In this episode of Hospital Medicine Unplugged, we pit CPAP vs BPAP—who’s first-line, who’s for the exceptions, and how to choose fast at the bedside.

We open with the big picture: CPAP remains first-line for uncomplicated OSA—it’s effective, more cost-effective, and no clear superiority of BPAP for routine outcomes or adherence in general OSA. BPAP shines when ventilation needs a boost or when CPAP isn’t tolerated.

How we call it (efficacy & outcomes):
• Both reduce AHI, sleepiness, and improve quality of life.
• No clinically meaningful outcome gap between CPAP and BPAP for uncomplicated OSA.
• BPAP ≠ better adherence in the general OSA population.

Tolerance & comfort—when BPAP helps:
• Pressure intolerance on CPAP? BPAP’s lower EPAP / higher IPAP can ease exhalation, cut aerophagia, and improve comfort.
• Switching CPAP→BPAP can reduce mouth dryness, bloating, and improve patient preference in those struggling with fixed pressure.

Special populations—where BPAP earns its keep:
• Hypoventilation phenotypes (OHS, COPD overlap): BPAP augments ventilation, drops PaCO₂, and improves gases better than CPAP.
• When residual hypercapnia persists on CPAP, escalate to BPAP (consider backup rate if needed).

What the guidelines say (clean takeaways):
• Start CPAP for most uncomplicated OSA.
• Use BPAP when there’s CPAP intolerance, inadequate AHI/RDI control, or documented hypoventilation/hypercapnia.
• In OHS with severe OSA, begin with CPAP; switch to BPAP if hypercapnia persists or CPAP fails.

Quick definitions (what they do):
• CPAP = single, constant pressure that splints the upper airway.
• BPAP = IPAP/EPAP levels that support ventilation and reduce work of breathing.

Clinical plays you can use tomorrow:
• Default: CPAP for routine OSA (optimize mask fit, humidification, behavioral support).
• If pressures climb and comfort tanks (exhalation difficulty, aerophagia): trial BPAP.
• If daytime hypercapnia/ABG abnormal or OHS/COPD overlap: favor BPAP to clear CO₂.
• Refractory residual AHI on CPAP (with good adherence): evaluate for positional/REM-predominant disease, mask leak, then consider BPAP or other modes.

Adherence pearls that actually work:
• Fit matters: interface options + proactive leak control.
• Humidification to fight dryness.
• Early follow-up + troubleshooting beats “set-and-forget.”
• Keep SpO₂ targets individualized; in overlap/COPD, avoid over-oxygenation.

Common pitfalls (and fixes):
• Chasing comfort with early steroids…oops, wrong episode. Here, the trap is escalating CPAP pressures without addressing exhalation load—switch to BPAP instead.
• Assuming BPAP boosts adherence for everyone—it doesn’t; use it selectively.
• Ignoring hypercapnia on CPAP—check ABGs/CO₂; upgrade to BPAP if needed.

Fast close:
Bottom line: CPAP first for most OSA—effective, economical, evidence-backed. BPAP is your targeted tool for pressure intolerance and hypoventilation syndromes (OHS/COPD overlap), where ventilatory support and CO₂ reduction matter. No broad adherence or outcome edge for BPAP in routine OSA—reserve it for the right patient, at the right time.