Trial Report Dysautonomia and Postural Orthostatic Syndrome of Hypocapnia in Long Covid Syndrome, 2023, O’Brien

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4.21 Dysautonomia and Postural Orthostatic Syndrome of Hypocapnia in Long Covid Syndrome

Shane O’Brien1,2, Edana Maher1, Conor Hayes1, Laura Piggott1, Ciara Scallan1, Zara Cunningham2, Thomas Butler1, Carol Buckley1, Deirdre B Fitzgerald1,2, Patrick D Mitchell1,2, Seamas C Donnelly1,2.

1Tallaght University Hospital, Dublin, Ireland. 2School of Medicine, Trinity College Dublin, Dublin, Ireland.

Background:

At least 10% of COVID-19 survivors will develop long covid syndrome (LCS).(1) Dysautonomia and orthostatic intolerance (OI) have been reported in both chronic fatigue syndrome and LCS. (2) Postural orthostatic syndrome of hypocapnia (POSH) has been demonstrated in patients with chronic fatigue syndrome and could be a contributing factor to LCS.(3) Objectives: This study aims to evaluate the prevalence of OI and POSH in a cohort of patients with LCS.

Methods:

50 patients with a diagnosis of LCS aged >18 underwent a NASA lean test (NLT) in our clinic. The NLT consists of measurements of respiratory rate, heart rate, blood pressure, pulse oximetry, end tidal CO2 and symptoms taken over 10 minutes in supine, followed by a leaning position.

Results:

Orthostatic symptoms developed in 50% (n=25) during the test. Supine or orthostatic hypocapnia occurred in 58% (n=29) of patients. Postural orthostatic tachycardia occurred in 32% (n=16) and postural orthostatic hypotension occurred in 32%(n=16).

Conclusion:

This study provides evidence of dysautonomia and hypocapnia in LCS. The NLT can be easily performed in clinic. Hypocapnia has been implicated in orthostatic cerebral vasoconstriction and this may be a treatable target for LCS. (4)

Disclosures: None

References:

1. Davis, H.E., McCorkell, L., Vogel, J.M. et al. Long COVID: major findings, mechanisms and recommendations. Nat Rev Microbiol 21, 133–146 (2023). https://doi.org/10.1038/ s41579-022-00846-2

2. Vernon SD et al. Orthostatic Challenge Causes Distinctive Symptomatic, Hemodynamic and Cognitive Responses in Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Med (Lausanne). 2022 Jun 23;9:917019. doi: 10.3389/fmed.2022.917019. PMID: 35847821; PMCID: PMC9285104.

3. Natelson BH et al. Physiological assessment of orthostatic intolerance in chronic fatigue syndrome. J Transl Med. 2022 Feb 16;20(1):95. doi: 10.1186/s12967-022-03289-8. PMID: 35172863; PMCID: PMC8849016.

4. Novak V et al. Hypocapnia and cerebral hypoperfusion in orthostatic intolerance. Stroke. 1998 Sep;29(9):1876-81. doi: 10.1161/01.str.29.9.1876. PMID: 9731612.