Implementation study reveals efficacy of Medovate’s novel HME safety device

19th February, 2021

A new study examining the performance of Medovate’s novel HME safety device HUMIDICARE® confirms proof of principle of the HUMIDICARE® engineered device. The technology – which provides a visual alert for healthcare staff if a Heated Humidifier (HH) and a Heat and Moisture Exchanger (HME) are inadvertently used in the same ventilator circuit – prompts early intervention actions thus helping to mitigate the associated patient safety risks.

The study, published in the Journal of Medical Engineering & Technology, examined HUMIDICARE® in simulated clinical conditions, undertaken at The Queen Elizabeth Hospital King’s Lynn NHS Foundation Trust in Norfolk.

Two simulation scenarios were carried out to determine how the device performed in instances of dual humidification error; the first to assess the temperature activation threshold of the device, and the second to determine its efficacy as an alert system in a simulated breathing circuit.

The study concludes that the device “performed reliably and activated rapidly when required across all simulations”. It also describes HUMIDICARE® HME as “a simple and unobtrusive device [that] can effectively alert the operator to the error of dual humidification.”

Artificial humidification in ventilated patients

Artificial humidification systems are used with ventilated patients in the operating theatre or intensive care unit to replicate the natural humidification which occurs in the upper airway during natural breathing.

Commonly used in clinical settings are both heated humidifiers (HH) or passive heat and moisture exchangers (HME). They replicate the functions of the body's upper airway in an artificial breathing circuit, by conserving expired heat and moisture and returning these to the patient during inhalation. This helps prevent drying of natural secretions in the airway and inflammation which can lead to complications such as lung damage, lung infection or airway obstruction.

Complications can arise when both HH and HME are inadvertently used in the same breathing circuit for a ventilated patient. If this occurs and the equipment error is not noticed and rectified it can result in partial or full blockage of the airway with potentially fatal outcomes.

HUMIDICARE is engineered to mitigate risks

When patients are transferred from operating theatres to intensive care, their breathing circuits are often changed to heated humidified breathing systems (HH). In the course of this transition, it is vital that HMEs are removed before connecting the patient to the humidified system. Failure to do so can result in the HME filter getting blocked, thereby also, over time, blocking the patient’s airway.

The inadvertent simultaneous use of both devices within the same circuit can cause critical airway occlusion within 24 hours.

Although numbers suggest incidences are infrequent at a local level, a search of the National Reporting and Learning System (NRLS) identified 76 incidents where a HME had accidentally been left attached to a wet circuit. In many cases the error was not recognised for several hours and caused respiratory distress. In 2015 the NHS issued a patient safety alert to raise awareness of this risk.

Safety engineered warning system

Medovate’s safety HME uses proprietary technology to visually alert healthcare staff and make them aware of the incidence of dual humidification in a ventilation circuit, prompting them to check equipment and take necessary corrective action, potentially saving the patient’s life.

HUMIDICARE® incorporates a temperature dependent HME warning system that visually alerts clinicians when the HME has been inadvertently placed in a circuit containing a HH. In all other circumstances HUMIDICARE® works and performs as a standard HME.

The device thus reduces the need for clinicians to rely on memory, experience or training alone in a complex clinical environment when a rare error occurs, and instead provides a rapid ‘prompt’ to warn clinicians at the critical moment of circuit connection.

The new study shows that the device performs reliably and consistently, providing a rapid early warning system, visually alerting staff to the incidence of dual humidification so positive action can be taken in a timely manner to protect the patient.

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