CPAP & Noninvasive Ventilation
Objective: Decide when CPAP/NIV helps (wet lungs, COPD work of breathing) and when it is the wrong tool — vomiting, unresponsive, or hypotensive patients.
Why This Is Hard
CPAP looks like “just a mask.” It is positive pressure. It can unload wet lungs and stent open collapsing airways in COPD. It can also drop blood pressure, inflate the stomach, and dump vomit into the lungs if you pick the wrong patient.
- Alert enough to protect the airway?
- Wet lungs / severe COPD work of breathing?
- No vomiting, no unprotected airway, no crashing hypotension
- Suction and BVM staged if CPAP fails
When It Fits (Education)
- Cardiogenic pulmonary edema / CHF: alert, working hard, wet lungs, hypertensive or at least not crashing-hypotensive — sit them up; CPAP when protocol includes it.
- COPD exacerbation: alert enough to cooperate, severe work of breathing; NIV/CPAP is often preferred over jumping to intubation when they can still participate.
- This is not the first move for asthma-with-a-silent-chest who needs exhalation time and meds (see the obstructive ventilation lesson).
When It Does Not
- Unresponsive or no protective airway reflexes.
- Active vomiting, massive upper GI bleed, or copious secretions you cannot control.
- Suspected pneumothorax / hypotension / shock where positive pressure may worsen venous return.
- Facial trauma that destroys the seal, or a patient who will rip the mask off and cannot be coached.
Street Habits
- Coach: “This will feel tight. Breathe with me.” Start and watch BP, mentation, SpO₂, and work of breathing.
- Have suction and a BVM staged. CPAP failure is an airway plan, not an argument with the machine.
- Settings and PEEP belong to your protocol and device training — this lesson does not authorize a number.
Field Pitfalls
- CPAP on a lethargic patient who then aspirates.
- Ignoring a falling BP after the mask goes on.
- Using CPAP as a delay tactic when they need a tube now.
Practice
60-second drill
Two vignettes in 30 seconds each: (1) alert, hypertensive, wet-lung CHF; (2) GCS 8, vomiting, SpO₂ 82%. Say CPAP yes/no, one reason, and your backup if the mask fails. Partner fails you if you never mention BP or suction.
Related: CHF / pulmonary edema, Oxygen titration.
Sources & Further Study
Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.
- GOLD COPD strategy — NIV preferred over jumping to intubation in selected COPD exacerbations
- 2022 AHA/ACC/HFSA Heart Failure Guideline — NIV/CPAP for selected acute cardiogenic pulmonary edema
- NASEMSO National Model EMS Clinical Guidelines (2022)
- CPAP/NIV for selected alert patients with pulmonary edema or COPD. Contraindications include unprotected airway, vomiting, and shock. Protocol owns settings.
Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.
Check Your Understanding
Street decisions from this lesson only. After you check, the key is highlighted. Education practice — not a certification exam.