Respiratory Physiology of COVID-19 and Influenza Associated Acute Respiratory Distress Syndrome

Differences in clinical characteristics between coronavirus disease 2019 (COVID-19) and influenza: a systematic review and meta-analysis

The coronavirus disease 2019 (COVID-19) epidemic has brought major challenges to the global health system, and influenza is also a problem that cannot be ignored. We aimed to explore and compare the clinical characteristics of COVID-19 and influenza to deepen the understanding of these two diseases and provide some guidance for clinicians to make differential diagnoses. We searched PubMed, Embase and Web of Science for articles and performed a meta-analysis using Stata 14.0 with a random-effects model. This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. One hundred articles involving 226,913 COVID-19 patients and 201,617 influenza patients were included, and all the articles included patients with these two diseases as experimental and control groups. Compared to influenza, COVID-19 was more common among men (OR = 1.46, 95% CI: 1.23-1.74) and people with a higher body mass index (MD = 1.43, 95% CI: 1.09-1.77). The proportion of current smokers among COVID-19 patients was lower than that among influenza patients (OR = 0.25, 95% CI: 0.18-0.33). Patients with COVID-19 had longer stays in the hospital (MD = 3.20, 95% CI: 2.58-3.82) and ICU (MD = 3.10, 95% CI: 1.44-4.76), required mechanical ventilation more frequently (OR = 2.30, 95% CI: 1.77-3.00), and had higher mortality (OR = 2.22, 95% CI: 1.93-2.55). We also found significant differences in some blood parameters between the two groups of patients. Upper respiratory symptoms were more obvious in influenza patients, and the proportion of comorbidities was higher than that among COVID-19 patients. There are some differences in the major characteristics, symptoms, laboratory findings and comorbidities between COVID-19 patients and influenza patients. COVID-19 patients often require more medical resources and have worse clinical outcomes.

Survival difference in patients treated with extracorporeal membrane oxygenation in COVID-19 vs. non-COVID ARDS: a systematic review and meta-analysis

INTRODUCTION

The COVID-19 pandemic has emphasized the need for effective management of severe acute respiratory distress syndrome (ARDS) using veno-venous extracorporeal membrane oxygenation (VV-ECMO). This meta-analysis aims to compare the effectiveness and outcomes of ECMO in patients with COVID-19 ARDS versus those with non-COVID ARDS, assessing its role in different respiratory virus infections.

EVIDENCE ACQUISITION

A systematic search was conducted in PubMed, Web of Science, and other relevant databases up to June 30, 2023, to identify studies comparing ECMO use in COVID-19 and non-COVID ARDS cases. This analysis adheres to PRISMA guidelines, with studies rigorously selected based on predefined inclusion and exclusion criteria and assessed for bias using validated tools.

EVIDENCE SYNTHESIS

The meta-analysis included 24 studies with 2,121 patients, revealing that non-COVID ARDS patients treated with ECMO had a lower mortality risk compared to those with COVID-19 ARDS. Specifically, the overall pooled risk difference in survival was -0.11 (95% CI: -0.17 to -0.05, P<0.001), indicating a statistically significant advantage for non-COVID patients. The standardized mean difference for ECMO duration was significantly longer in COVID-19 patients (SMD=0.70, 95% CI: 0.32 to 1.08, P<0.001), reflecting more prolonged treatment needs.

CONCLUSIONS

ECMO serves as a vital intervention in severe ARDS, with differential effectiveness observed between COVID-19 and non-COVID patients. The study's findings underline the need for precise patient selection and tailored ECMO application across different viral etiologies. These insights are crucial for enhancing clinical strategies and resource allocation during ongoing and future pandemics.

Comparison of Clinical Characteristics and Outcomes in Intensive Care Units Between Patients with Coronavirus Disease 2019 (COVID-19) and Patients with Influenza: A Systematic Review and Meta-Analysis

BACKGROUND

Severe infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or influenza virus can cause patients to be admitted to intensive care units (ICUs). It is necessary to understand the differences in clinical characteristics and outcomes between these two types of critically ill patients.

METHODS

We searched Embase, PubMed, and Web of Science for articles and performed a meta-analysis using Stata 14.0 with a random-effects model. This paper was written in strict accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Thirty-five articles involving 131,692 ICU patients with coronavirus disease 2019 (COVID-19) and 30,286 ICU patients with influenza were included in our meta-analysis. Compared with influenza patients, COVID-19 patients were more likely to be male (odds ratio (OR) = 1.75, 95% CI: 1.54-1.99) and older (standardized mean difference (SMD) = 0.16, 95% CI: 0.03-0.29). In terms of laboratory test results, COVID-19 patients had higher lymphocyte (SMD = 0.38, 95% CI: 0.17-0.59) and platelet counts (SMD = 0.52, 95% CI: 0.29-0.75) but lower creatinine (SMD = -0.29, 95% CI: -0.55-0.03) and procalcitonin levels (SMD = -0.78, 95% CI: -1.11-0.46). Diabetes (SMD = 1.27, 95% CI: 1.08-1.48) and hypertension (SMD = 1.30, 95% CI: 1.05-1.60) were more prevalent in COVID-19 patients, while influenza patients were more likely to have cancer (OR = 0.52, 95% CI: 0.44-0.62), cirrhosis (OR = 0.52, 95% CI: 0.44-0.62), immunodepression (OR = 0.38, 95% CI: 0.25-0.58), and chronic pulmonary diseases (OR = 0.35, 95% CI: 0.24-0.52). We also found that patients with COVID-19 had longer ICU stays (SMD = 0.20, 95% CI: 0.05-0.34), were more likely to develop acute respiratory distress syndrome (OR = 4.90, 95% CI: 2.77-8.64), and had higher mortality (OR = 1.35, 95% CI: 1.17-1.55).

CONCLUSIONS

There are some differences in the basic characteristics, comorbidities, laboratory test results and complications between ICU patients with COVID-19 and ICU patients with influenza. Critically ill patients with COVID-19 often require more medical resources and have worse clinical outcomes. PROSPERO Registration Number: CRD42023452238.

Outcomes of COVID-19 and Influenza in Cerebral Palsy Patients Hospitalized in the United States: Comparative Study of a Nationwide Database

Patients with cerebral palsy (CP) are particularly vulnerable to respiratory infections, yet comparative outcomes between COVID-19 and influenza in this population remain underexplored. Using the National Inpatient Sample from 2020-2021, we performed a retrospective analysis of hospital data for adults with CP diagnosed with either COVID-19 or influenza. The study aimed to compare the outcomes of these infections to provide insights into their impact on this vulnerable population. We assessed in-hospital mortality, complications, length of stay (LOS), hospitalization costs, and discharge dispositions. Multivariable logistic regression and propensity score matching were used to adjust for confounders, enhancing the analytical rigor of our study. The study cohort comprised 12,025 patients-10,560 with COVID-19 and 1465 with influenza. COVID-19 patients with CP had a higher in-hospital mortality rate (10.8% vs. 3.1%, p = 0.001), with an adjusted odds ratio of 3.2 (95% CI: 1.6-6.4). They also experienced an extended LOS by an average of 2.7 days. COVID-19 substantially increases the health burden for hospitalized CP patients compared to influenza, as evidenced by higher mortality rates, longer hospital stays, and increased costs. These findings highlight the urgent need for tailored strategies to effectively manage and reduce the impact of COVID-19 on this high-risk group.

Differences of respiratory mechanics in mechanical ventilation of acute respiratory distress syndrome between patients with COVID-19 and Influenza A

BACKGROUND

Whether COVID-19-induced acute respiratory distress syndrome (ARDS) should be approached differently in terms of mechanical ventilation therapy compared to other virus-induced ARDS is debatable. Therefore, we aimed to ascertain whether the respiratory mechanical characteristics of COVID-19-induced ARDS differ from those of influenza A induced ARDS, in order to establish a rationale for mechanical ventilation therapy in COVID-19-induced ARDS.

METHODS

This was a retrospective cohort study comparing patients with COVID-19-induced ARDS and influenza A induced ARDS. We included intensive care unit (ICU) patients with COVID-19 or Influenza A aged ≥ 19, who were diagnosed with ARDS according to the Berlin definition between January 2015 and July 2021. Ventilation parameters for respiratory mechanics were collected at specific times on days one, three, and seven after intubation.

RESULTS

The median age of the 87 participants was 71.0 (62.0-78.0) years old, and 63.2% were male. The ratio of partial pressure of oxygen in arterial blood to the fractional of inspiratory oxygen concentration in COVID-19-induced ARDS was lower than that in influenza A induced ARDS during the initial stages of mechanical ventilation (influenza A induced ARDS 216.1 vs. COVID-19-induced ARDS 167.9, p = 0.009, day 1). The positive end expiratory pressure remained consistently higher in the COVID-19 group throughout the follow-up period (7.0 vs. 10.0, p < 0.001, day 1). COVID-19 and influenza A initially showed different directions for peak inspiratory pressure and dynamic compliance; however, after day 3, both groups exhibited similar directions. Dynamic driving pressure exhibited opposite trends between the two groups during mechanical ventilation.

CONCLUSIONS

Respiratory mechanics show clear differences between COVID-19-induced ARDS and influenza A induced ARDS. Based on these findings, we can consider future treatment strategies for COVID-19-induced ARDS.