Drill two: time, volume remaining, titration, units per hour

Strip 1 — Infusion time

1000 mL running at 75 mL/hr. 1000 mL × (1 hr / 75 mL) = 13.33 hr. Convert the remainder: 0.33 hr × 60 min/hr = 20 min. 13 hours 20 minutes. Never chart a decimal hour.

Strip 2 — Volume remaining

A 1000 mL bag started at 0800 at 125 mL/hr. At 1400, elapsed time is 6 hr. 6 hr × 125 mL/hr = 750 mL infused. 1000 mL − 750 mL = 250 mL remaining

Strip 3 — Completion time

250 mL × (1 hr / 125 mL) = 2 hr. Two hours after 1400, the bag completes at 1600.

Strip 4 — Concentration first, always

Heparin 25,000 units in 250 mL. 25,000 units ÷ 250 mL = 100 units/mL. Ordered: 1200 units/hr. 1200 units/hr × (1 mL / 100 units) = 12 mL/hr

Strip 5 — Insulin, where the concentration is one

100 units in 100 mL of 0.9 % sodium chloride. 100 units ÷ 100 mL = 1 unit/mL. A pump running at 4.5 mL/hr delivers 4.5 units/hr. The two numbers match only because the concentration happens to be one, and that is verified against the bag label, never assumed.

Strip 6 — Titration from micrograms per minute

Norepinephrine 4 mg in 250 mL. 4 mg = 4000 mcg. 4000 mcg ÷ 250 mL = 16 mcg/mL. Ordered: 8 mcg/min. 8 mcg/min × (1 mL / 16 mcg) × (60 min / 1 hr) = 480 ÷ 16 = 30 mL/hr

Strip 7 — Weight-indexed titration

Dopamine 400 mg in 250 mL. 400 mg = 400,000 mcg. 400,000 mcg ÷ 250 mL = 1600 mcg/mL. Patient 70 kg, ordered 5 mcg/kg/min. 5 mcg/kg/min × 70 kg = 350 mcg/min. 350 mcg/min × 60 min/hr = 21,000 mcg/hr. 21,000 mcg/hr × (1 mL / 1600 mcg) = 13.125 = 13.1 mL/hr

Watch outHIGH ALERT INFUSION. Heparin, insulin and vasoactive drips carry an independent double check by a second nurse before the pump starts and before any rate change.

Memory hookconcentration first. Everything after it is one multiplication.

Margin notethis book prints no coagulation or glucose target. → BOOK 07 · P6

Takeawayreduce the bag to a concentration before you touch the order, and every titration collapses into arithmetic you already know.