Dose of thiopentone is?
**Core Concept**
Thiopentone, also known as thiopental, is a barbiturate used for inducing general anesthesia. Its dosage is critical due to its narrow therapeutic index and potential for toxicity.
**Why the Correct Answer is Right**
Thiopentone is administered intravenously, typically at a dose of 3-5 mg/kg to induce anesthesia. The dose is usually adjusted based on the patient's age, weight, and medical condition. The mechanism of action involves the inhibition of neuronal activity by enhancing the activity of GABA (gamma-aminobutyric acid), a neurotransmitter that has a calming effect on the nervous system.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is lower than the standard dose, which may not be sufficient for induction of anesthesia.
**Option B:** This option is incorrect because it is higher than the standard dose, which may increase the risk of thiopentone toxicity, including respiratory depression and hypotension.
**Option C:** This option is incorrect because it is not a standard dose for thiopentone, and the correct dose is typically given as a range (3-5 mg/kg).
**Clinical Pearl / High-Yield Fact**
When administering thiopentone, it is essential to monitor the patient's vital signs, including heart rate, blood pressure, and oxygen saturation, to avoid potential complications. A dose of 3-5 mg/kg is usually sufficient for most adult patients, but the dose may need to be adjusted in pediatric or geriatric patients.
**Correct Answer: C. 5 mg/kg.**