Clinical Exercise: Tracheostomy
Scenario:
A patient with a pharyngeal tumor causing progressive laryngopharyngeal obstruction is scheduled to undergo surgery to remove the tumor mass.
Diagnosis:
You recognize that the operation will involve accessing the pharynx, which will compromise the upper airways during the procedure. There is also the possibility of bleeding which could enter the larynx, trachea, and lungs during the surgery. Additionally, during recovery there may be retained oral secretions that could enter the larynx and lungs if the airways are not protected post-operatively.
As such, the decision is taken to perform an elective tracheostomy to establish an alternative airway during the operation and recovery phases.
Mechanism:
There are multiple indications for performing a tracheostomy procedure. It can be used as a solution for upper airway obstruction (e.g. trauma, chemical inhalation injuries, acute epiglottitis or anaphylaxis causing vocal cord edema) similar to the temporary access of a cricothyrotomy used in an emergency situation, but as a longer term option.
Tracheostomy is also used commonly for patients who cannot handle their own oral secretions and are in chronic danger of aspiration (e.g. traumatic brain injury, stroke, or prolonged mechanical ventilation for lung disease). In these cases, an oral, translaryngeal tube (endotracheal tube, “ET tube”) is replaced by a tracheostomy tube.
In cases of prolonged ventilation where a tracheostomy replaces an endotracheal intubation, a tracheostomy decreases the rate of subglottic stenosis (narrowing of the airway), decreases the dead space volume which decreases work of breathing for the patient, and provides better control of secretions of the respiratory tract.
The goal is to make an opening in the anterior neck inferior to the cricoid cartilage, between approximately the 2nd and 3rd tracheal ring. Through this opening a tube is inserted and secured, forming an alternative pathway for air to bypass the upper airways.
Treatment (perform these steps on the donor in a mock-procedure):
PREPARATION: Send a member of your team to the instrument supply tables to fetch one of the tracheostomy kits and a 10ml syringe. You only need one kit and one 10ml syringe per table, leave the remaining kits for other groups.
Clinically, tracheostomy tubes come in a variety of sizes from large to small to best match patient stature. In the lab we are using one of the smaller size tubes (6mm) so that it will be suitable across most statures of our donors.
Open the package and remove the tracheostomy tube, obturator and liner (do not dispose of kit packaging as we will re-use the kit for other training groups). The tracheal hook will be in the special instruments pencil box under the table (forceps or even a finger can be used to hold/verify openings if a hook is unavailable in the field).
Take the syringe and draw 7-8ml of air into the syringe, then attach the syringe to the end of the tracheostomy inflation mechanism.
Test the function by gently depressing the syringe and observing that the cuff around the distal end of the tube expands (the function of this cuff is to prevent air leaking out the nose/mouth or fluids leaking into the lungs after it is placed in the patient). The blue bellows near the syringe will expand when the cuff is fully inflated as a visual indicator of maximal expansion (do not over-expand as the cuff or connections can rupture). Draw the air back into the syringe such that the cuff and bellows are fully deflated.
Place the obturator into the tracheostomy tube. The obturator provides a 'handle' for controlling the tube as well as a plug preventing blood or tissue from entering the tube during insertion.
1) In this scenario, the procedure is planned, and the patient would be under general anesthesia.
2) Using your fingers feel along the exposed anterior side of the larynx for the laryngeal prominence of the thyroid cartilage (the Adam's apple).
3) Slide your finger inferiorly along the front edge of the thyroid cartilage to the point where you feel the space between the thyroid and cricoid cartilages (this space has previously been entered during the cricothyrotomy performed by the MS1 class).
4) Continue inferiorly to the isthmus of the thyroid gland (the thyroid isthmus is not palpable and is identified visually).
5) Transect the isthmus of the thyroid gland spreading the glandular tissue laterally exposing the anterior surface of the tracheal rings between approximately the 2nd to 3rd rings (note, the cricoid cartilage is the 1st ring so count from that cartilage).
6) Make a horizontal incision in the space between the 2nd and 3rd tracheal rings.
The width of this incision should be approximately one half the diameter of the trachea.
7) At each end of the tangential incision, make a superior to inferior cut through the 3rd tracheal ring on each side.
This creates a 'Bjork flap' (U-shape opening) in the anterior wall of trachea.
If there is insufficient space with opening through one tracheal ring, the incisions can be extended through the 4th ring such that the flap spans two tracheal rings.
There are numerous other opening shapes in common use (e.g. T-shape, Slit, Box-shape, Cruciate, H-shape). There is a lack of consensus on which opening shape is optimal, thus you may encounter individual surgeon differences to approach.
8) Insert the tracheostomy tube, with the angled side pointing inferiorly into the trachea.
9) Push the tube all the way in such that the flanges at the base of the tube become flush or nearly flush with where the skin would be.
10) Immediately remove the obturator (since the obturator prevents a patient from breathing it must be removed promptly).
11) Depress the syringe plunger until the blue bellows begins to inflate.
Since the cuff cannot be observed directly the bellows serves as a visual indicator of maximal inflation of the cuff within the patient's airway. The cuff presses gently against the internal surface of the trachea serving to stabilize the tube and to minimize 'scraping' of a hard tube against the airway mucosa.
12) Next insert the tube liner.
The tube liner serves as a removable/washable part allowing ready cleaning as mucus otherwise will build up inside the tube.
13) The tube remains in place during surgery and recovery phases until the care team is confident of the integrity of the laryngopharynx post-operatively.
14) Draw the air back into the syringe such that the bellows deflates and to the point where you feel resistance to the draw (meaning the cuff is fully deflated). Remove the tube so that other members of the team can practice inserting/inflating the apparatus.
15) When finished this exercise remove the tube to allow other members of your team to insert the tracheostomy tube (with obturator followed by switching out for liner)
16) When everyone has utilized the tubing, clean the components of the kit and the tracheal hook. Then repack the kit neatly and return the kit along with the tracheal hook to the supply tables for future use.
Outcome:
The tumor removal is successful and after several days the patient is able to have the tracheostomy tubing removed and the opening closed.