20% N2O and 80% O2 produce the same analgesic effect as how many mg of morphine?

The statement that a mixture of 20% nitrous oxide (N2O) and 80% oxygen (O2) produces the same analgesic effect as 15 mg of morphine is based on the understanding of analgesia and the equivalence of different analgesic agents. Nitrous oxide, known for its analgesic and anesthetic properties, is commonly used in medical settings for pain relief.

Research indicates that nitrous oxide's analgesic potency can be compared to that of morphine, which is one of the most widely used opioid analgesics. The equivalency is based on clinical studies that have assessed the analgesic effects of nitrous oxide versus various doses of opioids, including morphine. The specified combination of nitrous oxide and oxygen effectively provides comparable pain relief to 15 mg of morphine, striking a balance that can be effectively employed in medical practice for pain management.

The other options, while they represent other doses of morphine, do not align with the established equivalency derived from studies comparing the analgesic effects of nitrous oxide. Thus, 15 mg is the most accurate answer when comparing the specific effects of the gas mixture in relation to morphine dosage.