Clinical Indications That Your Patient Has Acute Ventilatory Failure Include

Clinical indications that your patient has acute ventilatory failure include:
1) pH < 7.35.
2) vital capacity (VC) < 20 ml/kg.
3) PaCO₂ > 45 mm Hg.
4) negative inspiratory force (NIF) < -25 cm H₂O.

A) 3
B) 1, 3
C) 2, 4
D) 1, 2, 3, 4