Effects of Kneipp Hydrotherapy in Post-COVID-19 Patients (HydroCoVitalB)

Eggensberger OHG

Status: Enrolling

Conditions: Post COVID-19 Condition (PCC); Post COVID-19 Condition; Long COVID-19 Syndrome; Post COVID-19 Syndrome; Post COVID-19

Treatments: Other: Cold water hydrotherapy

Study type: Interventional

Funder types: Industry; Other

Identifiers

NCT07110714

HydroCoVitalB

Details and patient eligibility

About

This randomized controlled study evaluates the effects of cold water hydrotherapy in patients with Post-COVID Syndrome. The primary aim is to assess changes in quality of life compared to an usual care setting without hydrotherapy treatment.

Full description

Patients recovering from Post-COVID Syndrome often experience persistent fatigue, autonomic dysregulation, microcirculatory disturbances, and low-grade inflammation, all of which may hinder their return to full function. Kneipp hydrotherapy-using cold water applications-can address these pathophysiological changes through several mechanisms:

Autonomic regulation: Cold stimuli trigger parasympathetic activation and improve sympathovagal balance, helping to stabilize heart rate variability and reduce symptoms of dysautonomia often seen in Post-COVID.

Enhanced microcirculation: Repeated vasoconstriction and reactive vasodilation promote endothelial function and tissue perfusion, which may alleviate muscle aches, dizziness, and fatigue by improving oxygen and nutrient delivery.

Anti-inflammatory effects: Hydrothermal stimuli have been shown to modulate cytokine profiles, increasing anti-inflammatory mediators and potentially dampening the persistent, low-grade inflammation implicated in Post-COVID pathophysiology.

Musculoskeletal recovery: Thermo-mechanical stimulation relaxes tense muscle fibers, reduces pain perception, and supports gradual increases in physical capacity, all of which are important for overcoming Post-COVID deconditioning.

Taken together, these effects suggest that adjunctive cold water hydrotherapy could accelerate functional recovery, reduce symptom burden, and enhance quality of life in Post-COVID rehabilitation.

Baseline Assessments:

At baseline, demographic data including sex, age, height, and weight will be collected. Participants will report their current main Post-COVID symptoms, which will be categorized into symptom clusters: Fatigue (A), Cognitive (B), and Somatic (C). Smoking history will be assessed, including smoking status (current, former, or never), number of cigarettes per day, years of smoking, and pack-years.

The time (in months) since the COVID-19 infection that led to Post-COVID syndrome will be documented, along with the number of COVID-19 vaccinations received at the time of infection. Employment status will be recorded, distinguishing between full-time or part-time employment, COVID-related work disability, retirement, unemployment, or disability pension.

Comorbidities will be documented across the following categories: cardiovascular, pulmonary, cerebrovascular, metabolic, musculoskeletal, psychiatric, and other conditions. The severity of the acute COVID-19 illness will be assessed using the WHO Clinical Progression Scale, including information on any hospital admission and length of stay (in days).

Autonomic function testing at baseline (V1) will be evaluated using the Schellong test. Additionally, self-reported work ability and the number of Post-COVID-related sick leave days within the past 12 weeks will be recorded.

Enrollment: 30 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Diagnosis of Post-COVID Syndrome (ICD-10 code: U08.9)
• Barthel-Index >80
• Owning a smartphone to receive digital questionnaires and to use the measurement app for heart rate variability
• Written informed consent

Exclusion criteria

• Existing contraindications for Kneipp hydrotherapy like severe cardiovascular diseases (e.g., decompensated heart failure, unstable angina pectoris, acute myocardial infarction), severe venous diseases (e.g., acute deep vein thrombosis of the leg), severe neurological diseases (e.g., uncontrolled epilepsy)
• Prior regular practice of Kneipp applications

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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30 participants in 2 patient groups

Post-COVID treatment with hydrotherapy

Experimental group

Description:

Cold water hydrotherapy (5-10 minutes each), four times daily during the 3-week program and once daily during the 6- month follow-up period. During the 3-week stay, standard medical care is provided by registered doctors as needed.

Treatment:

Other: Cold water hydrotherapy

Usual care setting

No Intervention group

Description:

Usual care setting at home with no hydrotherapy interventions.