Preemptive analgesia can lessen pain after anterior cruciate ligament (ACL) arthroscopic surgery, according to a study presented Saturday in scientific paper 273.
"This method uses analgesics and or anesthetic agents in addition to general anesthesia to prevent or reduce subsequent pain from arthroscopy, even though arthroscopy is much less painful than open procedures," said Richard D. Parker, MD, department of orthopaedics, section of sports medicine, at the Cleveland Clinic Foundation.
Thirty consecutive patients, ages 16 to 43, underwent identical primary ACL reconstruction arthroscopic surgeries. The patients were divided into three groups, with no statistical difference between the groups in terms of age, sex, length of symptoms, and preoperative pain scores. After patients were given general anesthesia, their injured knee joints were injected with different combinations of drugs.
The first group received 60 cc of normal saline and 1:400,000 of epinephrine; the second group received 60 cc of 0.25 percent bupivacaine and 1:400,000 of epinephrine; and the third group received 60 cc of 0.25 percent bupivacaine, 1 mg morphine, and 1:400,000 of epinephrine.
Pain scores were collected preoperatively: upon arrival to the recovery room, after 30 minutes, 60 minutes, 120 minutes, and at two-hour intervals until patients were discharged from the hospital the same day.
Patients in the third group (with the bupivacaine, morphine, and epinephrine) had the least pain, and the second group had less pain than the first group. Pain levels were the most obvious as patients arrived in the recovery room and after 30 minutes, but became less apparent over time, partially due to a narcotic medication that was administered to patients while in the recovery room. There was no statistical difference in pain scores preoperatively or at 24 hours or 48 hours postoperatively.
Additionally, less narcotic medication had to be used for the third group in the recovery room, than for the second or first group. During the first hour in recovery only three of the 10 patients in the third group required narcotic pain medication, compared to nine out of 10 in the second group and all 10 in the first group.
"When peripheral tissue is damaged by surgical procedures it can lead to inflammatory pain, which, in turn, changes the perception of pain by both the peripheral and central nervous systems. The role of preemptive analgesia is to prevent or diminish this post-injury pain hypersensitivity," said Dr. Parker.
Co-authors of the study, all from the Cleveland Clinic Foundation are: Dr. Parker; Charles J. Gatt, Jr., MD; and Audrey B. Dickerson, RN and BSN, department of orthopaedics; John E. Tetzlaff, MD and Martha Zorko Szabo, MD, from the department of anesthesiology.
|1996 Academy News Index|
Last modified 27/September/1996