What is the Effect of heated humidifier vs mist nebulizer on Endotracheal tube patency among intubated patients?

The process of humidification plays a crucial role in the comprehensive management of intubated patients undergoing invasive ventilation. Several studies have demonstrated the negative consequences of insufficient humidification on the respiratory system, including heightened respiratory effort, collapse of lung tissue (atelectasis), thick and dehydrated mucus, coughing and/or bronchospasm, obstruction or reduced openness of the endotracheal tube (ETT), and increased resistance to the flow of gases being delivered. The effects of the mist nebulizer and heated humidifier (HH) on the amount of endotracheal tube (ETT) blocking were compared by the authors.

This study consisted of a prospective, randomized controlled experiment including a total of 60 patients who had undergone overnight intubation and were spontaneously breathing. Of these patients, 30 were assigned to the HH group, while the other 30 were assigned to the mist nebulizer group. The quantitative measurement of endotracheal tube (ETT) patency decrease was conducted by calculating the difference in ETT volume between the pre-intubation and immediate post-extubation stages. This measurement was then compared between the two groups. Additionally, the study documented and analyzed the features of secretion, the temperature of inspired gas at the Y-piece, and the frequency of refilling the humidifier chamber.

The mist nebulizer group had a considerably greater decrease in endotracheal tube (ETT) capacity compared to the HH group (P-value 0.00026). The average temperature of the inspired gas, measured in degrees Celsius, was found to be significantly greater in the HH group (P-value < 0.0001). A higher proportion of patients in the mist nebulizer group had increased thickness (P-value 0.057) and reduced moisture content (P-value 0.005) of secretions in comparison to the HH group. There was no need for replenishing the humidifier chamber among the patients in the HH group, but the mist nebulizer group had an average frequency of 3.5 refills per patient.

The researchers reached the conclusion that the use of heated humidification (HH) in patients who are intubated overnight and undergoing spontaneous ventilation is linked to a reduced occurrence of undesired narrowing of the endotracheal tube (ETT) due to the presence of thick and dry secretions, as compared to the mist nebulizer. The use of HH as a consistent source of humidification has the potential to provide a dependable option that concurrently alleviates the burden on nursing personnel.

Reference-

Patil, Vijaya P.; Deb, Prakash; Agarwal, Vandana; Kumar, Pavan. Mist nebulizer versus heated humidifier on endotracheal tube patency in spontaneously breathing intubated patients: A prospective, randomized controlled trial. Journal of Anaesthesiology Clinical Pharmacology 39(1):p 51-55, Jan–Mar 2023. | DOI: 10.4103/joacp.joacp_121_21