Humidification during oxygen therapy and non-invasive ventilation: do we need some and how much?

Excerpt

Oxygen supply and non-invasive ventilation (NIV) are the first-line therapy for respiratory failure. However, despite the increasing use of NIV and continuous positive airway pressure (CPAP) to treat acute respiratory failure and the long use of oxygen therapy, there is, surprisingly, no explicit recommendation on the level of additional humidification that is necessary and how to deliver it. In fact, it is still not 100% clear if any humidification is actually required at all. There are a lack of studies addressing the benefit of humidification during oxygen therapy in terms of outcome, and those focusing on comfort have yielded contrasting results [1, 2]. A survey of intensive care unit (ICU) physicians’ practices in terms of humidification during NIV [3] revealed that 25% of the respondents did not use any sort of humidification device. This result is consistent with the preliminary results of a multicenter survey in which six of the 15 participating centers reported having no humidification protocol during NIV [4]. Thus, the question of whether or not the absence of humidification affects NIV outcome remains unanswered. In this same study [4], the rate of difficult intubation following NIV failure was 5.4%; among this very small group, 45% patients had no humidification. This lack of data for any association between the lack of humidification with NIV failure and difficult intubation does not mean, however, that patient comfort is not affected by the absence of humidification, as is the case during nasal CPAP for obstructive sleep apnea. …