Rational ordering of electrolytes in the emergency department.
OBJECTIVE
To validate the predictive abilities of a retrospectively developed set of clinical criteria for detecting clinically significant electrolyte abnormalities, using a different patient population.


METHODS
Cross-sectional study.


METHODS
The emergency department of a busy public hospital.


METHODS
Nine hundred eighty-two patients on whom the emergency physician ordered serum electrolytes.


METHODS
The predictive properties of ten clinical criteria were evaluated; these included poor oral intake, vomiting, chronic hypertension, taking a diuretic, recent seizure, muscle weakness, age of 65 years or more, alcoholism, abnormal mental status, and recent history of electrolyte abnormality.


RESULTS
Seven hundred thirty patients (74.3%) had one or more electrolytes outside of the laboratory normal range, but only 143 (14.6%) had clinically significant electrolyte abnormalities. The clinical criteria predicted 135 of the clinically significant electrolyte abnormalities (sensitivity, 94.4%). When the eight "false-negative" cases were reviewed, none of the electrolyte abnormalities affected patient outcome. Implementation of the criteria would have avoided unnecessary testing in 233 patients (23.7%).


CONCLUSIONS
Although no set of clinical criteria can eliminate the need for clinical judgment, use of a set of clinical criteria could substantially decrease electrolyte ordering without compromising patient care.
Lowe
R A
RA
Department of Emergency Medicine, Valley Medical Center, Fresno, California.
Arst
H F
HF
Ellis
B K
BK
D003430:Cross-Sectional Studies; D004573:Electrolytes / Q000097:blood*; D004635:Emergency Medicine / Q000592:standards*; D006801:Humans; D010818:Practice Patterns, Physicians' / Q000592:standards*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014883:Water-Electrolyte Imbalance / Q000175:diagnosis*
D004573:Electrolytes