Research Finds Heat and Moisture Exchanger Cassettes More Effective for Mucus Plugs After Larynx Removal in Cancer Patients

July 16, 2020

PHILADELPHIA (July 16, 2020)—Fox Chase Cancer Center researchers have concluded that heat and moisture exchanger (HME) cassettes are more effective at preventing mucus plugs following removal of the larynx than external tracheal humidification.

Tracheal dryness is a major concern for patients who have their larynx removed due to cancer because it can lead to a buildup of mucus—known as mucus plugs—that can potentially block airways.

“After a patient has a total laryngectomy, the trachea is turned out the front of their neck and they have what’s called a permanent tracheostoma. So they don’t breathe through their nose anymore, they breathe through their neck,” said Barbara Ebersole, BFA, MA, CCC-SLP, lead author on the study and assistant research professor for the Department of Surgical Oncology at Fox Chase.

Ebersole conducted the study with John A. Ridge, MD, PhD, FACS, vice-chair of the Department of Surgical Oncology, and other researchers from the Lewis Katz School of Medicine at Temple University and Villanova University.

“One of the things about breathing out of your neck is that you lose the function of the nose in filtering, warming, and moisturizing the air you breathe,” said Ebersole. “Once you lose that function, the air hitting the lungs tends to be colder, drier, and dirtier than the lower respiratory system is used to.”

To humidify the airway and prevent mucus plugs, patients who receive total laryngectomies are equipped with an external tracheal humidification device, also known as a trach collar, during their hospital stay. An HME cassette, which is used for the same purposes, is typically used in outpatient situations.

In the retrospective study, researchers implemented a patient safety initiative that compared outcomes before and after using HME during post-laryngectomy hospitalization. The number of mucus plug events was compared with a group using external tracheal humidification before the patient safety initiative was implemented.

The study found that the rate of mucus plug events was significantly lower in the HME group than in the external tracheal humidification group. The proportion of patients with one or more mucus plug events was also significantly reduced in the HME group.

Ebersole said although the outcomes weren’t necessarily surprising to researchers, the study speaks to the efficacy of using HME as a primary practice and underscores important steps for using it.

“I thought it was really important to get this data out there, because the larger body of evidence we have to support that it’s a safer change, the more comfortable other organizations will be with adopting this practice,” said Ebersole.

“We’re currently looking to implement a process to use HME instead of external trach humidification on all our trach patients,” she said.

The study, “Heat and Moisture Exchanger Cassettes: Results Of a Quality/Safety Initiative to Reduce Postoperative Mucus Plugging After Total Laryngectomy,” was published in the journal Head & Neck.


The Hospital of Fox Chase Cancer Center and its affiliates (collectively “Fox Chase Cancer Center”), a member of the Temple University Health System, is one of the leading cancer research and treatment centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase was also among the first institutions to be designated a National Cancer Institute Comprehensive Cancer Center in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are also routinely recognized in national rankings, and the Center’s nursing program has received the Magnet recognition for excellence five consecutive times. Today, Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research, with special programs in cancer prevention, detection, survivorship and community outreach. It is the policy of Fox Chase Cancer Center that there shall be no exclusion from, or participation in, and no one denied the benefits of, the delivery of quality medical care on the basis of race, ethnicity, religion, sexual orientation, gender, gender identity/expression, disability, age, ancestry, color, national origin, physical ability, level of education, or source of payment.
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