Transtracheal oxygen therapy (TTOT) is a method of delivering oxygen directly into the lungs through a tracheal catheter. Despite its use in treating chronic hypoxemia, a lack of exposure to the therapy leaves many clinicians unprepared when a TTOT patient is admitted to the hospital.
The following guest editorial is written by John R. Goodman, BS, RRT, executive vice president, Technical and Professional Services, for Transtracheal Systems. The medical advice and opinions expressed in this article are solely those of the author and do not reflect the views of RT: For Decision Makers in Respiratory Care, Allied Media LLC, its parent company or affiliates, or its employees.
By John R. Goodman, BS, RRT
Transtracheal oxygen therapy (TTOT) has been used in the treatment of patients with chronic hypoxemia since the early 1980s. Since that time, tens of thousands of patients have had transtracheal catheters inserted for a variety of disease states or conditions. While the vast majority are COPD patients, an increasing number of patients with severe interstitial lung disease (ILD) are being placed on TTOT for its immediate benefits, and in some cases patients awaiting lung transplantation.
While a great deal of information has been published regarding the day-to-day management of transtracheal catheters, very little has been published regarding the special concerns or questions that might arise when a transtracheal oxygen patient is admitted to the hospital for an exacerbation of their underlying disease. This may be complicated by the fact that there may be very few (if any) TTO patients within the hospital’s service area. Combine this with other factors, such as the lack of fundamental knowledge or exposure to TTOT for some respiratory therapists and the fact that TTOT is nonuniformly covered in RT curriculums, and you can see why the admission of a TTO patient may pose a challenge to the respiratory therapy department and the nursing floor to which the patient is admitted. The level of concern will obviously increase if the patient is admitted to the ICU and potentially intubated and placed on a ventilator.
In fact, problems unique to TTO patients can begin even before the patient gets to the emergency department (ED).
As RTs, you may face a scenario in which an ED nurse asks you to come down and evaluate a trach patient who is having severe respiratory distress. Frequently, no mention is made of the fact that the patient has a transtracheal oxygen catheter (TTOC) in place instead of a trach tube. EMTs, paramedics, ED physicians, and nurses who have no experience with TTO patients may well think that the cause of the patient’s difficulties is the TTOC itself. They may believe the catheter is part of the problem and remove it from the trachea—a scenario even more likely to happen if they feel they must intubate the patient.
Hospital policy usually dictates who on the hospital staff is allowed to intubate. In fact, if an airway must be established, whichever individual is doing the intubating should intubate over the TTOC. The catheter is soft enough and pliable enough that no case of tracheal wall trauma has ever been published in the literature even with the cuff inflated to the correct pressure. It is best to treat the catheter as if it were not there until the underlying problem can be corrected. Generally, since there is no gas going through the catheter while the patient is intubated, there is no maintenance required.
Catheter Maintenance
Routine cleaning and maintenance of the catheter can be reinitiated once the patient is extubated. Assuming the most positive outcome possible, the patient will recover from his hospitalization and will be discharged home on his transtracheal oxygen settings. Unfortunately, for a patient whose TTOC was pulled either in the field or in the emergency department, the removal of the catheter will inevitably lead to closure of the tract. This is especially true if the patient had the Modified Seldinger Technique used to establish their transtracheal tract instead of the Fast Tract procedure. This necessitates a repeat procedure for the patient, which is both costly and time-consuming for everyone involved. To prevent this, if you must intubate, remember to intubate over the catheter, treating it as though it were not there.
On the other hand, if your TTO patient is admitted in a more elective fashion, the cleaning and maintenance of the catheter itself becomes one of the more important tasks of the respiratory care department in conjunction with the nursing staff. The majority of TTO patients have been taught to have their routine cleaning supplies with them at all times, and this would especially be true of a TTO patient who was aware he was going to be hospitalized. However, we can’t rely on patients to have their cleaning supplies with them.
Respiratory therapy departments are encouraged to have a TTOT “stash,” in the event a TTO patient is admitted to the hospital. The kit should include one set of replacement catheters, a TTO connecting hose, and a couple of wire guides to help retrieve a lost tract, or to do a routine catheter stripping. In this way, if a patient forgets to bring his TTO supplies with him, there will be no interruption of his TTO therapy. Please note that a patient should never use a guide wire on himself; guide wires should be used only by experienced clinicians, as they are utilized for routine catheter stripping.
While most patients are taught how often to clean their catheter, no two patients follow the exact same cleaning regimen. Individual regimens also can become complicated by an exacerbation that increases both the volume and viscosity of mucus production.
As a rule, it is not a good idea for a catheter to be removed and reinserted for cleaning more than two times a day because catheter removals and reinsertions can induce tract trauma, such as tenderness or tracheal chondritis. What can be varied, however, is the number of times per day the patient may irrigate their catheter and clean out the lumen with the cleaning rod. This is called cleaning in place. Patients can clean in place up to four times a day, and may irrigate practically at will. This irrigation may be performed with either saline “bullets,” or by using the preferred pressurized cans of saline to help dislodge any mucus that may be at or near the tip of the catheter.
If the patient is too sick or incapacitated to the point they cannot do their own daily care, cleanings should be performed by respiratory care personnel. Removing, inspecting, and cleaning the TTOC are the hallmarks of quality transtracheal care and most certainly reflect the community standard.
If a respiratory therapist strips the catheter over the wire guide and the catheter comes out perfectly clean, but the patient is still (for example) coughing, you have at least ruled out the catheter as the cause of the problem. The source therefore must be somewhere else and may indicate a new pulmonary problem that is beginning to develop. However, if you strip the catheter and the patient coughs up or produces a mucus secretion the size of a grape, or larger, the problem is catheter-related. Once the secretion is removed, your patient should very quickly return to their previous oxygen saturation baseline.
Monitoring the Airway
Patients with TTOCs may develop blood-tinged mucus from time to time. The most common cause of blood-tinged sputum, or actual hemoptysis, is tracheal mucosal erosion. The mucosa of the trachea is very fragile and if there is a mucus secretion near the tip of the catheter, it will cause the patient to cough. This may set up a vicious cycle, as the cough will cause irritation, which in turn will cause more coughing, and so on. If this goes on for any period of time, it is possible to develop a small area of erosion or ulceration, as the tip of the catheter contacts the mucosa.
A quick tip to get control of the cough is to instill 2 mL of 1% plain lidocaine directly down the catheter. Your patient should receive immediate relief from the cough, which will allow you to continue your evaluation. The lidocaine’s effect can last for up to 40 minutes and may be repeated.
If, however, you have completed your TTO checklist and the patient is still coughing and producing blood-tinged mucus, I believe it is medically jurisprudent to perform a quick bronchoscopy to identify the source of the bleeding. If indeed there is an area of erosion or ulceration, the treatment of choice is to place a shorter catheter (usually a 9 cm catheter) in the tract. This will change the focus of the catheter tip, and allow the area of involvement time to heal. Typically, this takes 2 to 3 weeks.
Whether or not to go back to the original catheter is clinically debatable. If the patient continues to do well with the shorter catheter, it is perfectly fine to stay with that catheter.
Original research done in the early 1980s determined that the closer the tip of the catheter is to the carina, the better the efficiency of oxygen saturation. One caveat here: if the catheter tip gets too close to the carina, it may cause a tickle cough that is almost impossible to treat. On the other hand, if the catheter is too long, it can end up in the right main stem bronchus. Even if the tip of the catheter is sitting just above the carina, the flow of oxygen alone may be enough to induce tickle cough. That’s why as a clinical rule on a standard chest x-ray, the tip of the catheter should be 2 to 4 cm above the carina.
Mucus management of the transtracheal inpatient is of utmost importance. Adequate humidification of oxygen via the transtracheal catheter must be supplied, as the location of a TTOC bypasses the upper airway entirely. High flows of dry gas directly into the trachea not only can cause the development of clinically significant mucus secretions, but also can lead to tracheal mucosal bleeding. Even patients on very low transtracheal flow rates must be adequately humidified.
A standard bubble humidifier is probably sufficient until transtracheal flow rates get up to 5 to 6 liters per minute (LPM). Patients who have flow rates above 5 to 6 LPM benefit greatly from the addition of heated humidity. The TTOC is FDA-approved up to 12 LPM. Patients with severe ILD often require TT flow rates in this range. Some patients may be so hypoxic they need to combine high flow nasal cannula therapy with their TTOT to maintain adequate oxygen saturations. Combining these two therapies may buy you the time often needed to stabilize a patient and prevent an unnecessary intubation and a period of mechanical ventilation.
One additional advantage of higher flow rates through a TTC in addition to oxygenation is a possible reduction in the patient’s work of breathing. This has been identified as Transtracheal Augmented Ventilation, or TTAV. By definition, TTAV is the application of a heated and blended flow of oxygen at flow rates of 6-12 LPM through a transtracheal catheter. The effect is probably more pronounced in the COPD patient population, but even ILD patients may see some reduction in their work of breathing. TTAV has been used with regular success to wean long-term (trached) mechanical ventilation patients since the early 1990s.
A Life-Changing Therapy
In well-selected patients, TTOT can be a life-changing therapy. But considering these patients have advanced lung disease, they are still susceptible to occasional exacerbations, which can lead to direct hospital admission or EMT transport. In either event, if nursing personnel see a patient with a “twirly piece of plastic” hanging out of their neck, being admitted to their floor or the emergency department, it’s a safe bet that they will first call the respiratory care department. Which brings us back to the typical TTOT scenario.
Upon arriving in the ED and finding a TTO patient in severe respiratory distress, the following are some of the questions you should be asking (a family member of the patient can be helpful in answering many):
- What is the patient’s O2 saturation on arrival?
- Is this patient known to the hospital staff? (frequent flyer status?)
- Has he cleaned out the catheter within the hour before his visit to the ED?
- Is he coughing more than usual?
- Has he had a change in the character, volume, or consistency of his mucus?
- Has he been febrile?
- How long has he had his catheter? Was his TTO procedure recently performed or is he a long-time TTO patient?
- Has he been coughing up blood-tinged mucus, or having actual hemoptysis?
- Has the clinical picture been developing over the past few days, or is this an acute onset?
If you are fortunate, your patient will have remembered to bring his TTO supplies with him (even though it would be unusual for a patient to have a wire guide with him). In order to identify if the catheter is the primary problem, it must be removed, inspected, and reinserted. This routine catheter stripping should be familiar to all respiratory therapists, either through previous experience, or by consulting free information available on the Transtracheal Systems website.
Patients with long-standing tracts (for instance, over 6 months) can normally have the catheter removed, cleaned, and reinserted without fear of the tract closing. However, patients whose procedures were completed more recently should only have their catheter removed and reinserted over a wire guide to prevent losing the tract. Anytime the catheter is to be removed, remember to put the patient on a nasal cannula at their prescribed flow rate. It is helpful to put the cannula on from behind, so you have full access to the cervical area and catheter itself.
Once you answer the questions above, you will be operating with the knowledge of your patient’s recent history and the results of the catheter stripping. Whether or not the patient needs to be intubated and ventilated will depend on the normal indications of acute ventilatory failure. Hospital policies and respiratory therapy protocols should dictate what happens at this point.
Of course, there are simply no data that report on the number of transtracheal oxygen therapy patients who have had an exacerbation of their underlying disease and required intubation and mechanical ventilation. Couple this with the very small number of TTOT patients in the larger oxygen patient population, and you can easily see how the above patient scenario can occur anywhere a transtracheal patient happens to live.
I believe it is good policy for the respiratory therapy department to be aware of every TTO patient admitted to the hospital. I also know from experience that this notification rarely happens. But because TTOT requires knowledge of both upper airway anatomy and oxygen therapy, RTs should assume overall responsibility for the ongoing care and evaluation of these unique patients. With any luck and some critical thinking on the part of RTs, TTOT patients can overcome their exacerbations and avoid a prolonged hospital stay. RT
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