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Several studies have evaluated the incidence of hypoglycemia among patients who have received hyperkalemia
treatment with insulin; however, many of these studies have
been limited by methodological challenges including small
sample size.11 Some studies have specifically focused on
patients with underlying renal insufficiency since insulin is
dependent on adequate kidney function for clearance from
the body.12-14 The range of insulin doses used in clinical practice for treatment of hyperkalemia varies; however, most
institutions typically use 10 units of regular insulin administered intravenously along with 25 to 50 g of dextrose.11 In a
retrospective study, Schafers and colleagues looked at all
hospitalized patients regardless of underlying renal function
who received treatment with insulin for hyperkalemia and
found that 8.7% experienced hypoglycemia (blood glucose
<70 mg/dL) and 2.3% experienced severe hypoglycemia
(blood glucose level <40 mg/dL).15 Nearly all patients who
developed posttreatment hypoglycemia (95%) received concomitant dextrose with insulin. In a follow-up to this study,
investigators found that a weight-based insulin dosing protocol (0.1 unit/kg) for hyperkalemia treatment among hospitalized patients was associated with a lower incidence of
hypoglycemia when compared to patients who received the
standard 10 unit dose of insulin, although this difference was
not statistically significant (10.6% vs 19.7%, P = .22).16
Treatment of patients with hyperkalemia using insulin is
common in the emergency department; however, limited
data exist regarding the incidence of hypoglycemia associated with insulin treatment of hyperkalemia specifically in
this setting. The objective of this study was to evaluate the
incidence of hypoglycemia in patients who were treated for
hyperkalemia with regular insulin while receiving medical
care in the emergency department.

Methods
This was a retrospective, electronic medical chart review of
patients at 2 separate emergency departments associated
with a community hospital system from January 1, 2016 to
June 30, 2016. The emergency departments are located in a
community hospital health system found in a large metropolitan area of the United States with annual patient visits
numbering approximately 140 000. An emergency department hyperkalemia treatment order set has been integrated
into the computerized physician order entry system at the
institution since 2009. Prescribers are encouraged to use the
order set when ordering medications to treat patients presenting to the emergency department with hyperkalemia (normal
serum potassium range defined as 3.6-5.1 mmol/L). All adult
patients who were seen in the emergency department and
who received at least one dose of intravenous regular insulin
ordered from the emergency department hyperkalemia treatment order set were eligible for inclusion in the study, therefore no sample size was calculated. The electronic pharmacy
system, which is integrated into the electronic medical chart,

Hospital Pharmacy 54(3)
was used to identify orders for intravenous regular insulin
that were generated specifically from the emergency department hyperkalemia treatment order set during the specified
study period. Treatments available from this order set
included preset single-dose orders for intravenous calcium
chloride or gluconate 1 g, nebulized albuterol sulfate 5 mg,
intravenous sodium bicarbonate 8.4% 50 mEq, oral or rectal
sodium polystyrene sulfonate 60 g, and intravenous regular
insulin 10 units. Administration of 25 g of dextrose with
intravenous regular insulin is part of the order set; however,
physicians were able to adjust the dose of insulin and/or
grams of dextrose administered based on clinical judgment.
The order set does not include a specified follow-up time for
checking blood glucose after insulin administration.
Physicians and nurses were able to order posttreatment finger stick blood glucose measurements based on clinical
judgment and observation of the patient. Serum potassium
was measured using a regular serum blood draw. Patients
who did not have posttreatment serum potassium or capillary
finger stick blood glucose were excluded from the study. In
addition, pediatric patients (age <18 years) were ineligible
for inclusion in the study. Informed consent was not obtained
since the study involved observation of usual care. The
Institutional Review Boards from the investigators' institution and the study site approved the study protocol. This
study was conducted in accordance with accepted ethical
standards of research.
Baseline demographics included age, gender, weight, electrocardiographic changes, hospitalization, admission diagnosis, and past medical history of diabetes mellitus, chronic
kidney disease including use of dialysis, prior hyperkalemia,
and prior hypoglycemia. History of hyperkalemia or hypoglycemia was determined by examining records of prior visits to
the emergency department or hospital admissions at the study
institution. Laboratory parameters that were collected at baseline included serum potassium, magnesium, creatinine, and
blood glucose. Estimated creatinine clearance was calculated
using the Cockcroft-Gault formula. Additional clinical
parameters that were collected included treatments used for
hyperkalemia, insulin dose in units, grams of dextrose used,
posttreatment serum potassium, posttreatment capillary finger stick blood glucose, and time to posttreatment capillary
finger stick blood glucose measurement. Posttreatment blood
glucose measurements were obtained by reviewing the first
documented capillary finger stick reading within 24 hours of
intravenous regular insulin administration recorded in the
electronic medical chart by nurses as part of their usual practice. An interval of 24 hours was used for follow-up since the
current order set included no prespecified direction to physicians and nurses on the timing of follow-up blood glucose
measurement and therefore investigators wanted to determine
the average time from treatment to blood glucose measurement. Physicians or nurses ordered posttreatment capillary
blood glucose measurements based on clinical judgment and
observation of the patient. Time to posttreatment capillary
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