Pharmacology & Dosage Calculation
A nurse is preparing to administer an intravenous infusion of 2000 ml of Ringer's lactate over 12-hours.
The administration set has a chamber that delivers 15 drops per ml. How many drops per minute should be administered?
الشرح
Core Concept: Calculating intravenous drip rates manually is a fundamental nursing skill to ensure the correct volume of fluid is infused over the prescribed time, preventing fluid overload or dehydration.
Clinical Presentation:
- Classic symptoms: N/A (Calculation scenario).
- Complications: Fluid overload, phlebitis, or inadequate resuscitation.
Diagnosis:
- First-line diagnostic plan/tool: IV flow rate formula: (Total Volume in ml × Drop Factor in gtt/ml) / Total Time in minutes = gtt/min.
- Most accurate (gold standard) diagnostic test: Mathematical verification and use of an electronic infusion pump when available.
Management:
- Acute management: Calculate the time in minutes: 12 hours × 60 minutes = 720 minutes. Apply the formula: (2000 ml × 15 gtt/ml) / 720 min = 30,000 / 720 = 41.66 gtt/min.
- Gold standard long-term/definitive management: Round to the nearest whole drop, which is 42 drops per minute. Regulate the manual roller clamp accordingly and frequently assess the IV site and infusion rate.