Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1068 page)

   Magnesium forms insoluble complexes with normal urine constituents that precipitate as soon as urine is passed. Acidification is not required.

   Urine concentration is diet dependent.

   Magnesium depletion could be common condition found in 26% of hospitalized patients.

   High concentrations of gadolinium are known to interfere with most metals tests.

MATERNAL SCREENING

See Prenatal Screening.

MEAN CORPUSCULAR HEMOGLOBIN (MCH)
*

   Definition and Use

   MCH is the Hb concentration per RBC count. It has limited value in classifying anemias.

   
Normal range:
27–34 pg per red cell.

   Interpretation

Increased In

   Macrocytic anemias and infants as well as newborns

Decreased In

   Microcytic and normocytic anemias

MEAN CORPUSCULAR HEMOGLOBIN CONCENTRATION (MCHC)
^†

   Definition and Use

   MCHC is the Hct divided by Hb. It has limited value in classifying anemias, although it may identify hypochromasia better than MCH.

   
Normal range:
31.5–36 g.