Gynecologists use paracervical blocks in the office for decreasing pain during office based procedures. Paracervical blocks, in the office, work by injecting the cervix with local anesthetic, typically lidocaine, at the area of the uterosacral ligaments. The uterosacral ligaments contain the uterine nerve, which branches off of levels T12-L2. By injecting the uterine nerve with the local anesthetic patients are better able to tolerate the procedure and have decreased pain post procedure. In the office, paracervical blocks are performed vaginally with injections at the 3 o'clock and 9 o'clock position of the cervix. The use of paracervical blocks by Chudnoff et al reviewed the effectiveness of paracervical blocks in office based procedures, however no one has evaluated the effectiveness of injecting the uterosacral ligaments under direct visualization with the camera that is placed into the abdomen during a robotic assisted gynecologic procedure. We propose that by injecting the uterosacral ligaments and thus the uterine nerve during robotic assisted hysterectomies with Marcaine (Bupivacaine 0.5% with epinephrine 1:200,000) we can offer patients superior pain relief. The onset of action with Marcaine is rapid and anesthesia is long lasting. The duration of anesthesia is significantly longer with Marcaine than any other commonly used local anesthetic. It has also been noted that there is a period of analgesia that persists after the return of sensation, during which time the need for strong analgesics is reduced. By injecting Marcaine we hypothesize that patients will have decreased pain and need less narcotic pain medication. This will allow the patient to return to normal activities of daily living sooner.
This is a randomized controlled double blinded trial in which patients will be assigned to receive saline (control group) or bupivacaine 0.5% with epinephrine 1:200,000 (treatment group). The randomization will be performed through a computerized system in the pharmacy at the pharmacy of the hospital where the study is occurring. The randomization will occur once the patient has consented to the study. The treatment arm of the study will receive a total injection of 14ml of bupivacaine with 7ml directed into the right uterosacral ligament and 7ml into the left uterosacral ligament. The control arm of the study will receive a total injection of 14ml of normal saline with 7ml directed into the right uterosacral ligament and 7ml into the left uterosacral ligament. These injections will take place after the uterus and cervix have been surgically removed and the vaginal cuff has been surgically closed.
The maximum dose of bupivacaine with epinephrine is 225mg. The total amount of bupivacaine that we have chosen to inject is below the maximum allowable dosing and yet we believe will be an adequate amount for providing pain relief.
Eligible patients will be consented for the study while in the preoperative holding area. Once consented the patient will be given a medication diary form that they will take home. The form asks the patient to fill in the name of pain medication that they were prescribed and the dosage. They will also have an area for them to tally the number of pills they have taken since being discharged from the hospital. If they take anything for pain other than that prescribed by the physician who performed the surgery the patient will be taken out of the study. The Wong-baker faces pain rating scale is included on the form which they will be using to rate their pain during the telephone encounters.
The pharmacy will be notified once consent is obtained that the patient is participating in the study. After which, the injectable solution will be sent to the OR labeled "Study Drug." The surgical team and the patient will be blinded to which arm they are assigned to. With the use of a Bierman needle the solution will be injected into the uterine nerve as it courses with the uterosacral ligaments on each side at the level of the vaginal cuff. If the uterosacral ligaments cannot be easily identified, the patient will be excluded from the study.
Follow up will take place via telephone encounters.
