Hazard [Health Devices Oct 1995;24(10):422-3]

Problem

A hospital reported a case of ineffective emergency ventilation of a patient in respiratory arrest when a manual resuscitator was connected to the 15 mm male connector on the fenestrated inner cannula positioned inside a fenestrated low-pressure cuffed tracheostomy tube. During the resuscitation attempt, significant portions of the administered gas escaped through the fenestrations in both the inner cannula and the outer tube. Rather than entering the lungs, this gas exited through the patient's mouth and nose.

Serious injury did not occur because the tube's fenestrated inner cannula was quickly replaced with a nonfenestrated one. However, this problem could lead to a life-threatening situation if effective ventilation does not occur in a timely manner.

Note that similar problems could occur with several manufacturers' fenestrated tracheostomy tubes, as discussed below. Also, even facilities that do not purchase one of the affected products may encounter such tubes in patients brought to the facility from a long-term care or home-care setting.

Fenestrated tracheostomy tubes are typically used during weaning of tracheostomy patients from mechanical ventilators or from their artificial airway. These tubes have a hole (or holes) in the wall of the inserted portion that allows the patient to breathe through his mouth and nose. The exposed end of the tube often has a 15 mm connector to allow attachment to a ventilation device (e.g., a mechanical ventilator). In most designs, this connector is located either on the tube itself (outer tube) or on a nonfenestrated inner cannula, which is inserted in the outer tube when the fenestration needs to be occluded (e.g., for manual or mechanical ventilation). The tube used in the reported incident is supplied with a fenestrated and a nonfenestrated inner cannula, both of which include a 15 mm connector.

During the weaning process, the exposed end of the tracheostomy tube is often occluded with a decannulation cap or plug, forcing the patient to breathe through the fenestration and his upper airway. If manual or mechanical ventilation is required, the cap or plug and, if present, the fenestrated inner cannula are removed, and a nonfenestrated inner cannula is inserted. The ventilation device is then connected to the tube's 15 mm connector, and the ventilation gas is directed into the lungs.

The reported problem was able to occur because the fenestrated tube could be connected to a ventilation device without first occluding the fenestration. In this case, the use of a fenestrated inner cannula equipped with a 15 mm connector made the connection possible.

In January 1994, the manufacturer of the incident tube began packaging all of its Shiley fenestrated low-pressure cuffed and cuffless tracheostomy tubes with a fenestrated inner cannula equipped with a 15 mm twist-lock connector in addition to the nonfenestrated inner cannula that had been previously supplied. However, the products with both types of inner cannulas were marketed under the same product designation as those with only the nonfenestrated one.

In addition, the packaging differed only slightly: a sticker was added to the outer box, and a separate addendum was included in the instructions for use. Therefore, purchasers may not be aware that the package includes a fenestrated inner cannula, and users may misuse the tube. 

ECRI is aware of other manufacturers' fenestrated tracheostomy tubes that also provide access to a 15 mm connector without occluding the fenestrations in the outer tube. Although we are not aware of any reported problems or complaints related to this type of incident with the other products, user confusion or misuse could lead to a similar situation of inadequate ventilation.

Also, other tracheostomy tube manufacturers will, on request, offer products that provide access to a 15 mm connector without occluding any fenestrations in the outer tube. These custom-made fenestrated tracheostomy tubes pose the same risk of inappropriate connection to assisted ventilation devices.

Note that a variety of warning mechanisms are provided with some tubes in an attempt to alert clinicians to the potential for inappropriate connection to manual resuscitation or mechanical ventilation devices. In addition, a nonfenestrated inner cannula is packaged with these products for use when assisted ventilation becomes necessary. Such warning mechanisms may not be provided with custom tubes supplied by other manufacturers.

1. Warn all personnel trained in airway support that a tracheostomy tube may be fenestrated and therefore may be inappropriate to use for assisted ventilation—even if the tube has a 15 mm connector.
2. Instruct personnel to insert a nonfenestrated inner cannula, if available, before attempting assisted ventilation through a fenestrated tube. Be sure personnel are trained to check for adequate ventilation and know what to do if adequate ventilation cannot be achieved through a tracheostomy tube (regardless of the reason).
3. Identify all fenestrated tracheostomy tubes at your institution, and do the following:

A. Mark any packages that do not have appropriate labels with an applicable warning, such as "DO NOT USE FOR MANUAL OR MECHANICAL VENTILATION" or "INSERT NONFENESTRATED INNER CANNULA FOR ASSISTED VENTILATION" or a suitable equivalent. A similar warning should be kept in the vicinity of the patient, even during transport.

B. Strictly follow the manufacturer's instructions for use, as well as all package and/or product labeling and warnings.

C. Verify that all appropriate accessories (i.e., a nonfenestrated inner cannula) and spares are immediately available, even during transport, in case assisted ventilation becomes necessary.

Misuse of fenestrated tracheostomy tubes [Hazard Report]. 1978 Jan;7(3):91.

UMDNS Terms

• Tracheostomy Tube Adapters [14-92]
• Tubes, Tracheostomy [14-096]

Device factors: Design/labeling error; Packaging error

User errors: Failure to read label; Improper connection; Incorrect clinical use

Support system failure: Use of inappropriate devices

Failure to deliver therapy; Suffocation