Clinical Trial Details
— Status: Withdrawn
Administrative data
| NCT number |
NCT01495273 |
| Other study ID # |
Pro00026789 |
| Secondary ID |
|
| Status |
Withdrawn |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
May 2017 |
| Est. completion date |
January 2018 |
Study information
| Verified date |
March 2020 |
| Source |
University of Alberta |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Various medical procedures require different objects to be inserted into the airway; for
example, a bronchoscope - a fibreoptic camera device - can be guided down the windpipe to
gain real-time images of the airway. Since inserting objects down the throat is uncomfortable
for most patients, doctors have several options, one of which is putting the patient to sleep
using general anesthetic before inserting something into the windpipe. This may not always be
the best option, especially in cases where the patient needs to be awake during the
procedure. In these cases, the doctor may 'freeze' the windpipe before inserting a scope or a
tube into the airway. For this, the doctor inserts a needle through the front of the neck and
injects local anesthetic. Inserting a needle into the windpipe comes with some risks to the
patient, and the doctor wants to avoid puncturing nearby structures, such as arteries, veins,
and the esophagus. The investigators have come up with a new method for accurately guiding a
needle into the airway that will alert the user when they have successfully placed the needle
tip in the windpipe. The investigators hypothesize that this new method will prove to be
beneficial to clinicians and emergency medical personnel who need a fast, easy, and reliable
way to insert a needle into the airway.
Description:
Background and rationale
The trachea can be anesthetized by several different methods, one of which is transtracheal
injection of a local anesthetic such as lidocaine. This technique is performed to prepare a
patient for a variety of procedures, including awake fibreoptic intubation and
cricothyroidotomy. Tracheal anesthesia is performed by first identifying the cricothyroid
ligament; this structure is generally located by placing one finger on the thyroid cartilage
and another on the cricoid cartilage. Approximately 4-6 mL of local anesthetic is delivered
through a small needle or an intravenous catheter inserted in the neck midline. Anesthesia
occurs quickly and permits the patient to be awake and aware during the procedures that
follow.
Insertion of a needle into the trachea is not without risk to the patient. Several
complicating factors affect the success rate of tracheal needle insertion, and in emergency
situations where oxygen must be delivered through the insertion site, as in
cricothyroidotomy, accurate needle insertion can mean the difference between life and death
for the patient. One complicating factor in this procedure is that the thyroid cartilage and
the cricoid cartilage can be difficult to identify, especially in obese people. Needle
insertion is made more complicated due to the anatomy surrounding the cricothyroid membrane:
the carotid artery and jugular vein lie laterally to the membrane, the cricothyroid artery is
located superiorly and laterally, and the highly vascularized thyroid gland is located
inferiorly. Intravascular injection of anesthetic can lead to a seizure, and inaccurate
injection could lead to anesthesia of surrounding nerves. There is also a risk of puncturing
through the posterior wall of the trachea, which may cause esophageal perforation.
Given these complications, a quick and easy method of ensuring accurate tracheal needle
insertion, while avoiding damage to surrounding tissues, would greatly benefit clinicians and
could potentially save lives in emergency situations. We wish to evaluate a simple technique
to guide a needle tip into the trachea that mitigates the risks of conventional methods of
needle insertion. We will use nerve stimulation equipment to aid in the guidance and
placement of a needle tip into the tracheal lumen, which we predict will be faster and more
accurate than current conventional methods. The nerve stimulation technology can alert the
user to the exact moment the needle tip is suspended in the trachea and also alerts the user
to when the needle tip is in contact with body tissue, avoiding accidental puncture of the
lateral and posterior tracheal walls. We believe that this method of electrically-guided
needle insertion will be a significant improvement over current methods of percutaneous
needle insertion and transtracheal injection.
Study objective To assess the value of nerve stimulation equipment for guidance and placement
of a needle-catheter assembly for transtracheal injection.
Hypothesis Nerve stimulation equipment will help the physician guide and insert the needle
tip into the tracheal lumen with more accuracy than conventional techniques.
Study Design This is a prospective, descriptive, interventional study.
Study Procedures This study will involve recruiting consenting patients undergoing procedures
that require awake fibreoptic intubation following transtracheal injection of local
anesthetic. We intend to recruit 30 patients, who will be randomized into two groups, one
(experimental) that will undergo transtracheal injection using a needle connected to a nerve
stimulation device, and another (control) that will receive tracheal anesthetic using
standard, conventional needle insertion and injection technique.
Patients will lay supine with the head and neck in a neutral position on one pillow. The
physician will locate the cricothyroid ligament, through which the needle-catheter assembly
will be inserted. In the experimental group, a 21G 64 mm insulated needle with an 18G
catheter assembly (MultiSet, Pajunk, Germany) and a commonly used nerve stimulator (HNS 12,
B.Braun, Germany) will be used to access the airway (this nerve stimulator device has been
approved for use on live patients in Canada and is a common piece of equipment in operating
rooms). The nerve stimulator will be connected to a current meter, and a ground electrode
will be attached to the body. When the needle tip is in contact with body tissue (i.e.,
tracheal wall), the electrical circuit will be closed, producing a reading of 1.0 mA on the
current reader. Suspension of the needle tip in the airway will interrupt the circuit,
producing a reading of 0.0 mA. In addition, an audible signal built into the nerve stimulator
will alert the user to a change in current, warning that the needle tip has advanced too far
and is in contact with the posterior or lateral tracheal wall. Once the physician has
successfully inserted the needle tip into the tracheal lumen, the needle will be withdrawn
and 4-6 mL lidocaine (2-4%) will be delivered through the catheter, anesthetizing the airway.
Once the airway is anesthetized, a bronchoscope can be guided down the trachea. The control
group will undergo an identical procedure, except that no nerve stimulator will be connected
to the needle.
For each patient, the physician performing the transtracheal injection will document their
opinion of each needle insertion and injection, but no personal information about the patient
will be recorded at this time. For both the experimental and control groups, study
investigators will collect data documenting the time needed for each needle insertion and the
success of each attempt. These data will be statistically analyzed to determine the value of
the nerve stimulator-guided technique over the conventional technique.
