A 45-year-old,73-inch-tall,200 lb male patient is admitted to the emergency department with an exacerbation of myasthenia gravis.The respiratory therapist assesses the patient and finds the patient's maximum inspiratory pressure is 15 cm H₂O and his vital capacity is 1200 mL.It is decided that the patient requires ventilatory support.The most appropriate ventilator settings for this patient are which of the following?

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The patient is 73 inches and weighs 200 lb.Thus,ideal body weight (IBW)= 106 + 6(13)= 194 lbs,or 88 kg.The patient's body surface area (BSA)is 2.16 m².The estimated minute ventilation is 4 × 2.16 = 8.64 L.Using 7-10 mL/kg the set tidal volume should be between 617 and 880 mL.The positive end-expiratory pressure (PEEP)should be 5 cm H₂O and the fractional inspired oxygen (FɪO₂)should be 21% or close to it unless there is hypoxemia.A frequency of 12 with a tidal volume (Vᴛ)of 725 gives a minute volume of 8.7 L.This will give the patient full ventilatory support.Pressure support ventilation (PSV)is not appropriate because the patient appears too weak to breathe spontaneously.Noninvasive positive pressure ventilation (NPPV)is not appropriate because of the increased risk of aspiration.

A 45-Year-Old,73-Inch-Tall,200 Lb Male Patient Is Admitted to the Emergency