The following is a summary of “Inhaled drug delivery: a randomized study in intubated patients with healthy lungs,” published in the December 2023 issue of Critical Care by Dugernier et al.

Despite proven benefits, delivering inhaled drugs through ventilators is a tangled mess with no clear winner. Researchers conducted a retrospective study investigating ventilated lung drug delivery, scrutinizing four configurations, including optimized setups, via labeled aerosol deposition in vivo and in vitro.

They randomly assigned 31 intubated neurosurgery patients with healthy lungs to 4 aerosol delivery configurations using a vibrating-mesh nebulizer and specific ventilator settings. A specific circuit for aerosol therapy (SCAT) with the nebulizer placed at 30 cm of the wye, heated-humidified circuit switched off 30 min before nebulization or left on with the nebulizer at the inlet of the heated-humidifier, and lastly, a conventional circuit with the nebulizer between the filter and the endotracheal tube. Aerosol deposition was assessed using planar scintigraphy.

The results showed a two to three times greater lung delivery in the SCAT group, amounting to 19.7% (14.0–24.5) of the nominal dose compared to the other groups (P<0.01). Approximately 50 to 60% of lung doses reached the outer region of both lungs across all groups. In the SCAT group, drug doses in inner and outer lung regions significantly increased (P<0.01), except for the outer right lung region in the fourth group, due to preferential drug trickling. Similar lung delivery was observed whether the heated humidifier was switched off or left on. In vitro inhaled doses correlated with lung doses (R = 0.768, P<0.001).

Investigator concluded that optimizing delivery soared drug deep into the lungs, but translating it to routine needs further research.

Source: annalsofintensivecare.springeropen.com/articles/10.1186/s13613-023-01220-y