Ylva Konsberg, Pawel Szaro, Anders Aneman, Sanna Kjellberg, Nektarios Solidakis, Sara Svedlund, Bengt Nellgård, Keti Dalla
Abstract
Respiratory functional sequelae in COVID-19 patients admitted to the intensive care unit for invasive ventilation are sparsely reported. The aim of this study was to investigate the radiological lung appearance, lung function and their association at 6 months after hospital discharge. It was hypothesized that the degree of pathological morphology on CT scans would correlate with lung function at the time of follow-up.
Introduction
The aim of this study was to investigate the radiological lung appearance, lung function and their association 6 months after hospital discharge, in COVID-19 patients who underwent invasive ventilation in the ICU. It was hypothesized that the degree of pathological lung morphology on CT scans would correlate with impairment of lung function at the time of follow-up.
Materials and Methods
This single-centre, prospective observational study was conducted at the Department of Anaesthesiology and Intensive Care at Sahlgrenska University Hospital/Mölndal. Ethical approval for the study was granted (National Ethical Authority, approval number Dr 2020–03660). The clinical trial number was NCT 05299346. Patients were included if ≥18 years with confirmed COVID-19 pneumonia by a positive SARS-CoV-2 PCR nasopharyngeal test, and admitted to ICU for invasive respiratory treatment between the 24th of March 2020 and 20th of May 2021. Patients were excluded if not surviving to hospital discharge, declined participation, or had moved outside Swedish healthcare.
Results
A total of 154 patients received invasive ventilatory treatment in the ICU for COVID-19 pneumonia during the study period and 86 of these attended the follow-up visit (Fig 1). CT scanning was performed in 85 (99%), dynamic spirometry (FEV1, FVC and FEV1/FVC) in 65 (76%) and DLCO in 62 (72%) of patients. During the two phases of the study, dynamic spirometry (SVC) was performed in 30 (75%) patients during early follow-up and plethysmography (TLC, FRC and RV) in 29 (63%) patients during late follow-up. Vital capacity (VC) was performed as part of plethysmography during the late follow-up in 33 (72%) patients. The mean time to follow-up after discharge from the ICU was 197±43 days.
Discussion
A total of 154 patients received invasive ventilatory treatment in the ICU for COVID-19 pneumonia during the study period and 86 of these attended the follow-up visit (Fig 1). CT scanning was performed in 85 (99%), dynamic spirometry (FEV1, FVC and FEV1/FVC) in 65 (76%) and DLCO in 62 (72%) of patients. During the two phases of the study, dynamic spirometry (SVC) was performed in 30 (75%) patients during early follow-up and plethysmography (TLC, FRC and RV) in 29 (63%) patients during late follow-up. Vital capacity (VC) was performed as part of plethysmography during the late follow-up in 33 (72%) patients. The mean time to follow-up after discharge from the ICU was 197±43 days.
Conclusion
Mechanically ventilated ICU-patients surviving COVID-19 showed persistent radiological abnormalities on chest CT and reduced lung volumes, impaired DLCO and patterns indicative of restrictive impairment on PFTs at 6 months after discharge from ICU. Weak correlations were found between CT severity score, DLCO z-scores, VA z-scores and SVC z-score. What remains to be elucidated is whether they continue to improuve over time. Thus, further studies with a long-term follow-up of lung function in this group of patients are needed.
Citation: Konsberg Y, Szaro P, Aneman A, Kjellberg S, Solidakis N, Svedlund S, et al. (2023) Radiological appearance and lung function six months after invasive ventilation in ICU for COVID-19 pneumonia: An observational follow-up study. PLoS ONE 18(9): e0289603. https://doi.org/10.1371/journal.pone.0289603
Editor: Tai-Heng Chen, Kaohsuing Medical University Hospital, TAIWAN
Received: November 18, 2022; Accepted: July 22, 2023; Published: September 1, 2023
Copyright: © 2023 Konsberg et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data for this study are publicly available from the Swedish National Data Service repository (https://doi.org/10.5878/c4nr-bt90).
Funding: Prof. Bengt Nellgård ALF ("Avtal om Läkarutbildning och Forskning") connected to the University of Gothenburg
https://www.alfvastragotaland.se/ This sponsor played no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Stohnes Foundation https://www.stohnesstiftelse.se/en-GB This sponsor played no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Gamla Tjänarinnor https://www.stiftelseansokan.se/Pages/GamlaTjanarinnor.aspx This sponsor played no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0289603#abstract0
