Table 2 Future research direction of aerosol delivery via different respiratory support devices

Common

• Studies on short-term and long-term clinical outcomes are needed:

o Evaluation on the short-term outcomes depends on the effects of aerosolized medications. For example, bronchodilation effects for bronchodilator delivery; the effects on pulmonary arterial resistance and oxygenation for pulmonary vasodilator delivery. If the aerosolized medications do not have short-onset, and short-term effects are lacking, such as inhaled steroids or antibiotics, assessments of bronchoalveolar lavage or systemic levels such as the drug concentration in the urine or blood are also needed. Sufficient intervals for wash out are needed

o Long-term outcomes include the duration of respiratory support, the need for escalation of respiratory support, length of ICU stay, etc

• Evaluation on the cost-effectiveness is also needed, such as the cost on the aerosol generators, aerosolized medications, respiratory support device, and healthcare providers’ time at bedside

• Translational studies on new technology are needed, especially those with significant improvement in aerosol delivery found in bench studies, such as inspiration-synchronized mesh nebulizer, the utilization of soft-mist inhalers via respiratory support devices, etc.

Specific

• The clinical effects of humidification on aerosol delivery

• The effects of antibiotics on the treatment for ventilator-associated pneumonia

• Aerosol delivery via NIV with dual-limb circuits

• The clinical benefits of titrating gas flow in aerosol delivery via HFNC