Hemodynamic Evaluation and Fluid Response Observation Through Respiratory Maneuvers

University Hospital Pilsen26 enrolled

Overview

This study evaluates whether respiratory maneuvers can induce measurable hemodynamic changes and whether these changes may be used to assess fluid responsiveness in healthy volunteers. Hemodynamic parameters are continuously monitored non-invasively during four respiratory maneuvers, passive leg raising, and a fluid challenge. The hemodynamic responses to individual respiratory maneuvers are compared with the response to fluid administration.

Fluid responsiveness is commonly assessed using dynamic tests that transiently modify cardiac preload. In spontaneously breathing patients, however, assessment of fluid responsiveness remains challenging because many established dynamic indices rely on controlled mechanical ventilation. This proof-of-concept physiological study investigates whether respiratory maneuvers performed during spontaneous breathing induce measurable hemodynamic changes that could potentially be used for the assessment of fluid responsiveness. Healthy volunteers undergo four respiratory maneuvers: maximal inspiration followed by breath-hold, maximal expiration followed by breath-hold, Valsalva maneuver, and Müller maneuver. Hemodynamic variables are continuously monitored non-invasively. The hemodynamic responses to the respiratory maneuvers are evaluated in relation to passive leg raising and a subsequent fluid challenge.

Study Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Fluid Responsiveness Hemodynamics

Interventions

Respiratory Maneuvers and Fluid Responsiveness Assessment ProtocolPROCEDURE

Participants perform four respiratory maneuvers: maximal inspiration followed by breath-hold (M1), maximal expiration followed by breath-hold (M2), Valsalva maneuver (M3), and Müller maneuver (M4). Each respiratory maneuver lasts 20 seconds. The respiratory maneuvers are followed by passive leg raising and a fluid challenge consisting of 500 mL of balanced crystalloid administered intravenously over 10 minutes. Hemodynamic variables are continuously monitored non-invasively throughout the protocol.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 100 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy volunteers able to understand and perform the study procedures Exclusion Criteria: * Age \<18 years * History of cardiac arrhythmia, coronary artery disease, or valvular heart disease * Bronchial asthma or other respiratory disease associated with reduced vital capacity * History of increased intraocular pressure, including glaucoma, retinopathy, or intraocular implants * Inability to cooperate with the study procedures

Locations (1)

University Hospital Pilsen

Pilsen, Czech Republic, Czechia

Outcomes

Primary Outcomes

Change in heart rate during respiratory manoeuvres

Change in heart rate (HR), measured in beats per minute (bpm), during each of four respiratory maneuvers using continuous non-invasive hemodynamic monitoring.