Oxygen wall humidifiers are used regularly in the hospital. Although the humidifiers in mechanical ventilators have been extensively investigated, oxygen wall humidifiers are often neglected in the literature. Both reusable and disposable humidifiers are available, and according to the recommendation from the Centers for Disease Control (CDC), both types of humidifiers are acceptable. For reusable humidifiers however, it is crucial that they be washed daily as recommended and that water left in the reservoir be discarded before refilling.
In the CDC guideline for the prevention of nosocomial pneumonia, it is stated that disposable humidifiers for wall oxygen outlets “may be safe for long periods.” However, studies that actually assess the efficacy of these humidifiers on patients are rarely reported, and, to the best of our knowledge, only one such study has been published.