Evidence based practice (EBP) and aerosol therapy in the mechanically ventilated critically ill patient.
EBP has been modifying clinical practice for many years. Research studies are carried out, evidence evaluated, and guidelines established based on validated evidence and/or expert opinion. This leads normally to changes in clinical practice.
At different intervals further studies are carried out in response to questions and consequences arising from earlier recommendations. These further studies may result in new evidence contradicting earlier results and leading to revised guidelines.
Over 20 years ago studies showed that aerosol therapy with invasive ventilation was more effective when administered with dry air rather than with heated humidified gas. This led to the recommendation by some clinicians and researchers to turn off heated humidifiers during nebulisation to optimise aerosol delivery – especially when administering antibiotics.
Concerns over possible detrimental effects of this practice on the lungs led to further studies being carried out.
These more recent studies found no significant improvement in efficacy of aerosol delivery using dry gas – the practice of turning off humidifiers to improve aerosol delivery lacked sufficient evidence (1).
A recent study by Lellouche et al., evaluating the effects of turning off the heated humidified gas during aerosol administration, was published in the October edition of the Respiratory Care journal. Their findings showed potential risks associated with turning off the heated humidifiers for prolonged periods occurring in certain situations (2).
An international group of experts reviewed the new evidence and recommended that « heated humidifiers should not be turned off for aerosol therapy during mechanical ventilation »(3).
The Editorial for the article mentions that, among clinicians questioned, a survey showed that only between 4 to 37% followed the recommendations in their clinical practice (4).
Was this because many clinicians were unaware of the recommendation or because their clinical expertise made them question the evidence.
The editorial emphasises the importance of “critically evaluating existing recommendations and generating new evidence where needed”.
Nothing is written in stone!
You can download the articles here.
1) Jacquier et al: Effect of interrupting heated humidification on nebulised drug delivery …
https://pubmed.ncbi.nlm.nih.gov/38563793/ DOI:10.1089/jamp.2023.0028
2) Lellouche & Bouchard: Consequences of pausing heated humidification during invasive ventilation.
https://pubmed.ncbi.nlm.nih.gov/39079722/ DOI: 10.4187/respcare.12084
3) Jie Li et al: Aerosol therapy in adult critically ill patients: a consensus statement.
https://pubmed.ncbi.nlm.nih.gov/37436585/ DOI: 10.1186/s13613-023-01147-4
4) Editorial: reassessing the role of heated humidification during nebulisation: implications for clinical practice.
https://pubmed.ncbi.nlm.nih.gov/39327025/ DOI: 10.4187/respcare.12438
