Mucus Management and Humidifier Guidelines For Patients Receiving Transtracheal Oxygen Therapy John R.Goodman BS RRT The Problem: Delivery of dry oxygen to the lower trachea has the potential for causing inspissation of mucus and dessication of mucosa. During Phase III when the SCOOP catheter is cleaned in place, some individuals develop pea or marble sized accumulations of inspissated mucus which adhere to the outside of the catheter just behind the tip. Twice daily removal for cleaning in Phase IV prevents small accumulations from turning into mucus balls. Mucus balls clinically present as unexplained cough or dyspnea that may be sudden in onset, or may develop over a few days. The are almost exclusively seen during Phase III when the SCOOP catheter must be left in place. If recognized by the clinician, mucus balls are easily treated by removal and reinsertion of the catheter over a wire guide. This simple maneuver strips the mucus off the catheter and allows the patient to expectorate the mucus ball. If not recognized, the patient may experience severe and prolonged paroxysms of coughing before the mucus ball is dislodged from the catheter. Dessication, chapping and cracking of the tracheal mucosa induced by high flows of dry oxygen could explain minor hemoptysis that is occasionally observed in some patients. Hemoptysis occurring longer than a few weeks following the procedure is rare and could be a manifestation of pulmonary disease unrelated to the transtracheal catheter. A routine bronchoscopy is indicated if there is persistent hemoptysis or blood tinged sputum that does not resolve on it’s own. Patients on anticoagulation therapy and others with significant coagulation disorders are at increased risk for hemoptysis. However, many of these patients have been successfully treated with SCOOP catheters without serious complications. Patients at Risk: As noted above, mucus balls occur in probably 50% of all patients during Phase III. Risk factors include high flow rates (i.e. >4 L/min), thick, tenacious, or copious secretions (i.e. Cystic Fibrosis or Bronchiectasis) weak cough effort, and residence in climates with low ambient humidity (i.e. Denver, Phoenix). There may also be a dramatic drop in absolute humidity associated cold temperatures in winter. Relative humidity reported in the local newspaper is misleading since inspired cold air holds much less water than warm air and requires more added humidity to become saturated at body temperature. Humidification requirements usually increase in winter, and the transtracheal team should be on the watch for mucus problems. This is most notable in the beginning of winter and may improve as patients adapt to the drier weather. Patients who are taking Coumadin for anticoagulation therapy may be at increased risk for the development of “bloody mucus balls”, especially at higher flow rates. Although 50% of patients in Phase III may develop mucus balls, only 10-20% will be symptomatic enough for the patient to seek treatment. If the patient’s cough effort is sufficient to dislodge the mucus ball from the
catheter and allow it to be expectorated, it is much less problematic. Vigilance is the key to successful management of mucus related problems. Mucus stuck to the outside of the catheter can result in a “tracheal tug” as the catheter is removed for cleaning. If it is very adherent, it may get pulled into the tract where it can form a cork-like plug and difficulties with reinsertion. This is one reason why even patients with fully mature tracts should only remove their catheter at the recommended times of 8:00am and 4:00pm. In this way if there is a problem, the patient can come to the TTOT follow-up center for a catheter stripping, while the more experienced team members are still at the hospital or office. If mucus sticks to the catheter and does not strip off, it may stretch the tract causing mild trauma and bleeding. A simple measure to soften the mucus is to squirt a few millimeters of saline down the catheter about 5 minutes before removing it. This often softens the mucus and makes it easier to remove. Another adjunctive therapy that has proven beneficial would be to have the patient breathe a cool mist from a nebulizer for 15-20 minutes before you attempt to remove the catheter. Routine catheter stripping over a wire guide is the cornerstone of mucus management associated with transtracheal oxygen therapy. Catheter stripping should only be done in a controlled setting with appropriately trained personnel to insure patient safety. If a mucus ball has adhered to the catheter, the patient will cough it out upon catheter stripping. If the catheter comes out clean and the patient continues to cough or be dyspneic, you have ruled out the catheter as the source of the problem, and the patient should be evaluated for their symptomology independent of the catheter. All transtracheal patients should have routine catheter stripping twice a week for the two weeks following the Fast Tract procedure (i.e. Monday-Thursday or Tuesday- Friday), and at least once per week for the entire 6-8 week maturation period if they have had the Modified Seldinger procedure. The cleaning, humidification and stripping protocols can be adjusted up or down to meet the needs of every SCOOP patient. Low, moderate, and high-risk patients are detailed in the SCOOP Clincian Guide. Patients who develop symptomatic mucus balls should be reassured that routine daily catheter stripping during Phase IV puts an end to mucus balls. Physicians supervising a transtracheal team should emphasize that all members should be familiar with current protocols for avoiding the development of mucus balls. These have been set forth in the appropriate SCOOP Clinical Guide which is provided by Transtracheal Systems with each procedure tray and upon request. Not all transtracheal teams are offering their patients the benefits of the latest refinements in the SCOOP program, and continue to use protocols that have been substantially improved over protocols developed nearly 20 years ago. Failure to follow the instructions set forth in the SCOOP Clinician Guide, and sometimes intentional deviations from recommended protocols, invite the development of symptomatic mucus balls
Guidelines for Humidifiers A humidifier is recommended for all patients with transtracheal catheters in place. This is most important when the patient is using their stationary oxygen source. When the patient is using their portable oxygen for ambulation, (trips away from the home, shopping, socializing etc.) humidification is not as clinically important as the patient is mobilizing secretions while they are active. This seems to be true even at the higher flow rates most patients find necessary to maintain adequate oxygen saturations with increased activity. Humidification is especially important at night while the patient is sleeping, as secretions tend to collect during periods of inactivity. Pooling of secretions can of course, become problematic if humidification is inadequate. All humidifiers (especially inexpensive disposable humidifiers) have the potential for leaking at the cap, at the connectors, or at the pressure relief (pop-off) valve. At low flow rates, even near total occlusion of the SCOOP catheter and hose will usually result in a slow build up of pressure and a silent leak rather than an audible pop. A non-disposable humidifier with a true gasket seal (i.e. Hudson non-disposable) is recommended for patients who may be at greater risk for the development of mucus balls, and is recommended for all transtracheal in-patients. A standard bubble humidifier (preferably with a gasket seal) is required for all patients who have resting flow rates up to 4-5 liters per minute. Patients who require transtracheal flow rates greater than 4-5 liters per minute or individuals with specific conditions such as Cystic Fibrosis or Bronchiectasis may begin with a standard bubble humidifier, however a servo controlled heated humidifier with heated wire circuit such as Fisher Paykel should be immediately available if inspissated secretions become a problem. A custom circuit for the Fisher-Paykel heated humidifier is available for purchase through Transtracheal Systems. It incorporates a 5-psi safety valve and unique patient connecting system. Adjunctive measures: Mucus balls may be avoided to a large extent if patients at risk are identified and given proper follow-up and humidification. The clinician may elect to have the patient return on a weekly or bi-weekly basis during Phase III for prophylactic removal, cleaning and reinsertion of the SCOOP catheter over a wire guide. Room humidification may be of some benefit especially in dry climates. The addition of Guaifenesin (1200mg BID) to the routine post-procedural orders has significantly decreased both the frequency and severity of mucus balls acrosss the spectrum of patients. Guaifenesin is available over the counter as Mucinex. It should be considered part of the routine post-operative orders,
at least initially for all transtracheal patients irrespective of flow rate and baseline secretion level. As always, systemic hydration must be adequately maintained and judiciously monitored to contribute to normalizing mucus viscosity. As a closing comment, it must again be emphasized that the transtracheal team from the hospital to the home care setting must be aware of current cleaning, humidification, and catheter stripping protocols and should remain vigilant about preventing mucus problems, especially with patients who are at risk. Ongoing problems with mucus balls, which are more than a transient inconvenience for the patient, should signal a need to review established protocols.