Which of the following conditions are listed as requiring increased minute ventilation on a ventilator?

• A. DKA
• B. Hyperthermia
• C. Morbid obesity
• D. All of the above

Answer: (D)

The key idea is that minute ventilation needs to rise when a patient is making more CO2 or when ventilation becomes less effective. In diabetic ketoacidosis, metabolic acidosis drives a compensatory increase in ventilation to blow off CO2, so you need to raise minute ventilation on the ventilator. Hyperthermia boosts metabolic rate and CO2 production, which similarly requires higher ventilation to prevent CO2 buildup. Morbid obesity makes breathing more work and can reduce ventilation efficiency, increasing CO2 retention and the need for a higher minute ventilation. Because all of these conditions raise the demand for CO2 removal, the ventilator settings should be adjusted to increase minute ventilation.