LACTOSE TOLERANCE Mnemonic MISC Synonym Lactose Tolerance Test used to Diagnose Lactose Malabsorption - Disaccharide Found in Milk - Lactase Deficiency Includes Fasting, 15, 30, 60, 90 and 120 minute glucose post LAC-TOL Specimen Collection Requirements Patient Preparation Patient should fast for 8-14 hours before administering test. Draw fasting specimen. For adults, administer 50g LAC-TOL (lactose sugar). Pediatric doses vary by child’s weight. Draw specimens at 15, 30, 60, 90 and 120 minutes post sugar. Collect Preferred: Plasma, one 4.0 mL gray (sodium fluoride/potassium oxalate) top tube Also acceptable: Serum or Plasma, one 5.0 mL gold (SST), 7.0 mL red or 3.0 mL mint green (lithium heparin, PST) top tube Handling The gold, red and green top tubes must be delivered to the lab immediately. Allow serum to clot completely at room temperature (minimum: SST - 30 minutes and red top tubes - 60 minutes). Preferably, separate serum or plasma from cells within 1 hour of collection. If unable to spin, preferred specimen is gray (sodium fluoride/potassium oxalate) top tube. Preferred Volume 1.0 mL Serum/Plasma per specimen Minimum Volume 0.25 mL Serum/Plasma (Whole Blood 0.60 mL minimum draw) per specimen Transport Refrigerated (2-8°C) Rejection Criteria Grossly hemolyzed specimens, timed specimens collected outside the ±10 minute window (±5 minutes for 15 minute specimen) Stability AFTER SEPARATION FROM CELLS: SODIUM FLUORIDE/POTASSIUM OXALATE PLASMA: Room Temperature (18-26°C): 24 hours; Refrigerated (2-8°C): 7 days; Frozen (≤ -20°C): 1 month SERUM OR LITHIUM HEPARIN PLASMA: Room Temperature (18-26°C): 8 hours; Refrigerated (2-8°C): 3 days; Frozen (≤ -20°C): 1 month Testing Information Performed Schedule testing with one of the approved Legacy Facilities. Please refer to Lactose Tolerance Tests - Patient Preparation Instructions. Reported 24 hours Method UV spectrophotometry Reference Values Reference Values Interpretation provided. CPT Codes For 3 specimens: 82951; For each additional specimen: 82952 Last Updated: Thursday, January 5, 2017 03:42:19 AM