Transtracheal oxygen therapy (TTOT) can be an effective means of palliating hypoxemia and dyspnea, as well as easing some of the patient’s burdens of using supplemental oxygen. However, the technique has not gained widespread acceptance or popularity, likely because of several reasons. Few physicians are trained to either perform the catheter insertion or manage patients with it. Others fear performing this invasive procedure on hypoxemic, fragile patients. Finally, physicians typically focus on curing the underlying cause of hypoxemia and could underestimate the benefits of this palliative procedure.
In our hands, TTOT decreases the amount of oxygen necessary to maintain saturation at rest, improves exercise capacity, and improves patient cosmesis and comfort. The complications are minimal in a carefully selected population with an experienced operator. The following is how we identify patients, perform catheter insertion, and manage patients using TTOT at our institution.
Heimlich first described tracheal catheterization for oxygen deliver in 1982.1 Since then, multiple companies have developed equipment sets. They consist of catheters with proximal flanges that are inserted percutaneously. A chain around the neck anchors the flanges and holds the catheters at the insertion site. We have been using the SCOOP catheter system (Transtracheal Systems, Inc., Englewood, Colorado) for over a decade now because of the low incidence of complications, especially subcutaneous emphysema, with this delayed oxygen use system. This is not an endorsement of equipment or a company. The following approach is based on a combination of the manufacturer’s guidelines2 and our experience.
We perform the initial insertion procedure in either a dedicated procedure room for outpatients or at the bedside for inpatients. A physician, with either a respiratory therapist or nurse to assist, places the catheter. Fluoroscopy to verify catheter position is used, but if not available, posterior–anterior and lateral chest radiographs are obtained immediately after insertion.
We consider TTOT for patients who require supplemental oxygen at rest and need increased flow with exertion. Patients should be ambulatory and able to care for the catheter as described subsequently. Candidates undergo a complete history and physical examination to identify any key contraindications such as significant bronchorrhea, which could lead to desiccation of tracheal mucus and catheter obstruction, uncontrolled bronchospasm, coagulopathy, or a history of poor wound healing. These are relative contraindications and patients with these issues should not have a catheter placed except in situations in which the additional oxygen delivery outweighs the contraindication.
The physical examination includes a close inspection of the anatomic landmarks of the neck to identify any anomaly, scar, or severe obesity. A tracheostomy scar is not a contraindication for catheter insertion. Obesity or redundant skin in the neck can make placement more difficult, but it is not a contraindication.
Laboratory studies obtained before insertion include a complete blood count to assess for anemia and thrombocytopenia. A chest radiograph is used to screen for herniation of the pleural space over the trachea, which could lead to pneumothorax during catheter placement, and to assess for tracheal deviation and tracheal length.
The procedure and potential complications are discussed during the initial evaluation. Often patients are reluctant to have a semipermanent procedure for only palliation when first presented with the option. However, after careful consideration, and especially after seeing others with the device and speaking with them, many patients have the catheter placed. Patients are also given the Patient Workbook and Guide, which comes with the SCOOP kit, before the procedure. Informed consent is obtained before the procedure, and patients are instructed to have nothing by mouth for 6 hours before the initial catheter placement.
INITIAL STENT PLACEMENT
The first step is accurate identification of pertinent landmarks. The patient sits upright and the upper border of the thyroid cartilage, the cricoid cartilage, and sternal notch are identified and marked with a marker (Fig. 1). Patients with significant anxiety benefit from 10 mg diazepam given by mouth at this time to reduce anxiety during the later procedure.
The beaded stainless steel necklace, which will ultimately fit through flanges, is next fitted around the neck and extra length is removed with a wire cutter. The necklace should fit snugly but allow 2 fingers to be placed between the chain and neck with ease. The chain should lie over the first or second tracheal ring interspace (Fig. 2). The point at which the chain crosses the midline of the trachea is where the stent will be inserted. Careful note of any tracheal deviation should be made at this time because lateral deviation of the introducer needle is a common difficulty with mobile tracheas in elderly persons. Cricothyroid puncture should be avoided because it causes hoarseness, from damaging the cricovocal membrane, poor tract formation, and keloid formation.
Once the landmarks are identified, the clinician then proceeds with the patient sitting at a 45° angle. The neck is cleaned with alcohol and 2 to 4 mL of 2% lidocaine containing 1:100,000 epinephrine is injected using a 5-cm syringe with a 25-gauge 5/8″ needle at the previously identified insertion site. A circle 2 cm in diameter should be well anesthetized. The trachea is then transfixed in its usual position with the nondominant hand. A 20-gauge needle with syringe is held perpendicular to the trachea and then inserted into the trachea at the catheter insertion site. Aspiration of air confirms tracheal location, and the patient is warned of a cough and 2 mL of 2% lidocaine containing 1:100,000 epinephrine is then injected into the trachea.
The operator changes to sterile gloves and the field is sterilized with chlorhexidine and then draped. A stab-incision is made with a no. 15 scalpel at the insertion site in the cranial–caudal direction. Care should be taken to make the incision no longer than the width of the no. 15 scalpel. An 18-gauge 7-cm thin-walled introducer needle attached to a syringe with 1 mL of saline is held nearly perpendicular to the trachea with 15° deviation of the end of the syringe cephalad (Fig. 3). Care is taken that the bevel of the needle directs caudally, and the needle is then inserted into the trachea through the skin incision and the intercartilaginous ligament. Aspiration of the air confirms intratracheal location. The syringe is then detached and a guide wire is inserted through the needle to the 11-cm reference mark. The needle is then removed over the guide wire.
A lubed dilator is passed over the guide wire and gently rotated while being advanced into the tracheal space. The dilator should be pushed to the black mark on the dilator, indicating 8 cm of insertion. The guide wire is removed and the dilator is left in place to gently dilate the intercartilaginous ligament. After 2 minutes, the guide wire is then reinserted and the dilator is removed. A lubricated pre-SCOOP stent is inserted over the guide wire into the trachea. The guide wire is then removed. Air should be aspirated to ensure intratracheal position and the patient should be asked to talk to ensure no hoarseness. A hoarse voice indicates the stent is directed cephalad and resides between the vocal cords, and it needs to be removed and the insertion procedure repeated. The catheter is then sewn into place, and a nonocclusive dressing is applied.
A chest radiograph or fluoroscopy is used to confirm the position of the stent and to evaluate for pneumothorax. The patient is then discharged with a prescription for prophylaxis against skin flora for a week with over-the-counter pain medication and a cough suppressant.
The patient is warned about possible development of cellulites or chondritis. The patient should observe for erythema, purulence, or pain around the insertion site. The patient should also report any fever, chills, chest pain, change in dyspnea, or hoarseness.
The stent is left in place for a week. The patient continues to use oxygen through the nasal prongs during this time. This gives the patient time to familiarize him- or herself with the transtracheal device and allows a tract to develop, avoiding subcutaneous emphysema, which can occur with immediate use of the stent for oxygen delivery. During this week, the patient should clean the tract site twice daily with a cotton-tipped applicator dipped in 3% hydrogen peroxide.
At the end of this week, the patient returns for exchange of the stent for a functional SCOOP catheter. This is done with the patient in a sitting position. The area around the stent is cleaned with a cotton-tipped applicator and 3% hydrogen peroxide. One milliliter of aqueous lidocaine is then injected through the stent. The stent is then removed over a guide wire and a new functional catheter is then inserted. The catheter comes in 9-, 11-, and 13-cm lengths, although we find that the 11-cm catheter is most appropriate, because it does not reach the carina in a majority of patients.
The oxygen flow rate is then titrated to the patient’s need at rest. The patient is also fitted with an oxygen hose that fits under the shirt and emerges at the waist where it is attached to a security clip on a belt. The hose is then connected to the oxygen tank. The SCOOP oxygen hoses are available in different lengths, thus allowing freedom of movement without creating a tripping hazard.
Oxygen saturation is then assessed during exertion and supplemental oxygen is titrated according to the patient’s needs. We typically find that the amount of supplemental oxygen required at rest to maintain adequate saturation is reduced by half. The benefits with exertion appear to be disease-specific. In obstructive lung disease, the liter flow rate of supplemental oxygen can be reduced by 30% to 50% while maintaining adequate saturation. However, in restrictive lung disease, patients continue to desaturate despite maximal transtracheal oxygen supplementation of 6 L per minute, but their exercise tolerance is significantly increased affording benefit from the procedure.
The patient is sent home, but the transtracheal tract is still immature and the catheter could be dislodged and the tract lost, thus we do not have the patient remove the catheter for cleaning. Rather, the patient is instructed to clean the catheter in place with 5 mL of saline solution and a cleaning rod placed through the catheter twice daily. These steps are important to prevent mucus desiccation and either mucus ball formation or catheter obstruction. In addition, the patient is taught to recognize signs and symptoms of mucus buildup and to report any new respiratory symptoms immediately, because plugging or a mucus ball can drastically reduce the flow of supplemental oxygen.
MATURE CATHETER REPLACEMENT AND LONG-TERM RISKS
In 6 to 8 weeks, the transtracheal tract has matured, allowing changing for cleaning without a guide wire in 6 to 8 weeks. The patient is seen in the outpatient clinic and instructed how to remove the dirty catheter and self-insert a clean one using a mirror. The patient is given 2 catheters and instructed to clean the unused catheter under a faucet and then rinse with sterile saline. We instruct our patients to remove dirty catheters daily and replace with a clean one. Because of some stiffening with age, the SCOOP catheters should be replaced every 3 months. We routinely examine our patients in follow up every 2 to 3 months to ensure adequate oxygenation and that they are facile and following cleaning techniques.
If patients have excessive mucus or fail to regularly clean the catheter, the catheter mucus can plug the catheter’s interior or coat the exterior and make routine changes difficult. In these situations, we use multiple aliquots of 5 mL of normal saline through the catheter to liquefy the dried mucus, allowing catheter removal. We find repeat saline instillations and patience to be more effective than mucolytics such as N-acetylcysteine.
Tracheal bleeding is a feared long-term complication and is best avoided rather than treated. We avoid this by not placing catheters in patients requiring permanent high-level anticoagulation such as for chronic thromboembolic pulmonary disease or artificial heart valves. In addition, all nonportable oxygen should be humidified for all patients.
A final long-term risk is inadvertent removal of the catheter, typically at night. In these situations, we have the patient use supplemental oxygen through a nasal cannula and report immediately to the outpatient clinic. Using a soft-tipped guide wire, we are able to recannulate the original tract in almost all patients.
Despite these long-term risks, we find patients prefer the transtracheal catheter over a nasal cannula because of improved cosmesis, reduced oxygen flow allowing portable oxygen supplies to last longer, and increased exertional ability.
1. Heimlich HJ. Respiratory rehabilitation with transtracheal oxygen system. Ann Otol Rhinol Laryngol
2. Transtracheal Oxygen Therapy SCOOP Clinical Guide. Englewood, CO: Transtracheal Systems, Inc; 1990.