Cases & Commentaries

It's All in the Syringe

Commentary By Saul N. Weingart, MD, PhD

The Case

A 33-year-old man with type 2 diabetes presented
to his physician's office to discuss his diabetes management. The
patient admitted not taking his medications or checking his blood
sugars regularly. In the office, his blood sugar was 335 mg/dL, so
the nurse practitioner (NP) ordered 6 units of regular insulin to

After the medical assistant brought the insulin
and syringe, the NP prepared the medication and injected the
insulin. Immediately after the injection, the NP discovered that a
tuberculin syringe was used instead of an insulin one. As a result
of the error, the patient inadvertently received 60 units of
insulin rather than 6 units. The patient was given orange juice, a
sandwich, and his blood sugars were closely monitored for 4 hours
with no significant events.

The Commentary

Office-based physicians prescribe pills and
potions at a dizzying rate. Altogether, clinicians wrote more than
1.6 billion prescriptions in the United States in 2004.(1)
This amounts to 5.4 prescriptions for every U.S.
Patients leave the doctor's office with a prescription in hand in 7
out of 10 visits.(1) An
increasing number of prescriptions are written electronically,
although the precise number is not known.(3) While doctors and nurses interview, examine, diagnose,
and counsel, the prescription pad is never far away.

Although most prescription medications are
dispensed by the pharmacy for patients to self-administer at home,
ambulatory practices also provide and administer medications in the
office. We dispense and administer antihistamines, antipyretics,
and analgesics to relieve the symptoms of allergy, fever, and pain.
We administer injection therapies, including vaccinations, vitamin
B12, intramuscular antibiotics and analgesics, depot contraceptives
and antipsychotics, and intramuscular, articular, or bursal
anti-inflammatories. Some offices also administer injection
medications that patients are uncomfortable administering at home,
such as erythropoietin, testosterone, and interferon. Finally, we
may offer urgent treatments with triptans for acute migraine,
albuterol for asthma, epinephrine for anaphylaxis, nitroglycerin
for chest pain, and insulin for hyperglycemia. A striking feature
of this list is the variety of medications administered and the
broad indications they address, with the likelihood that a given
practice or provider might only care for a few patients requiring a
specific drug.

Although medication administration in the office
is widespread, it is potentially risky, as illustrated in the case
presented. In this case, a medical assistant handed a tuberculin
syringe to a NP who assumed it was an insulin syringe, accidentally
administering a 10-fold insulin overdose to a patient with moderate
hyperglycemia. Although the error was detected immediately and
addressed appropriately, the potential for harm was real.

This case illustrates the paucity of safeguards
for medication administration in the ambulatory setting. Consider
first the medication use process in the inpatient setting. For
medications to be administered to a hospitalized patient, the
physician must order the medication in an electronic system or on a
paper form. If the system is electronic, safeguards include typed
orders to ensure legibility, fixed fields to enforce complete
prescriptions, dose-range checks, drug allergy and drug interaction
checks, and accessible drug reference materials. In paper-based
systems, orders are usually transcribed and then reviewed by a
nurse for accuracy and completeness before being forwarded to the
pharmacy. In the pharmacy, orders are again entered and reviewed to
ensure they are safe and complete before the medication is
dispensed. Dispensing then requires multiple checks before the
drugs are finally delivered to the unit. Pharmacists in many
hospitals place medications in electronic dispensing cabinets,
where nurses must enter a code to retrieve the medications. The
nurse then follows a standard protocol for confirming the patient's
identity and the drug name, dose, route, and time before
administering the medication.

Compare this multi-step approach to the
medication administration process in office practice. In the
simplest case, the physician, physician assistant, or NP decides to
administer a medication that is stocked onsite. He or she draws up
an injection medication and administers the drug directly to the
patient. That's it. In a slightly more elaborate scenario, he or
she may ask another staff member to fetch the drug or to prepare
and deliver the medication themselves, a dramatically abbreviated
process compared to inpatient medication administration.

The simplicity of office-based medication
administration avoids many hazards of inpatient care related to
complexity, miscommunication, and handoffs. However, improved
efficiency comes with the loss of checks and redundancies that help
ensure patient safety. Unless the patient obtains a drug at the
pharmacy and carries it back to the office for administration,
there is no written prescription, no decision support, no second
clinician double-check, no pharmacist intervention, no "smart"
cabinet. Documentation may be inconsistent and difficult to find,
perhaps included in an office note or listed on a flow sheet or
problem list. When we administer medications in the office, we are,
in effect, driving without standard safety equipment: no bumpers,
no high beams, no horn, no anti-lock brakes, no airbags, no
seatbelts. We can do better.

If we performed a root cause analysis of the case
of the mixed-up syringe, we might ferret out latent conditions
that contributed to this error. The analysis might uncover
environmental factors that increased the risk of a mix-up, such as
poor lighting in the "med" room. In addition, the tuberculin
syringe might have been boxed next to the insulin syringe, or
perhaps they were mixed together in a common bin on a crowded
shelf. The analysis might also identify deficiencies in education
and training. For example, the medical assistant may have been new
to the job, not properly oriented or trained, and unaware of the
difference between various syringe types. There were probably
communication problems. The NP may not have specified that she
wanted an insulin syringe. Perhaps she was unable to confer
with a physician about the management of the case and the need for
immediate treatment. Working conditions may have contributed as
well. Heavy patient volume, urgent cases, add-on visits, and
unexpected staff absences could all have increased the day's
workload and production pressure. Finally, the practice probably
lacked policies for the use of high-hazard drugs such as insulin,
such as mandatory double-checks of drug name and dose.

Insulin holds a special place in the pantheon of
high-risk medications. Insulin errors and injuries are common among
hospitalized patients.(4-9)
The risk of treatment-related hypoglycemia is particularly high
among frail elderly patients after hospital discharge.(9)

Insulin overdoses due to confusion between
insulin and tuberculin syringes are well known, at least in the
hospital setting. In a case reported in a 2002 Institute for Safe
Medication Practices alert, a nurse administered a 10-fold overdose
to a hospitalized patient after the hospital switched its syringe
The new tuberculin and insulin syringes had similar packaging and
were accidentally stocked in the same drawer. The "mL" markings on
the syringe were mistaken for units. And, the tuberculin syringe
had an orange plunger tip similar to that used for many years on
insulin syringes. In 2004, the Pennsylvania Patient Safety
Authority also issued a tuberculin-insulin syringe advisory
following three 10-fold insulin overdoses attributed to packaging
and syringe design.(11)

Informed by the inpatient experience,
professional organizations have advanced a variety of
recommendations for improving insulin safety in the
For example, the work environment should be organized into bins and
buckets that are clearly labeled and appropriately stocked. Staff
members should be oriented and trained. Organizations should create
policies and procedures that specify double-checks for insulin (or
other high-risk medications) and "read-back" confirmation of verbal
orders. Special care should be exercised and training instituted
with packaging and labeling changes and when items are obtained
from new vendors.

Most of these recommendations are also
appropriate for ambulatory care and are consistent with our root
cause analysis. The challenge, of course, is redesigning systems
for solo or small group practices that ensure safety while
maintaining efficiency. In addition to striking such balances,
office-based practitioners should consider the opportunity to
partner with patients and their families.(12) In the case of the mixed-up syringe, could the
patient have prevented the incident? It is likely that the patient
had more experience administering insulin than his or her
caregivers. Had the patient been invited to review the drug and
dose or to administer the medication, the error might have been
averted. Clinicians certainly cannot abdicate responsibility for
patient safety.(13)
Nevertheless, patients and their families may offer an untapped
source of resilience, a resource for enhancing safety in ambulatory

Take-Home Points

  • Clinicians administer a wide range of
    medications in ambulatory care.
  • Few of the medication safeguards
    required or available in hospitals are used routinely in
    office-based practice.
  • Office-based clinicians should implement
    medication safety measures, particularly for high-risk drugs such
    as insulin. These safe practices should ensure that medications and
    related supplies are clearly labeled and stocked, that staff
    members receive appropriate training, and that clinicians double
    check the drug name, dose, and patient identification prior to
  • Office-based clinicians should also seek
    opportunities for patient participation in medication safety.

Saul N. Weingart, MD, PhD
Vice President for Patient Safety and Director of the Center for
Patient Safety, Dana-Farber Cancer Institute
Assistant Professor of Medicine, Harvard Medical School


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