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Reporting a Medication Error

Confusing Syringe Scale

Published May 1, 2022

Caregivers and patients might be confused when measuring liquid medicine doses using the syringe scale printed on Covidien’s Monoject 3 mL ENFit syringes. An ENFit syringe is specially designed for medicines taken by mouth or given through tubes that go into the digestive track. The scale on these syringes is marked as ½, 1, ½, 2, ½, and 3 mL (Figure 1). This can easily be misunderstood, reading the intended 1½ mL or 2½ mL as just ½ mL. The confusion could lead to preparing and administering the wrong dose. Syringe scales should never indicate doses using fractions but should indicate the entire volume using decimals (0.5, 1.5, 2.5). The company is aware of our concerns. Avoid using these syringes.

Figure 1. Syringe scale using fractions at midpoints could confuse users, as the “½” symbol between two whole numbers could easily be misread as just ½ mL.

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