Patient Safety Tip of the Week
April 14, 2015 Using Insulin
Safely in the Hospital
It’s been almost 5
years since we last did a comprehensive column on insulin-related issues (see
our November 2, 2010 Patient Safety Tip of the Week “Insulin:
Truly a High-Risk Medication”). More recently we’ve focused more on
issues related to insulin pumps and insulin pens and related devices. But 3
recent articles again remind us of the myriad of problems that may occur with
insulin.
The first, published by ISMP Canada, is a very instructive
case in which insulin administered via an incorrect route for treatment of hyperkalemia
resulted in profound hypoglycemia and consequent brain injury (ISMP
Canada 2015). The patient was a nondiabetic patient receiving hemodialysis
who was admitted to a surgical unit with a bowel obstruction. The patient was
found to have significant hyperkalemia and a physician handwrote orders for
salbutamol by inhalation, 1 ampule of D50W (route not specified), and regular
insulin 10 units (route not specified). The D50W was given intravenously but the
regular insulin was given by subcutaneous injection. When later found
unresponsive, the patient’s blood glucose level was undetectable. Subsequently
it was also determined that the initial potassium level was falsely elevated
due to specimen hemolysis.
ISMP Canada does an excellent job describing multiple
aspects of the case. But perhaps the most salient lesson is has to do with the
difference in duration of action for the D50W and regular insulin administered
via the subcutaneous route. For management of hyperkalemia insulin is supposed
to be delivered via the IV route, where its action is immediate. But when
administered via the subcutaneous route the action of the insulin is delayed
and its duration is prolonged. Hence, in this case the action of insulin
extended beyond the period of protection by D50W and profound hypoglycemia
resulted.
The original orders were handwritten and routes were not
specified by, nor subsequently clarified with, the ordering physician. The
insulin order was not reviewed by a pharmacist (ward stock availability of both
the D50W and insulin bypassed pharmacist review). The nurse’s familiarity with
the subcutaneous route for insulin administration may have introduced confirmation
bias. A second nurse reviewing the order verified the route of administration
that had been on the transcription of the handwritten order (rather than seeing
the original handwritten order?). And no order had been given for monitoring
blood glucose levels after administration of the insulin. They also noted that
different treatment approaches would likely have resulted if the hemodialysis
service had been consulted and if the falsely elevated potassium level had been
recognized. A significant problem was the lack of a standardized order set for
management of hyperkalemia.
They provide a number of recommendations for hospitals,
prescribers, healthcare IT systems, nurses and pharmacies to help avoid similar
occurrences. But a key recommendation is development and use of order sets for
off-label use of commonly used medications, particularly those that are
high-alert medications.
This is an excellent article with multiple lessons learned.
We hope you will read the article
in full.
The second recent article reminds us of the continuing
dangers related to U-500 insulin (Leuck
2015). The article is written from the perspective of a pharmacist
and contends that any order for U-500 insulin should be considered a red flag
and require review by a pharmacist. We couldn’t agree more! The article points
out the two biggest reasons for errors related to U-500 insulin: (1) the
syringes used and (2) the different units/mL.
Unfortunately, there still are currently no syringes calibrated for the higher
concentrations so healthcare workers often use this dosage form with insulin
syringes that are calibrated for 100 unit per mL insulin preparations. That’s a
setup for errors. The author also notes that it may be unclear when a physician
writes a prescription for, say, 25 units of U-500 insulin whether they really
mean 25 units or 25 mL (the latter representing 125 units of insulin). So the
author recommends electronic prescribing systems and EHR’s be programmed to present an alert that would
result in a pharmacist reviewing the order with the prescriber and then making
sure that nursing staff understand how it is to be administered.
We discussed the
syringe issue in our November 2, 2010 Patient Safety Tip of the Week “Insulin:
Truly a High-Risk Medication”. In that column we also recommended
that the 500 unit per mL preparations be stored completely separate from the
other insulin preparations and only be used by specially designated
healthcare workers who have received specific training in use of the higher
concentration product. Certainly, they should never be stored as part of “floor
stock” where they might be easily mixed up with the more common 100 unit per mL
preparations. We even raised the question as to whether U-500 insulin should be
stocked at all in a hospital. Unfortunately, the need for that higher
concentration has been increasing in recent years as more obese patients with
insulin resistance have been requiring much higher insulin doses and the higher
concentrations may also be needed for patients having implanted insulin pumps.
We recommended that if you need to stock the higher concentration, make sure
you have some mechanism (like a “hard stop”) to ensure that a pharmacist is
involved in validating and preparing the dose and always have an independent
double check before such preparations are administered.
The third recent article by the ECRI Institute highlights
the vulnerabilities that occur at each step of the entire medication process continuum
for insulin (ECRI
2015). They start at the prescribing
stage where the classic problem is use of the abbreviation “U” for units.
The problem arises when the “U” looks like a zero so the patient inadvertently
is given 10 times too high a dose. (Note that similar problems can arise when
the abbreviation “IU” for international units is used.). In our November 2, 2010 Patient Safety Tip of
the Week “Insulin:
Truly a High-Risk Medication” we also noted that we have
occasionally found these dangerous abbreviations in old order sets on computer
systems or in order sets “customized” by physicians and not properly vetted.
Under the prescribing stage the ECRI article also includes the risk of
confusion among the many look-alike sound-alike (LASA) insulin formulations. In
our previous article we gave some examples of the LASA errors and noted the
importance of using tall-man lettering to help avoid some of these
errors. We also highlighted the problem that occurs when computerized screens truncate
choices on drop-down menus.
At the transcribing
stage the ECRI article highlights the problems related to illegible writing
and use of acronyms. They also highlight the problem of using outdated
medication lists during medication reconciliation when the patient arrives at
the hospital. Obviously, insulin doses can be changed frequently and careful
reconciliation on admission (and discharge or transfer) is very important.
Equally important when medication reconciliation is done on admission is
determining accurately when the patient took their last dose of insulin
(and their last meal). That is one of the most common errors we find with
medication reconciliation. One other problem we have encountered is that many
notes, even in the electronic medical record, are still dictated and
transcribed. If a physician does not carefully review those transcriptions,
errors in insulin dose or preparation may be propagated to other settings.
At the dispensing
stage the ECRI article emphasizes failure
to double check. That double check should include the insulin product, the
concentration, and the dosage. Care needs to be taken here to avoid look-alike sound-alike (LASA) errors.
Our November 2, 2010 Patient Safety Tip
of the Week “Insulin:
Truly a High-Risk Medication” discussed the many reported errors in
which heparin and insulin vials are confused.
At the administration
stage the ECRI article discusses incorrect doses, formulations, and
concentrations plus LASA errors. It also includes here issues with misuse of
insulin pens (see our many columns on insulin pen issues listed at the end of
today’s column) and problems with erroneous recording of patient’s glucose.
Problems with patient identification appear here. They also note here the issue
of timing of meals (or lack thereof) in relation to insulin administration.
Here we again would add failure to double check as a hazard.
In our October 16, 2012 Patient Safety
Tip of the Week “What
is the Evidence on Double Checks?” we did recommend that double checks be
done before administering high-risk medications such as insulin. It is
important here also not to over-rely on technology. One problem encountered
several times is when the physician prescribes the wrong insulin dose. The
nurse may recognize it might be too high a dose but the bar coding system tells
the nurse that this is the correct patient and this is the correct insulin
preparation and dose that is in the computer. So use of a barcoding system does
not obviate the need for double checks.
At the monitoring
stage the ECRI article notes problems such as failure to monitor a
patient’s response to insulin so that appropriate changes in insulin dose are
not made.
We refer you to our November
2, 2010 Patient Safety Tip of the Week “Insulin:
Truly a High-Risk Medication” for numerous other important details
and links to some excellent resources. It also deals with issues such as
problems that can arise during hospital transports and handoffs, problems with
co-management of patients, use of insulin drips, and avoiding “sliding scale”
insulin coverage. But we think most of the recommendations listed in that
column are still worth repeating here:
- First,
do an inventory of the various insulin preparations currently in stock in
your organization (what they are, which manufacturers, where they are, who
has access to them, etc.).
- Look
at all the vials containing insulin to determine which ones look alike.
- Make
sure that other medications in vials that may be confused with insulin
(such as heparin) are not stored in proximity to insulin vials. In
particular, don’t allow vials of insulin to be kept on counter tops or
carts or under pharmacy medication hoods where they might be easily confused
with heparin vials.
- If
necessary, consider using different manufacturers for different
preparations to avoid look-alike vials.
- Query
your pharmacy IT system to see what types of insulin have actually been
prescribed in the past 6-12 months.
- In
particular, see whether you stock and use the 500 units/mL preparation of
insulin. If you rarely use it, don’t stock it. Then, if you need to use if
for an individual patient, make sure you remove it after that patient has
been discharged. If you must use it, restrict the number of nursing or
pharmacy staff who may prepare this high dose preparation.
- Review
and revise, if necessary, your TPN policies as they relate to use of
insulin and heparin.
- Make sure
that “U” is on your “do not use” abbreviation list and that abbreviation
has been purged from all your software.
- Use
“tall man” lettering to help distinguish insulin products with look-alike
names.
- Include
“last dose taken” on your medication reconciliation forms for insulin and
other high-risk drugs.
- Review
your policy on how daily medications are given in relation to admission
orders (to make sure you do not omit an insulin dose today because the
hospital policy moves the first dose to the next day after a certain
time).
- Use
standardized order sets or protocols wherever possible for insulin.
- Make
sure your computer displays don’t truncate critical information about each
insulin formulation.
- Make
sure you know who is responsible for ordering insulin when patients are
being “co-managed” by more than one physician.
- Make
sure you have correct insulin syringes available on all units where
insulin is prepared or administered and that all staff are competent in
correct use of insulin syringes.
- If you
use insulin pens in your facility, make sure you follow all the recommendations
in the FDA
alert about insulin pens (see also our several columns on insulin pen
safety listed at the end of today’s column)
- Determine
whether you would be able to use alerts on your computerized systems if an
order for a certain dosage of insulin were exceeded.
- Use
independent double checks in both the preparation and administration
phases for insulin.
- Make
sure that instructions on what to do regarding insulin are included on
handoff tools when patients are transported to radiology or other areas of
the hospital
- Make
sure your MRI unit is aware of the issues regarding insulin pumps.
- Have a
monitoring plan in place for glycemia
management. Use trigger tools such as flagging any use of 50% glucose as a
likely sign of an insulin error.
- Most
importantly, learn from your mistakes and from the mistakes others have
made in use of insulin.
- Educate
and re-educate all your staff on insulin issues. While we always say that
education and training are “weak” patient safety interventions, there is a
real value in promoting a culture of patient safety when high risk
situations are reiterated. Remember, tell stories – that’s what
gets staff to think “could that happen here?”.
- Use an
audit tool such as those available through the ASHP
to see how your organization stacks up in its safe approach to insulin
management.
ISMP reminds us that not all healthcare providers have a
good understanding of insulin dosing. A 2011 report by ISMP noted instances
where residents or other physicians were administering insulin and made
significant errors (ISMP
2011). It is a reminder that many physicians have never received formal
training on insulin administration. We should never assume providers know how
to administer insulin.
In 2013 the American Society of Health-System Pharmacists
(ASHP) Research and Education Foundation convened a multidisciplinary panel of
experts to address safe insulin practices. The panel made 10 recommendations (Cobaugh
2013) that address the areas of prescribing, dispensing and storage,
administering, monitoring, evaluating and planning:
- Develop protocol-driven
and evidence-based order sets for specific uses of insulin such as
transition of administration route from intravenous to subcutaneous,
administration via implantable insulin pumps, post-discharge dosing,
diabetic ketoacidosis, hyperosmolar states, hyperkalemia, and post-cardiac
surgery care. These order sets should include orders for glucose monitoring
and decision support capabilities that guide insulin use based on the
patients’ nutrition status. In addition, protocol-driven and
evidence-based order sets for the management of hypoglycemia should be
developed and integrated into the care of all hospitalized patients who
receive insulin.
- Eliminate the routine
administration of correction/sliding scale insulin doses as a primary
strategy to treat hyperglycemia.
- Eliminate the use of “free
text” insulin orders in electronic and paper medical records and replace them
with protocol-driven and evidence-based order sets that allow for the prescribing
of complex insulin regimens.
- Store only U100
concentration insulin and U100 administration devices (e.g., syringes, pens)
in patient care areas and ensure that they are stored in a secure fashion
and segregated from other medications.
- Develop hospital-wide
standard concentrations for insulin infusions to be adopted and used in
all patient care areas.
- Limit preparation,
including for procedural areas, of all intravenous bolus insulin doses and
intravenous insulin infusions to the pharmacy department.
- Hospitals must develop
policies and procedures to ensure that insulin pens are used for individual
patients only. In addition, hospitals must establish policies and
educational programs to ensure the safe use of insulin pens and disposable
needle tips.
- Ensure that insulin use is
linked directly to patients’ nutrition status. Meal delivery, point-of-care
glucose testing and insulin administration should be well-coordinated and standardized.
Patients and their family caregivers should be educated to request administration
of rapid-acting insulin when the patient begins her/his meal. In patients with
variable nutritional intake, insulin administration should be delayed
until completion of the meal. Protocol-driven and evidence-based order
sets should be developed for insulin use and blood glucose monitoring
during planned and unplanned interruption of enteral nutrition or total
parenteral nutrition.
- Every hospital should
prospectively monitor/measure rates of hypoglycemia and hyperglycemia;
insulin use; and coordination of insulin administration, glucose testing and
nutrition delivery. Real-time, institution-wide glucose reports should be
provided to health care team members to ensure appropriate surveillance
and management of patients with unexpected hypoglycemia and hyperglycemia.
- Provide standardized
education, including competency assessment, to all hospital-based health
professionals who are responsible for the use (e.g., prescribing, compounding,
dispensing, administering, monitoring) of insulin.
And while most of our discussion has focused on insulin
errors in hospitals, we should be reminded that they also occur in the
ambulatory setting. A review of data from poison control centers showed a
substantial trend of increasing reports of unintentional therapeutic errors
involving insulin from 2000 to 2009 (Spiller 2011). These
were primarily in adults age 40 and older but females were disproportionately
involved and events occurred more often in late evening. It is not clear
whether this reflects the types of error or simply who uses the poison control
centers. Unfortunately, the study did not include data on the nature of the
therapeutic errors.
When hospitals ask us what are good topics for FMEA’s
(failure mode and effects analyses) we often suggest insulin management as an
excellent one. Problems can occur at so many stages of the whole insulin
management system that doing a FMEA on this can be very rewarding.
Some of our prior
columns highlighting the safety issues of insulin, insulin pumps, insulin pens
and similar devices:
November 2, 2010 “Insulin:
Truly a High-Risk Medication”
September 18, 2012 “Insulin
Pump Safety”
February 26, 2013 “Insulin
Pen Re-Use Incidents: How Do You Monitor Alerts?”
April 2013 “More
Tips on Insulin Pen Safety”
April 2014 “Insulin
Pens - Again”
July 2014 “Joint
Commission Sentinel Event Alert: Don’t Misuse Vials”
March 10, 2015 “FDA
Warning Label on Insulin Pens: Is It Enough?”
References:
ISMP Canada. Wrong-Route Incident Involving Insulin and
Dextrose Prescribed for Hyperkalemia. ISMP Canada Safety Bulletin 2015; 15(2):
1-4 March 5, 2015
http://www.ismp-canada.org/download/safetyBulletins/2015/ISMPCSB2015-02_DextroseInsulin.pdf
Leuck S. Dosing Dangers of U-500
Insulin. Pharmacy Times 2015; April 7, 2015
ECRI Institute. Insulin Errors Occur Across the Medication
Use Process. ECRI Institute’s PSO Monthly Brief. February 2015
https://www.ecri.org/EmailResources/PSO_Monthly_Brief/2015/PSO_Brief_0215.pdf
FDA. FDA Drug Safety Communication: FDA requires label
warnings to prohibit sharing of multi-dose diabetes pen devices among patients.
FDA Safety Announcement 2015; February 25, 2015
http://www.fda.gov/Drugs/DrugSafety/ucm435271.htm
ASHP (American Society of Health-System Pharmacists) and Hospital
and Health-System Association of Pennsylvania. Professional practice
recommendations for safe use of insulin in hospitals. Rockville (MD): American
Society of Health-System Pharmacists
http://www.ashp.org/s_ashp/docs/files/Safe_Use_of_Insulin.pdf
Cobaugh DJ, Maynard G, Cooper L,
et al. Enhancing insulin-use safety in hospitals: Practical recommendations
from an ASHP Foundation expert consensus panel. Am J Health-Syst
Pharm 2013; 70(16): 1404-1413
http://www.ashpmedia.org/AJHP/Enhancing-insulin-use-safety-in-hospitals.pdf
ISMP (Institute for Safe Medication Practices).
Misadministration of IV insulin associated with dose measurement and
hyperkalemia treatment. ISMP Medication Safety Alert! Acute Care Edition.
August 11, 2011
https://www.ismp.org/newsletters/acutecare/articles/20110811.asp
Spiller HA, Borys DJ, Ryan ML, et
al. Unintentional Therapeutic Errors Involving Insulin in the Ambulatory
Setting Reported to Poison Centers. The Annals of Pharmacotherapy 2011; 45(1):
1-6
http://aop.sagepub.com/content/45/1/17.abstract
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