The Effect of Ischemic Preconditioning on Postoperative Pain After Total Knee Arthroplasty, a Randomized, Controlled Trial

Not Applicable

Completed

Conditions: Ischemic Preconditioning
Total Knee Arthroplasty
Postoperative Pain

Interventions: Procedure: Ischemic Preconditioning

Registration Number: NCT01333969

Lead Sponsor: Hospital for Special Surgery, New York

Brief Summary: The application of a tourniquet for 5 minutes and subsequent reperfusion before actual inflation of the tourniquet for total knee arthroplasty (ischemic preconditioning) decreases the level of local inflammation and therefore postoperative pain in response to reperfusion of the ischemic extremity.

Detailed Description: During knee surgery your surgeon routinely uses a device called a tourniquet that allows us to temporarily cut of blood supply to the site of surgery. This helps to reduce blood loss and improves operating conditions. When allowing blood back into your leg at the end of the procedure, debris (bone, fat, tissue breakdown products and cement from the surgery) gets washed out and gains access to the rest of your body. In the vast majority of cases this event bares no major clinical consequences, but can rarely result in signs of inflammation of various body systems. Patients with evidence of impaired organ system function such as pre-existing lung and heart disease may be more vulnerable. Previous studies suggest that cutting off the blood supply for a short period of time just before a prolonged episode, could lead to a decrease in the extent of tissue breakdown products in this extremity and may thus be associated with a decrease in the inflammation of other organ systems. We propose to study this theory in knee surgery patients by looking at levels of markers of inflammation present in the blood before and after surgery.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 60

Inclusion Criteria

All patients undergoing primary total knee arthroplasty

Exclusion Criteria

Patients who chronically use narcotics (<1 month).
Patients with contraindications (severe peripheral vascular disease, presence of femoral-popliteal bypass grafts, etc.) or no plan for tourniquet use as determined by the clinical care team.
Patients who are on corticosteroids prior to their surgery

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Ishcemic Preconditioning	Ischemic Preconditioning	In the study group, the patients' operative limb will be preconditioned by inflating the tourniquet for 5 minutes, followed by deflation and a 5-minute reperfusion period. Subsequently, the tourniquet will be inflated for the entire length of the operation (before skin incision to after insertion of the final components).

Primary Outcome Measures

Name	Time	Method
Postoperative Pain at Rest and Exercise as Assessed by Visual Analogue Scale (VAS) Scores at 48h After Surgery	48hrs after surgery	Visual Analogue Scale (VAS) are used to measure the intensity of pain. The total scale ranged from 0 (no pain) to 10 (excruciating pain). The average value at POD 48hours was reported for each arm/group.

Secondary Outcome Measures

Name	Time	Method
Overall Epidural Volume	At 48hrs after surgery	Postoperative pain management included an epidural infusion of 10mcg/ml bupivacaine 0.06%/hydromorphone with a basal rate of 4 mL, a demand dose of 4 mL, and a lockout of 10 minutes. Basal rates were reduced to 2 mL and 0 mL in the morning of postoperative Days 1 and 2, respectively and epidural catheters removed on postoperative Day 2. Overall epidural volume was the total volume given over 48 hours.
Muscle Oxygenation Over Calf at 48h After Surgery	At 48 hrs after surgery	muscle tissue oxygenation was measured using a novel noninvasive near infrared spectroscopy device at baseline and at 48 hours postoperatively
Levels of Interleukin 6 (IL6) in Drainage Fluid at 24hr Postoperatively	At 24 hours postoperatively
Periarticular Circumference of the Knee at 6h, 24h, and 48h	measured at 6 hours, 24 hours, and 48 hours	Periarticular circumference of the knee as compared to contralateral side as crude marker of swelling at 6h, 24, and 48h postoperatively. The data from the specified time points (6h, 24h, and 48h) were combined and the average value was reported for each arm/group.
Hospital Length of Stay	Up to discharge date
Physical Therapy Milestone	Up to discharge date	Amount of time until patients reached their physical therapy milestone (40 ft ambulation) during admission
Levels of Leukocytes in Drainage Fluid at 24hr Postoperatively	24 hours postoperatively
Levels of TNF-alpha in Drainage Fluid at 24hr Postoperatively	24 hours postoperatively