"Comparison of Intra-articular of 2% Ropivacaine vs. 7.5% Ropivacaine in Postoperative of Knee Arthroscopy"
Condition: Knee Arthroscopy; Acute Pain
MeSH terms: Acute Pain
Study type: Interventional
Phase: Phase 4

Summary: 
      All patients with acute lesions that attend the orthopedic and trauma center of the ABC
      medical center are invited to participate in the study. Those that meet the inclusion
      criteria and later sign an informed consent are randomized to receive 10 ml of a solution
      with ropivacaine at 7.5% and 2.0% intraarticular for the first 5 minutes after the end of
      surgery (closing of surgical wounds). Both the patient, the physician who applies it and the
      evaluator of outcomes remain blinded to the dose of ropivacaine the patient receives.

      Two hours after the end of the surgery, while the patient is in his room, the presence of
      pain is evaluated by a visual analog scale (VAS), while the patient is asked to flex and
      extend his knee. The result is quantified continuously, to later categorize the pain in none
      to slight pain (0-3 points) and moderate-severe pain (4-10 points). All the information is
      recorded on established forms in the clinical file (general data), that includes the
      variables of interest for the study, and is reported by the physicians after standardization
      of all those in charge with collecting information to comply with the conceptual and
      operative operationalization of the variables described in the research protocol. In addition
      to the evaluation of pain, the administration of opioids to patients for necessary reasons
      (presence of pain) by the physicians in charge is recorded.

      It is hoped that, in patients with knee arthroscopy for acute lesion, there is a difference
      in the frequency of moderate-severe pain of 30% in the post-operative (frequency of 37.5% in
      patients with ropivacaine at 2% and frequency of 7.5% in patients with ropivacaine at 7.5%).
    

Detailed description: 
      In previous studies the prevalence of moderate-severe intensity pain in patients post knee
      arthroscopy is 71.2%, and the prevalence of acute pain in post-operative is 37.5%, surpassing
      the prevalence when compared with other surgical procedures of various specialties.

      The administration of opioids is part of common practice in managing pain. However, it
      represents a risk for patients due to adverse effects and the high risk of dependence. It is
      necessary to seek alternatives that reduce the consumption of opioids in patients post knee
      arthroscopy.

      Characteristics of the patients reported in other studies, such as sex, body mass index,
      sedentarism, the cause, duration and use of tourniquet in surgery, in addition to the type of
      lesion of articular cartilage and the presence of neuropathies, may influence in the presence
      of pain severity.
    

Intervention name(s): Ropivacaine 7.5% Injectable Solution; Ropivacaine 2% Injectable Solution
Intervention type(s): Drug; Drug
Intervention description(s): The patients receive 10 ml of intraarticular solution in the knee (at the anatomical point at the level of the upper pole of the ball joint, under the iliotibial band), with different content of ropivacaine 7.5%; the vehicle for application presents the same physical appearance for all patients and is applied by previously standardized treating physicians.; The patients receive 10 ml of intraarticular solution in the knee (at the anatomical point at the level of the upper pole of the ball joint, under the iliotibial band), with different content of ropivacaine 2%; the vehicle for application presents the same physical appearance for all patients and is applied by previously standardized treating physicians.
Intervention MeSH terms: Ropivacaine; Pharmaceutical Solutions
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: After confirming that the patients meet the selection criteria, they are invited to participate in the study. Upon accepting through signed informed consent, the physician in charge of randomization (physician 1) is informed and the surgery scheduled. The day of the surgery, the physician in charge of randomization reports the maneuver to be received from the anesthesiologist (physician 2) in charge, who prepares the dose of ropivacaine and gives it to a physician blinded to the maneuver (physician 3); this physician applies the ropivacaine intraarticular to the patient. The level of pain is evaluated two hours after the end of surgery by a physician blinded to the maneuver the patient has received (physician 4), while the patient is in his room, and the presence of acute-moderate-severe pain (4-10 points) is evaluated by a visual analog scale (vas) while the patient is requested to flex and extend the knee.
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Knee Arthroscopy; Acute Pain; Ropivacaine