Four vs. Ten Local Anesthetic Injections for SMR
Condition: Submucosal Resection of the Nasal Septum (SMR)
Study type: Interventional

Summary: 
      Submucosal resection of the nasal septum (SMR) could be performed under local anesthetic
      infiltration performed through ten injections in addition to general anesthesia which was
      associated with less postoperative pain and shorter hospital stay.

      However, the local infiltration technique is time-consuming and requires a large number of
      facial injections. This gave rise to the idea of reducing the number of injections while
      retaining the effectiveness of the local anesthetic technique.

      Decreasing the number of injections could be achieved by blocking the superior maxillary
      nerve (V2) and the infra-orbital nerve since it would result in anesthetizing the surgical
      area as well after induction of general anesthesia.

      The purpose of this prospective double-blind clinical trial was to compare the effectiveness
      of four versus ten local anesthetic injections in terms of postoperative pain relief. The
      secondary objective was to compare patients' and surgeons' satisfaction between the two
      techniques.
    

Detailed description: 
      Informed consent will be obtained from patients (ASA I and II) scheduled to undergo elective
      submucosal resection of the nasal septum between May and November 2015.

      The sealed envelope technique is used to randomly assign patients into two groups. The
      anesthetists, surgeons, and nurses who collected the will be blinded to the study groups.
      Patients in both groups will receive general anesthesia and six injections on each side of
      the face at the following points: suprazygomatic maxillary (V2) area, infra-orbital area,
      supratrochlear area, medial to the medial canthus, nasal still and anterior septum. Group II
      patients will receive local anesthetic infiltration in two injections on each side of the
      face at the maxillary and infra-orbital areas and the remaining injections are placebo
      (saline). Group V patients will receive local anesthesia in five injections on each side of
      the face at the infra-orbital area, supratrochlear area, medial to the medial canthus, nasal
      still and anterior septum. The remaining maxillary injection is placebo.

      To maintain double-blindness, three syringes (one 5 ml and two 10 ml) will be used for the
      six injections. They are prepared by a nurse who is not involved in the study. The 5 ml
      syringe (Becton Dickinson, Franklin Lakes New Jersey, USA) is labeled "F" indicating that it
      should be used at the infra-orbital area for both groups. The total injected solution is
      about 2 ml. One of the 10 ml syringes (Becton Dickinson, Franklin Lakes New Jersey, USA) is
      labeled "I" indicating that it should be used for infiltration at the supratrochlear area,
      medial to the medial canthus, nasal still and anterior septum. The total injected solution is
      6 ml. The second 10 ml syringe is labeled "Z" to be used for the suprazygomatic maxillary
      nerve block.

      The syringe labeled "F" always contains the local anesthetic solution. When syringe "I"
      contains the anesthetic mixture (group V), then syringe "Z" is placebo. In contrary, when
      syringe "Z" contains the anesthetic solution (group II), syringe "I" is placebo. The local
      anesthetic mixture is composed of 3 ml lidocaine 2%, 3 ml bupivacaine 0.5%, and 1 ml fentanyl
      50 µg/ml. In addition, syringe "F" contains 50 µg clonidine while syringes "I" and "Z" have
      100 µg clonidine (when they contain the anesthetic solution).

        -  Suprazygomatic maxillary nerve block technique:

      The needle is inserted perpendicular to the skin and advanced to reach the greater wing of
      the sphenoid. The needle is then angulated at 200 and 100 in the anterior and caudal
      directions respectively. The needle is advanced about 3-3.5 cm through the pterygopalatine
      fossa. The total amount of injected solution is 0.1 ml/kg with a maximum volume of 3.5 ml on
      each side of the face.

        -  General anesthesia technique:

      Induction of general anesthesia is achieved by using 1-2 mg/kg propofol, 1-1.5 µg/kg
      intravenous fentanyl and 2-3 ml midazolam. Endotracheal intubation is facilitated by 0.5
      mg/kg atracurium. Anesthesia is maintained using 1-1.5% sevoflurane, 0.5-0.75 µg/kg/hr
      fentanyl, 70% nitrous oxide and 30% oxygen. Any hemodynamic change of ±25% from pre-induction
      values results in a gradual increase or decrease of the sevoflurane concentration.

        -  Surgical procedure:

      Following preparation and draping of the nose, the septum is infiltrated using a solution of
      xylocaine with 1% adrenaline. This would facilitate vasoconstriction and hydrodissection. A
      hemitransfixion incision is made in which the mucoperiosteal and mucoperichondrial flaps are
      elevated and then the deviated septum is resected. The flaps are sutured (Vicryl sutures) and
      packed with two Merocel packs. The patients will be asked to visit the clinic after 48 hours
      to remove the packs.

        -  Data collection:

      Data will be collected at predetermined time intervals by trained nurses. Patients will be
      followed-up for ten postoperative days and contacted daily through phone calls after hospital
      charge.

      Mean arterial pressure (MAP) and heart rate (HR) are collected preoperatively, before
      incision and post incision. Monitoring devices are pulse oximeter and noninvasive arterial
      blood pressure. Postoperative pain is assessed at rest using the Numeric Rating Scale. The
      number of patients who will consume analgesics is recorded. Pain scores, incidence of oozing,
      headache, edema, hematoma, toothache, as well as postoperative nausea and vomiting (PONV) are
      collected during the first postoperative day every six hours (at 0, 6 and 12 hours) and after
      that once daily for the next nine days. Postoperative oozing is defined as changing three
      nasal dressings in 24 hours.

      Patients' and surgeons' satisfaction will be asked to rate their satisfaction on a four point
      scale (very satisfied, satisfied, little satisfied or dissatisfied). Surgeon satisfaction is
      based on intraoperative hemodynamic stability of the patient and bleeding. Postoperative
      surgeon satisfaction is dependent on patients' feeling of pain (especially upon pack
      removal), bleeding and number of phone calls made to the surgeon. Surgeons are asked to
      generally recall the number of calls.

      Patients' satisfaction is based on their postoperative comfort determined by their feeling of
      pain, headache and PONV.

        -  Postoperative pain management:

      During the first 6 hours only, 1-1.5 mg/kg intravenous tramadol hydrochloride is given if the
      pain score was four or greater. If the score was less than four, patients are given 1 g
      intravenous perfalgan. After the first six postoperative hours, patients are given two
      tablets 500 mg oral paracetamol if the pain score is less than four. In case paracetamol is
      not sufficient, patients are prescribed 100 mg Voltarene, a non-steroidal anti-inflammatory
      drug.
    

Intervention name(s): suprazygomatic maxillary area infiltration; non-suprazygomatic maxillary area placebo; non-suprazygomatic maxillary area infiltration; suprazygomatic maxillary area placebo
Intervention type(s): Other; Other; Other; Other
Intervention description(s): Local anesthetic infiltration in two injections on each side of the face at the maxillary and infra-orbital areas.; The remaining injections at supratrochlear area, medial to the medial canthus, nasal still and anterior septum are placebo (saline); Local anesthetic infiltration in five injections on each side of the face at the infra-orbital area, supratrochlear area, medial to the medial canthus, nasal still and anterior septum.; The remaining maxillary injection is placebo.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)