Use this worksheet to practice essential dosage calculations, unit conversions, and IV infusion rates for nursing exams.

Let's solve each problem step by step using the dosage calculation formula and infusion rate formulas, along with the conversion chart provided.

---

Part 1: Dosage Calculations

We use the formula:

> Volume to administer (mL) = Desired dose / Concentration (mg/mL or units/mL)

---

#### 1. Morphine 0.5 mg IV every 4 hours, vial labeled 2 mg/mL

- Desired dose = 0.5 mg
- Concentration = 2 mg/mL

$$
\text{Volume} = \frac{0.5\ \text{mg}}{2\ \text{mg/mL}} = 0.25\ \text{mL}
$$

✔ Answer: 0.25 mL per dose

---

#### 2. Versed 4 mg IV, vial labeled 1 mg/mL

- Desired dose = 4 mg
- Concentration = 1 mg/mL

$$
\text{Volume} = \frac{4\ \text{mg}}{1\ \text{mg/mL}} = 4\ \text{mL}
$$

✔ Answer: 4 mL per dose

---

#### 3. Heparin 100 units subq daily, vial labeled 50 units/mL

- Desired dose = 100 units
- Concentration = 50 units/mL

$$
\text{Volume} = \frac{100\ \text{units}}{50\ \text{units/mL}} = 2\ \text{mL}
$$

✔ Answer: 2 mL per dose

---

#### 4. Benadryl 25 mg IV, vial labeled 1000 mcg/mL

⚠️ First, convert mg to mcg:
- 1 mg = 1000 mcg → 25 mg = 25 × 1000 = 25,000 mcg

- Desired dose = 25,000 mcg
- Concentration = 1000 mcg/mL

$$
\text{Volume} = \frac{25,000\ \text{mcg}}{1000\ \text{mcg/mL}} = 25\ \text{mL}
$$

✔ Answer: 25 mL per dose

---

#### 5. Digoxin 0.125 mg IV stat, vial labeled 500 mcg/2 mL

Convert 0.125 mg to mcg:
- 0.125 mg = 0.125 × 1000 = 125 mcg

Now find concentration in mcg/mL:
- 500 mcg / 2 mL = 250 mcg/mL

Now calculate volume:

$$
\text{Volume} = \frac{125\ \text{mcg}}{250\ \text{mcg/mL}} = 0.5\ \text{mL}
$$

✔ Answer: 0.5 mL per dose

---

Part 2: Infusion Rate Calculations

Use the formula:

> Hourly Rate (mL/hr) = Total Volume (mL) / Time (hours)

---

#### 1. 300 mL of NS over 6 hours

$$
\text{Rate} = \frac{300\ \text{mL}}{6\ \text{hr}} = 50\ \text{mL/hr}
$$

✔ Answer: 50 mL/hr

---

#### 2. 2 L of D5W1/2 NS over 48 hours

Convert 2 L to mL:
- 2 L = 2000 mL

$$
\text{Rate} = \frac{2000\ \text{mL}}{48\ \text{hr}} ≈ 41.67\ \text{mL/hr}
$$

Rounded to nearest whole number: 42 mL/hr

✔ Answer: 42 mL/hr

---

#### 3. 0.8 L of NS over 45 minutes

Convert 0.8 L to mL:
- 0.8 L = 800 mL

Convert 45 minutes to hours:
- 45 min = 45/60 = 0.75 hours

$$
\text{Rate} = \frac{800\ \text{mL}}{0.75\ \text{hr}} = 1066.67\ \text{mL/hr}
$$

✔ Answer: 1066.67 mL/hr (or approximately 1067 mL/hr)

---

✔ Final Answers Summary:

#### Dosage Calculations:
1. Morphine: 0.25 mL
2. Versed: 4 mL
3. Heparin: 2 mL
4. Benadryl: 25 mL
5. Digoxin: 0.5 mL

#### Infusion Rates:
1. 300 mL over 6 hr: 50 mL/hr
2. 2 L over 48 hr: 42 mL/hr
3. 0.8 L over 45 min: 1067 mL/hr

---

Let me know if you'd like these problems explained in a video format or need help with drop factor calculations next!