What is the metabolic oxygen consumption rate that must not be exceeded in a closed anesthetic system?

What is the metabolic oxygen consumption rate that must not be exceeded in a closed anesthetic system?

• A. 5-10 mL/kg/min
• B. 1-3 mL/kg/min
• C. 10-15 mL/kg/min
• D. 20-25 mL/kg/min

Answer: (A)

In a closed anesthetic breathing system, the oxygen supply must meet the body's metabolic oxygen consumption to keep arterial oxygen content adequate. For a typical adult, metabolic O2 use at rest is around 3.5 mL/kg/min, but under anesthesia and surgery it generally rises to about 5 mL/kg/min, and in states of fever, shivering, or high metabolic demand it can approach roughly 10 mL/kg/min. Therefore, using a range around 5–10 mL/kg/min as the threshold reflects the usual and potential maximum needs that the system must be able to supply. The lower option would undersupply even at rest, while the higher options exceed common requirements and aren’t the standard reference for this context.

In a closed anesthetic breathing system, the oxygen supply must meet the body's metabolic oxygen consumption to keep arterial oxygen content adequate. For a typical adult, metabolic O2 use at rest is around 3.5 mL/kg/min, but under anesthesia and surgery it generally rises to about 5 mL/kg/min, and in states of fever, shivering, or high metabolic demand it can approach roughly 10 mL/kg/min. Therefore, using a range around 5–10 mL/kg/min as the threshold reflects the usual and potential maximum needs that the system must be able to supply. The lower option would undersupply even at rest, while the higher options exceed common requirements and aren’t the standard reference for this context.