Tag: blood volume

Decreased Pulmonary Blood Flow and Airway Volumes in Patients With Long COVID Syndrome Assessed by Functional Respiratory Imaging

Abstract:

Introduction: In contrast to normal chest X-ray, lung computed tomography (CT), and physiological lung and cardiac functions, many patients with long COVID syndrome suffer from shortness of breath.

Hypothesis: The aim of this study was to quantify the pulmonary blood and airway volumes of long COVID patients compared with that of healthy controls.

Methods: Patients with long COVID syndromes were included if they had PCR-verified previous (≥3 months) SARS-CoV-2 infection, had normal laboratory (e.g. inflammation, coagulation, cardiac or other organ) parameter, normal pulmonary morphology (chest X-ray and CT) and function (spirometry and body plethysmography). The lung CT images were postprocessed by Functional Respiratory imaging analysis by using 3D reconstruction with automated lung vessel segmentation algorithm. Data of the quantitative images were compared with age, gender, and BMI-matched healthy controls.

Results: Thirty patients (45±13 years, 37% male, 25.9±4.3 kg/m^2) at a median time of 256 (118-574) days after a confirmed COVID infection and 30 healthy controls (55±7y, 37% male, 26.3±2.7 kg/m^2) were included. All long COVID patients complained of dyspnoea and 14 (48.3%) patients reported thoracic pain. The total pulmonary blood volume was significantly lower in the long COVID patients compared to controls (190±24.3 mL/m^2 vs230.6±26.2 ml/m^2, p<0.001). Similarly, the capillary-small vessel blood flow (vessel cross sectional area <5 mm^2) was reduced in the long COVID population (118±19 mL vs 132±23 mL, p=0.011). (Figure). The specific image-based airway volume of the distal lung regions was lower than that of the healthy population (11.1±6.74 mL vs 17.33±7.7 mL, p<0.05).

Conclusions: Both the reduced global and capillary pulmonary blood flow, and distal airway volumes indicate impaired gas exchange and might explain the pulmonary complaints of patient with long COVID syndromes even severe months after Coronavirus infection.

Source: Mariann Gyongyosi, Emilie Han, Dominika Lukovic, Eslam Samaha, Jutta K Bergler-Klein and Ena Hasimbegovic. Decreased Pulmonary Blood Flow and Airway Volumes in Patients With Long COVID Syndrome Assessed by Functional Respiratory Imaging. Originally published6 Nov 2023Circulation. 2023;148:A16513 https://www.ahajournals.org/doi/abs/10.1161/circ.148.suppl_1.16513

Long COVID: A Chronic Shortage of Blood. Pathophysiology and Treatment Proposal

Abstract:

My hypothesis is that the signs and symptoms of Long COVID can be explained by a shortage of blood in the body and a resulting deficient blood flow through nearly all organs. This shortage arises through damage to the blood-producing organs during the acute phase, while the breakdown of blood continues as normal, after an initial increase.

In order to ensure the perfusion of organs that are directly necessary for survival, the body takes the emergency measure of diverting blood from other organs and tissues. The perfusion of the blood-producing organs is also affected by this distribution measure, which hinders the smooth recovery of the total blood volume. The body is stuck in this vicious circle: a shortage of circulating blood hinders the recovery of blood production. This explains the long duration of Long COVID.

My proposed treatment of Long COVID focuses on the recovery of the correct volume of blood in the body of the right composition by the very careful administration of donor blood products under continuous expert supervision. A trial treatment can be performed in any hospital without much additional preparations, and has a lower associated risk for the patient than analysing the total blood. A diagnosis ex juvantibus, by therapeutic response, is therefore preferable, and will result in the healing process starting earlier.

Indications in blood laboratory values of a shortage of blood are a high serum ferritin due to internal breakdown of blood and values for haematocrit and albumin at reciprocal extremes of the reference ranges due to a stagnation of blood production.

Source: Molenaar, P.A. Long COVID: A Chronic Shortage of Blood. Pathophysiology and Treatment Proposal. Preprints 2023, 2023092109. https://doi.org/10.20944/preprints202309.2109.v1 https://www.preprints.org/manuscript/202309.2109/v1 (Full text available as PDF file)

Comparison of the finger plethysmography derived stroke volumes by Nexfin CO Trek and suprasternal aortic Doppler derived stroke volume measurements in adults with myalgic encephalomyelitis/chronic fatigue syndrome and in healthy controls

Abstract:

Background: Finger plethysmography derived stroke volumes are frequently measured during tilt table testing. There are two algorithms to determine stroke volumes: Modelflow and NexfinCO Trek. Most tilt studies used Modelflow, while there are differences between the two algorithms.

Objective: To compare stroke volume indices by Nexfin CO Trek (SVINexfinCOTrek) with suprasternal Doppler derived SVI (SVIDoppler) in healthy controls (HC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients during tilt testing. These patients may have a large SVI decrease during the tilt enabling a large range of SVI to be studied.

Methods: One hundred and fifty-four patients and 39 HC with a normal tilt test were included. Supine and end-tilt SVIDoppler and SVINexfinCOTrek were compared using the Bland-Altman analysis. Also, the effect of calibrating supine SVINexfinCOTrek to SVIDoppler was studiedRESULTS: Supine and end-tilt SVINexfinCOTrek were significantly higher than SVIDoppler: both P< 0.005. Bias, limits of agreement, and percent error (PE) were high with PE’s between 37 and 43%. The calibration procedure resulted in an acceptable variance with a PE of 29%.

Conclusions: SVINexfinCOTrek overestimates stroke volumes compared to SVIDoppler, leading to high PE’s. Calibration reduced variance to an acceptable level, allowing SVINexfinCOTrek to be used for assessment of SVI changes during tilt testing.

Source: van Campen CLMC, Verheugt FWA, Rowe PC, Visser FC. Comparison of the finger plethysmography derived stroke volumes by Nexfin CO Trek and suprasternal aortic Doppler derived stroke volume measurements in adults with myalgic encephalomyelitis/chronic fatigue syndrome and in healthy controls. Technol Health Care. 2021 Apr 25. doi: 10.3233/THC-202669. Epub ahead of print. PMID: 33998565. https://pubmed.ncbi.nlm.nih.gov/33998565/