Francis Podbielski, MD
INTRODUCTION
Establishment of long-term airway access is necessary in critically ill patients who are dependent on mechanical ventilation or those unable to protect their airway and clear secretions effectively. More recently, morbidly obese patients with chronic obstructive sleep apnea and hypersomnolence have become a substantial subpopulation amongst intensive care unit patients.
Chronic indwelling oral endotracheal tubes are associated with sinusitis, pharyngitis, poor oral hygiene, and deleterious long-term effects on vocal cord function. While subglottic stenosis is uncommon in the era of low volume, low pressure, endotracheal tubes cuffs, weaning a patient from mechanical ventilation with a short length, low resistance tracheostomy offers a more physiologic transfer to independent ventilation. Trials of independent ventilation can be attempted with greater comfort when a return to mechanical ventilation is readily available via an established airway.
Absolute criteria for tracheostomy remain a subject of debate. A medical condition with a protracted recovery period (i.e., months) should be considered a relative indication for early tracheostomy, while even severe injuries in patients who are neurologically intact and who have good lung function should be offered an opportunity for weaning from mechanical ventilation. Patients with extensive cervical injury may require early tracheostomy but due to technical considerations need an open rather than percutaneous approach.
Open tracheostomy is one of the most commonly performed procedures in patients with respiratory failure who require long-term mechanical ventilation.1,2 With the widespread use of mechanical ventilation, even in a long-term setting, tracheostomy has gained acceptance for providing patients with reliable, direct airway access. A routine maintenance regimen of cleaning and occasional tracheostomy change has enabled patients to be maintained almost indefinitely via mechanical ventilation.
Elective percutaneous tracheostomy using sequential dilation was first reported in the literature by Ciaglia in 1985 and is the most commonly employed method.3 It has become a mainstay in the treatment of patients requiring chronic airway access. By using techniques of percutaneous access and wire placement, sequential dilation of the tract is performed with ultimate tracheostomy insertion. The Griggs technique uses a modified forceps for creation of a tract from the skin to the tracheal wall.4 While the end result of both open and percutaneous tracheostomy is the same, the means in which placement is achieved are fundamentally different. The open technique employs a low cervical, transverse incision with dissection through the platysma muscle, longitudinally through the avascular plane in the midline between the strap musculature of the neck, to the pretracheal space. A simple incision, U-shaped trapdoor, or partial resection of the anterior surface of the trachea is performed to allow passage of the tracheostomy tube. Under direct vision, the oral endotracheal tube is withdrawn by the anesthesia service so the tracheostomy can be inserted.
Percutaneous tracheostomy has been championed by some and reviled by others. A thorough knowledge of cervical anatomy and extensive familiarity with the open technique are essential to make the percutaneous technique safe. It is a dangerous belief by some physicians that percutaneous tracheostomy is a simple or foolproof procedure because it is “percutaneous” and it is often done at the bedside. Many clinicians prefer to use bronchoscopy in concert with tracheostomy placement to verify needle, wire, dilator, and tracheostomy placement. Improper placement of the tracheostomy can result in acute decompensation due to airway obstruction or injury to adjacent structures, namely large arteries and veins.
A candidate for percutaneous tracheostomy should be evaluated thoroughly prior to initiation of the procedure. Hemodynamic instability or severe respiratory impairment may disqualify a patient from tracheostomy via either technique. Extensive cervical, airway, or neurologic injuries may be relative contraindications to the percutaneous approach due to an inability to properly position the patient. Similarly, a bleeding diathesis (disseminated intravascular coagulopathy, uremia, thrombocytopenia) necessitates correction prior to embarking on tracheostomy placement. Finally, the operator should be prepared psychologically to abandon a bedside procedure and either personally proceed to the operating room or work in concert with a surgeon if the patient experiences difficulty during a percutaneous attempt.
TECHNICAL CONSIDERATIONS
Our preferred approach to percutaneous tracheostomy is to begin with a therapeutic bronchoscopy. Patients requiring tracheostomy have often been ventilated for time periods of seven days to over one month. A brief look at the beginning of the procedure not only delineates the anatomy, but also establishes the patency of the existing endotracheal tube–which often can be significantly narrowed due to inspissated secretions adherent to its inner surface. Once in the airway, a patient with marginal respiratory mechanics can be markedly improved by directed aspiration of secretions from the segmental bronchial orifices. Having cleared the airway and mechanically optimized the patient for the procedure, the conduct of the tracheostomy begins.
The patient is placed either supine or at 30° in the intensive care unit bed. A roll behind the shoulders is used to gently hyperextend the neck. These maneuvers are facilitated by small doses of intravenous sedation given by the nursing staff. Our preference is for morphine sulfate and midazolam. Despite the critically ill nature of the patient, usage of these drugs is indicated to not only make the procedure easier for the operator, but also be compassionate for the patient. A potential pitfall is over-sedation during the actual procedure. Once the noxious stimulus of tracheostomy placement ceases, blood pressure can fall precipitously. In these patients it is wise to have intravenous fluids readily available, as well as vasopressors to provide temporary blood pressure support during the immediate post-procedure period.
After prepping the neck from the tip of the chin to the just below the clavicles and laterally beyond the lateral border of the sternomastoid muscle, the anterior surface of the trachea is palpated. The prominence of the thyroid cartilage is readily identified, as is the cricoid cartilage. The interspace between the second and third, or third and fourth cartilaginous rings is targeted. After infiltration of the skin and subcutaneous tissues with local anesthetic (usually with epinephrine to limit the oozing or dermal arterioles), the trachea is percutaneously cannulated with a hollow needle or dissection through the subcutaneous tissues is performed with a sterile blunt hemostat. Some surgeons directly cannulate the trachea, while others prefer to make a small transverse skin incision marginally larger than the diameter of the largest dilator. We believe this reduces the drag of the dilators as they are passed through the skin.
Access to the trachea is also important as improper needle and wire placement can result in dilator placement through a tracheal cartilage. It is important to avoid excessive pressure on the trachea during dilation to prevent a crush injury that might result in tracheal stenosis in the future when a patient has recovered sufficiently to be decannulated.
When and how the endotracheal tube is manipulated during the procedure also stirs debate. Certain investigators prefer to partially remove the tube prior to cannulation with the needle. This precludes cannulation of the endotracheal tube, but can have catastrophic results in the event of accidental extubation in a marginal patient with a difficult airway. A second approach is to cannulate the airway with the tube in place. The wire is passed, and its position is verified by flexible bronchoscopy distally in the airway (and not through the tube or tunneled between the mucosa and the cartilage). In cooperation with the anesthesiologist/anesthetist/respiratory therapist, the endotracheal tube is then extracted only the point of entry of the wire through the tracheal wall. The bronchoscope can be left in place during the remainder of the procedure for added security of the airway, and verification of the passage of each dilator, and eventually the tracheostomy tube.
Ideally, the tract should be expanded by smooth passage of sequentially larger dilators. It is helpful to leave the dilator in place for a brief period of time to allow the tract to expand. A potential pitfall exists in obese or anasarcic patients whereby the wire can be looped on itself in the subcutaneous tissue, resulting in creation of a substernal tract.
Failure to recognize this will result in improper tracheostomy placement, and potential injury to the brachiocephalic vein or innominate artery with disastrous results. Once again, flexible bronchoscopy enables diligent observance of the proper trajectory of each dilator. A situation that complicates dilator placement is a calcified or fibrotic tracheal wall. We have provided one solution to this problem using a hybrid Ciaglia/Griggs technique by which a fine hemostat is gently passed along the tract of the wire. Once traversing the tracheal wall, the jaws of the hemostat are opened and the aperture enlarged to accommodate the dilator.
Despite fastidious technique, the bête noire of surgery is bleeding. The most common sources for hemorrhage during percutaneous tracheostomy include: dermal vessels, external jugular vein branches (which can generally be visualized prior to the procedure by direct inspection), thyroid gland/vessels, tracheal vessels, inhabitants of the carotid sheath (jugular vein, carotid artery), and brachiocephalic vein. Dermal vessel bleeding can almost uniformly be controlled by injection of additional epinephrine-containing local anesthetics followed by a brief period of digital compression. External jugular vein branches can rarely be treated successful with epinephrine solutions and may respond to digital compression and if necessary, suture ligation at the bedside. Students of gross anatomy know the notoriously random anatomic distribution of the external jugular vessels; injury to them probably occurs more often than reported. Sequential dilation and final placement of the tracheostomy tube often effectively tamponades the injured vessel. Similarly, injury to richly vascularized thyroid tissue may be effectively tamponaded with final tracheostomy tube placement. Injuries to the carotid artery, internal jugular vein, or brachiocephalic artery are usually catastrophic and mandate immediate neck exploration or sternotomy.
One of the arts of percutaneous tracheostomy is the clinical judgment to know when to abort the procedure completely, or perform a limited neck exploration at the bedside to control a bleeding vessel prior to completion of the procedure. It is critical to remember that once the tracheostomy tube is in place, and the oral endotracheal tube out, exposure to the cervical tract is nil. Brisk pooling of blood in the wound tract should alert the operator to the need for possible exploration. This can be accomplished with a portable light (or headlamp), an assistant, and a minor surgery tray. The oral endotracheal tube is passed beyond the tracheal entry site of the wire and the balloon reinflated – the airway is now secure. The skin wound is extended one centimeter laterally in either direction and using systematic digital compression about the edges of the wound, the offending vessel is usually localized. If this can be done successfully, a figure eight suture is used to achieve hemostasis. Ongoing bleeding, or inadequate exposure mandates digital compression. If not successful in controlling the bleeding, a formal exploration in the operating room is required.
If all has proceeded uneventfully, the largest dilator is passed and the tracheostomy tube slid into position. Inability to pass the next larger dilator or tracheostomy requires a step down in size and re-passage of that dilator. In some instances it is helpful to have a smaller size tracheostomy tube available should the larger tube not pass. Upon passage of the tracheostomy, the assistant secures the tube and a flexible bronchoscopy is performed to verify position of the tube centrally in the lumen of the trachea and above the carina. If these criteria are met, the oral endotracheal tube is removed and the cuff of the tracheostomy tube inflated. The patient is returned to the ventilator circuit via the tracheostomy and oxygen saturation and vital signs noted. After equilibration, a final look with the bronchoscopy is performed to once again verify positioning and aspirate secretions. The collar of the tracheostomy tube is used to secure the appliance to the neck.
If the tracheostomy tube extends beyond the carina, the procedure needs to be reinitiated with a new access point in a higher cartilaginous ring on the trachea. In rare instances, a custom tracheostomy tube may be required in a patient with an exceptionally short or deformed airway.
It is our protocol to follow patients until post-operative day number two. We recommend to the managing service that the tube not be changed or downsized until at least two weeks after the initial procedure. By that time a well-formed tract is present and a new tube can be easily and safely placed.
COMPLICATIONS
Reported complications can be divided into two groups, those occurring at the time of placement, and long terms effects on the tracheal wall. In a collective series by Petros, bleeding was the most commonly reported perioperative complication, ranging from 4.1– 2.0%, with incidences of peri-operative death between 0 and 1.6%.5 Bliznikas, in a large review study of 21 reports consisting of 3520 percutaneous tracheostomies, showed a perioperative hemorrhage rate of 2.44%, and death rate of 0.4%.6 Retrospective data analyses by Upadhyay and Wease demonstrated acute complication rates for percutaneous tracheostomy of 5.4–6.3%.7,8 A large meta-analysis by Dulguerov showed that percutaneous tracheostomy compared to surgical tracheostomy has a higher rate of perioperative complications (10% vs. 3%), while post-operative complications occur more frequently in the surgical group (10% vs. 7%).9
Long-term issues that arise, most specifically tracheal stenosis secondary to cartilage damage and scar tissue have been recognized from the outset. Briche and colleagues reported two cases of tracheal stenosis after percutaneous tracheostomy by an experienced surgeon.10 They recommend flexible bronchoscopy for airway assessment at the time of decannulation, at the six-month mark, and again at one year. Other important technical issues for percutaneous tracheostomy have been noted. van Heurn et al. noted the importance of not placing the cannula at an oblique angle to avoid direct apposition to the anterior tracheal wall and hence obstruction.11 A study of 422 percutaneous tracheostomies by Norwood, et al. analyzed multiple end points. Of this study group, 340 (81%) were long-term survivors.12 One hundred (29%) of these patients were interviewed and underwent either flexible bronchoscopy or computed tomography. Tracheal stenosis was defined as greater than 10% narrowing of the lumen of the airway. Voice changes were reported in 27% of patients with 2% of patients noting severe hoarseness. Ten patients had persistent respiratory problems after decannulation. Two patients had moderate tracheal stenosis and one had severe stenosis. Dollner and colleagues evaluated 19 of 32 long-term survivors after percutaneous tracheostomy (Griggs technique).13 Results of flexible bronchoscopy showed a tracheal stenosis of greater than 10% in 63% of the study group. A correlation was found between the puncture site and the grade of stenosis.
As experience with the technique has grown, an emerging body of literature supports the safety and reliability of percutaneous tracheostomy. Türkmen and colleagues reviewed a series of patients undergoing percutaneous versus open tracheostomy one month after decannulation using MRI scanning.14 Early and late complications were minor. Two patients in the percutaneous tracheostomy group had mild (not clinically significant) tracheal stenosis on MRI. Diaz-Regañón et. al., reported their experience with 800 percutaneous tracheostomy procedures of which 86% were performed by residents with the oversight of an attending staff member.15 Four percent of patients had some type of complication, of which half were during the procedure itself. There were no deaths in the series attributable to the procedure. It was noted that complications were greatest in residents performing their first five procedures versus procedures performed thereafter (9.2% vs. 2.6% – p < .05).
Beltrame analyzed outcomes for 367 consecutive patients undergoing bedside percutaneous tracheostomy and compared them to an historical cohort of 161 patients undergoing surgical tracheostomy.16 Percutaneous tracheostomy was performed significantly sooner than open tracheostomy (8.7 vs. 12.4 days – p < .05). The overall ICU stay and length of mechanical ventilation were also both significantly lower in the percutaneous versus open tracheostomy groups (18.4 vs. 23.3 days – p < .05 and 14.2 vs. 20.1 days – p < .05). There was no significant difference between ICU and overall survival between the two groups.
Obesity has reached epidemic proportions not only in the United States and the United Kingdom, but in other parts of the world as well. Given the multitude of medical comorbidities in these patients, not the least of which is obstructive sleep apnea and chronic alveolar hypoventilation, it is not surprising that they have come to account for a significant percentage of patients mechanically ventilated in the ICU. Anecdotal reports have begun to suggest a salutary effect of tracheostomy on weight loss in these obese patients. Romero and colleagues from the University of Chile segregated a cohort of 120 patients undergoing tracheostomy into an obese vs. a non-obese group.17 The average body mass index for the obese group was 38 kg/m versus 22 kg/m for the non-obese group (p < .001). Both groups were mechanically ventilated for an equivalent time period before tracheostomy. The incidence of operative and early post-operative complications for both groups was similar and not statistically significant.
Tracheal ring fractures and their potential for resultant tracheal stricture have long been a concern with the percutaneous tracheostomy technique. Higgins, et al. reviewed 207 patients who underwent tracheostomy and were evaluated post-cannulation by an otolaryngologist who examined their airways with nasoendoscopy.18 A total of 16 tracheal ring fractures were noted, none of which appeared to result in significant airway narrowing.
Finally, a thoughtful evaluation of the patient’s chances for long-term survival must be taken into account before a tracheostomy is performed. While early tracheostomy has clearly been shown to reduce length of ICU and hospital stay, our group have demonstrated a median survival of only 7.3 months after tracheostomy with the poorest survival being noted in patients of age > 70 years.19 The six month mortality in patients undergoing percutaneous tracheostomy after cardiac surgical procedures was 74%.
SUMMARY
Percutaneous tracheostomy has been proven to be a safe and cost-effective procedure with results comparable to, or better than, its open technique counterpart. As with any minimally invasive procedure, it should not be perceived as “simple” solely due to its ability to be performed at the bedside. The practitioner must be comfortable with the open tracheostomy technique and be ready to either convert the procedure to an open neck exploration or seek immediate surgical assistance should unrelenting hemorrhage, airway obstruction, or any other technical misadventure occur. As with any invasive surgical procedure, proper training and instruction coupled with patient selection is the key factor in safety and success.
References
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- Wood, DE. Tracheostomy. Chest Surg Clin North Am. 1996;6:749-64.
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- Griggs, WM, Worthley, LIG, Gilligan, JE, Thomas, PD, Myburg, JA. A simple percutaneous tracheostomy technique. Surg Gynec Obstet. 1990;170:543-45.
- Petros, S. Percutaneous tracheostomy. Crit Care. 1999;3:R5-R10.
- Bliznikas, D, Baredes, S. Percutaneous tracheostomy. 2003. Available at: http://www.emedicine.com/ent/topic682.htm.
- Upadhyay, A, Maurer, J, Turner, J, Tiszenkel, H, Rosengart, T. Elective bedside tracheostomy in the intensive care unit. J Am Coll Surg. 1996;182:51-5.
- Wease, GL, Frikker, M, Villalba, M, Glover, J. Bedside tracheostomy in the intensive care unit. Arch Surg. 1996;131:552-55.
- Dulguerov, P, Gysin, C, Perneger, TV, Chevrolet, JC. Percutaneous or surgical tracheostomy: a meta-analysis. Crit Care Med. 1999;27(8):1617-25.
- Briche, T, Le Manach, Y, Pat, B. Complications of percutaneous tracheostomy. Chest. 2001;119(4):1282-3.
- van Heurn, LW, Theunissen, PH, Ramsey, G, et al. Pathologic changes of the trachea after percutaneous dilatational tracheotomy. Chest. 1996;109:1466-9.
- Norwood, S, Vallina, VL, Short, K, Saigusa, M, Fernandez, LG, McLarty, JW. Incidence of tracheal stenosis and other late complications after percutaneous tracheostomy. Ann Surg. 2000;232(2):233-41.
- Dollner, R, Verch, M, Schweiger, P, Deluigi, C, Graf, B, Wallner, F. Laryngotracheoscopic findings in long-term follow-up after Griggs tracheostomy. Chest. 2002;122(1):206-12.
- Türkmen, A, Altan, A, Turgut, N, Yildirim, G, Ersoy, A, Koksal, C, Ayşe, M, Kamali, S. Comparison of percutaneous dilatational tracheostomy with surgical tracheostomy. Middle East J Anesthesiol. 2008;19(5):1055-67.
- Diaz-Regañón, G, Miñambres, E, Ruiz, A, González-Herrera, S, Holanda-Peña, M, López, F. Safety and complications of percutaneous tracheostomy in a cohort of 800 mixed ICU patients. Anaesthesia. 2008;63(11):1198-1203.
- Beltrame, F, Zussino, M, Martinez, B, Dibartolomeo, S, Saltarini, M, Vetrugno, L, Giordano, F. Percutaneous versus surgical bedside tracheostomy in the intensive care unit: a cohort study. Minerva Anestesiol. 2008;74(10):529-35.
- Romero, CM, Cornejo, RA, Ruiz, MH, Gálvez, LR, Llanos, OP, Tobar, EA, Larrondo, JF, Castro, JS. Fiberoptic bronchoscopy-assisted percutaneous tracheostomy is safe in obese critically ill patients: A prospective and comparative study. J Crit Care. 2008;Sept 10. [E-pub ahead of print]
- Higgins, D, Bunker, N, Kinnear, J. Follow-up of patients with tracheal ring fractures secondary to antegrade percutaneous dilatational tracheostomy. Eur J Anaesthesiol. 2009;26(2):147-9.
- Podbielski, FJ, Bagley, PH, Connolly, AE, Bagley, PH. Percutaneous tracheostomy experience at a single institution. Chest. 2005;128(4):305S.