PaCO₂
ABGNormal range
35–45 mmHg
SI: 4.7–6.0 kPa
Critical low: < 20 mmHg · Critical high: > 60 mmHg
☎ When to call
Rising CO₂ with decreasing alertness — call now; CO₂ narcosis precedes respiratory arrest.
What you do
- The RESPIRATORY number — it moves opposite to pH in respiratory problems
- High CO₂ + sedation: check the MAR for opioids/benzos; stimulate, consider naloxone conversation
- COPD retainers live high — compare to their baseline, not the textbook
Causes of HIGH paco₂
Causes of LOW paco₂
Source: Pagana, Mosby's Manual of Diagnostic and Laboratory Tests, 7th ed.Reference only — verify against your facility's policy.
