You have 1: 10,000 adrenaline solution in a l. If you want to inject 1 mg of adrenaline, how much volume of this solution should be injected?
**Core Concept**
Adrenaline (epinephrine) is a potent vasoconstrictor and bronchodilator used in emergency medicine for anaphylaxis, cardiac arrest, and severe asthma. The concentration of adrenaline in a solution is crucial for accurate dosing, as it determines the amount of adrenaline administered per unit volume.
**Why the Correct Answer is Right**
To calculate the volume of the 1:10,000 adrenaline solution needed for a 1 mg dose, we can use the formula: Volume (mL) = Dose (mg) / Concentration (mg/mL). Since the concentration is 1 mg adrenaline per 10,000 mL, we need to convert this to mg/mL. There are 10,000 mg in 10,000 mL, so the concentration is 1 mg/10,000 mL = 0.0001 mg/mL. Now, we can plug in the values: Volume = 1 mg / 0.0001 mg/mL = 10,000 mL. However, this is the volume of the entire solution, and we need to administer only a small fraction of it. Since 1 mg is 1/10,000th of the solution, we need to inject 1/10,000th of the total volume, which is 1 mL.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not take into account the concentration of the solution. Simply dividing 1 mg by 10,000 mL would result in an incorrect answer.
**Option B:** This option is incorrect because it is the volume of the entire solution, not the volume of the solution needed for a 1 mg dose.
**Option C:** This option is incorrect because it is a fraction of the volume, but it does not accurately represent the fraction needed for a 1 mg dose.
**Clinical Pearl / High-Yield Fact**
When administering adrenaline, it's essential to remember that the concentration and volume of the solution are critical for accurate dosing. Always check the concentration and volume of the solution before administering adrenaline, and use a syringe or other measuring device to ensure accurate delivery.
**Correct Answer:** B. 1 mL.