Question

Calculate the hourly dosage of heparin (units/hr). Order: 20,000 units of heparin in \(1,000 \mathrm{~mL}\) D5W to infuse at \(45 \mathrm{~mL} / \mathrm{hr}\).

Short answer

The hourly dosage of heparin is 900 units/hr.

Step-by-step solution

Understand the Problem

The doctor has ordered a heparin solution containing 20,000 units of heparin in 1,000 mL of D5W. This solution needs to be infused at a rate of 45 mL per hour. We need to calculate how many units of heparin are being administered each hour.

Determine Heparin Concentration

Calculate the concentration of heparin in the solution. Since there are 20,000 units of heparin in 1,000 mL, the concentration is given by the formula: \[ \text{Concentration} = \frac{20000\, \text{units}}{1000\, \text{mL}} = 20\, \text{units per mL} \]

Apply Infusion Rate

Now, use the infusion rate to calculate the hourly dosage of heparin in units. Since the solution is infused at 45 mL per hour, and there are 20 units per mL, the hourly dosage is: \[ \text{Hourly dosage} = 20\, \text{units/mL} \times 45\, \text{mL/hr} = 900\, \text{units/hr} \]

Key concepts

Pharmacology

Pharmacology is the study of how drugs interact with living organisms to produce a change in function. It is a key area in medical science, providing essential insights into how medications can both treat diseases and improve overall health. In the context of medical dosage calculation, pharmacology helps healthcare providers determine the optimal dose to achieve desired therapeutic effects while minimizing side effects. This involves understanding the drug's properties, the patient's condition, and any other medications being used. Pharmacology ensures that medications are used safely and effectively, highlighting the importance of precision when calculating dosages.

Infusion Rate

The infusion rate is a crucial parameter in medical dosage calculations, particularly for intravenous therapies. It refers to the speed at which a substance, like a medication in fluid form, is administered to a patient intravenously. This rate is typically expressed in milliliters per hour (mL/hr) and is critical for ensuring the correct dosage. Calculating the infusion rate accurately prevents both underdosing and overdosing. In our example, the infusion rate is set at 45 mL per hour. This ensures that the desired amount of medication, in this case, heparin, is delivered consistently over time. Understanding how to calculate and adjust infusion rates is vital for healthcare professionals to maintain therapeutic levels of medication in their patients' systems.

Heparin Administration

Heparin administration is a common medical practice when there is a need to prevent blood clots. Heparin is an anticoagulant, meaning it helps to inhibit the clotting processes in the body. Accurate dosing is essential due to its powerful effect on the body’s coagulation pathways. The amount administered must be carefully calculated based on the specific needs of the patient and the method of delivery. In this scenario, the solution contains 20,000 units of heparin in a 1,000 mL D5W solution, with an infusion rate of 45 mL/hr. This calculation shows that 900 units of heparin are administered each hour. Healthcare professionals rely on precise calculations for heparin administration to avoid risks like excessive bleeding or inadequate anticoagulation, emphasizing the significance of proper dosage calculations in clinical settings.