Inner Cannula: Tracheostomy Care and Airway Management

An inner cannula is a removable component found in many tracheostomy tubes and some laryngectomy tubes. It fits inside the outer cannula and provides a pathway through which air moves between the patient and the external environment or respiratory equipment.

Because mucus, blood, and dried secretions can accumulate inside an artificial airway, the ability to remove, clean, or replace the inner cannula can help maintain airway patency.

Understanding its function, airflow effects, cleaning requirements, and role in specialized tracheostomy systems is essential for safe airway management.

What Is an Inner Cannula?

An inner cannula is a hollow tube that fits inside the outer cannula of a dual-cannula tracheostomy tube. The outer cannula is the main portion of the tracheostomy tube that remains positioned through the tracheostomy stoma and into the trachea.

Once the outer cannula is correctly positioned, the inner cannula is inserted into it and secured at the proximal end. Depending on the design, the cannula may lock into place by twisting, snapping, or using another manufacturer-specific mechanism.

When inserted, the inner cannula becomes part of the patient’s functional airway. Air passes through its lumen during spontaneous breathing, oxygen therapy, aerosol delivery, or mechanical ventilation.

Many inner cannulas include a standard 15-mm connection at the proximal end. This permits attachment of common respiratory equipment, including ventilator circuits, manual resuscitation devices, oxygen-delivery systems, and other airway accessories.

Inner cannulas may be:

• Disposable
• Reusable
• Fenestrated
• Nonfenestrated
• Designed for specific tracheostomy tube systems

Note: Not all tracheostomy tubes contain an inner cannula. Single-cannula tubes do not include this removable component.

Components of a Dual-Cannula Tracheostomy Tube

Understanding the inner cannula is easier when its relationship to the rest of the tracheostomy tube is clear.

Outer Cannula

The outer cannula is the main structural component of the tracheostomy tube. It passes through the stoma and remains within the trachea. The outer cannula typically contains a flange at its proximal end. Tracheostomy ties or a commercial tube holder are connected to the flange to secure the tube around the patient’s neck.

Depending on the type of tracheostomy tube, the outer cannula may also contain:

• An inflatable cuff
• A fenestration
• A subglottic suction port
• Specialized connectors

Note: The inner cannula fits inside this outer structure.

Inner Cannula

The inner cannula forms a removable internal airway. Its most important advantage is that it can be removed if secretions or other material obstruct the lumen.

Instead of replacing the entire tracheostomy tube, the clinician may be able to remove the obstructed inner cannula and either clean it or replace it with another one. This can restore airflow rapidly while leaving the outer cannula safely positioned within the trachea.

Obturator

The obturator is sometimes confused with the inner cannula, but the two serve very different purposes.

The obturator is used during placement of the tracheostomy tube. It fits temporarily inside the outer cannula and provides a smooth, rounded distal tip that helps guide the tube through the stoma while reducing tissue trauma.

After the tracheostomy tube enters the trachea, the obturator must be removed immediately because it blocks airflow through the tube. The inner cannula is then inserted into the outer cannula and secured. The obturator is therefore an insertion device, while the inner cannula is an ongoing functional component of the airway.

Primary Purpose of the Inner Cannula

One of the most important purposes of an inner cannula is to help maintain airway patency. Respiratory secretions can accumulate within artificial airways. This is especially important in tracheostomy patients because the upper airway has been bypassed.

Normally, the nose and upper airway warm, humidify, and filter inspired gas. A tracheostomy causes inspired gas to enter directly through the neck, which reduces exposure to these natural conditioning mechanisms. Without adequate humidification, secretions can become thick and difficult to remove.

Mucus, dried secretions, or blood may accumulate inside the inner cannula and gradually narrow its lumen. In severe cases, the airway can become completely obstructed. Because the inner cannula is removable, it can often be taken out quickly when obstruction is suspected. This is one of the major safety advantages of the dual-cannula design.

Inner Cannula and Airway Obstruction

Airway obstruction is a potentially serious complication in patients with tracheostomy tubes.

Possible causes include:

• Thick mucus
• Dried secretions
• Blood clots
• Crusting
• Inadequate humidification
• Poor secretion clearance
• Improper positioning of the tube
• Accumulated material inside the inner cannula

Signs of possible tracheostomy obstruction can include:

• Sudden respiratory distress
• Increased work of breathing
• Tachypnea
• Diaphoresis
• Reduced airflow
• Difficulty passing a suction catheter
• Decreased delivered tidal volume
• Increased ventilator pressures
• Oxygen desaturation
• Abnormal breath sounds

Note: When the inner cannula is obstructed, removing it can immediately eliminate the blockage. If breathing improves after its removal, the obstruction was likely located within the inner cannula. A clean replacement cannula may then be inserted if required.

Inability to Pass a Suction Catheter

An important sign of obstruction is the inability to advance a suction catheter through the tracheostomy tube. If a patient has a dual-cannula tracheostomy and suddenly develops respiratory distress while a suction catheter cannot be passed, the inner cannula should be considered a possible source of obstruction.

Removing and replacing the inner cannula can often restore airway patency more rapidly than repeatedly attempting suctioning through the blocked lumen. Increasing suction pressure does not correct a physical obstruction that prevents catheter passage.

Inner Cannula and Airway Resistance

Although an inner cannula provides important safety benefits, it also reduces the internal diameter available for airflow. The outer cannula has a certain internal diameter. When another tube is placed inside it, the available opening becomes smaller.

For example, a tracheostomy tube that has an internal diameter of approximately 8 mm without an inner cannula may have a smaller effective diameter when the inner cannula is inserted. Exact dimensions vary according to the manufacturer and tube design.

This reduction matters because airway resistance increases as airway diameter decreases. Even relatively small reductions in diameter can substantially increase resistance to airflow.

A patient may therefore experience greater work of breathing through a tracheostomy tube when an inner cannula is present than when it is removed.

Clinical Effects of Increased Resistance

Possible consequences of excessive airway resistance include:

• Increased work of breathing
• Dyspnea
• Respiratory muscle fatigue
• Difficulty tolerating spontaneous breathing
• Increased ventilator pressure requirements
• Reduced airflow

Note: Clinicians should consider the effective internal diameter rather than relying only on the nominal size printed on the tracheostomy tube. This is especially important when evaluating patients who are transitioning away from mechanical ventilation.

Tracheostomy Tube Size and the Inner Cannula

The presence of an inner cannula affects how tracheostomy tube size should be interpreted. Manufacturers may report internal diameter differently depending on whether measurements refer to the outer cannula alone or the airway with the inner cannula inserted.

For this reason, two tracheostomy tubes labeled with similar sizes may not provide the same functional airway diameter. The outer diameter is also important.

A dual-cannula design may require a larger overall outer diameter than a similar single-cannula tube. This can reduce the amount of space available between the tube and the tracheal wall. That space becomes especially important when airflow must travel around the tube toward the upper airway.

Pediatric Considerations

Many tracheostomy tubes intended for infants and small children do not contain inner cannulas. The airway diameter in pediatric patients is already small.

Placing an additional tube inside the outer cannula would further reduce the available lumen and potentially cause excessive resistance. For this reason, smaller tracheostomy tubes commonly use single-cannula designs.

Disposable and Reusable Inner Cannulas

Inner cannulas can generally be divided into disposable and reusable designs.

Disposable Inner Cannula

A disposable inner cannula is removed and replaced with a new cannula according to the manufacturer’s recommendations or institutional protocol. Disposable designs can simplify airway care because the clinician does not need to clean and reuse the contaminated cannula.

When secretions obstruct the cannula, the blocked cannula can be removed and immediately replaced with a clean one.

Reusable Inner Cannula

Reusable inner cannulas are designed to be removed, cleaned, rinsed, dried, and reinserted. The exact cleaning procedure depends on the device manufacturer’s instructions and institutional policy.

Cleaning is necessary because secretions can dry on both the internal and external surfaces of the cannula. If deposits remain, they can gradually narrow the airway and increase resistance.

Cleaning the Inner Cannula

Routine care of a reusable inner cannula helps maintain a clear airway. Before beginning, clinicians should have all necessary equipment available and ensure that the tracheostomy tube remains stable throughout the procedure.

Depending on the patient’s condition and tube design, a spare inner cannula may be inserted while the original is being cleaned. This can be especially important for patients who depend on mechanical ventilation.

Typical Cleaning Process

A general cleaning sequence may include:

1. Stabilizing the tracheostomy tube.
2. Unlocking and removing the inner cannula.
3. Inserting a replacement cannula when appropriate.
4. Placing the removed cannula into the designated cleaning solution.
5. Using an appropriate tracheostomy brush to remove secretions.
6. Cleaning both the inside and outside surfaces.
7. Rinsing the cannula thoroughly according to the recommended procedure.
8. Allowing it to dry appropriately.
9. Reinserting the cannula.
10. Locking it securely into position.

Sterile water or sterile saline may be used depending on the device and care protocol.

Some older procedures have included diluted hydrogen peroxide to loosen dried secretions. Current practice should always follow the manufacturer’s instructions because some materials can be damaged by certain cleaning agents.

Importance of Proper Cleaning

Cleaning serves several purposes. It removes mucus and crusted material that could reduce airflow. It also allows the clinician to inspect the cannula for damage, deformation, or retained debris.

Even partial blockage can become significant because a small reduction in airway diameter can sharply increase resistance. Proper maintenance therefore supports both airway patency and patient comfort.

Humidification and Secretion Management

Inner cannula obstruction is closely related to humidification. Because a tracheostomy bypasses the nose and upper airway, inspired gas may not receive normal warming and humidification. Dry gas can cause airway secretions to become thick and difficult to clear.

Methods of providing humidification may include:

• Heated humidification
• Heat and moisture exchangers
• Aerosol systems
• Other prescribed humidification devices

Adequate hydration may also contribute to secretion management when clinically appropriate. Suctioning is another important component of maintaining tracheostomy patency.

However, suctioning does not eliminate the need to evaluate the inner cannula. Material can become stuck to the walls of the cannula even when a suction catheter is able to pass through it. Regular assessment remains necessary.

Routine Tracheostomy Care

Inner cannula care is only one part of overall tracheostomy management. The clinician must also assess the stoma, surrounding skin, tracheostomy dressing, tube position, and securing device.

Stoma Assessment

The area surrounding the tracheostomy should be evaluated for:

• Redness
• Swelling
• Drainage
• Bleeding
• Purulent secretions
• Foul odor
• Skin breakdown
• Excessive moisture

The stoma and surrounding skin are generally cleaned according to institutional policy, often using sterile normal saline or another approved solution.

A skin barrier may be applied when excessive moisture threatens skin integrity. Appropriate tracheostomy dressings can be placed beneath the flange when drainage is present.

Securing the Tube

The outer cannula must remain properly secured. Tracheostomy ties or commercial tube holders attach to the flange and prevent accidental displacement. During tie changes, the tracheostomy tube must be stabilized carefully.

A commonly used guideline is to leave approximately one finger-width of space between the securing device and the patient’s neck. The device should be tight enough to maintain tube stability without causing excessive pressure.

Emergency Equipment at the Bedside

Patients with tracheostomy tubes should have appropriate replacement equipment readily available.

This commonly includes:

• A replacement tracheostomy tube of the same size
• A tracheostomy tube one size smaller
• An obturator
• Spare inner cannulas when appropriate
• Suction equipment
• Oxygen equipment
• Manual ventilation equipment

Note: The smaller tracheostomy tube is important because the stoma may narrow after accidental decannulation, making insertion of the original tube difficult. Keeping emergency supplies readily available reduces delays during airway emergencies.

Inner Cannula and Fenestrated Tracheostomy Tubes

The inner cannula has an additional function in fenestrated tracheostomy tubes. A fenestration is an opening in the wall of the tracheostomy tube that permits airflow to move toward the upper airway.

Fenestrated tubes may be used when a patient is transitioning toward more normal breathing, speech, or eventual decannulation. Depending on the design, the fenestration can be opened or closed by changing the inner cannula.

Nonfenestrated Inner Cannula

A nonfenestrated inner cannula has a solid wall. When inserted into a fenestrated outer cannula, it covers the fenestration.

Air therefore travels through the lumen of the tracheostomy tube rather than through the upper airway. This configuration may be used when mechanical ventilation is required.

Fenestrated Inner Cannula

Some systems offer a fenestrated inner cannula with openings that align with the fenestration in the outer cannula. This allows airflow through the fenestration while the inner cannula remains inserted.

Other systems require the inner cannula to be removed completely before the fenestration becomes functional. Clinicians must understand the specific design being used.

Inner Cannula and Capping

Capping, sometimes called plugging, involves closing the proximal opening of the tracheostomy tube so that the patient must breathe through the upper airway. In a fenestrated tracheostomy system, this may require removal of the inner cannula to expose the fenestration.

The cuff must also be fully deflated when capping is performed.

With the cuff deflated and the airway appropriately configured, inhaled and exhaled gas can travel through or around the tracheostomy tube and move through the upper airway. This may be used to assess whether the patient can tolerate upper-airway breathing before decannulation.

Safety During Capping

The patient should be closely observed for:

• Increased respiratory rate
• Dyspnea
• Stridor
• Oxygen desaturation
• Anxiety
• Increased work of breathing
• Reduced airflow through the upper airway

Note: If respiratory distress develops, the cap should be removed and the airway configuration reassessed.

Speaking Valves and the Inner Cannula

Speaking valves allow many tracheostomy patients to produce speech. A speaking valve is a one-way device placed over the proximal end of the tracheostomy tube.

During inspiration, the valve opens and allows gas to enter through the tracheostomy. During expiration, the valve closes.

Exhaled gas must then travel around the tracheostomy tube or through a fenestration toward the upper airway. As gas passes through the larynx, airflow across the vocal cords can produce speech.

Importance of Cuff Deflation

The cuff generally must be completely deflated before a speaking valve is used. If the cuff remains inflated around the tracheal wall, exhaled gas may have no pathway around the tracheostomy tube.

Because the speaking valve also prevents exhalation through the tube, this could trap gas and produce severe respiratory distress.

Role of the Inner Cannula

With a fenestrated tracheostomy tube, the fenestration must be open for airflow to pass through it. If a nonfenestrated inner cannula covers the fenestration, it must be removed or replaced with a fenestrated inner cannula when required by that particular tube design.

Incorrect configuration can significantly impair exhalation. For this reason, clinicians must understand how the cuff, fenestration, inner cannula, and speaking valve interact before placing a valve.

Inner Cannula and Mechanical Ventilation

Many mechanically ventilated tracheostomy patients breathe through an inner cannula. The 15-mm connector on the cannula allows the ventilator circuit to be attached directly to the airway. Because the cannula decreases internal diameter, it may contribute to airway resistance.

This can influence:

• Peak airway pressure
• Delivered tidal volume
• Work of breathing
• Spontaneous breathing tolerance

If an inner cannula becomes obstructed while a patient is mechanically ventilated, peak airway pressure may rise while delivered tidal volume falls. Ventilator alarms may activate.

The patient may also develop respiratory distress or oxygen desaturation. Removing an obstructed inner cannula can rapidly restore the airway in some situations.

Some tracheostomy systems permit short-term ventilation through the outer cannula while the inner cannula is removed. Other systems may require a functioning inner cannula for proper ventilator attachment. The manufacturer’s specifications should therefore be known.

Inner Cannula During Tracheostomy Tube Changes

The inner cannula must be managed correctly whenever the entire tracheostomy tube is changed. Before insertion of the new tube, the inner cannula is generally removed and the obturator is placed inside the outer cannula.

After lubrication when appropriate, the tube is advanced through the stoma and into the trachea.

Once the tube is positioned:

1. The obturator is removed immediately.
2. The inner cannula is inserted.
3. The inner cannula is locked into place.
4. The cuff is inflated when indicated.
5. Oxygen or ventilatory support is restored.
6. Placement and airflow are assessed.
7. The tube is secured.

Note: The obturator should always remain readily available after the procedure in case reinsertion becomes necessary.

Resistance During Inner Cannula Insertion

An inner cannula should normally slide smoothly into the outer cannula. Unexpected resistance should be investigated rather than overcome with force.

Possible causes include:

• Dried secretions
• Tube deformation
• Incorrect cannula size
• Malposition
• Obstruction from tissue
• Problems involving a fenestration

This is particularly important with fenestrated tubes. Soft tissue may occasionally protrude into the fenestration and interfere with inner cannula insertion.

Forcing the cannula could injure tracheal tissue. When unusual resistance is encountered, the cannula should be withdrawn and the cause evaluated.

Single-Cannula Versus Dual-Cannula Tubes

A major difference between tracheostomy tube designs is whether an inner cannula is present.

Dual-Cannula Tube

Advantages may include:

• Rapid removal of an obstructed lumen
• Easier secretion management
• Replaceable or cleanable airway component
• Compatibility with certain fenestrated systems
• Added safety for patients prone to thick secretions

Potential disadvantages include:

• Reduced internal diameter
• Increased airflow resistance
• Larger external dimensions in some designs
• Additional equipment and maintenance

Single-Cannula Tube

A single-cannula tube does not contain a removable inner cannula. This may provide a larger internal airway for a given outer diameter. However, if significant material accumulates within the tube, the clinician cannot simply remove an inner cannula to restore airflow.

The entire tube may eventually need replacement. The choice between designs depends on the patient’s airway requirements, secretion burden, ventilation needs, anatomy, and clinical goals.

Inner Cannulas in Laryngectomy Tubes

Some laryngectomy tubes also contain an inner and outer cannula. A total laryngectomy permanently separates the trachea from the upper airway. The patient breathes entirely through the neck stoma.

Because all ventilation occurs through the stoma, maintaining airway patency is essential. The inner cannula may be removed for cleaning when secretions accumulate.

When airway obstruction is suspected in a patient with a laryngectomy tube, removable accessories may need to be taken off so that the airway can be directly evaluated.

These may include:

• Heat and moisture exchangers
• Stoma filters
• Speaking devices
• Inner cannulas

Note: A suction catheter can then be advanced through the airway when appropriate.

Metal Tracheostomy Tubes

Some older or specialized tracheostomy systems are constructed from metal. The Jackson tracheostomy tube is a well-known example. It typically contains an outer cannula and a removable inner cannula but does not function exactly like many modern plastic cuffed tracheostomy tubes.

Traditional metal tubes may lack:

• An inflatable cuff
• A standard 15-mm ventilator connector
• Features required for routine positive-pressure ventilation

Note: They are more commonly associated with patients who require a long-term artificial airway but do not require cuff-dependent mechanical ventilation. The inner cannula in these tubes still allows removal and cleaning of accumulated secretions.

Clinical Assessment of the Inner Cannula

The inner cannula should always be considered during assessment of a patient with a dual-cannula tracheostomy.

Important questions include:

• Is the cannula properly inserted?
• Is it locked into position?
• Can air move freely through it?
• Are secretions accumulating?
• Can a suction catheter pass through the airway?
• Is a replacement cannula available?
• Is the patient receiving adequate humidification?
• Is the cannula appropriate for the current airway configuration?
• Is the patient using a fenestrated system or speaking valve?
• Has increased resistance contributed to the patient’s work of breathing?

Note: A problem involving the inner cannula may initially appear to be a pulmonary or ventilator problem. Systematic assessment helps distinguish airway obstruction from other causes of respiratory deterioration.

Important Safety Principles

Several basic principles help support safe inner cannula management. The airway must remain patent at all times. An obstructed inner cannula should be removed promptly when clinically appropriate.

Reusable cannulas should be cleaned according to established procedures. Disposable cannulas should be replaced as directed. Spare equipment should remain readily available.

The cuff must be managed correctly during speaking valve use and capping. Nonfenestrated inner cannulas must not unintentionally block airflow through a fenestration when upper-airway breathing is required.

Unexpected resistance during insertion should not be overcome by force. Clinicians should also remember that an inner cannula changes the functional diameter of the artificial airway and can therefore influence airflow resistance.

Note: Understanding these principles allows problems involving the inner cannula to be recognized before they progress to complete airway obstruction.

Inner Cannula Practice Questions

1. What is an inner cannula?
A removable hollow component that fits inside the outer cannula of a dual-cannula tracheostomy tube and forms part of the patient’s airway.

2. What is the primary purpose of an inner cannula?
To help maintain airway patency by allowing the internal portion of the tracheostomy tube to be removed, cleaned, or replaced.

3. What is the main advantage of a dual-cannula tracheostomy tube when secretions obstruct the airway?
The inner cannula can be removed and cleaned or replaced without removing the entire tracheostomy tube.

4. What is the function of the outer cannula of a tracheostomy tube?
It forms the main structural portion of the tracheostomy tube and remains positioned through the stoma and within the trachea.

5. What is the difference between an obturator and an inner cannula?
The obturator is used temporarily during tracheostomy tube insertion, while the inner cannula is inserted afterward and functions as part of the airway.

6. What type of tracheostomy tube contains both an outer cannula and an inner cannula?
A dual-cannula tracheostomy tube.

7. What may accumulate inside an inner cannula and cause airway obstruction?
Mucus, thick secretions, dried secretions, blood, or blood clots.

8. Why is a removable inner cannula useful when a patient produces thick secretions?
It can be removed rapidly if secretions obstruct the airway, allowing it to be cleaned or replaced.

9. What can happen to airflow when secretions narrow the lumen of an inner cannula?
Airway resistance increases and airflow becomes more difficult.

10. What should be suspected if a tracheostomy patient suddenly develops respiratory distress and a suction catheter cannot be advanced through the tube?
Obstruction of the tracheostomy airway, including possible blockage of the inner cannula.

11. What is an appropriate early action when an inner cannula is suspected of being obstructed?
Remove the inner cannula and replace or clean it as appropriate.

12. Why does increasing suction pressure not solve an obstruction that prevents a catheter from passing through the tracheostomy tube?
Because the problem may be a physical blockage of the airway lumen rather than inadequate suction pressure.

13. How does an inner cannula affect the effective internal diameter of a tracheostomy tube?
It decreases the internal diameter available for airflow.

14. What effect does a smaller internal diameter have on airway resistance?
It increases airway resistance.

15. How can an inner cannula affect a patient’s work of breathing?
By decreasing the airway diameter and increasing resistance, it may increase the work required to breathe.

16. Why are inner cannulas less common in very small pediatric tracheostomy tubes?
The airway lumen is already small, and an inner cannula would further reduce the internal diameter and increase resistance.

17. What are the two general types of inner cannulas based on reusability?
Disposable and reusable inner cannulas.

18. What is done with a disposable inner cannula when it needs replacement?
It is removed and replaced with a new cannula according to device instructions or clinical protocol.

19. What is done with a reusable inner cannula during routine care?
It is removed, cleaned, rinsed, dried, and reinserted.

20. Why should a reusable inner cannula be cleaned regularly?
To remove retained secretions that could narrow the lumen, increase resistance, or cause complete obstruction.

21. What equipment may be used to remove dried secretions from a reusable inner cannula?
An appropriate tracheostomy cleaning brush.

22. Why may a spare inner cannula be inserted while the original cannula is being cleaned?
To maintain a patent airway while the removed cannula is being cleaned.

23. Why is adequate humidification important in patients with a tracheostomy?
It helps prevent secretions from becoming thick, dry, and difficult to remove.

24. How can inadequate humidification contribute to inner cannula obstruction?
It can cause secretions to thicken or dry, allowing mucus and crusted material to accumulate inside the cannula.

25. What is one important safety item that should be kept available for a patient with a dual-cannula tracheostomy?
A spare inner cannula that can be used if the existing one becomes obstructed or requires cleaning.

26. What is the purpose of the 15-mm adapter found on many inner cannulas?
It allows standard respiratory equipment to be connected to the tracheostomy tube.

27. Where is the inner cannula positioned in relation to the outer cannula?
It fits inside the outer cannula and extends through its lumen.

28. How is an inner cannula typically secured after insertion?
It is locked, twisted, or snapped into place at the proximal end according to the tube design.

29. Why is it important to make sure the inner cannula is securely locked into place?
To prevent accidental removal and maintain a stable airway connection.

30. What should be checked about the inner cannula before a new tracheostomy tube is inserted?
It should fit properly, lock easily into position, and be removable without difficulty.

31. What happens to the fenestration of a fenestrated tracheostomy tube when a nonfenestrated inner cannula is inserted?
The fenestration is covered, preventing airflow through the opening.

32. What happens to airflow when the inner cannula is removed from certain fenestrated tracheostomy tubes?
Air can pass through the fenestration and toward the upper airway.

33. Why might the inner cannula be removed from a fenestrated tracheostomy tube during weaning?
To allow airflow through the upper airway and assess the patient’s ability to breathe without relying entirely on the tracheostomy lumen.

34. What must generally be done with the cuff before a fenestrated tracheostomy tube is capped?
The cuff must be completely deflated.

35. Why must the cuff be deflated before capping a tracheostomy tube?
An inflated cuff can block the path of exhaled air and cause respiratory distress.

36. What is the purpose of an outer cannula plug or cap?
To block airflow through the proximal tracheostomy opening and redirect breathing through the upper airway.

37. How can a fenestrated tracheostomy tube assist with speech?
It allows exhaled air to move through the upper airway and across the vocal cords.

38. What type of inner cannula may be used to keep a fenestration open while the cannula remains inserted?
A fenestrated inner cannula.

39. Why should a nonfenestrated inner cannula be removed or exchanged before using the fenestration for speech?
Because it can cover the fenestration and block airflow toward the upper airway.

40. How does a speaking valve change the direction of exhaled airflow?
It closes during exhalation and redirects air through the upper airway instead of allowing it to exit through the tracheostomy opening.

41. Why can leaving the cuff inflated while using a speaking valve be dangerous?
It may prevent exhaled air from escaping through the upper airway, potentially causing severe respiratory distress.

42. What dangerous situation can occur if a speaking valve is used with an inflated cuff and a nonfenestrated inner cannula blocking the fenestration?
The patient may have no adequate pathway for exhalation.

43. What role does the inner cannula play when a fenestrated tracheostomy patient returns to mechanical ventilation?
It can be reinserted to close the fenestration and restore a conventional airway pathway for positive-pressure ventilation.

44. What should be done if unusual resistance is felt while inserting an inner cannula into a fenestrated tracheostomy tube?
The cannula should not be forced and the cause of resistance should be evaluated.

45. Why should an inner cannula never be forced into place when resistance is encountered?
Forcing it may injure tracheal tissue or worsen an obstruction.

46. What might cause resistance during insertion of an inner cannula?
Dried secretions, tissue obstruction, tube deformation, malposition, or use of an incorrect cannula.

47. How can an inner cannula affect peak airway pressure during mechanical ventilation?
If it becomes narrowed or obstructed, airway resistance may increase and peak airway pressure may rise.

48. What ventilator change may occur if an inner cannula becomes severely obstructed?
Delivered tidal volume may decrease while airway pressures increase.

49. Why is a blocked inner cannula an important consideration when ventilator alarms suddenly activate?
The obstruction may be increasing resistance and interfering with effective ventilation.

50. Why should clinicians consider the actual internal diameter of a tracheostomy tube rather than only its labeled size?
The inner cannula can reduce the functional airway diameter and significantly affect airflow resistance.

51. What is the main difference between a single-cannula and dual-cannula tracheostomy tube?
A single-cannula tube does not have a removable inner cannula, while a dual-cannula tube does.

52. Why may a single-cannula tracheostomy tube require complete tube replacement if it becomes obstructed?
Because there is no removable inner cannula that can be taken out and cleaned or replaced.

53. How can a larger outer diameter of a dual-cannula tracheostomy tube affect upper-airway breathing?
It can reduce the space available for airflow around the tube and make speaking valve use or capping more difficult.

54. Why might a patient need a tracheostomy tube with a smaller outer diameter?
To provide more space between the tube and tracheal wall for airflow toward the upper airway.

55. What should be assessed around the tracheostomy stoma during routine care?
Redness, swelling, drainage, bleeding, skin breakdown, purulent material, and foul odor.

56. What can purulent drainage or a foul odor around a tracheostomy stoma suggest?
A possible local infection or other complication requiring further evaluation.

57. Why is stabilization of the outer cannula important when tracheostomy ties are changed?
To prevent accidental displacement or decannulation of the tracheostomy tube.

58. How much space is commonly maintained between a tracheostomy securing device and the patient’s neck?
Approximately one finger-width.

59. Why should an extra tracheostomy tube of the same size be kept near the patient?
It can be used if the existing tracheostomy tube must be replaced unexpectedly.

60. Why should a tracheostomy tube one size smaller also be kept nearby?
The stoma may partially narrow and make insertion of the original tube difficult.

61. What is accidental decannulation?
Unintended removal or displacement of the tracheostomy tube from the stoma.

62. Why is accidental decannulation especially dangerous in a patient who depends on the tracheostomy for ventilation?
Loss of the tube can interrupt the patient’s primary airway and compromise ventilation.

63. What should be removed from a new tracheostomy tube before the obturator is inserted for a tube change?
The inner cannula.

64. What is inserted into the outer cannula before a new tracheostomy tube is passed through the stoma?
The obturator.

65. What should be done immediately after a new tracheostomy tube is successfully inserted?
The obturator should be removed so that airflow can occur.

66. When is the inner cannula inserted during a routine tracheostomy tube change?
After the new outer cannula is positioned and the obturator has been removed.

67. What may be passed through an existing tracheostomy tube to help guide a difficult tube exchange?
A large suction catheter.

68. What must be removed before a suction catheter is used as a guide during certain tracheostomy tube exchanges?
The inner cannula.

69. Why can a removable inner cannula be especially useful for patients discharged home with a tracheostomy?
It provides a practical way to manage secretion buildup and maintain airway patency without replacing the entire tube.

70. Why are patients receiving inadequate airway humidity at greater risk for inner cannula obstruction?
Their secretions are more likely to become thick, dry, and difficult to clear.

71. What is the purpose of air-drying a reusable inner cannula after cleaning and rinsing?
To prepare it for safe reinsertion after visible secretions and cleaning solution have been removed.

72. What should be done if visible dried secretions remain inside a reusable inner cannula after soaking?
They should be removed with an appropriate cleaning brush before the cannula is reinserted.

73. Why should both the internal and external surfaces of a reusable inner cannula be cleaned?
Secretions can accumulate on either surface and interfere with proper fit or airway function.

74. What type of patient may benefit from having a spare inner cannula inserted during cleaning?
A patient who depends on mechanical ventilation or requires continuous maintenance of a secure airway pathway.

75. What is the overall clinical benefit of being able to remove an inner cannula quickly?
It provides a rapid method of restoring or assessing airway patency when blockage of the tracheostomy is suspected.

76. What type of tracheostomy tube design is particularly helpful for patients who frequently develop thick secretions?
A dual-cannula tracheostomy tube.

77. Why can blood inside an inner cannula create an airway emergency?
Blood can clot and partially or completely obstruct the lumen.

78. What does the term airway patency mean?
It means keeping the airway open so that gas can move freely.

79. Why is airway patency especially important in a tracheostomy patient?
The tracheostomy provides the pathway for ventilation, oxygen delivery, and secretion removal.

80. How can retained secretions inside an inner cannula affect spontaneous breathing?
They can narrow the lumen and increase the effort required to move air.

81. What should be considered if a patient breathes more comfortably after the inner cannula is removed?
The inner cannula may have been contributing to increased resistance or obstruction.

82. Why should the inner cannula be inspected after removal?
To look for mucus, blood, crusting, damage, or other material that could interfere with airflow.

83. What can happen if an inner cannula is not fully seated within the outer cannula?
It may not function properly and could interfere with airway stability or connection to respiratory equipment.

84. Why is compatibility important when selecting a replacement inner cannula?
The replacement must match the specific tracheostomy tube design and fit securely within the outer cannula.

85. What should be done before reinserting a cleaned reusable inner cannula?
The cannula should be thoroughly rinsed, appropriately dried, and inspected for remaining debris.

86. Why can dried mucus inside an inner cannula be more difficult to manage than thin secretions?
It can adhere firmly to the cannula wall and create a fixed narrowing of the airway.

87. What is one reason suctioning alone may not fully correct inner cannula narrowing?
Secretions may remain stuck to the inner wall even after loose material is suctioned away.

88. How can an HME help reduce the risk of secretion buildup in a tracheostomy patient?
It helps conserve heat and moisture in inspired gas, which can support secretion hydration.

89. Why should a patient using a speaking valve be monitored closely after placement?
To detect respiratory distress, oxygen desaturation, excessive resistance, or impaired exhalation.

90. What should be evaluated if a patient develops distress shortly after a speaking valve is applied?
The cuff position, upper-airway patency, inner cannula configuration, and availability of an exhalation pathway.

91. Why is understanding the exact design of a fenestrated tracheostomy tube important?
Different systems use different inner cannula configurations to open or close the fenestration.

92. What happens when the fenestration is closed by the inner cannula?
Air is directed primarily through the tracheostomy tube lumen instead of through the upper airway.

93. Why can opening the fenestration help during progression toward decannulation?
It allows the patient to use the upper airway and helps assess tolerance of more normal airflow.

94. What is the purpose of assessing upper-airway breathing before tracheostomy removal?
To determine whether the patient can move air adequately through the natural airway.

95. Why may speech improve when airflow is redirected through the upper airway?
Exhaled air can pass across the vocal cords and produce phonation.

96. What is one important difference between a traditional plastic tracheostomy tube and a Jackson metal tracheostomy tube?
A Jackson tube may contain inner and outer cannulas but typically lacks a cuff and standard 15-mm adapter.

97. Why is a Jackson metal tracheostomy tube generally unsuitable for patients who require a cuff seal for positive-pressure ventilation?
It does not typically have an inflatable cuff to create the necessary seal.

98. What airway components may need to be removed first if a laryngectomy patient develops suspected airway obstruction?
Removable accessories such as the HME, speaking device, stoma filter, and inner cannula.

99. Why is removing the inner cannula useful during evaluation of suspected laryngectomy airway obstruction?
The inner cannula itself may contain the blockage and its removal provides more direct access to the airway.

100. What is the most important overall principle when managing an inner cannula?
Maintain a patent airway by recognizing obstruction early and cleaning, replacing, or removing the cannula when clinically appropriate.

Final Thoughts

The inner cannula is a removable component that plays an important role in maintaining many tracheostomy and laryngectomy airways. Its ability to be removed, cleaned, or replaced provides a practical method for managing secretions and responding to obstruction without removing the entire tracheostomy tube.

However, the inner cannula also reduces the effective airway diameter and may increase resistance to airflow.

Safe management requires proper cleaning, adequate humidification, secretion control, correct cuff and fenestration management, readily available replacement equipment, and close assessment whenever respiratory distress or difficulty passing a suction catheter develops.