Intra-articular Versus Intravenous Dexmedetomidine in Arthroscopic Knee Surgeries Under Local Anesthesia
Condition: Knee Arthroscopy
Study type: Interventional

Summary: 
      The present study will be carried to evaluate the efficacy of intra-articular 0.5 bupivacaine
      with intra-articular or intravenous alpha-2agonist; Dexmedetomidine; for intraoperative
      anesthesia and postoperative analgesia after arthroscopic knee surgery.

      Arthroscopic knee surgery is one of the most common minimally invasive orthopedic procedures
      in recent practice which is frequently performed as a day surgery procedures. It can be done
      under general, regional or local anesthesia (LA) with or without sedation. It is associated
      with varying amount of postoperative pain. Postoperative pain negatively influences patient's
      early ambulation, rehabilitation and psychology which consecutively prolonged the hospital
      stay.

      Intra-articular administration of local anesthetic for knee arthroscopy is a well-documented
      procedure that offers many advantages over other anesthesia types. Many anesthesiologists are
      still trying to improve the technique of local anesthetic administration through using many
      combinations with LA solutions in order to administer safe anesthesia to those patients and
      to obtain a pain-free knee with good operating conditions.

      Dexmedetomidine is a highly selective α2 adrenergic agonist. It has analgesic, sedative,
      anxiolytic, hypnotic, sympatholytic, antihypertensive properties with anesthetic sparing
      effects. It becomes an attractive alternative to the current opioids because it does not have
      a respiratory depressant or addictive effect.
    

Detailed description: 
      All patients were kept fasting after midnight and received midazolam 5 mg orally as
      premedication. All patients were premedicated with I.V. midazolam 0.03 mg/kg ten minutes
      before starting the operation. The anesthetic technique was standardized for all patients.
      All surgical procedures were performed by the same surgeon and consisted of arthroscopic
      removal of torn meniscus. Both intra-articular and intravenous solutions were prepared by an
      individual not involved in the study and the intra-articular drugs were injected by the
      surgeon (without knowing the contents). The anesthesiologist managing and monitoring the
      patient throughout the surgery provides IV drugs. No leg holder or tourniquet or surgical
      drain was used for any of the cases. After preparation and draping the patient's leg,
      patients were warned prior to each needle stick to decrease anxiety. All procedures were
      performed under complete aseptic conditions. Skin and subcutaneous tissues at each
      arthroscopic portal site were anesthetized with LA consisting of injection of a mixture of 2%
      lidocaine 5 mL with 1:200,000 epinephrine.

      Care should be taken to avoid infiltration of the fat pad. It is a relatively aneural
      structure; as, too much local infiltration allows it to bulge out into the joint during the
      surgery. Flexion and extension of the knee joint several times help to spread of
      intra-articular solution and then waiting 20 minutes for anesthesia to take effect is helpful
      before the surgical incision.

      The arthroscope was inserted into the knee, and inflow through the sheath was established. No
      pump was used for the saline inflow which was maintained through the arthroscope by the
      gravity. Gravity outflow drained through the superolateral portal. A separate egress cannula
      was used if indicated. The patient was encouraged to view the video monitor during the
      procedure. Constant verbal communication between the surgeon and the patient is important
      throughout the arthroscopic examination and surgery. This keeps the patient anxiety and
      muscle tension to the minimum which facilitates manipulation of the leg and thorough
      examination of the entire joint. Once finishing, instruments were removed and portals were
      closed with a 4-0 absorbable suture subcutaneously and steri-strips. A compression dressing
      was applied for three days to the knee.
    

Intervention name(s): Intra-articular dexmedetomidine; Intravenous dexmedetomidine
Intervention type(s): Drug; Drug
Intervention description(s): Patients will receive an intra-articular mixture of 19 ml bupivacaine 0.5% with epinephrine 1:200.000 added to 1ml (1 µg/kg) of dexmedetomidine (total volume 20 ml), and i.v. saline 20 ml infused over 10 min starting with local anesthesia; Patients will be injected intra-articularly with mixture of 19 ml 0.5% bupivacaine with epinephrine 1:200.000 and 1 ml of isotonic saline (total volume 20 ml), in addition to i.v. 20 ml saline containing 1 µg/kg dexmedetomidine over 10 min infusion starting with local anesthesia.
Intervention MeSH terms: Dexmedetomidine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care
Keywords: Elective; local anesthesia; knee arthroscopy; Dexmedetomidine