Chart — Aerosol Therapy & Pharmacology
Aerosol Device Comparison Chart
The same drug deposits very differently depending on the device and the breath that drives it — a slow deep inhalation suits a pMDI, while a DPI demands a fast forceful one. This chart contrasts the pMDI, spacer, DPI, nebulizer, and soft-mist inhaler so you can match the device to the patient’s inspiratory ability and acuity.
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Aerosol Devices Side by Side
| Device | Inhalation Pattern | Coordination Needed | Best For | Key Limitation |
|---|---|---|---|---|
| pMDI | Slow, deep | High (actuate while inhaling) | Cooperative patients, maintenance | Coordination; oropharyngeal deposition |
| pMDI + spacer / VHC | Slow, deep (or tidal with a mask) | Low to moderate | Children, acute use, inhaled corticosteroids | Bulkier to carry |
| DPI | Fast, forceful | Low (breath-actuated) but needs high flow | Patients who can generate >60 L/min | Fails with low inspiratory flow |
| SVN (nebulizer) | Normal tidal breathing | Minimal | Acute distress, high doses, poor coordination | Slower; needs equipment |
| SMI (soft mist) | Slow, deep | Moderate (less than a pMDI) | Maintenance; lower flow needs | Multi-step setup |
Clinical Notes
- Match the device to the patient. Device choice is driven by the patient’s inspiratory ability and acuity, not by habit.
- A DPI needs flow. A dry-powder inhaler is useless without adequate inspiratory flow, so it is a poor choice in a patient who cannot inhale fast and forcefully.
- Default to low-coordination in distress. A nebulizer or pMDI-plus-spacer is the safer choice in acute distress.
- Always spacer the steroid. Use a spacer with every inhaled corticosteroid to cut oropharyngeal deposition.
Related Resources
Sources
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021.
- Gardenhire DS. Rau's Respiratory Care Pharmacology. 10th ed. Elsevier; 2019.