Gradual Deflation of Thigh Tourniquet for Attenuation of Hemodynamic Post-tourniquet Response in Old Patients

Study Overview
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Brief Summary
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Deflation of the pneumatic tourniquet used in lower limb surgery is usually associated with hemodynamic instability, metabolic and respiratory changes. These changes are usually tolerated by young, healthy patients; However, these complications are risky for elderly and cardiac patients. The aim of this study is to assess the effect of gradual deflation of thigh tourniquet on the hemodynamics and arterial blood gases compared to the usual practice

Detailed Description
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Pneumatic tourniquet will be applied on the mid- thigh with cuff pressure of 350 mm Hg. After the end of surgery, the lower limb will be elevated at 45-degree and the patients will randomized into one of the three groups: G 50 (n=30) : The tourniquet cuff pressure will be deflated gradually by 50 mm Hg every 2 minutes till complete deflation. G 100 (n=30): The tourniquet cuff pressure will be deflated gradually by 100 mm Hg every 2 minutes till complete deflation. G 0 (n=30): The tourniquet cuff will be released till complete deflation. If hypotension is observed during the procedure, it will be managed by 10 mg ephedrine.

Official Title
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Gradual Deflation of Thigh Tourniquet for Attenuation of Hemodynamic Post-tourniquet Response in Old Patients :Randomized Control Study

Conditions
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Tourniquet

Intervention / Treatment
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* Other: deflation of pneumatic tourniquet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled for elective orthopedic lower limb surgery under pneumatic tourniquet Exclusion Criteria: BMI ≥35Kg/ m2 patients with unstable angina, left ventricular dysfunction , cerebrovascular disease ,bleeding disorders contraindication to tourniquet insertion patients requiring massive intraoperative blood transfusion (Blood loss more than 50% of the patients' blood volume (70 ml/Kg) ).

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| G50<br>The tourniquet cuff pressure will be deflated gradually by 50 mm Hg every 2 minutes till complete deflation. | Other: deflation of pneumatic tourniquet<br>* gradual deflation with variable degrees<br>|
| G100<br>The tourniquet cuff pressure will be deflated gradually by 100 mm Hg every 2 minutes till complete deflation. | Other: deflation of pneumatic tourniquet<br>* gradual deflation with variable degrees<br>|
| G0<br>The tourniquet cuff will be released till complete deflation. | Other: deflation of pneumatic tourniquet<br>* gradual deflation with variable degrees<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mean arterial blood pressure | The lowest mean arterial blood pressure during a 15-minute period after starting deflation of the tourniquet. | 15 minutes after start of deflation of cuff | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| hypotension | incidence of post tourniquet hypotension | 15 minutes after start of deflation of cuff | 
| cardiac output | cardiac output after starting deflation using non invasive electrical cardiometry | 15 minutes after start of deflation of cuff |