Humidification of oxygen prior to administration by nasal cannula is an expensive practice. It has been justified on the basis that it improves the comfort of patients receiving supplemental low-flow oxygen therapy.

In view of the high costs of adding humidity to nasal oxygen—and its questionable justification—we undertook a study of subjective complaints of: 1) patients receiving dry supplemental nasal cannula oxygen via oxygen concentrators; and 2) patients currently on humidified nasal cannula oxygen via oxygen concentrators.

Mark A. Chmielinski

When supplemental oxygen is provided by nasal cannula, patients inspire through an intact upper airway, so normal airway humidification mechanisms are intact. The sole justification for humidifying oxygen administered by this route is prevention of patient discomfort related to dehydration of the upper-airway mucosa. Routinely humidifying oxygen for low flow (4 L or less/min) via nasal cannula administration is still a common practice among hospice nurses, alternative-site caregivers, and most nursing agencies.

Respiratory home care providers have long accepted problems such as cross-threading, rain-out, cross-contamination, routine maintenance programs, and hidden costs associated with operating a humidifier bottle. But legislative and reimbursement trends are forcing providers to find ways to reduce their operating costs without jeopardizing patient care.

Advanced hollow fiber membranes, successfully employed in the food, pharmaceutical, and other industries, are now being applied to help respiratory providers improve the quality, safety, and reliability of humidification programs while reducing their costs. This type of product, called Humidiflow™, is manufactured by St Paul, Minn-based Porous Media Corp. It was developed in response to home care respiratory providers interested in a humidification technology that could reduce or eliminate service calls related to the above-mentioned problems. This product significantly reduces the high cost, training, ongoing maintenance and cleaning, trouble-shooting calls, technician service calls, and hassles required with conventional bubble humidification bottles.

Humidiflow technology uses advanced hollow-fiber membranes to act as a moisture exchanger. The unit, which houses the membranes inside a cylinder-shaped shell, is plumbed in-line and upstream of the oxygen concentrator's air compressor. Oxygen flows through the inside of the membranes while ambient air—drawn in by the air compressor—flows countercurrently on the outside of the membrane. The moisture from the surrounding atmosphere diffuses across the membrane into the dry oxygen stream, invisibly humidifying the oxygen and providing increased patient comfort. The Humidiflow device is designed to deliver 95% to 98% of the room air's relative humidity level.

Thus far, our organization has provided Humidiflow-retrofitted oxygen concentrators to 16 carefully selected existing oxygen patients using traditional bubble humidifiers. Pre-Humidiflow surveys were provided to each patient in this double-blind study to determine frequency of use, water refilling, rain-out in tubing, and cross-threading/clogging issues. Post-Humidiflow surveys were also conducted, including daily phone calls by an RRT to assess sufficient nasomucosal hydration based on symptoms experienced. All 16 patients were asymptomatic with respect to nasomucosal irritation, nose bleeding, or feeling of nasal dryness; and they did not notice any difference in hydration. All 16 patients have expressed their satisfaction with the Humidiflow device, especially with the convenience of not having to maintain a bubble humidifier and not having to contend with rain-out in their tubing.

We were so impressed with these results and cost savings that we decided to retrofit all of our concentrators with this technology. From an operational standpoint, this device has already reduced expenses. From a marketing standpoint, the device provides a value-added service to all of our patients. It is an opportunity to supply universal oxygen humidification without the concern of additional increased support costs. This technology is so effective that oxygen concentrator manufacturers are offering this product as an option.

Mark A. Chmielinski, RRT, LRCP, is vice president of clinical services, Home Care of Michigan Inc, Allen Park, Mich.