<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02189681</url>
  </required_header>
  <id_info>
    <org_study_id>L5S1 study</org_study_id>
    <nct_id>NCT02189681</nct_id>
  </id_info>
  <brief_title>Landmark Guided Midline Versus Pre-procedural Ultrasound Guided Paramedian at L5S1 for Spinal Anaesthesia</brief_title>
  <official_title>Comparison of Conventional Landmark Guided Midline (Group C) Versus Pre-procedural Ultrasound Guided Paramedian at L5S1 (Group P) Technique for Spinal Anaesthesia</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Cork University Hospital</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Cork University Hospital</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Spinal anesthesia is widely performed using a surface landmark based 'blind' technique.&#xD;
      Multiple passes and attempts while administering spinal anesthesia are associated with a&#xD;
      greater incidence of post dural-puncture headache, paraesthesia and spinal hematoma.&#xD;
&#xD;
      Real time and pre-procedural neuraxial ultrasound techniques have been used to improve the&#xD;
      success rate of spinal anesthesia. The use of real time ultrasound-guided spinal anesthesia&#xD;
      has to date been limited to case series and case reports.Its use may be limited by the&#xD;
      requirement for wide bore needles and the technical difficulties associated with simultaneous&#xD;
      ultrasound scanning and needle advancement. The use of pre-procedural ultrasound has been&#xD;
      shown to increase the first pass success rate for spinal anesthesia only in patients with&#xD;
      difficult surface anatomic landmarks. No technique has been shown to improve the success rate&#xD;
      of dural puncture when applied routinely to all patients. Routine use of pre-procedure&#xD;
      ultrasound guided paramedian approach results in 50% reduction in number of passes required&#xD;
      for spinal anaesthetic, from a study at Cork University Hospital (awaiting publication).&#xD;
      L5-S1 is the widest interlaminar space and provides minimal contribution to overall movement&#xD;
      of lumbar spine.This interspinous space might still be accessible even if the patient has&#xD;
      minimal spine flexion. We also noted that spinal needle insertion via the L5-S1 interspace&#xD;
      was associated with the fewest passes in the pre-procedure guided ultrasound group (although&#xD;
      non-significant).&#xD;
&#xD;
      We hypothesise that the routine use of pre-procedural ultrasound-guided paramedian spinal&#xD;
      technique at L5S1 interspinous space will result in fewer needle passes to enter the&#xD;
      subarachnoid space when compared to the conventional landmark based midline approach.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      This will be a prospective, randomised, controlled study. All consented patients scheduled to&#xD;
      undergo elective total knee or total hip arthroplasty under spinal anesthesia will be&#xD;
      included in the study. A written informed consent will be obtained from all patients&#xD;
      participating in the study. Patients with contraindications to spinal anesthesia (allergy to&#xD;
      local anesthetic, coagulopathy, local infection and indeterminate neurological disease) will&#xD;
      be excluded from the study.&#xD;
&#xD;
      The patients will be randomised using random number generating software (Research Randomizer&#xD;
      Version 4.0 ) to undergo either conventional landmark-guided spinal anesthesia (Group C) or&#xD;
      pre-procedural ultrasound-guided paramedian L5S1 spinal (Group P). Group allocation will be&#xD;
      concealed by enclosing the codes in a sealed opaque envelope and will be seen by the&#xD;
      attending anesthesiologist immediately before performing the procedure. Patients will be&#xD;
      blinded as to their allocated study group.&#xD;
&#xD;
      In both groups, spinal anesthesia will be performed by one of three consultant&#xD;
      anesthesiologists (FL, PL, GI), each having performed more than 75 neuraxial ultrasound scans&#xD;
      prior to the study. On arrival to the anesthesia induction room baseline monitoring&#xD;
      (non-invasive blood pressure, pulse oximetry and 3 lead ECG) and intravenous access will be&#xD;
      established. The patients will be then positioned sitting on a level trolley with feet&#xD;
      resting on a foot rest. They will be given a pillow to hug and requested to maintain an&#xD;
      arched back posture with an assistant holding the patient to aid positioning.&#xD;
&#xD;
      In group C, the anesthesiologist will palpate the landmarks after positioning and graded the&#xD;
      ease of palpation on a 4 point scale (easy, moderate, difficult or impossible) as described&#xD;
      in previous studies.10 Strict asepsis will be followed throughout the procedure with&#xD;
      anesthesiologist scrubbed prior to procedure, wearing mask and sterile gloves. The skin will&#xD;
      be prepped with 2% Chlorhexidine (Chloraprep 3 ml applicator, CareFusion Corporation, San&#xD;
      Diego, CA 92130,USA) following which 2-5 ml of 1% lidocaine will be used to infiltrate the&#xD;
      skin. The anesthesiologist performing the spinal technique will be allowed to choose the&#xD;
      appropriate needle length ( 90 or 119 mm 25 G Whitacre needle, Becton, Dickinson and Company,&#xD;
      Franklin Lakes, New Jersey, 07417-1880, USA), gauge (25 or 22G), depth and angle of&#xD;
      insertion. Hyperbaric bupivacaine will be used in both groups. After completion of spinal&#xD;
      anesthetic injection, and positioning the patient in lateral decubitus, ultrasound will be&#xD;
      used to identify the interspinous level at which the injection will be administered.&#xD;
&#xD;
      In group P, a portable ultrasound unit with a curved 2-5 MHz probe will be used for initial&#xD;
      pre-procedural marking. A paramedian sagittal oblique view of the neuraxis will be obtained&#xD;
      and the sacrum will be identified, following which the interlaminar space between L5 and S1&#xD;
      will be noted. At this interspace with the probe positioned to obtain the clearest ultrasound&#xD;
      image of the anterior complex (ligamentum flavum dura complex- LFD) and posterior complex&#xD;
      (posterior longitudinal ligament- PLL) possible, a skin marker will be used to mark the&#xD;
      midpoint of the long border of the probe and the midpoints of the short borders of the probe.&#xD;
      The medial angulation of the probe will also be noted to guide the insertion of the spinal&#xD;
      needle. At the same horizontal level as the midpoint of the long border of the probe, the&#xD;
      midpoint of the line drawn between the two short border midpoints of the probe will be used&#xD;
      as paramedian insertion point for the spinal needle. A transverse median (TM) view at the&#xD;
      same level will also be obtained and the midline will be marked. This marking will be used to&#xD;
      aid the medial angulation of the spinal needle. Both PSO and TM views would be graded as good&#xD;
      (both LFD and PLL visible), intermediate (either LFD or PLL visible) and poor (both LFD and&#xD;
      PLL not visible).15 Following skin marking, care will be taken to make sure that the needle&#xD;
      entry site will be free of ultrasound gel prior to needle insertion. In group P, the&#xD;
      anesthesiologist will not palpate the landmarks for grading until the spinal injection is&#xD;
      complete. Spinal anesthesia will be performed in the same aseptic manner as mentioned&#xD;
      earlier.&#xD;
&#xD;
      In both groups the anesthesiologists will be given the option to use alternative methods if&#xD;
      unsuccessful after 3 attempts. For patients in group C another interspinous space could be&#xD;
      used or ultrasound employed. For patients in group P a midline approach or a conventional&#xD;
      landmark palpation technique could be used.&#xD;
&#xD;
      The outcomes will be noted by a single observer for all patients. Due to the nature of the&#xD;
      study, the observer will not be blinded to the groups. A timer will be used to record the&#xD;
      various time intervals. Time for identifying landmarks in group C will be defined as time&#xD;
      from which the anesthesiologist started palpating to identify the landmarks to completion of&#xD;
      the process as declared by the anesthesiologist. In group P it will be defined as time from&#xD;
      which the ultrasound probe will be placed on the skin to the anesthesiologist declaring that&#xD;
      the markings are completed. Time taken for performing spinal anesthetic will be defined as&#xD;
      time taken from insertion of introducer needle to completion of injection. The number of&#xD;
      passes, defined as the number of forward advancements of the spinal needle in a given&#xD;
      interspinous space (i.e. withdrawal and redirection of spinal needle without exiting the&#xD;
      skin) and number of spinal needle insertion attempts (defined as the number of times the&#xD;
      spinal needle will be withdrawn from the skin and reinserted) will be noted.10 The number of&#xD;
      passes and attempts will be recorded either until the completion of spinal anesthetic or&#xD;
      until the anesthesiologist converts to an alternate technique.&#xD;
&#xD;
      Incidence of radicular pain, paraesthesia and blood in the spinal needle will also be noted.&#xD;
      All patients who experienced paraesthesia or radicular pain will be followed over the next 24&#xD;
      hours and any patients with persistent symptoms will be further evaluated as per department&#xD;
      protocol.&#xD;
&#xD;
      In both groups following administration of spinal anesthesia, patients will be positioned on&#xD;
      either left or right lateral position depending on the site of surgery. After positioning and&#xD;
      prior to administration of sedation, patients will be asked for their peri-procedural pain&#xD;
      scores measured using an 11 point verbal rating scale (0=no pain, 10=most pain imaginable)&#xD;
      and peri-procedural discomfort scores measured using an 11 point verbal rating measured (0=&#xD;
      no discomfort, 10=most discomfort imaginable). Level of block (loss of cold sensation) will&#xD;
      be noted 30 minutes after spinal anesthetic injection. Type and dose of sedation (Midazolam&#xD;
      +/- Propofol infusion) will be left to the discretion of the anesthesiologist.&#xD;
&#xD;
      Study Outcomes The primary outcome will be the difference in number of passes between the two&#xD;
      groups.&#xD;
&#xD;
      Secondary outcomes includes the following,&#xD;
&#xD;
        1. Number of spinal needle insertion attempts&#xD;
&#xD;
        2. Time for identifying landmarks&#xD;
&#xD;
        3. Time taken for performing spinal anesthetic&#xD;
&#xD;
        4. Level of block&#xD;
&#xD;
        5. Incidence of radicular pain, paraesthesia and blood in the spinal needle.&#xD;
&#xD;
        6. Peri-procedural pain&#xD;
&#xD;
        7. Peri-procedural discomfort score Statistics Based on our previous study with same group&#xD;
           of consultants done here in CUH, the average number of passes in group C was 6.4 +/-8.6&#xD;
           (mean +/- SD). We hypothesised that by using pre-procedural paramedian spinal done at&#xD;
           L5S1, the number of passes could be reduced to 1.5. Fourty eight patients in each group&#xD;
           will be needed to achieve a power of 0.8 and type 1 error of &lt;0.05. We are hoping to&#xD;
           randomise 60 patients per group to allow for dropouts. All data will be analysed based&#xD;
           on intention to treat. Data will be visually inspected for normality. Categorical data&#xD;
           were analysed using the Chi-square test. Normally distributed parametric data were&#xD;
           analysed using Students-t test (two groups) or ANOVA (more than 2 groups). A p value of&#xD;
           less than 0.05 will be considered significant. SPSS version 20 will be used for the&#xD;
           statistical analysis.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>July 2014</start_date>
  <completion_date type="Actual">July 2015</completion_date>
  <primary_completion_date type="Actual">July 2015</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <masking>Double (Participant, Outcomes Assessor)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>difference in number of passes between the two groups.</measure>
    <time_frame>30 minutes within completion of apinal anaesthetic</time_frame>
    <description>The number of passes, defined as the number of forward advancements of the spinal needle in a given interspinous space (i.e. withdrawal and redirection of spinal needle without exiting the skin)</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Number of spinal needle insertion attempts</measure>
    <time_frame>Up to 45 minutes from the start of insertion of spinal needled for administration of spinal anaesthetic</time_frame>
    <description>number of spinal needle insertion attempts (defined as the number of times the spinal needle was withdrawn from the skin and reinserted) were noted</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Blood in spinal needle</measure>
    <time_frame>Up to 45 minutes from the start of insertion of spinal needled for administration of spinal anaesthetic</time_frame>
    <description>Presence of blood in spinal needle</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Time for identifying landmarks</measure>
    <time_frame>Up to 10 minutes fraom start of plapating for landmarks - Completed once anethetist declares that markings are complete</time_frame>
    <description>Time for identifying landmarks in group C was defined as time from which the anesthesiologist started palpating to identify the landmarks to completion of the process as declared by the anesthesiologist. In group P it was defined as time from which the ultrasound probe was placed on the skin to the anesthesiologist declaring that the markings are completed</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Time taken for performing spinal anesthetic</measure>
    <time_frame>Up to 45 minutes from the start of insertion of spinal needled for administration of spinal anaesthetic</time_frame>
    <description>defined as time taken from insertion of introducer needle to completion of injection</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Incidence of radicular pain</measure>
    <time_frame>Up to 24 hours after administration of spinal anaesthetic</time_frame>
    <description>Shooting pain going down along one of the dermatomal levels in the leg</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Presence of paresthesia</measure>
    <time_frame>Up to 24 hours after administration of spinal anaesthetic</time_frame>
    <description>Paresthesia along dermatomal distribution during performing spinal anaesthetic</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Grading of palpated landmarks</measure>
    <time_frame>Up to 10 minutes fraom start of plapating for landmarks - Completed once anethetist declares that markings are complete</time_frame>
    <description>Anesthesiologist palpated the landmarks after positioning and graded the ease of palpation on a 4 point scale (easy, moderate, difficult or impossible)</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Peri-procedural VAS scores of pain at injection site</measure>
    <time_frame>up to 30 minutes following spinal anaesthetic injection and prior to sedation</time_frame>
    <description>After positioning and prior to administration of sedation, patients were asked for their peri-procedural pain scores measured using an 11 point verbal rating scale (0=no pain, 10=most pain imaginable)</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>peri-procedural discomfort scores</measure>
    <time_frame>up to 30 minutes following spinal anaesthetic injection and prior to sedation</time_frame>
    <description>peri-procedural discomfort scores measured using an 11 point verbal rating measured (0= no discomfort, 10=most discomfort imaginable).</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Level of block</measure>
    <time_frame>15 minutes after spinal anaesthetic injection</time_frame>
    <description>Dermatomal level at which loss of cold sensation (ethyl chloride spray) occurs</description>
  </secondary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">120</enrollment>
  <condition>Anaesthesia</condition>
  <arm_group>
    <arm_group_label>Group C</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Patients in this group underwent Conventional landmark guided midline spinal anaesthesia.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Group P</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>This group had pre-procedure ultrasound guided L5S1 paramedian spinal anaesthesia performed</description>
  </arm_group>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>Conventional landmark guided midline spinal anaesthesia</intervention_name>
    <description>Spinal anaesthesia was administered based on conventional landmark based midline approach.</description>
    <arm_group_label>Group C</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>pre-procedure ultrasound guided L5S1 paramedian spinal</intervention_name>
    <description>In group P, a portable ultrasound unit was used for initial pre-procedural marking. The L5 S1 interspinous space with best image of the anterior complex (ligamentum flavum dura complex- LFD) and posterior complex (posterior longitudinal ligament- PLL) was obtained. At this selected interspace, and with the probe positioned to obtain the clearest ultrasound image, a skin marker was used to mark the midpoint of the long border of the probe and the midpoints of the short borders of the probe . At the same horizontal level as the midpoint of the long border of the probe, the midpoint of the line drawn between the two short border midpoints of the probe was used as paramedian insertion point for the spinal needle.Spinal anaesthesia is then administered based on these landmarks.</description>
    <arm_group_label>Group P</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>spinal anaesthesia</intervention_name>
    <description>Spinal anaesthesia is administered with appropriate spinal needle</description>
    <arm_group_label>Group C</arm_group_label>
    <arm_group_label>Group P</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  All consented patients scheduled to undergo elective total knee or total hip&#xD;
             arthroplasty under spinal anesthesia will be included in the study.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Patients with contraindications to spinal anesthesia (allergy to local anesthetic,&#xD;
             coagulopathy, local infection and indeterminate neurological disease) will be excluded&#xD;
             from the study.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>20 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Karthikeyan Kallidaikurichi Srinivasan, FCARCSI,MD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Cork University Hospital</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Cork University Hospital</name>
      <address>
        <city>Cork,Ireland</city>
        <state>Cork</state>
        <country>Ireland</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Ireland</country>
  </location_countries>
  <verification_date>August 2015</verification_date>
  <study_first_submitted>July 5, 2014</study_first_submitted>
  <study_first_submitted_qc>July 10, 2014</study_first_submitted_qc>
  <study_first_posted type="Estimate">July 14, 2014</study_first_posted>
  <last_update_submitted>August 26, 2015</last_update_submitted>
  <last_update_submitted_qc>August 26, 2015</last_update_submitted_qc>
  <last_update_posted type="Estimate">August 28, 2015</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Cork University Hospital</investigator_affiliation>
    <investigator_full_name>Karthikeyan Kallidaikurichi Srinivasan</investigator_full_name>
    <investigator_title>Specialist Registrar,Anaesthetics,Cork University Hospital</investigator_title>
  </responsible_party>
  <keyword>spinal anaesthesia</keyword>
  <keyword>ultrasound</keyword>
  <keyword>paramedian</keyword>
  <intervention_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Anesthetics</mesh_term>
  </intervention_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02189681
org study id: L5S1 study
nct id: NCT02189681
lead sponsor: 
has dmc: No
Spinal anesthesia is widely performed using a surface landmark based 'blind' technique.
      Multiple passes and attempts while administering spinal anesthesia are associated with a
      greater incidence of post dural-puncture headache, paraesthesia and spinal hematoma.

      Real time and pre-procedural neuraxial ultrasound techniques have been used to improve the
      success rate of spinal anesthesia. The use of real time ultrasound-guided spinal anesthesia
      has to date been limited to case series and case reports.Its use may be limited by the
      requirement for wide bore needles and the technical difficulties associated with simultaneous
      ultrasound scanning and needle advancement. The use of pre-procedural ultrasound has been
      shown to increase the first pass success rate for spinal anesthesia only in patients with
      difficult surface anatomic landmarks. No technique has been shown to improve the success rate
      of dural puncture when applied routinely to all patients. Routine use of pre-procedure
      ultrasound guided paramedian approach results in 50% reduction in number of passes required
      for spinal anaesthetic, from a study at Cork University Hospital (awaiting publication).
      L5-S1 is the widest interlaminar space and provides minimal contribution to overall movement
      of lumbar spine.This interspinous space might still be accessible even if the patient has
      minimal spine flexion. We also noted that spinal needle insertion via the L5-S1 interspace
      was associated with the fewest passes in the pre-procedure guided ultrasound group (although
      non-significant).

      We hypothesise that the routine use of pre-procedural ultrasound-guided paramedian spinal
      technique at L5S1 interspinous space will result in fewer needle passes to enter the
      subarachnoid space when compared to the conventional landmark based midline approach.
This will be a prospective, randomised, controlled study. All consented patients scheduled to
      undergo elective total knee or total hip arthroplasty under spinal anesthesia will be
      included in the study. A written informed consent will be obtained from all patients
      participating in the study. Patients with contraindications to spinal anesthesia (allergy to
      local anesthetic, coagulopathy, local infection and indeterminate neurological disease) will
      be excluded from the study.

      The patients will be randomised using random number generating software (Research Randomizer
      Version 4.0 ) to undergo either conventional landmark-guided spinal anesthesia (Group C) or
      pre-procedural ultrasound-guided paramedian L5S1 spinal (Group P). Group allocation will be
      concealed by enclosing the codes in a sealed opaque envelope and will be seen by the
      attending anesthesiologist immediately before performing the procedure. Patients will be
      blinded as to their allocated study group.

      In both groups, spinal anesthesia will be performed by one of three consultant
      anesthesiologists (FL, PL, GI), each having performed more than 75 neuraxial ultrasound scans
      prior to the study. On arrival to the anesthesia induction room baseline monitoring
      (non-invasive blood pressure, pulse oximetry and 3 lead ECG) and intravenous access will be
      established. The patients will be then positioned sitting on a level trolley with feet
      resting on a foot rest. They will be given a pillow to hug and requested to maintain an
      arched back posture with an assistant holding the patient to aid positioning.

      In group C, the anesthesiologist will palpate the landmarks after positioning and graded the
      ease of palpation on a 4 point scale (easy, moderate, difficult or impossible) as described
      in previous studies.10 Strict asepsis will be followed throughout the procedure with
      anesthesiologist scrubbed prior to procedure, wearing mask and sterile gloves. The skin will
      be prepped with 2% Chlorhexidine (Chloraprep 3 ml applicator, CareFusion Corporation, San
      Diego, CA 92130,USA) following which 2-5 ml of 1% lidocaine will be used to infiltrate the
      skin. The anesthesiologist performing the spinal technique will be allowed to choose the
      appropriate needle length ( 90 or 119 mm 25 G Whitacre needle, Becton, Dickinson and Company,
      Franklin Lakes, New Jersey, 07417-1880, USA), gauge (25 or 22G), depth and angle of
      insertion. Hyperbaric bupivacaine will be used in both groups. After completion of spinal
      anesthetic injection, and positioning the patient in lateral decubitus, ultrasound will be
      used to identify the interspinous level at which the injection will be administered.

      In group P, a portable ultrasound unit with a curved 2-5 MHz probe will be used for initial
      pre-procedural marking. A paramedian sagittal oblique view of the neuraxis will be obtained
      and the sacrum will be identified, following which the interlaminar space between L5 and S1
      will be noted. At this interspace with the probe positioned to obtain the clearest ultrasound
      image of the anterior complex (ligamentum flavum dura complex- LFD) and posterior complex
      (posterior longitudinal ligament- PLL) possible, a skin marker will be used to mark the
      midpoint of the long border of the probe and the midpoints of the short borders of the probe.
      The medial angulation of the probe will also be noted to guide the insertion of the spinal
      needle. At the same horizontal level as the midpoint of the long border of the probe, the
      midpoint of the line drawn between the two short border midpoints of the probe will be used
      as paramedian insertion point for the spinal needle. A transverse median (TM) view at the
      same level will also be obtained and the midline will be marked. This marking will be used to
      aid the medial angulation of the spinal needle. Both PSO and TM views would be graded as good
      (both LFD and PLL visible), intermediate (either LFD or PLL visible) and poor (both LFD and
      PLL not visible).15 Following skin marking, care will be taken to make sure that the needle
      entry site will be free of ultrasound gel prior to needle insertion. In group P, the
      anesthesiologist will not palpate the landmarks for grading until the spinal injection is
      complete. Spinal anesthesia will be performed in the same aseptic manner as mentioned
      earlier.

      In both groups the anesthesiologists will be given the option to use alternative methods if
      unsuccessful after 3 attempts. For patients in group C another interspinous space could be
      used or ultrasound employed. For patients in group P a midline approach or a conventional
      landmark palpation technique could be used.

      The outcomes will be noted by a single observer for all patients. Due to the nature of the
      study, the observer will not be blinded to the groups. A timer will be used to record the
      various time intervals. Time for identifying landmarks in group C will be defined as time
      from which the anesthesiologist started palpating to identify the landmarks to completion of
      the process as declared by the anesthesiologist. In group P it will be defined as time from
      which the ultrasound probe will be placed on the skin to the anesthesiologist declaring that
      the markings are completed. Time taken for performing spinal anesthetic will be defined as
      time taken from insertion of introducer needle to completion of injection. The number of
      passes, defined as the number of forward advancements of the spinal needle in a given
      interspinous space (i.e. withdrawal and redirection of spinal needle without exiting the
      skin) and number of spinal needle insertion attempts (defined as the number of times the
      spinal needle will be withdrawn from the skin and reinserted) will be noted.10 The number of
      passes and attempts will be recorded either until the completion of spinal anesthetic or
      until the anesthesiologist converts to an alternate technique.

      Incidence of radicular pain, paraesthesia and blood in the spinal needle will also be noted.
      All patients who experienced paraesthesia or radicular pain will be followed over the next 24
      hours and any patients with persistent symptoms will be further evaluated as per department
      protocol.

      In both groups following administration of spinal anesthesia, patients will be positioned on
      either left or right lateral position depending on the site of surgery. After positioning and
      prior to administration of sedation, patients will be asked for their peri-procedural pain
      scores measured using an 11 point verbal rating scale (0=no pain, 10=most pain imaginable)
      and peri-procedural discomfort scores measured using an 11 point verbal rating measured (0=
      no discomfort, 10=most discomfort imaginable). Level of block (loss of cold sensation) will
      be noted 30 minutes after spinal anesthetic injection. Type and dose of sedation (Midazolam
      +/- Propofol infusion) will be left to the discretion of the anesthesiologist.

      Study Outcomes The primary outcome will be the difference in number of passes between the two
      groups.

      Secondary outcomes includes the following,

        1. Number of spinal needle insertion attempts

        2. Time for identifying landmarks

        3. Time taken for performing spinal anesthetic

        4. Level of block

        5. Incidence of radicular pain, paraesthesia and blood in the spinal needle.

        6. Peri-procedural pain

        7. Peri-procedural discomfort score Statistics Based on our previous study with same group
           of consultants done here in CUH, the average number of passes in group C was 6.4 +/-8.6
           (mean +/- SD). We hypothesised that by using pre-procedural paramedian spinal done at
           L5S1, the number of passes could be reduced to 1.5. Fourty eight patients in each group
           will be needed to achieve a power of 0.8 and type 1 error of <0.05. We are hoping to
           randomise 60 patients per group to allow for dropouts. All data will be analysed based
           on intention to treat. Data will be visually inspected for normality. Categorical data
           were analysed using the Chi-square test. Normally distributed parametric data were
           analysed using Students-t test (two groups) or ANOVA (more than 2 groups). A p value of
           less than 0.05 will be considered significant. SPSS version 20 will be used for the
           statistical analysis.
allocation: Randomized
intervention model: Parallel Assignment
masking: Double (Participant, Outcomes Assessor)
measure: difference in number of passes between the two groups.
time frame: 30 minutes within completion of apinal anaesthetic
description: The number of passes, defined as the number of forward advancements of the spinal needle in a given interspinous space (i.e. withdrawal and redirection of spinal needle without exiting the skin)
measure: Number of spinal needle insertion attempts
time frame: Up to 45 minutes from the start of insertion of spinal needled for administration of spinal anaesthetic
description: number of spinal needle insertion attempts (defined as the number of times the spinal needle was withdrawn from the skin and reinserted) were noted
measure: Blood in spinal needle
time frame: Up to 45 minutes from the start of insertion of spinal needled for administration of spinal anaesthetic
description: Presence of blood in spinal needle
measure: Time for identifying landmarks
time frame: Up to 10 minutes fraom start of plapating for landmarks - Completed once anethetist declares that markings are complete
description: Time for identifying landmarks in group C was defined as time from which the anesthesiologist started palpating to identify the landmarks to completion of the process as declared by the anesthesiologist. In group P it was defined as time from which the ultrasound probe was placed on the skin to the anesthesiologist declaring that the markings are completed
measure: Time taken for performing spinal anesthetic
time frame: Up to 45 minutes from the start of insertion of spinal needled for administration of spinal anaesthetic
description: defined as time taken from insertion of introducer needle to completion of injection
measure: Incidence of radicular pain
time frame: Up to 24 hours after administration of spinal anaesthetic
description: Shooting pain going down along one of the dermatomal levels in the leg
measure: Presence of paresthesia
time frame: Up to 24 hours after administration of spinal anaesthetic
description: Paresthesia along dermatomal distribution during performing spinal anaesthetic
measure: Grading of palpated landmarks
time frame: Up to 10 minutes fraom start of plapating for landmarks - Completed once anethetist declares that markings are complete
description: Anesthesiologist palpated the landmarks after positioning and graded the ease of palpation on a 4 point scale (easy, moderate, difficult or impossible)
measure: Peri-procedural VAS scores of pain at injection site
time frame: up to 30 minutes following spinal anaesthetic injection and prior to sedation
description: After positioning and prior to administration of sedation, patients were asked for their peri-procedural pain scores measured using an 11 point verbal rating scale (0=no pain, 10=most pain imaginable)
measure: peri-procedural discomfort scores
time frame: up to 30 minutes following spinal anaesthetic injection and prior to sedation
description: peri-procedural discomfort scores measured using an 11 point verbal rating measured (0= no discomfort, 10=most discomfort imaginable).
measure: Level of block
time frame: 15 minutes after spinal anaesthetic injection
description: Dermatomal level at which loss of cold sensation (ethyl chloride spray) occurs
arm group label: Group C
arm group type: Active Comparator
description: Patients in this group underwent Conventional landmark guided midline spinal anaesthesia.
arm group label: Group P
arm group type: Experimental
description: This group had pre-procedure ultrasound guided L5S1 paramedian spinal anaesthesia performed
intervention type: Procedure
intervention name: Conventional landmark guided midline spinal anaesthesia
description: Spinal anaesthesia was administered based on conventional landmark based midline approach.
arm group label: Group C
intervention type: Procedure
intervention name: pre-procedure ultrasound guided L5S1 paramedian spinal
description: In group P, a portable ultrasound unit was used for initial pre-procedural marking. The L5 S1 interspinous space with best image of the anterior complex (ligamentum flavum dura complex- LFD) and posterior complex (posterior longitudinal ligament- PLL) was obtained. At this selected interspace, and with the probe positioned to obtain the clearest ultrasound image, a skin marker was used to mark the midpoint of the long border of the probe and the midpoints of the short borders of the probe . At the same horizontal level as the midpoint of the long border of the probe, the midpoint of the line drawn between the two short border midpoints of the probe was used as paramedian insertion point for the spinal needle.Spinal anaesthesia is then administered based on these landmarks.
arm group label: Group P
intervention type: Device
intervention name: spinal anaesthesia
description: Spinal anaesthesia is administered with appropriate spinal needle
arm group label: Group C
arm group label: Group P
criteria: 
gender: All
minimum age: 20 Years
maximum age: N/A
healthy volunteers: No
last name: Karthikeyan Kallidaikurichi Srinivasan, FCARCSI,MD
role: Principal Investigator
affiliation: Cork University Hospital
facility: 
country: Ireland
responsible party type: Principal Investigator
investigator affiliation: Cork University Hospital
investigator full name: Karthikeyan Kallidaikurichi Srinivasan
investigator title: Specialist Registrar,Anaesthetics,Cork University Hospital
mesh term: Anesthetics