Fink JB, Dhand R, Grychowski J, Fahey PJ, Tobin MJ. Am J Respir Crit Care Med 1999;159(1): 63–68.
aerosol delivery from MDI during mechanical ventilation aerosol delivery from MDI during mechanical ventilation with humidified circuitwith humidified circuit
bronchibronchi
30.4%
16.2%
22.0%
12.3%
Device related-NebulizerTypeFill volume Particle size Aerosol output rate Gas flow rateCycling: Continuous or intermittent nebulizationDuration of nebulizationPosition of the aerosol device in the ventilator circuitDevice related-Metered-dose inhalerAdapter/spacer Timing of actuationType of MDI Position of the aerosol device in the ventilator circuit
Factors that affect aerosol delivery and depositionFactors that affect aerosol delivery and deposition
continuous
Mass of budesonide deposited in inspiratory and expiratory filters. A: 1 mg of budesonide nebulized continuously and delivered into the inspiratory limb. B: 1 mg of budesonide nebulized continuously and delivered between Y-piece and ETTC: Nebulized intermittently and delivered between Y-piece and ETT
Pelkonen AS, Nikander K, Turpeinen M. Pediatr Pulmonol 1997;24(4):282–286.
Jet nebulization of budesonide in neonatal ventilator circuitContinuous VS intermittent nebulization
intermittent
Inspired limb
Y piece- ETT
Y piece- ETT
Y piece- ETT
Y piece- ETT
Inspired limb
intermittentcontinuous
NebulizerNebulizerBest Aerosol deliveryBest Aerosol deliveryposition 30 position 30 cmscms from ETTfrom ETT
Position of the aerosol device in ventilator circuit
pMDIpMDIBest Aerosol deliveryBest Aerosol deliveryposition 15 position 15 cmscms from ETTfrom ETT
ประโยชนของ spacer
1. เปน reservoir ใหยา aerosol ลอยอยูกอนหายใจเขา
2. ลด velocity ของ particle ที่ออกจากกระบอกยา
ทําให particle ขนาดเล็กลง
3. ลดผลขางเคียงจาก cold Freon ที่ทําใหเกิด
apnea เมื่อพน MDI
ขนาด spacer
inspiratory volume หรอื tidal volume ผป.
โดยทั่วไปใชขนาด 140-750 มล.
เด็กเล็ก (tidal volume <50 มล.) ใชขนาด 150 มล.ได
Metered dose inhaler with spacer
inline MDI actuators for delivery of beta agonist/ corticosteroid with a mechanically-ventilated lung
Rau JL, Dunlevy CL, Hill RL. Respir Care 1998;43(9):705–712.
Metered dose inhaler with spacer Metered dose inhaler with spacer in ventilator circuitin ventilator circuit
Drug relatedFormulationDoseparticle sizetargeted siteduration of action
Factors that affect aerosol delivery and depositionFactors that affect aerosol delivery and deposition
Dhand R, Tobin MJ. Am J Respir Crit Care Med 1997;156(1):3–10.
Factors that influence aerosol delivery Factors that influence aerosol delivery
Aerosol particle size&
device
Ventilator circuit
Artificial airway
Ventilator setting
Factors that influence Factors that influence aerosol delivery aerosol delivery in mechanically in mechanically
ventilated patientsventilated patients
Mode: PC vs vCRR, TV Inspiratory flow rate I : E ratio
Position of device in ventilator circuit
Density of gasHumidification ETT Size
Aerosol particle sizeDevice related-NebulizerTypeGas flow rateCycling: Continuous or intermittent nebulizationDevice related-Metered-dose inhaler Adapter/spacer Timing of actuation
Aerosol delivery with Aerosol delivery with pMDIpMDI
ACE spacer connect to resuscitating bagACE spacer connect to resuscitating bag
Aerosol delivery with Aerosol delivery with pMDIpMDI
ACE spacer connect to ventilator circuitACE spacer connect to ventilator circuit
Aerosol delivery with Aerosol delivery with pMDIpMDI
adapter connect to ventilator circuitadapter connect to ventilator circuit