A 45-Year-Old Female (58-Kg IBW)with a Past Medical History of Asthma

A 45-year-old female (58-kg IBW) with a past medical history of asthma arrives at the emergency department short of breath,anxious,diaphoretic,and unable to perform a peak expiratory flow measurement.She also has a combined acidosis.Breath sounds reveal the patient is not moving much air.The patient is intubated,stabilized,and transported to the ICU.The ventilator settings are: PC-CMV,f = 12/min,PIP = 30 cm H₂O,FɪO₂ = 0.6,and PEEP = 3 cm H₂O.The patient is sedated and paralyzed; the resulting ABGs are: pH 7.17,PₐCO₂ 69.3 mm Hg,PₐO₂ 90 mm Hg,and HCO₃⁻ 21 mEq/L after continuous bronchodilator therapy.The respiratory rate is increased to 20/min,and the next ABG results are: pH 7.26,PₐCO₂ 58 mm Hg,PₐO₂ 96 mm Hg,and HCO₃⁻ 22 mEq/L.The respiratory therapist should suggest which of the following at this time?

A) Increase PIP to 38 cm H₂O.
B) Decrease PIP to 25 cm H₂O.
C) Continue with current therapy.
D) Change to VC-CMV, f = 12/min, Vᴛ = 700 mL.