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

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

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