Efficacy of Continuous Infusion Ropivacaine Interscalene Blocks

Efficacy of Continuous Infusion Ropivacaine Interscalene Blocks Versus Placebo for Pain Control After Arthroscopic Rotator Cuff Repair

Arthroscopic rotator cuff repair is a common and painful procedure routinely performed on an outpatient basis. Postoperative pain control regimens can include narcotic pain medicine, non-steroidal anti-inflammatory medications and regional anesthesia such as an interscalene block (ISB). Regional blocks such as ISB can safely provide complete pain relief for the shoulder and upper extremity for eight to twelve hours1. However, the shoulder is still very painful when the block wears off. The purpose of this study is to:

1. Examine the efficacy of continuous infusion scalene block ropivacaine catheters during the first two days after arthroscopic rotator cuff repair.
2. Examine narcotic consumption after continuous infusion scalene block ropivacaine and placebo catheters after arthroscopic rotator cuff repair.
3. Evaluate for any continued pain relief benefit of continuous infusion scalene block ropivacaine catheters during the three days after the infusion catheters have finished.

Patients undergoing arthroscopic rotator cuff repair by one of the three attending surgeon authors at Orlando Orthopaedic Outpatient Surgery Center will be candidates for the study. Further inclusion criteria will be a full-thickness rotator cuff tear, age eighteen or greater, a reparable rotator cuff tear and willingness to consent to study participation. Patients will not be excluded for concomitant procedures such as acromioplasty, distal clavicle resection, biceps tenotomy and biceps tenodesis.

Exclusion criteria will include age less than eighteen, irreparable rotator cuff tear, subscapularis tear requiring repair, labral tear requiring repair, allergy to ropivacaine or a similar local anesthetic agent and allergy to oxycodone.

All patients will undergo an ultrasound guided ISB with 30cc of 0.5% ropivacaine with epinephrine in the preoperative holding area by an anesthesiologist trained in regional block anesthesia. A continuous infusion catheter will be placed under ultrasound guidance to confirm appropriate position. An adhesive dressing on the skin will be used to keep the catheter in position and away from the operating field.

All patients will receive a reservoir for their catheters containing 280cc of either ropivacaine or saline that will infuse at a rate of 6cc per hour. The reservoirs will be attached in the operating room at the completion of the rotator cuff repair. Patients will be randomized intraoperative to receive either the ropivacaine or the saline. Randomization will be performed by block number randomization and the group assignments will be placed in sealed envelopes. The envelopes will be opened by the operating room circulating nurse. Both patients and surgeons will be blinded to the randomization.

Patients and their families will be educated preoperative and postoperative on the removal of the pain catheters. There will be written instructions regarding catheter removal. Patients or their family members will remove the catheters after the reservoirs are empty. The study authors will be available to assist with any catheter removal issues that the patients may have.

Patients will be prescribed oxycodone 5mg tablets for their postoperative pain control. Patients will receive diaries to record their pain levels utilizing visual analog scores (VAS) for the first five postoperative days. The first pain level will be recorded in the post anesthesia care unit. Pain levels will then be recorded twice daily. Patients will also be asked to log their oxycodone use during the first five postoperative days. Patients will be educated preoperative on the postoperative diaries. They will also receive a call from an OOOSC nurse on postoperative day one to address any questions or concerns.

Patients will be evaluated in the office by the operating surgeon at one week postoperative. At that time, study diaries will be collected.

Inclusion Criteria:

• Patients will be eligible for inclusion in the study if they have a full-thickness rotator cuff tear that has been deemed reparable by preoperative MRI. They will be included in the study if they are medically stable to undergo the surgery and consent to involvement in the study.

Exclusion Criteria:

1. Prior surgery on the involved shoulder
2. Preoperative MRI suggesting that the rotator cuff tear is irreparable
3. Patients with known allergies to oxycodone, ropivacaine or a similar drug
4. Workman's compensation patients
5. Patients who do not fill out their visual analog scores or their medication diaries
6. Patients with labral or subscapularis tears requiring repair