Clinical trial NCT07013903: Effects of Hydrotherapy During Post-COVID-19 Rehabilitation
Official title: Effects of Kneipp Hydrotherapy During Inpatient Post-Covid-19 Rehabilitation: A Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Post-COVID / Long-COVID
POST-Covid 19
Post COVID Syndrome
Post-COVID Condition
Keywords: rehabilitation
therapy
Post-COVID
Long COVID
intervention
hydrotherapy
Kneipp
balneotherapy
Post-COVID condition
quality of life
Lead sponsor: Schön Klinik Berchtesgadener Land
Sponsor class: OTHER
Collaborators: name: Bavarian Health and Food Safety Authority (LGL)
First posted: 2025-06-10
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This randomized controlled study evaluates the effects of cold water hydrotherapy as an adjunct to standard rehabilitation in patients with Post-COVID Syndrome. The primary aim is to assess changes in quality of life compared to standard rehabilitation alone.

Detailed 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).

Pulmonary function testing at baseline (V1) will include FEV₁, FVC, FEV₁/FVC ratio, and total lung capacity (TLC), all expressed as percent predicted. Autonomic function will be evaluated using the Schellong test. Vascular status will be assessed by four-limb blood pressure measurement. Additionally, self-reported work ability and the number of Post-COVID-related sick leave days within the past 12 weeks will be recorded.

Eligibility criteria: Inclusion Criteria:

* Diagnosis of Post-COVID Syndrome (ICD-10 code: U08.9)
* Barthel-Index \>80
* Referred to the reference center for Post-COVID rehabilitation
* 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

Primary outcomes:
measure: Health-related quality of life by Short Form-12 Health Survey (SF-12)
timeFrame: From baseline (Visit 1) to end of inpatient rehabilitation (3 weeks, Visit 2)
Secondary outcomes:
measure: Fatigue severity by Fatigue Severity Scale
timeFrame: From baseline (Visit 1) to end of inpatient rehabilitation (3 weeks, Visit 2)
measure: Sleep quality by Pittsburgh Sleep Quality Index
timeFrame: From baseline (Visit 1) to end of inpatient rehabilitation (3 weeks, Visit 2)
measure: Health status by EuroQol-5 Dimensions-5 Levels
timeFrame: From baseline (Visit 1) to end of inpatient rehabilitation (3 weeks, Visit 2)
measure: Autonomic function (heart rate variability by photoplethysmography)
timeFrame: Daily during first 3 weeks of rehabilitation (Visit 1 to Visit 2)
measure: Resting blood pressure (systolic and diastolic)
timeFrame: Daily during first 3 weeks of rehabilitation (Visit 1 to Visit 2)
measure: Post-COVID work-absence days
timeFrame: From baseline (Visit 1) to 3 months (Visit 3) and to 6 months (Visit 4)
measure: Long-term quality of life by Short Form-12
timeFrame: From baseline (Visit 1) to 3 months (Visit 3) and to 6 months (Visit 4)
measure: Long-term fatigue by Fatigue Severity Scale
timeFrame: From baseline (Visit 1) to 3 months (Visit 3) and to 6 months (Visit 4)
measure: Adherence to hydrotherapy
timeFrame: During the 3-week intervention phase (up to Visit 2) and over the 6-month follow-up period (to Visit 4)
measure: Adverse events recording
timeFrame: From start of intervention (Visit 1) through end of study (Visit 4, 6-month follow-up)
measure: Long-term heart rate variability changes (HRV)
timeFrame: From baseline (Visit 1) to 3 months (Visit 3) and to 6 months (Visit 4)
measure: Post-exertional malaise severity
timeFrame: From baseline (Visit 1) to 6-month (Visit 4) follow-up
measure: Daily well-being documentation
timeFrame: Daily throughout the intervention and 6 months follow-up phase (Visit 1 to Visit 4)
Other outcomes:
Locations:
Study officials:
affiliation: Schön Klinik Berchtesgadener Land
name: Rembert Koczulla, MD
role: PRINCIPAL_INVESTIGATOR
References: