## **Core Concept**
The blood/gas solubility coefficient is a measure of how much of an inhalational anesthetic agent dissolves in blood compared to air. It is an important determinant of how quickly an inhalational anesthetic can induce and recover from anesthesia. Agents with low blood/gas solubility coefficients allow for rapid induction and recovery.

## **Why the Correct Answer is Right**
Sevoflurane has a relatively low blood/gas solubility coefficient compared to other inhalational agents listed. The blood/gas solubility coefficients for common inhalational agents are approximately: Sevoflurane (0.69), Desflurane (0.42), Isoflurane (1.4), and Halothane (2.4). Desflurane, having the lowest value among these, enables very rapid induction of and recovery from anesthesia because it does not dissolve much in blood, thus it acts quickly.

## **Why Each Wrong Option is Incorrect**
* **Option A:** Isoflurane has a higher blood/gas solubility coefficient (1.4) compared to Desflurane, making it less ideal for rapid induction and recovery.
* **Option B:** Halothane has an even higher blood/gas solubility coefficient (2.4), which slows down induction and recovery.
* **Option C:** While Sevoflurane does have a relatively low blood/gas solubility coefficient (0.69), it is not as low as Desflurane's.

## **Clinical Pearl / High-Yield Fact**
A key clinical point to remember is that inhalational anesthetic agents with low blood/gas solubility coefficients (like Desflurane and Sevoflurane) are preferred in situations where rapid recovery is desired, such as outpatient surgeries. Desflurane's very low solubility makes it particularly useful for procedures requiring quick turnaround times.

## **Correct Answer:** D. Desflurane