PDF《Tracheostomy Tubes and Related》

Tracheostomy Tubes and Related Appliances Dean R Hess PhD RRT FAARC Introduction Metal Versus Plastic Tracheostomy Tubes Tracheostomy Tube Dimensions Tracheostomy Tube Cuffs Changing the Tracheostomy Tube Fenestrated Tracheostomy Tubes Dual-Cannula Tracheostomy Tubes Percutaneous Tracheostomy Tubes Subglottic Suction Port Stoma Maintenance Devices Mini-Tracheostomy Tubes Summary Tracheostomy tubes are used to administer positive-pressure ventilation, to provide a patent air- way, to provide protection from aspiration, and to provide access to the lower respiratory tract for airway clearance.

They are available in a variety of sizes and styles, from several manufacturers. The dimensions of tracheostomy tubes are given by their inner diameter, outer diameter, length, and curvature. Differences in length between tubes of the same inner diameter, but from different manufacturers, are not commonly appreciated but may have important clinical implications. Tra- cheostomy tubes can be angled or curved, a feature that can be used to improve the fit of the tube in the trachea. Extra proximal length tubes facilitate placement in patients with large necks, and extra distal length tubes facilitate placement in patients with tracheal anomalies. Several tube designs have a spiral wire reinforced flexible design and have an adjustable flange design to allow bedside adjustments to meet extra-length tracheostomy tube needs. Tracheostomy tubes can be cuffed or uncuffed. Cuffs on tracheostomy tubes include high-volume low-pressure cuffs, tight-to- shaft cuffs, and foam cuffs. The fenestrated tracheostomy tube has an opening in the posterior portion of the tube, above the cuff, which allows the patient to breathe through the upper airway when the inner cannula is removed. Tracheostomy tubes with an inner cannula are called dual- cannula tracheostomy tubes. Several tracheostomy tubes are designed specifically for use with the percutaneous tracheostomy procedure. Others are designed with a port above the cuff that allows for subglottic aspiration of secretions. The tracheostomy button is used for stoma maintenance. It is important for clinicians caring for patients with a tracheostomy tube to understand the nuances of various tracheostomy tube designs and to select a tube that appropriately fits the patient. Key words: airway management, fenestration, inner cannula, tracheostomy button, tracheostomy tube, cuff, tracheostomy, suction, stoma. [Respir Care 2005;

50(4):497C510. ?

2005 Daedalus Enterprises] Dean R Hess PhD RRT FAARC is affiliated with the Department of Respiratory Care, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts. Dean R Hess PhD RRT FAARC presented a version of this paper at the 20th Annual New Horizons Symposium at the 50th International Respiratory Congress, held December 4C7, 2004, in New Orleans, Lou- isiana. Correspondence: Dean R Hess PhD RRT FAARC, Respiratory Care, Ellison 401, Massachusetts General Hospital,

55 Fruit Street, Boston MA 02114. E-mail: [email protected]. RESPIRATORY CARE ? APRIL

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4 497 Introduction Tracheostomy tubes are used to administer positive- pressure ventilation, to provide a patent airway in patients prone to upper-airway obstruction, to protect against as- piration, and to provide access to the lower respiratory tract for airway clearance. Tracheostomy tubes are avail- able in a variety of sizes and styles from several manu- facturers. The inner diameter (ID), outer diameter (OD), and any other distinguishing characteristics (percutaneous, extra length, fenestrated) are marked on the flange of the tube as a guide to the clinician. Some features are rela- tively standard among typical tracheostomy tubes (Fig. 1). However, there are many nuances among them. It is im- portant for clinicians caring for patients with a tracheos- tomy tube to understand these differences and to use that understanding to select a tube that appropriately fits the patient. Surprisingly little has been published in the peer- reviewed literature on the topic of tracheostomy tubes and related appliances.1C3 This paper describes characteristics of tracheostomy tubes used in adult patients. Metal Versus Plastic Tracheostomy Tubes Tracheostomy tubes can be metal or plastic (Fig. 2). Metal tubes are constructed of silver or stainless steel. Metal tubes are not used commonly because of their ex- pense, their rigid construction, the lack of a cuff, and the lack of a 15-mm connector to attach a ventilator. A smooth rounded-tip obturator passed through the lumen of the tra- cheostomy tube facilitates insertion of the tube. The ob- turator is removed once the tube is in place. Plastic tubes are most commonly used and can be made from polyvinyl chloride or silicone. Polyvinyl chloride softens at body temperature (thermolabile), conforming to patient anat- omy and centering the distal tip in the trachea. Silicone is naturally soft and unaffected by temperature. Some plastic tracheostomy tubes are packaged with a tracheal wedge (Fig. 3). The tracheal wedge facilitates removal of the ventilator circuit while minimizing the risk of dislodge- ment of the tracheostomy tube. Tracheostomy Tube Dimensions The dimensions of tracheostomy tubes are given by their ID, OD, length, and curvature. The sizes of some tubes are given by Jackson size, which was developed for metal tubes and refers to the length and taper of the OD. These tubes have a gradual taper from the proximal to the distal tip. The Jackson sizing system is still used for most Shiley dual-cannula tracheostomy tubes (Table 1). Single-can- nula tracheostomy tubes use the International Standards Organization method of sizing, determined by the ID of the outer cannula at its smallest dimension. Dual-cannula tracheostomy tubes with one or more shaft sections that are straight (eg, angled tubes) also use the International Standards Organization method. The ID of the tube is the functional ID. If an inner cannula is required for connec- tion to the ventilator, the published ID is the ID of the inner cannula. The OD is the largest diameter of the outer cannula. When selecting a tracheostomy tube, the ID and OD must be considered. If the ID is too small, it will increase the resistance through the tube, make airway clearance more difficult, and increase the cuff pressure required to create a seal in the trachea. Mullins et al4 estimated the Fig. 1. Components of a standard tracheostomy tube. (Courtesy of Smiths Medical, Keene, New Hampshire.) Fig. 2. Tracheostomy tube with inner cannula and obturator. Fig. 3. The tracheal wedge is used to disconnect the ventilator circuit while minimizing the risk of dislodgement of the tracheos- tomy tube. (Courtesy of Smiths Medical, Keene, New Hampshire.) TRACHEOSTOMY TUBES AND RELATED APPLIANCES