NurseSavvy Cheat SheetProcedure

Continuous Infusion Calculations

Overview

Continuous IV infusions deliver high-alert drugs (heparin, insulin, norepinephrine and other vasopressors) at a precisely titrated rate. The core skill is converting an ordered dose into a pump rate in mL/hr using the drug concentration, then re-titrating that rate to a target lab or hemodynamic value (aPTT, blood glucose, MAP). Weight-based drips (units/kg/hr or mcg/kg/min) require the client weight in kilograms and a x60 min/hr conversion before dividing by concentration.

Technique

Dose → pump rate (mL/hr)

  1. Ordered dosee.g. 0.08 mcg/kg/min
  2. x weight (kg)0.08 x 92 kg
  3. x 60 min/hr= 441.6 mcg/hr = 0.4416 mg/hr
  4. ÷ concentration÷ 0.016 mg/mL (4 mg/250 mL)
  5. Pump rate= 27.6 mL/hr

During — Monitoring

Heparin: aPTT trended to goalaPTT goal 60–100 sec
Weight-based; titrate units/kg/hr per protocol
Insulin: serial blood glucoseDKA target 120–180 mg/dL
Watch rate of fall, not just the absolute value
Vasopressor: MAPMAP goal ≥ 65 mmHg
Titrate mcg/kg/min to MAP; respect dose ceiling
Pump settings reverified each titration

Interpretation

Trend the full data set, not one value
A single in-range glucose can hide a steep decline
Rapid glucose fall predicts hypoglycemia
~90–100 mg/dL/hr drop: reduce rate, recheck in 30 min
Persistent subtherapeutic aPTT despite escalation
Suspect heparin resistance after repeated dose increases
Honor protocol dose ceiling
Vasopressor max e.g. 0.5 mcg/kg/min; heparin has a practical ceiling

Patient Teaching

Report bleeding or bruising on heparin
Report tremor, sweating, palpitations
Adrenergic signs of hypoglycemia on insulin
Do not adjust the pump independently
Report Nowescalate immediately
Active bleeding on heparin
Hold infusion and notify provider
aPTT critically high (supratherapeutic)aPTT above critical/goal range
Bleeding risk; hold/adjust per protocol
aPTT subtherapeutic after repeated escalations
Notify provider for possible heparin resistance; do NOT hold for low aPTT with active clot
Adrenergic symptoms with falling glucose
Tremor + diaphoresis: reduce insulin rate, recheck in 30 min
MAP below goal despite max vasopressorMAP < 65 mmHg at dose ceiling
Pump misprogramming on high-alert drip
Stop, recompute, independent double-check

Clinical Pearl

The pump speaks mL/hr, the order speaks dose — convert, double-check, then titrate to the trend (aPTT, glucose, MAP), never to a single number.

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