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Review
. 2018 Mar;30(1):86-97.
doi: 10.5935/0103-507x.20180015.

Humidification and heating of inhaled gas in patients with artificial airway. A narrative review

[Article in English, Spanish]
Gustavo Adrián Plotnikow  1 , Matias Accoce  1 , Emiliano Navarro  1 , Norberto Tiribelli  1
Affiliations
Review

Humidification and heating of inhaled gas in patients with artificial airway. A narrative review

[Article in English, Spanish]
Gustavo Adrián Plotnikow et al. Rev Bras Ter Intensiva. 2018 Mar.

Abstract

Instrumentation of the airways in critical patients (endotracheal tube or tracheostomy cannula) prevents them from performing their function of humidify and heating the inhaled gas. In addition, the administration of cold and dry medical gases and the high flows that patients experience during invasive and non-invasive mechanical ventilation generate an even worse condition. For this reason, a device for gas conditioning is needed, even in short-term treatments, to avoid potential damage to the structure and function of the respiratory epithelium. In the field of intensive therapy, the use of heat and moisture exchangers is common for this purpose, as is the use of active humidification systems. Acquiring knowledge about technical specifications and the advantages and disadvantages of each device is needed for proper use since the conditioning of inspired gases is a key intervention in patients with artificial airway and has become routine care. Incorrect selection or inappropriate configuration of a device can have a negative impact on clinical outcomes. The members of the Capítulo de Kinesiología Intensivista of the Sociedad Argentina de Terapia Intensiva conducted a narrative review aiming to show the available evidence regarding conditioning of inhaled gas in patients with artificial airways, going into detail on concepts related to the working principles of each one.

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Conflict of interest statement

Conflicts of interest: None.

Figures

Figure 1
Figure 1
Graphical description of absolute and relative humidity.
Figure 2
Figure 2
Bypass of the airway based on the type of artificial airway.
Figure 3
Figure 3
Schematic description of the working principle of a heat and moisture exchanger and placement in the ventilator circuit.
Figure 4
Figure 4
A) Heat and moisture exchangers for patients with artificial airways in spontaneous ventilation (particularly in tracheotomized patients). B) Graphic comparison between volumes of a conventional heat and moisture exchanger for use in patients with artificial airway in mechanical ventilation and one for use in tracheotomized patients with spontaneous ventilation.
Figure 5
Figure 5
Correlation between internal volume and humidity delivered in Eckerbom's study. The programming of the ventilator corresponds to "Setting II" of the study (tidal volume of 500 -mL, respiratory frequency of 20 breaths per minute). Pearson's correlation coefficient was used for the statistical analysis.
Figure 6
Figure 6
Correlation between the internal volume of the heat and moisture exchanger and the absolute humidity delivered. The programming of the ventilator corresponds to "Setting I" (tidal volume of 500mL, respiratory frequency of 20 breaths per minute). In "B", the same analysis as in "A" was conducted, but excluding the 3 bacterial filters (Pall, Intertech HEPA, Intersurgical). Pearson's correlation coefficient was used for the statistical analysis.
Figure 7
Figure 7
Algorithm for the selection of the humidification device. ICU - intensive care unit; AA - artificial airway; NIV - non-invasive mechanical ventilation; VT - tidal volume; HMEF - heat and moisture exchanger with filter.
Figure 8
Figure 8
Recommendations to take into account for placement of an active humidifier.
Figure 9
Figure 9
Recommendations to take into account for the placement of a heat and moisture exchanger.
See this image and copyright information in PMC

References

    1. Lindemann J, Leiacker R, Rettinger G, Keck T. Nasal mucosal temperature during respiration. Clin Otolaryngol Allied Sci. 2002;27(3):135–139. - PubMed
    1. Keck T, Leiacker R, Riechelmann H, Rettinger G. Temperature profile in the nasal cavity. Laryngoscope. 2000;110(4):651–654. - PubMed
    1. Walker AK, Bethune DW. A comparative study of condenser humidifiers. Anaesthesia. 1976;31(8):1086–1093. - PubMed
    1. Mercke U. The influence of temperature on mucociliary activity. Temperature range 40 degrees C to 50 degrees C. Acta Otolaryngol. 1974;78(3-4):253–258. - PubMed
    1. Burton JD. Effects of dry anaesthetic gases on the respiratory mucous membrane. Lancet. 1962;1(7223):235–238. - PubMed