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Ackermann M, Tafforeau P, Brunet J, Kamp JC, Werlein C, Kühnel MP, Jacob J, Walsh CL, Lee PD, Welte T, Jonigk DD. Comment on: Intrapulmonary shunt and alveolar dead space in a cohort of patients with acute COVID-19 pneumonitis and early recovery. Eur Respir J 2023; 61:2202121. [PMID: 36634926 PMCID: PMC9909205 DOI: 10.1183/13993003.02121-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 11/13/2022] [Indexed: 01/14/2023]
Abstract
With the greatest interest we read the paper by Harbut et al. [1] describing the role of intrapulmonary shunting and alveolar dead space in patients with acute COVID-19 pneumonitis. We are grateful for them sharing their valuable functional blood and alveolar gas exchange data, pointing out a significant alveolar dead space of nearly 30% in recovered COVID-19 patients, suggesting a persistent pulmonary vascular pathology. Although COVID-19 related hypoxaemia is characterised by preserved oxygen saturation, a ventilation–perfusion mismatch and increased alveolar ventilation/perfusion ratio heterogeneity, the underlying morphological evidence of this physiological enigma has not been fully understood. A compelling explanation for mosaic-like micro-ischaemia in the severe pathology of COVID-19 pneumonitis, which reflects the vasculopathy affecting the secondary lobule and the interlobular septae http://bit.ly/3GwMkII
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Affiliation(s)
- Maximilian Ackermann
- Institute of Pathology and Molecular Pathology, Helios University Clinic Wuppertal, University of Witten/Herdecke, Witten, Germany
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Joseph Brunet
- European Synchrotron Radiation Facility, Grenoble, France
| | - Jan C Kamp
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | | | - Mark P Kühnel
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
- Institute of Pathology, Hannover Medical School, Hannover, Germany
| | - Joseph Jacob
- Centre for Medical Image Computing, University College London, London, UK
- Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK
| | - Claire L Walsh
- Department of Mechanical Engineering, University College London, London, UK
| | - Peter D Lee
- Department of Mechanical Engineering, University College London, London, UK
| | - Tobias Welte
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Danny D Jonigk
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
- Institute of Pathology, University Clinics of RWTH University, Aachen, Germany
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Harutyunyan G, Benítez Bermejo RI, Harutyunyan V, Harutyunyan G, Sánchez Gimeno A, Cherkezyan A, Petrosyan S, Gnuni A, Soghomonyan S. Hypoxaemia in the early stage of COVID-19: prevalence of physical or biochemical factors? Eur Respir Rev 2022; 31:31/165/220138. [PMID: 36130788 PMCID: PMC9724909 DOI: 10.1183/16000617.0138-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 07/31/2022] [Indexed: 12/14/2022] Open
Abstract
We read with interest the reply from Busanaet al. [1] to our correspondence [2]. We fully agree with the authors and with the cited references [3–6] stating that the affinity of haemoglobin (Hb) for oxygen (O2) is not affected in the arteries or in the veins of coronavirus disease 2019 (COVID-19) patients. The confusion arises as our concept is based on the biochemical shunt due to the quaternary conformational change of Hb with a temporary decrease of Hb–O2 affinity, which is applicable only to the affected alveolar-capillary bed. The ventilation–perfusion mismatch can't explain the high PaCO2–PETCO2 gap in the setting of COVID-19 induced hypoxaemia and cannot be considered as the sole pathophysiological basis for the treatment in the early stage of COVID-19https://bit.ly/3BKmGxJ
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Affiliation(s)
- Gurgen Harutyunyan
- Hospital 9 de Octubre, Urgency Department, Valencia, Spain,Gurgen Harutyunyan ()
| | | | | | | | | | | | | | - Anatoli Gnuni
- Ministry of Health of the Republic of Armenia, Yerevan, Armenia
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