studies using crowd sourcing data for mathematical modeling but not reporting clinical data were excluded. The study was reported according to the PRISMA guideline. Data were extracted by independent reviewers. Proportions and mean values were pooled across component studies by using the meta-analytic approach. Data were pooled with fixed or random-effects model as appropriate. Clinical characteristics such as age, gender, symptoms, treatment and mortality outcome were pooled across studies if appropriate. Risk factors for development of severe cases were reported.Results: A total of 13 studies involving 5,729 patients were included for quantitative analysis. The mean age of the study population was 50 years (95% CI: 47 to 53). The most common initial symptoms were cough (68.0%; 95% CI: 65.6 to 70.4%), followed by fever (56.5%; 95% CI: 53.9 to 58.9%), fatigue (42.5%; 95% CI: 39.9 to 45.1%) and anorexia (31.7%; 95% CI: 26.5 to 38.4%). The severe cases accounts for 22.5% of the whole population (95% CI: 21.4 to 23.6%). The overall mortality rate was 1.8% (95% CI: 1.5 to 2.2%), which was consistent with the real time epidemic tracking data. There was substantial heterogeneity across included studies (O = 0.84; p < 0.001). A number of comorbidities and symptoms such as hypertension, COPD, dyspnea, elevated C-reactive protein and procalcitonin were found to be associated with increased risk of developing severe cases.Conclusions: Our study described clinical characteristics of the 2019-nCov pneumonia in a systematic way. Multiple risk factors were identified for severe cases.