Information on Clinical Assay Interferences and Limitations
It is the policy of the laboratory to notify the ordering location of any laboratory results which are so far from the reference range that they indicate a potentially dangerous condition requiring immediate attention by the clinician. The ordering locations are notified even to those areas with computer printers or terminals. Critical laboratory results are always reported by telephone. In accordance with JCAHO requirements, it is required that we request a read-back of results to ensure that the results were properly noted by the recipient.
| ANALYTE | CRITICAL VALUES |
| Absolute Neutrophil (non-oncology) | <0.5 THOU/µL |
| Bilirubin, newborn (under 30 days old) | >12.0 mg/dL |
|
Blood Gases, Adult
|
<7.20 or >7.58 |
|
Blood Gases, Newborn
|
<7.25 or >7.50 |
| Calcium, ionized | <0.78 or >1.58 mmol/L |
| Calcium, total | <7.0 or >13.0 mg/dL |
| Carbon Dioxide | <5 or >38 meq/L |
| Carbon Monoxide | >20% |
| Fibrinogen | <100 mg/dL |
| Glucose, adult | <45 or >500 mg/dL |
| Glucose, newborn | <40 or >200 mg/dL |
| Glucose, CSF | <20 mg/dL |
| Hematocrit | <20% |
| Hemoglobin by oximetry | <6.0 g/dL |
| Magnesium | <1.2 or >4.2 mg/dL |
| Osmolality | /<250 or >350 mOsm/kg |
| Partial thromboplastin time | >120 sec |
| Phosphate | <1.0 mg/dL |
|
Platelet Count
|
<60 THOU/µL |
| Potassium | <2.5 or >6.0 meq/L |
| Prothrombin Time | INR >5 |
| Sodium | <120 or >152 meq/L |
| T4, adult | >18.0 µg/dL |
| T4, newborns | <3.5 or >18.0 µg/dL |
Toxic Drug Levels are those results that are so far from the therapeutic range that they indicate a potentially dangerous condition requiring immediate attention by the clinician. Critical laboratory results are always reported by telephone. In accordance with JCAHO requirements, it is required that we request a read-back of results to ensure that the results were properly noted by the recipient.
| DRUG | TOXIC LEVEL |
| Acetaminophen | >300 µg/mL |
| Amikacin | >30.0 µg/mL |
| Carbamazepine | >14.0 µg/mL |
| Cyclosporine by HPLC | >600 ng/mL |
| Cyclosporine by Immunoassay | >700 ng/mL |
| Digoxin | >3.0 µg/mL |
| Disopyramide | >7.0 µg/mL |
| Ethosuximide | >150 µg/mL |
| Flecainide | >0.8 µg/mL |
| Gentamicin |
>10.0 µg/mL PEAK >2.0 ug/mL TROUGH |
| Isoniazid | >25 µg/mL |
| Lidocaine | >7.0 µg/mL |
| Lithium | >2.0 mmol/L |
| Mysoline | >15.0 µg/mL |
| Phenobarbital | >60.0 µg/mL |
| Phenytoin (Dilantin) | >30.0 µg/mL |
| Phenytoin, Free | >4.0 µg/mL |
| Procainamide | >15.0 µg/mL |
| Total Procainamide | >40.0 µg/mL (TPcain= Pcain + NAPA) |
| Salicylate | >50 mg/dL |
| Theophylline | >25.0 µg/mL |
| Thiocyanate | >20 mg/mL |
| Tobramycin |
>10.0 µg/mL PEAK >2.0 µg/mL TROUGH |
| Tricyclic Antidepressants | >500 ng/mL |
| Quinidine | >7.0 µg/mL |
| Vancomycin |
>40.0 µg/mL PEAK >10.0 µg/mL TROUGH |
| Valproic Acid (VPA) | >150 µg/mL |
Critical Values for Microbiology
Critical Values in Microbiology are results that indicate a potentially dangerous condition requiring immediate attention by the clinician. Critical laboratory results are always reported by telephone. In accordance with JCAHO requirements, it is required that we request a read-back of results to ensure that the results were properly noted by the recipient. They include the following:
Information on Clinical Assay Interferences and Limitations
Information is available on clinically significant limitations and interferences for the following tests:
Critical values last reviewed: February 2003
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Created: June 14, 2000; Last updated: 12/5/03
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