The Status of Autonomic Tone Before Tourniquet Deflation During Total Knee Replacement

The Effects of Sympathovagal Balance Before Tourniquet Deflation on a Decrease in Arterial Blood Pressure Following the Deflation During Total Knee Replacement Arthroplasty

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT03408301

Enrollment

Registered

2018-01-24

Start date

2014-01-29

Completion date

2014-07-30

Last updated

2018-01-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Blood Pressure, Low, Hypotension

Brief summary

This study evaluates the influences of the status of sympathovagal balance before tourniquet deflation on a decrease in arterial blood pressure following the deflation during total knee replacement arthroplasty

Detailed description

Patients present with different hemodynamic profiles after intraoperative tourniquet deflation during total knee replacement arthroplasty. Sympathovagal balance can be measured before tourniquet deflation and might determine the hemodynamic response to tourniquet deflation.

Interventions

PROCEDURETourniquet deflation

Tourniquet deflation

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

50 Years to 80 Years

Inclusion criteria

1. American Society of Anesthesiologists physical status I - II 2. Body mass index \< 35 kg/m2

Exclusion criteria

1. Coagulation deficiencies 2. Known allergies to local anesthetics 3. Neurologic deficit on the side being operated on 4. Inflammation at the lumbar puncture site 5. Cardiac conduction disorders or arrhythmias 6. Congestive heart failure 7. Serum electrolyte abnormalities 8. Psychiatric disorders 9. Patient's refusal 10. Difficulty communicating with medical personnel 11. Severe hypovolemia 12. Increased intracranial pressure 13. Severe aortic stenosis 14. Severe mitral stenosis

Design outcomes

Primary

Measure	Time frame	Description
Sympathovagal balance	During 5 minutes before tourniquet deflation	The ratio of low-to-high frequency power of heart rate variability calculated from the 5-minute long electrocardiogram waveform

Secondary

Measure	Time frame	Description
Noninvasive hemodynamic parameters	During 5 minutes before tourniquet deflation	Average cardiac index
Maximum percent change in mean arterial blood pressure	During 10 minutes after tourniquet deflation	The discrepancy between minimum mean arterial blood pressure after tourniquet deflation and mean arterial blood pressure immediately before tourniquet deflation, which is divided by mean arterial pressure immediately before tourniquet deflation

Countries

South Korea

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026