A 70 kg patient in septic shock is prescribed an intravenous infusion of Noradrenaline at 0.1 mcg per kg per minute. The pharmacy prepares a solution containing 4 mg of Noradrenaline diluted in 250 mL of 0.9% normal saline. At what rate in mL per hour should the nurse set the infusion pump?

1. A

   35 mL/hr

2. B

   16.5 mL/hr

3. C

   26.25 mL/hr

4. D

   6.5 mL/hr

Appeared in: NORCET-11 Prelims

Explanation

• Dose required: 0.1 mcg/kg/min x 70 kg = 7 mcg/min.
• Hourly dose: 7 mcg/min x 60 = 420 mcg/hr.
• Solution concentration: 4 mg = 4000 mcg in 250 mL, so 16 mcg/mL.
• Infusion rate: 420 mcg/hr ÷ 16 mcg/mL = 26.25 mL/hr.
• Setting the pump at 26.25 mL/hr delivers the correct dose.

Why Other Options Were Wrong

• Option A: 35 mL/hr would deliver a higher dose than prescribed, risking overdose and adverse effects.
• Option B: 5 mL/hr underdoses the patient, providing less noradrenaline than required for effective shock management.
• Option D: 5 mL/hr is much too low and would result in subtherapeutic noradrenaline delivery.

Related Visual

Clinical Relevance

• Nursing practice connection: Prioritize focused assessment, early escalation, and real-time monitoring when managing Calculation of IV infusion rate for weight-based noradrenaline dosing in acute care settings.
• Accurate calculation of infusion rates is critical in managing septic shock to avoid under- or overdosing.
• Nurses must double-check calculations and infusion pump settings to ensure patient safety.
• What if? If the patient's weight was different or the solution concentration changed, the mL/hr rate would need to be recalculated accordingly.

How to Approach the Question

• Identify the prescribed dose per kg per minute and calculate the total dose per minute for the patient's weight.
• Convert the dose to an hourly requirement (multiply by 60).
• Determine the concentration of the prepared solution (total drug in mcg divided by total volume in mL).
• Divide the hourly dose by the concentration to get the required infusion rate in mL/hr.
• Match your answer to the closest option provided.

Concept Tested & Keywords

• Concept Tested: Calculation of IV infusion rate for weight-based noradrenaline dosing
• Stem keywords: 70 kg patient, septic shock, Noradrenaline, 0.1 mcg/kg/min, 4 mg in 250 mL, infusion pump rate
• Lead-in keywords: at what rate, mL per hour, should the nurse set
• Clinical cues: weight-based dosing
• Clinical cues: critical care setting

Question ID

QsDSo6fnBULDoB-zxKKFeP

Copy ID

Reference Book

E6 Pharmacology Nurses Shanbhag 3e p. 54-56