Pressurised metered dose inhalers (pMDI): risk of airway obstruction from aspiration of loose objects

Remind patients to check and remove the mouthpiece cover properly before inhaling a dose and to shake the inhaler to remove loose objects that may have become trapped in the inhaler during storage. The mouthpiece cover should be replaced securely after use. We have received reports of patients who have inhaled objects into the back of the throat, resulting in coughing. In some cases, objects were aspirated, causing airway obstruction.

Advice for healthcare professionals:

  • train patients in the correct use of their inhaler; instructions for patients are provided in the patient information leaflet
  • tell patients to remove the mouthpiece cover fully, shake the inhaler to remove loose objects that may not be visible, and check the inside and outside of the mouthpiece are clear before inhaling a dose
  • to prevent objects entering the mouthpiece during storage, remind patients to replace the cover immediately after use, ensuring it clicks into place
  • pharmacists dispensing a pMDI should emphasise to patients the need to clean the device regularly by following the instructions in the patient leaflet and to inspect the device for signs of damage; devices that are damaged should be replaced immediately
  • please continue to report adverse incidents during use of inhalers, as well as suspected adverse reactions to the medicine, on a Yellow Card

Background

Pressurised metered dose inhalers (pMDI) are widely used for delivery of rescue and maintenance bronchodilator and anti-inflammatory therapies for asthma. The mouthpiece of the inhaler is protected by a removable plastic cover.

To avoid accidental inhalation of the mouthpiece cover, the patient must fully remove the cover before inhaling a dose. If the inhaler is stored without the cover, loose objects can become trapped within the mouthpiece and inhaled into the back of the throat, resulting in coughing. In some cases, objects were aspirated, causing airway obstruction.

Reports of accidental inhalation

Since 1987, we have received 22 reports from Yellow Cards and other sources of accidental inhalation of the mouthpiece cover or objects that have become trapped in the inhaler after dispensing when stored by patients. Additionally, we are aware of 36 cases reported outside of the UK.

Loose/foreign objects reported in these cases include tissues, stickers, coins, and plastic items. Some incidents resulted in pharyngeal injury, temporary asphyxiation, or surgical removal of aspirated objects. One patient experienced a pneumothorax.

Recently, we have received a report in which a foreign body was aspirated; it became lodged in the bronchus causing granulation and had to be removed bronchoscopically.

It is estimated that 5.4 million people are being treated for asthma in the UK.1 Serious injuries from loose objects in inhalers are reported rarely. However, patients should be reminded to use caution.

It is essential that patients know to:

  • remove the mouthpiece cover completely

  • shake the device and check both the outside and inside of the mouthpiece is clear and undamaged before inhaling a dose

  • store the inhaler with the mouthpiece cover on

Call for reporting

Please continue to report adverse incidents during use of the inhaler, as well as suspected adverse reactions to the medicine, on a Yellow Card.

Medication incidents where no harm has occurred should continue to be reported via local risk management systems.

Article citation: Drug Safety Update volume 11, issue 12; July 2018: 2.

  1. Asthma UK. Asthma facts and statistics. Accessed July 2018. 

Published 17 July 2018