Minimal Inflation Tourniquet Pressure Using Induced Hypotension

Minimal Inflation Tourniquet Pressure Using Induced Hypotension With Limb Occlusion Pressure Determination or Arterial Occlusion Pressure Estimation in Upper Limb Surgery: A Randomized Double Blinded Comparative Study

Limb occlusion pressure (LOP) and arterial occlusion pressure (AOP) are the terms that mean the lowest tourniquet pressure required to stop the arterial blood flow into the limb distal to the cuff. LOP can be determined manually or automatically by slow cuff inflation until disapper of pulsation with Doppler flow-meter or pulse oximeter

Study Overview

• Status: Unknown
• Conditions: Vascular Diseases
• Intervention / Treatment: Other: estimation method for arterial occlusion pressure; Other: the limb occlusion pressure

Detailed Description

The advantages of the tourniquet during upper or lower limb procedures are providing bloodless operative field and so less intra-operative blood lossIt has been reported that using the lowest effective inflation pressure minimize tourniquet induced nerve injury .). Limb occlusion pressure (LOP) and arterial occlusion pressure (AOP) are the terms that mean the lowest tourniquet pressure required to stop the arterial blood flow into the limb distal to the cuff. LOP can be determined manually or automatically by slow cuff inflation until disapper of pulsation with Doppler flowmeter or pulse oximeter .AOP can be estimated by a formula (AOP = [SBP + 10]/KTP) using patient's systolic blood pressure (SBP) and tissue padding coefficient (KTP) values. In both methods, addition of a safety margin to LOP or AOP is recommended for potential hemodynamic fluctuations during surgery

• Study Type: Observational
• Enrollment (Anticipated): 20

Contacts and Locations

Study Locations

• Egypt
  • Banī Suwayf, Egypt, 6215
    • Recruiting
    • Beni-Suef University hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 50 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

The study will include the patients scheduled for elective upper limb surgery under general anesthesia who met the inclusion criteria The patient will be scheduled into either group A or B.

Group (A): The patients will receive induced hypotensive anaesthesia and the tourniquet pressure will be based on the AOP .

Group (B): the patients will receive induced hypotensive anaesthesia and tourniquet pressure will be based on LOP.

,

Description

Inclusion Criteria:

• • ASA physical status I and II.

  • Male and female patient
  • Age group 20-50 years old

Exclusion Criteria:

• • Patient who refuse to participate in the study

  • Patients with contraindication of using the tourniquet (e.g. peripheral vascular disease or coronary artery disease sickle cell anemia neuromuscular disorders,)
  • Contraindications of using induced hypotensive anesthesia (cerebrovascular disease, Impaired kidney function , chronic liver disease, pregnancy).
  • Patients on medications influencing blood flow such as nitrogycerine
  • Surgery extends more than 90 minutes.
  • Hypertensive patients

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Induced hypotension and arterial occlusion pressure; The patients will receive induced hypotensive anesthesia and the tourniquet pressure will be based on the the tourniquet pressure will be determined based on the AOP which will be determined by the estimation formula (AOP=[SBP+10]/KTP) . The calculation is based on using initial SBP and tissue padding coefficient values , according to limb circumferences of the patient.After calculation of AOP, tourniquet pressures will be determined by adding a safety margin of 20 mmHg to AOP values(tourniquet pressure=AOP+20 mmHg).	Other: estimation method for arterial occlusion pressure; The patients will receive induced hypotensive anaesthesia and the tourniquet pressure will be based on the AOP.the tourniquet pressure will be determined based on the AOP which will be determined by the estimation formula (AOP=[SBP+10]/KTP) . The calculation is based on using initial SBP and tissue padding coefficient values , according to limb circumferences of the patient.After calculation of AOP, tourniquet pressures will be determined by adding a safety margin of 20 mmHg to AOP values(tourniquet pressure=AOP+20 mmHg).; Other: the limb occlusion pressure; : using the ultrasound Doppler technique and the tourniquet will be inflated until the arterial pulsations disappear at the side of the operation. This pressure will be recorded as LOP.using the ultrasound Doppler technique and the tourniquet will be inflated until the arterial pulsations disappear at the side of the operation. This pressure will be recorded as LOP .the tourniquet cuff will be inflated to the pressure according to theguidelines of the Association of Perioperative Registered Nurses(AORN) which recommends that a safety margin of 40 mmHg should be added for AOP below 130 mmHg, 60 mmHg for AOP between 131 mmHg and 190 mmHg, and 80 mmHg for AOP above 190 mmHg for adult patients
induced hypotension and limb occlusion pressure; the patients will receive induced hypotensive anesthesia and the tourniquet pressure will be based on the LOP.using the ultrasound Doppler technique and the tourniquet will be inflated until the arterial pulsations disappear at the side of the operation. This pressure will be recorded as LOP .the tourniquet cuff will be inflated to the pressure according to theguidelines of the Association of Perioperative Registered Nurses(AORN) which recommends that a safety margin of 40 mmHg should be added for AOP below 130 mmHg, 60 mmHg for AOP between 131 mmHg and 190 mmHg, and 80 mmHg for AOP above 190 mmHg for adult patients	Other: estimation method for arterial occlusion pressure; The patients will receive induced hypotensive anaesthesia and the tourniquet pressure will be based on the AOP.the tourniquet pressure will be determined based on the AOP which will be determined by the estimation formula (AOP=[SBP+10]/KTP) . The calculation is based on using initial SBP and tissue padding coefficient values , according to limb circumferences of the patient.After calculation of AOP, tourniquet pressures will be determined by adding a safety margin of 20 mmHg to AOP values(tourniquet pressure=AOP+20 mmHg).; Other: the limb occlusion pressure; : using the ultrasound Doppler technique and the tourniquet will be inflated until the arterial pulsations disappear at the side of the operation. This pressure will be recorded as LOP.using the ultrasound Doppler technique and the tourniquet will be inflated until the arterial pulsations disappear at the side of the operation. This pressure will be recorded as LOP .the tourniquet cuff will be inflated to the pressure according to theguidelines of the Association of Perioperative Registered Nurses(AORN) which recommends that a safety margin of 40 mmHg should be added for AOP below 130 mmHg, 60 mmHg for AOP between 131 mmHg and 190 mmHg, and 80 mmHg for AOP above 190 mmHg for adult patients

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tourniquet inflation pressure	the tourniquet inflation pressure will be determined based on the Arterial occlusion pressure or the limb occlusion pressure	tourniquet inflation pressures will be recorded at 0, 5, 15, 30, 60, and 120 min.
time required to set the tourniquet inflation pressures	Time needed to estimate AOP or to determine LOP and set the tourniquet cuff pressure.	one minute before inflation of the tourniquet cuff

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
tourniquet performance	tourniquet performance as determined by the quality of bloodless surgical field.	at the middle and end of surgery

Collaborators and Investigators

• Sponsor: Beni-Suef University

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2019
• Primary Completion (Anticipated): November 1, 2019
• Study Completion (Anticipated): November 1, 2019

Study Registration Dates

• First Submitted: July 27, 2019
• First Submitted That Met QC Criteria: August 10, 2019
• First Posted (Actual): August 14, 2019

Study Record Updates

• Last Update Posted (Actual): August 14, 2019
• Last Update Submitted That Met QC Criteria: August 10, 2019
• Last Verified: August 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypotension
• Other Study ID Numbers: Beni-Suef University Hospital

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No