COVID-19 clinical phenotypes and short-term outcomes: differences between the first and the second wave of pandemic in Italy

ABSTRACT

Objectives: There are no comparative studies between patients belonging to the first and second waves of the SARS-CoV-2 pandemic, the virus triggering coronavirus disease 2019 (COVID-19). In this retrospective observational study, we analyzed the clinical characteristics and the short-term outcomes of two groups of laboratory-confirmed COVID-19 patients with moderate-to-severe acute respiratory distress syndrome (ARDS) belonging to two different waves of the pandemic. Methods: We analyzed 97 consecutive patients from 11 March 2020 to 31 May 2020 and 52 consecutive patients from 28 August 2020 to 15 October 2020. Results: Patients belonging to the second wave were younger, had a lower number of concomitant chronic conditions (multimorbidity), and had a milder clinical phenotype. Medical treatments and respiratory support use have changed during the COVID-19 pandemic, based on different laboratory results and disease clinical features. Patients in the second wave had better short-term clinical outcomes, with lower death rates and more step-down transfers to a general ward. Conclusion: The present findings show a clear phenotypic difference in patients hospitalized at different stages of the COVID-19 pandemic in Italy. These results can help to stratify clinical risk and to better tailor medical treatments and respiratory support for patients with ARDS and COVID-19 pneumonia.

KEYWORDS:

• Critical care
• assisted ventilation
• intermediate RICU
• survival
• pandemic
• Italy

ARTICLE HIGHLIGHTS

• Since the beginning of the pandemic, the study of phenotypic manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus triggering coronavirus disease 2019 (COVID-19), has aroused great interest. Different ‘waves’ of the spread of the virus can be recognized, with phases of intense viral diffusion alternating with phases of reduction of infections. Nevertheless, there are no comparison studies between patients belonging to the first and second waves. In the present study, we analyzed the different demographic, clinical, and prognostic characteristics of laboratory-confirmed COVID-19 patients with moderate-to-severe acute respiratory distress syndrome (ARDS) admitted to our intermediate Respiratory Intensive Care Unit (RICU) during these two different periods of the pandemic.

• We analyzed the different clinical characteristics and the short-term outcomes of 97 consecutive patients from 11 March 2020 to 31 May 2020 and 52 consecutive patients from 28 August 2020 to 15 October 2020. Laboratory-confirmed COVID-19 patients with moderate-to-severe ARDS belonging to the second wave were younger, had a lower number of concomitant chronic conditions (multimorbidity), and a milder clinical phenotype. Furthermore, medical treatments and respiratory support use have changed during the COVID-19 pandemic, according to different laboratory results and clinical features of the disease. Finally, patients in the second wave had better short-term clinical outcomes, with a lower death rate and more step-down transfers to GW.

• In the Italian intermediate RICU, there was a clear phenotypic difference in patients hospitalized at different stages of the COVID-19 pandemic in Italy. The present findings can help to stratify clinical risk and to better tailor medical treatments and respiratory support for patients with ARDS and COVID-19 pneumonia.

Abbreviations

SARS-CoV-2: severe acute respiratory syndrome coronavirus 2

COVID-19: coronavirus disease 2019

ARDS: acute respiratory distress syndrome

CT: computed tomography; RICU: Respiratory Intensive Care Unit

ICU: Intensive Care Unit

PaO₂/FiO₂: arterial oxygen partial pressure to fractional inspired oxygen ratio

FWG: First Wave Group

SWG: Second Wave Group; NIV: noninvasive ventilation

HFOT: high-flow oxygen therapy

BPAP: bilevel positive airway pressure

CPAP: continuous positive airway pressure

IMV: invasive mechanical ventilation

ACE: angiotensin-converting enzyme

LMWH: low molecular weight heparin

Acknowledgments

The authors thank all the participants from this study.

Authors’ Contributions

Conception and design of the study: A. Portacci, G.E. Carpagnano, V. Solfrizzi, F. Panza, and O. Resta. Collection of data: M.G. Tummolo, C. Ssantomasi, L. Palma, D. Fasano, and M. Lozupone. Analyzed the data: V. Solfrizzzi. Wrote the manuscript: A. Portacci, G.E. Carpagnano, F. Panza, and O. Resta. Final supervision and guarantee of the paper: G.E. Carpagnano, F. Panza, and O. Resta.

Ethics approval and consent to participate

Ethics approval was obtained through the Institutional Review Board and all patients provided consent to participate.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.