Is routine electrolyte testing necessary for diabetic patients who present to the emergency department with moderate hyperglycemia?
OBJECTIVE
No consensus standard is established for the workup of diabetic patients with moderate hyperglycemia [fingerstick glucose of 11.00-33.00 mmol/l (200-600 mg/dl)]. We measured the incidence of serious electrolyte abnormalities in patients with moderate hyperglycemia and attempted to identify a subset of these patients who can safely forego routine electrolyte testing.


METHODS
Prospective cohort study in two affiliated emergency departments.


METHODS
Moderate hyperglycemia.


METHODS
new onset diabetes or renal failure. The composite outcome was defined as an abnormal potassium K >5.00 or <3.50 mmol/l or diabetic ketoacidosis. Univariate analyses were performed using t-test and Fisher's exact test (alpha=0.05, two-tails). Logistic regression models were generated to identify variables that could predict the composite outcome.


RESULTS
Three hundred and ninety-nine adults were enrolled (294 type II, 38% men). Mean age was 59+/-15 (20-97 years) years. The incidence of the composite outcome was 22% (95% confidence interval, 17.8-26.0%, n=86). The univariate analysis identified potassium-altering medications and insulin use as risk factors for the composite outcome. Logistic regression analysis identified potassium-altering medications as an increased risk (relative risk: 1.64, 95% confidence interval, 1.14-2.37) and use of oral hypoglycemics as a decreased risk (relative risk: 0.62, 95% confidence interval, 0.43-0.90) of the composite outcome. Cross-validation of the model demonstrated poor sensitivity (76%) and even worse accuracy (51%).


CONCLUSIONS
We failed to identify any subgroup of patients with moderate hyperglycemia who can be safely excluded from routine electrolyte testing. We recommend routine electrolyte testing for all moderate hyperglycemia patients in the emergency department.
Zehtabchi
Shahriar
S
Department of Emergency Medicine, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA. zehtab@yahoo.com
Sinert
Richard
R
Wallace
David
D
Caton
Mamie
M
Chen
Jerrica
J
Chang
Betty
B
Lucchesi
Michael
M
D000328:Adult; D000368:Aged; D003661:Decision Support Techniques; D003920:Diabetes Mellitus / Q000097:blood* / Q000453:epidemiology; D003955:Diagnostic Tests, Routine / Q000706:statistics & numerical data*; D004573:Electrolytes / Q000097:blood*; D004636:Emergency Service, Hospital / Q000592:standards*; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood* / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D011446:Prospective Studies; D012307:Risk Factors; D014882:Water-Electrolyte Balance
D004573:Electrolytes; D011188:Potassium