pH (arterial)
ABGNormal range
7.35–7.45
Critical low: < 7.25 · Critical high: > 7.55
☎ When to call
pH < 7.25 or > 7.55, or an acidotic patient becoming drowsy — rapid response territory. Bring the full ABG and vitals when you call.
What you do
- Read pH → PaCO₂ → HCO₃ in that order (see ABG walkthrough in this app)
- Acidotic + rising CO₂ + sleepy = failing ventilation — think BiPAP/intubation trajectory
Causes of HIGH ph
Causes of LOW ph
Source: Pagana, Mosby's Manual of Diagnostic and Laboratory Tests, 7th ed.Reference only — verify against your facility's policy.
