Does Anesthetic Technique Affect Pneumatic Tourniquet Pressures in Upper Limb Fracture Surgery?
Condition: Initial Systolic Blood Pressure (mmHg); Arterial Occlusion Pressure (mmHg); Tourniquet Time (Minutes); Quality of Bloodless Surgical Field (4 Point Scale); Initial Tourniquet Pressure (mmHg); Maximal Systolic Blood Pressure (mmHg); Maximal Tourniquet Pressure (mmHg)
MeSH terms: Arterial Occlusive Diseases; Systolic Murmurs
Study type: Interventional

Summary: 
      In pneumatic tourniquet applications, the use of an individualized, lowest-effective
      tourniquet pressure (TP) has been recommended, in order to avoid pressure related
      complications. The aim of this study is to compare the effects of general anesthesia and
      axillary block on arterial occlusion pressure (AOP) estimation based TP settings in upper
      limb fracture surgery.

      After, ethical committee approval 80 adult patients undergoing upper limb fracture surgery
      who gave their signed informed consent will be included. The age below 18 and above 85 years,
      American Society of Anesthesiology (ASA) physical status >2, any contraindication to axillary
      block or GA, adverse reaction history to anesthetic drugs, severe anemia, and refusal to give
      informed consent will be the exclusion criteria. The patients will be randomized to one of
      two study groups using a computer-generated randomization list to receive GA (Group 1) and
      axillary block (Group 2).

      Main endpoints are initial and maximal blood pressures, AOP, initial and maximal TPs, and
      tourniquet time. Additionally, the surgeon will evaluate the quality of bloodless surgical
      area with respect to the amount of blood using a 4-point scale (1: Excellent= No blood in the
      surgical field, 2: Good= Some blood in the surgical field but no interference with surgery,
      3: Fair= Blood in the surgical field but no significant interference with surgery, 4: Poor=
      Blood in the surgical field obscures the view) at the beginning, in the middle, and at the
      end of the surgical procedure. The patients will be observed for signs of tourniquet related
      complications by a blind investigator. SPSS 20.0 for Windows is used for data analysis. The t
      test and the χ2 test will be used for continuous and categorical data respectively. A P value
      below 0.05 will be considered as statistically significant.
    


Intervention name(s): Upper limb fracture surgery and arterial occlusion pressure (AOP) estimation based tourniquet pressure (TP) setting
Intervention type(s): Procedure
Intervention description(s): Upper limb fracture surgery will be performed with the aid of a pneumatic tourniquet.
The cuff (11 cm) of the tourniquet will be placed around the arm with the distal edge 5 cm above the olecranon. AOP estimation formula according to initial systolic blood pressure (SBP) and Tissue Padding Coefficient (KTP) values (AOP= [SBP+10]/KTP) from a list (Table 1) will be used to calculate AOP (17). After calculation of AOP, a safety margin of 20 mmHg will be added to AOP to determine the TP (TP=AOP+20 mm Hg). Exsanguination of the limb will be provided with an Esmarch bandage and the cuff will be inflated to the predetermined TP. TP will be manually raised in response to each 10 mmHg increase in SBP during the surgical procedure.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Pneumatic tourniquet; Pressure; Upper extremity; General anesthesia; Axillary brachial plexus block.