Passive Leg Raising - an Important Diagnostic Manoeuvre

Study Overview
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Brief Summary
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The aim is to describe the physiological background for PLR and the interpretation of a PLR manoeuvre. The protocol entails the measurement of stroke volume (SV) at baseline (semirecumbent patient position), during PLR and after returning to semirecumbent position. Simultaneously blood pressure (BP), pulse rate (PR), pulse oximetric saturation (SpO2) and ECG are recorded. The procedure is performed in ten normal subjects, ten patients recruited in the cardiology outpatient department and ten critically ill patients under analgosedation in the ICU. Analysis includes changes in measured variables and heart rate variability in the frequency domain during the three phases of the experiment.

Detailed Description
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See above

Official Title
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Passive Leg Raising - an Important Diagnostic Manoeuvre and Its Dependency on the Activity of the Autonomous Nervous System in Critically Ill Patients and Healthy Subjects

Conditions
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Cardiovascular Insufficiency

Intervention / Treatment
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* Diagnostic Test: Passive Leg Raising


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consenting after written and oral information Exclusion Criteria: Contraindications to PLR: intracranial or abdominal hypertension

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Normal subjects<br>Normal subjects 'Passive Leg Raising' | Diagnostic Test: Passive Leg Raising<br>* See above<br>|
| Active Comparator: ICU patients<br>ICU patients 'Passive Leg Raising' | Diagnostic Test: Passive Leg Raising<br>* See above<br>|
| Active Comparator: Cardiac Outpatients<br>Cardiac Outpatients 'Passive Leg Raising' | Diagnostic Test: Passive Leg Raising<br>* See above<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in cardiovascular variables I | stroke volume, SV (mL) | 10 minutes | 
| Changes in cardiovascular variables II | pulse rate, PR (min^-1) | 10 minutes | 
| Changes in cardiovascular variables III | blood pressure, BP (mmHg) | 10 minutes | 
| Changes in cardiovascular variables IV | pulse oximetric saturation, SpO2 (%) | 10 minutes | 
| Changes in HRV frequency domain variables V | Heart rate variability, HRV, variables in frequency domain (low frequency, LF, 0.04-0.15 Hz, high frequency, HF, 0.15-0.4 Hz) | 10 minutes | 
| Changes in HRV frequency domain variables VI | HRV absolute power (ms^2, natural logarithm transformed values of absolute powers of very low frequency, VLF, LF, and HF bands) | 10 minutes | 
| Changes in HRV frequency domain variables VII | HRV relative power (absolute power/total power) | 10 minutes | 
| Changes in HRV frequency domain variables VIII | HRV normalized power (%, normalized units, n.u.) | 10 minutes | 
| Changes in HRV frequency domain variables IX | HRV total power given by VLF + HF + LF (ms2) and LF/HF ratio. | 10 minutes |