Inter-semispinal Plane Block and Cervical Spine Surgery
Condition: Post Operative Pain; Cervical Spine Instability
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      The inter-semispinal plane (ISP) block is a novel ultrasound-guided technique that involves
      local anesthetic injection into the fascial plane between the semispinalis cervicis and
      semispinalis capitis muscles with subsequent block of the dorsal rami of the cervical spinal
      nerves and hence can get adequate postoperative analgesia.

      The authors hypothesized that ISP block can reduce the postoperative analgesic consumption in
      patients undergoing posterior cervical spine surgeries.

      The aim of this study is to evaluate the analgesic efficacy of ISP block in patients
      undergoing posterior cervical spine surgery.
    

Detailed description: 
      This study will be performed in the in the Fayoum University hospital after the local
      Institutional Ethics Committee and local institutional review board approval. The study
      design will be double-blind randomized controlled study . A detailed informed consent will be
      signed by the eligible patients before recruitment and randomization.

      Patients were randomly allocated into two groups using computer generated sequence and
      concealed in sealed opaque envelopes.

      Control group (C): patients received general anesthesia only. Inter-semispinal plane (ISP)
      block group: patients received bilateral ultrasound guided ISP block at the level of C5.

      All patients will be assessed Preoperative VAS score then premedicated orally with midazolam
      0.5 mg/kg 30 min prior to surgery. All patients were monitored by 5 lead ECG, pulse oximetry,
      non-invasive blood pressure and capnography and an intravenous (IV) access will be
      established.

      The technique of general anesthesia will be standardized for all patients. General anesthesia
      will be induced by intravenous (IV) 2 mg/kg propofol and 1 μg/kg fentanyl induction. After IV
      atracurium 0.5 mg/kg, orotracheal intubation was performed. Anesthesia will be maintained
      with isoflurane (1.2%-1.5%) in oxygen-air mixture (50%-50%). Muscle relaxation will be
      maintained during the procedure with atracurium in increments.

      After induction of general anesthesia, ISP blocks will be performed in the allocated group
      with the patient in the prone position. In both groups, the treating anesthesiologist left
      the operating room while another anesthesiologist experienced in ultrasound guided nerve
      block techniques; with no subsequent role in the study; either performed the ISP blocks in
      the ISP group, or just prepared the skin and scanned the site of the block using the
      ultrasound probe in the control group. Fifteen minutes will be awaited in all patients before
      the surgical procedure was allowed to start.

      fentanyl 0.5 μg/kg IV will be administered in case of inadequate analgesia as indicated by
      >20% increase in heart rate or mean arterial blood pressure. Total intraoperative fentanyl
      consumption will be recorded.

      All anesthetics will be discontinued at the end of the surgical procedure. Extubation will be
      performed when spontaneous breathing was adequate and following prompt reversal using 0.05
      mg/kg of neostigmine and 0.02 mg/kg of atropine. At the end of surgery, paracetamol 1 g will
      be administered IV to be repeated every 6 h postoperatively. Patients will be transferred to
      the PACU where HR, respiratory rate, SpO2 and systolic, diastolic and mean arterial blood
      pressure were monitored.

      Sample size was calculated using G* Power 3.1.7.9 software program. Calculation of the sample
      size was based on the VAS value measured at different time points. Based on the results of a
      study by Mostafa et al, the authors calculated the sample size to be able to detect a
      difference in VAS score of 10 points with an effect size of 0.8. Using the previous data, at
      least 23 patients in each group were required to detect a significance difference in the
      postoperative pethidine consumption at α value of 0.05 and study power of 90%. The authors
      decided to recruit 25 patients in each group to compensate for any possible withdrawals. The
      sample size calculation was based on a 2-sample independent t-test (2-sided)
    

Intervention name(s): Bupivacaine Hydrochloride; Lidocaine Hydrochloride; Ultrasound; Needle
Intervention type(s): Drug; Drug; Device; Device
Intervention description(s): 10 ml of 0.25% bupivacaine on each side of cervical region at C5; 10ml xylocaine on each side of cervical region at C5; The same anesthesiologist who is experienced in US guided regional anesthesia will perform the block.The five-layered posterior cervical muscles were identified at the level of C5 with a 6-15-MHz linear probe oriented in the transverse plane (SonoSite Edge, Bothell, Washington). The fifth cervical spine was counted from the C7 spinous process with the probe sliding cranially.; the needle (22- G, 50-mm block needle (Visioplex, Vygon) was introduced in-plane through the skin and advanced into the fascial plane between the semispinalis cervicis and semispinalis capitis muscles. After negative aspiration for blood, 20 ml of bupivacaine 0.25% was injected5.
Other intervention name(s): 0.25% bupivacaine HCL; Xylocaine
Intervention MeSH terms: Lidocaine; Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Patients were randomly allocated into either of the two groups using computer generated sequence and concealed in sealed opaque envelopes.
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Prevention
Keywords: inter-semispinal plane block; Cervical spine surgery; Postoperative analgesia