Epidural Space Verification With the CompuFlo®
Condition: Epidural; Anesthesia
Study type: Observational

Summary: 
      The purpose of this single arm open-label study is to capture additional data that can add to
      the original COMPASS (CompuFlo® Assessment Study) clinical trial database that supported the
      510(k) application, which was given clearance by the FDA on June 9, 2017.
    

Detailed description: 
      Patients will receive lumbar epidural anesthesia by a HCP, as detailed below. The CompuFlo
      Epidural System will be utilized only for steps d-g, all other steps are performed in the
      same way as with the Loss of Resistance Syringe. Refer to User Manual for detailed
      instructions on how to set up the system.

        1. American Society of Anesthesiologists standard monitors will be attached and patients
           will be placed in a sitting position. Sedation will not be permitted due to potential
           confounding of the data and/or making it impossible to assess neurological
           injury/paresthesias during the procedure. Limited Vital signs (blood pressure, apical
           heart rate, oral temperature, respiration rate) will be obtained and documented in the
           CRF.

        2. Set up the CompuFlo System disposable kit and attach kit to instrument.

             1. Connect the pressure sensor to the ID adapter.

             2. Connect the ID adapter to the CompuFlo instrument.

             3. Connect the external pressure sensor to the filled 20 mL syringe.

             4. Connect the extension tubing to the other end of the pressure sensor.

        3. The lumbar area will be disinfected and draped in the usual fashion. The skin in the
           lumbar area will be locally infiltrated with a local anesthetic solution, according to
           local practice.

        4. The epidural needle will be introduced in the lumbar area to a depth of approximately 3
           cm. Insertion to a depth of 3 cm is typical in clinical practice, to avoid accidental
           epidural space puncture by inserting the needle too deep, while at the same time
           inserting the needle to a depth at which it will be supported by the tissue.

        5. Purge (i.e., prime) the extension tubing connected to the CompuFlo instrument.

        6. The CompuFlo extension tubing set will be held at the same vertical height as the
           puncture level of the epidural needle to calibrate the pressure by depressing the "Zero"
           button of the CompuFlo® instrument. This will zero the pressure prior to connection of
           the epidural needle to the extension tubing. The stylet of the epidural needle will be
           removed and extension tubing will be connected after making the zeroed pressure
           calibration at the puncture's level.

        7. The CompuFlo Epidural Instrument will be set to deliver normal saline at a rate of 0.050
           mL/sec during these measurements with an exit-pressure limit not to exceed 120 mm/Hg.

        8. The epidural Tuohy needle (18-gauge 3-1/2 inch or any other size) will then be advanced
           until the pressure readings on the CompuFlo Epidural System indicate position in the
           epidural space as defined below.

           The following criteria is used to differentiate a True-Loss of Resistance (True-LOR)
           versus the identification of a False-Loss of Resistance (False-LOR) using the CompuFlo
           Epidural Instrument:

           A True-LOR defined as:

           An increase in pressure followed by a sudden and sustained (> 5 seconds) drop in
           pressure (typically greater than 50% of the maximum pressure), resulting in the
           formation of a "low and stable pressure plateau"

           A False-LOR defined as:

           An increase of pressure followed by a drop in pressure (typically less than 50% of the
           maximum pressure) that is either not sustained or inconclusive of representing a "low
           and stable pressure plateau"

           -If the pressure rapidly increases after a drop of pressure this is identified as a
           False-Loss of Resistance and the operator may elect to continue to advance the needle.

           A Inconclusive-LOR defined as:

           -If the pressure does not increase or is deemed to be inconclusive (Undeterminable) loss
           of resistance the operator should withdraw the needle and/or redirect the needle. This
           will be considered an Inconclusive-LOR (I-LOR)

           Number of attempts* will be defined and measured as follows:

             1. Number of needle withdrawals and reinsertions at the same interspace

             2. Number of needle withdrawals and reinsertions at a different interspace

             3. Number needle redirections in case of bone contact

             4. Number needle redirections due to operator's uncertainty of needle location
                (inconclusive or undeterminable) loss of resistance *Definitions: 1 and 2: the
                needle is completely withdrawn and reinserted from the skin 3 an 4: the needle is
                redirected and/or partially withdrawn to allow redirection within the tissues of
                the chosen interspace

           NOTE: When every a drop of pressure occurs during the advancement** of a needle it is
           critical that the operator simultaneously STOP ALL NEEDLE MOVEMENT to determine if any
           further pressure changes will occur based on the position of the needle.

           ** NOTE: The CompuFlo-Epidural Instrument is a highly accurate device capable of
           recording all information continuously and precisely. Be aware that the operator can
           introduce pressure artifacts to the data recordings if imprecise needle movements are
           used, such as a rapid advancement and/or rapid withdrawals of the needle not
           representative of standard clinical needle movements. The pressure wave-form slope of
           the curve is impacted by imprecise needle movements. Therefore, slow deliberate needle
           movements are recommended.

           The readings on the CompuFlo Epidural Instrument that correlate with correct epidural
           space identification (True-LOR) based on the previous trial conducted by Ghelber et al.
           consist of the following criteria:

           After documenting the significant drop in pressure for at least 5 seconds, with no
           further needle movement:

             1. Record an additional 5 seconds of pressure data, with the motor running to identify
                the formation of a low and stable low pressure plateau, (typically greater than 50%
                of the maximum pressure).

             2. Press STOP and continue to record pressure for 5 additional seconds, after the
                motor has stopped, while the needle is still in the epidural space to record the
                EPIDURAL SPACE PRESSURE.

             3. To investigate possible waveform patterns which may confirm the entrance of the
                needle in the epidural space, after these additional 5 seconds, request that
                patient either "cough" and record the epidural pressure (PRESSURE AFTER COUGH) or
                perform a 2-3 seconds Valsalva maneuver and record the epidural pressure at the
                apex of the maneuvre (PRESSURE AFTER VALSALVA) .

             4. Once the CompuFlo® procedure is complete, Press END PROCEDURE to ensure that the
                data file is properly saved. Then Press YES to terminate procedure. NOTE: Avoiding
                this step will lead to the loss and/or corruption of data file.

           These steps provide a secondary means of verification of the epidural space. If the
           correct position of the epidural Tuohy needle in the epidural space (as indicated by the
           readings on the CompuFlo® Epidural System) can NOT be obtained or dye injection
           indicates incorrect position or an epidural catheter cannot be advanced into the
           epidural space, then the epidural Tuohy needle will be withdrawn or redirected and a new
           attempt of epidural Tuohy needle insertion and identification of the epidural space with
           the CompuFlo® Epidural System will begin. Alternatively, the HCP and/or anesthesiologist
           can choose to completely remove the epidural Tuohy needle and insert at a new puncture
           site and a new attempt of epidural Tuohy needle insertion and identification of the
           epidural space with the CompuFlo® Epidural System will begin. The local investigator may
           decide after a number of failed recorded attempts to suspend the procedure. Then,
           epidural anesthesia with the CompuFlo® Epidural System will be considered unsuccessful
           and the patient will be converted to other forms of analgesia.

        9. After successful epidural space identification, the CompuFlo® Epidural System will be
           disconnected from the epidural needle and an epidural catheter will be advanced 3-5cm
           into the epidural space, or injection will proceed according to standard medical
           practice if there is no introduction of an epidural catheter.

           4. After removal of the epidural needle and securing of the epidural catheter, an
           epidural test dose consisting - in the case of epidural labor analgesia - of the
           therapeutic dose, if a low concentration local anesthetic solution is used (e.g.,
           bupivacaine 0.0625%) or a 3 mL epidural test dose (lidocaine 15 mg/mL with epinephrine 5
           mcg/mL), if a high concentration (e.g., bupivacaine 0.25, 0.125%) is used, will be
           manually infused to rule out intrathecal or intravascular catheter position for those
           procedures where test dose is considered standard medical practice.

       10. Epidural anesthesia or any medical treatment according to HCP order will then be
           delivered by dosing the epidural catheter with a local anesthetic/medication of the
           HCP's choice and a volume of their choice that should conform to that described in the
           local anesthetic's labeling.

      For a woman in labor, successful performance of epidural procedure will be defined as the
      occurrence of analgesia assessed by Visual Analogue Pain Scale (VAPS), after a predetermined
      period of time from the epidural loading dose. (Ex., a VAPS < 10 at 20 min.) For other
      epidural procedures, successful performance of an epidural procedure will be defined as a
      loss of sensation to cold in at least in one dermatome. Alternatively, for subjects not in a
      labor while undergoing epidural procedures that are assisted by fluoroscopy, successful
      performance will be defined as correct spread of dye in the epidural space, as judged by an
      independent HCP.

      At that time limited vital signs (blood pressure, apical heart rate, oral temperature,
      respiration rate) will be obtained and documented in the CRF.

      In case of a unilateral block, the HCP will be permitted to manipulate the catheter at their
      discretion (e.g., withdraw the catheter) and re-dose the catheter. In such case, another
      assessment of loss of sensation to cold as described above will be permitted 30 min after
      catheter re-dosing to assess whether epidural anesthesia was successful (same criteria as
      above).

      If analgesia for women in labor or one dermatome for other patients cannot be established,
      epidural procedure/anesthesia will be considered unsuccessful and the patient will receive
      analgesia or anesthesia at the discretion of the HCP.

      The number of attempts (needle redirection and reinsertions) will be recorded.

      For those sites performing fluoroscopy/dye injection, an indication of incorrect spread of
      the dye will be considered failure.

      Within thirty minutes after dosing the epidural catheter, a blinded investigator will assess
      the patient for sensory and motor blockade.

      Concomitant medication, including conversion to general anesthesia, along with any adverse
      events will also be recorded.

      All of these assessments will be recorded in the source documents and on the appropriate
      CRFs.

      After the completion of the epidural procedure, the physician will complete the Compuflo
      Assessment Score Questionnaire (Section 9.4) to assess the agreement between the physician' s
      reported sensation and the variation of pressure given by the CompuFlo® during the needle
      tracking from its insertion until the identification of the epidural space.

      Any occurrence of accidental dural puncture with the Tuohy needle during the epidural
      procedure assisted by Compuflo will be recorded on the data sheet.

      The occurrence of Post Dural Puncture Headache (PDPH) will be also recorded. PDPH will be
      defined according to the Classification Committee of The International Headache Society
      (https://www.ichd-3.org/7-headache-attributed-to-non-vascular-intracranial-disorder/7-2-heada
      che-attributed-to-low-cerebrospinal-fluid-pressure/7-2-1-post-dural-puncture-headache/)
    

Intervention name(s): CompuFlo® Epidural Computer Controlled System
Intervention type(s): Device
Intervention description(s): The CompuFlo® Epidural Instrument allows the objective identification of the epidural space by pressure measurement at the needle tip and consequently enables the HCP to perform epidural anesthesia and epidural injections using standard methods. Currently, HCPs rely on their subjective perception to feel a "loss of resistance" when inserting an epidural needle to identify the epidural space. The CompuFlo® Epidural Computer Controlled Anesthesia System has received a CE mark in the European Union and it received 510(k) clearance from the FDA in June 2017.
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The subject population for this study will consist of up to 800 adult subjects between the
        ages of 18 and 90 (had 18th birthday and had not had their 91st birthday - except for State
        of Alabama where legal consent for adults is age of 19), of any ethnic background, for whom
        an epidural procedure is indicated according to their HCP. The subject will meet all the
        inclusion criteria, have none of the exclusion criteria, give their written Informed
        Consent to participate in this clinical study after undergoing informed consent process, In
        the event that a subject's ability to comprehend and communicate is compromised (per the
        discretion of the Principal Investigator), a legal representative may discuss the study,
        agree on participation and sign the ICF, on behalf of the subject.