IV Therapy
Infusion Time Calculator
How long a bag will last at a set rate.
Formula
Time (hr) = volume (mL) ÷ rate (mL/hr)
How it is used
- Use this to plan when to hang the next bag and to check that a medication finishes within its stability time.
Related one-pagers
- Dosage Calculation for the ExamInfusion time · Total mL ÷ mL/h · 1,000 ÷ 80 = 12.5 h; 0900 → 2130
- Sepsis and Septic Shock BundleAntibiotic time is when the infusion starts, not when it is ordered or verified. Hang the first dose in the ED rather than waiting for ICU transfer.
- Heart FailureDOSE (NEJM 2011; 308 patients) found boluses every 12 h and a continuous infusion equivalent; 2.5 times the oral dose given IV produced more diuresis and only a transient creatinine rise. A spot urine sodium below 50–70 mEq/L at 2 h, or urine output below 100–150 mL/h over the first 6 h, signals an inadequate response: double the dose (HFA position statement, Mullens 2019), then add a second diuretic (2022 guideline 2a).
- Toxidromes and AntidotesOpioids kill by hypoventilation, hypoxemia and arrest. Fentanyl is 50–100 times as potent as morphine (CDC), acts within minutes, can cause chest-wall rigidity with rapid IV doses and is missed by standard opiate screens; carfentanil and nitazenes may need repeated naloxone. Naloxone's half-life is 30–81 min (label), shorter than methadone or extended-release opioids, so watch for re-sedation: repeat doses or an infusion of two-thirds of the waking dose per hour (AHA 2023), and observe until mental status and vital signs normalize.
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For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.