Vascular Diseases
Conditions
Brief summary
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
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
Interventions
OTHERestimation 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).
OTHERthe 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
Sponsors
Beni-Suef University
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
20 Years to 50 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Tourniquet inflation pressure | tourniquet inflation pressures will be recorded at 0, 5, 15, 30, 60, and 120 min. | the tourniquet inflation pressure will be determined based on the Arterial occlusion pressure or the limb occlusion pressure |
| time required to set the tourniquet inflation pressures | one minute before inflation of the tourniquet cuff | Time needed to estimate AOP or to determine LOP and set the tourniquet cuff pressure. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| tourniquet performance | at the middle and end of surgery | tourniquet performance as determined by the quality of bloodless surgical field. |
Countries
Egypt
Contacts
Primary ContactSamaa ak Rashwan, MD
Outcome results
None listed