CLINICAL CHEMISTRY

DELTA CHECKS

The difference between a patient's present laboratory result and the previous result which exceeds a predefined limit is referred to as a delta check. Delta checks are investigated by the lab internally to rule out: 1) mislabeling, 2) clerical error or 3) possible analytical error.

At times, a phone call to the physician or charge nurse may be made by the laboratory technologist to investigate possible pre-analytical errors such as: 1) obtaining specimens from IV lines, 2) mislabeling, or 3) actual changes in a patient's condition.

A comment on the patient's report will indicate what actions were taken and that the specimen was rerun for verification. The delta variances defined for the UAMS Chemistry Lab are as follows:

Chemistry (serum)

Albumin	2.0 g/dl
Bilirubin	2.0 mg/dl
*BUN	25 mg/dl
Calcium (Ca)	3.0 mg/dl
Carbon Dioxide	15 mEq/L
Chloride (Cl)	15 mEq/L
*Creatinine	10 mg/dl
Magnesium	2.0 mEq/L
Osmolality	20 mOsm/kg
Potassium (K)	2.5 mEq/L
Sodium (Na)	15 mEq/L
Total Protein	2.0 gm/dl
**Uric Acid	2.0 mg/dl

* Non-Renal
** Non-Heme/Onc