Critical Values
Critical values are those results that indicate a high risk of morbidity or mortality in the absence of rapid intervention to treat the abnormal value or its underlying cause.
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 The Joint Commission (TJC) requirements, it is required that we request and receive 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/mcL |
| Bilirubin, newborn (under 30 days old) | >12.0 mg/dL |
Blood Gases, Adult
|
|
Blood Gases, Newborn
(under 30 days old)
|
|
| Calcium, ionized | <0.78 or >1.58 mmol/L |
| Calcium, total | <6.0 or >13.0 mg/dL |
| Carbon Dioxide | <10 or >40 meq/L |
| Carbon Monoxide | >20% |
| Fibrinogen | <100 mg/dL |
Glucose
|
|
| Glucose, CSF | <20 mg/dL |
Glucose, POCT
|
|
| Hematocrit | <20% |
Hemoglobin by oximetry
|
|
| Heparin Induced Platelet Antibodies | Positive |
| Lead | ≥70 mcg/dL |
| Magnesium | <1.2 or >4.7 mg/dL |
| Methemoglobin | >30.0 % |
| Osmolality | <250 or >350 mOsm/kg |
| Partial thromboplastin time | >120 sec |
| Phosphate | <1.0 mg/dL |
Platelet Count
|
|
| Potassium | <2.5 or >6.0 meq/L |
| Prothrombin Time | INR >5 |
| Sodium | <120 or >160 meq/L |
| Sodium, CSF | <120 or >160 meq/L |
T4
|
|
| Troponin I | ≥0.40 ng/mL (first critical value per 24 hour period for each patient) |
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 The Joint Commission (TJC) requirements, it is required that we request and receive a read-back of results to ensure that the results were properly noted by the recipient. They include the following:
- Positive blood culture
- Positive direct exam or culture on spinal fluid (CSF)
- Positive Cryptococcal antigen (serum or CSF)
- Positive direct exam on any specimen from the Operating Room
- Positive AFB stain or culture from any specimen
- Positive Herpes simplex virus PCR on cerebral spinal fluid (CSF)
Toxic Drug Levels
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 The Joint Commission (TJC) requirements, it is required that we request and receive a read-back of results to ensure that the results were properly noted by the recipient.
DRUG |
TOXIC LEVEL |
| Acetaminophen | >50 mcg/dL |
| Alcohol (Methyl) | >24 mg/dL |
| Amikacin (Trough) | >30.0 mcg/mL |
| Amitriptyline+Nortriptyline* | =1000 ng/mL |
| Caffeine | ≥50.0 mcg/mL |
| Carbamazepine | >14.0 mcg/mL |
| Cyclosporine by LC-MS/MS (Trough) | >600 ng/mL |
| Desipramine* | ≥500 ng/mL |
| Digoxin | >3.0 ng/mL |
| Doxepin+Nordoxepin* | ≥500 ng/mL |
| Ethylene Glycol | ≥10 mg/dL |
| Gentamicin (Trough) | >10.0 mcg/mL |
| Imipramine+Desipramine* | ≥1000 ng/mL |
| Isopropanol and Acetone | >200 mg/dL |
| Lidocaine | >7.0 mcg/mL |
| Lithium | >2.0 mmol/L |
| Methotrexate | >100 mcmol/L |
| Nortriptyline* | ≥500 ng/mL |
| Phenobarbital | >60.0 mcg/mL |
| Phenytoin (Dilantin) | >30.0 mcg/mL |
| Phenytoin, Free | >4.0 mcg/mL |
| Salicylate | >50 mg/dL |
| Theophylline | >25.0 mcg/mL |
| Thiocyanate | >20 mg/dL |
| Tobramycin (Trough) | >10.0 mcg/mL |
| Tricyclic Antidepressants | >500 ng/mL |
| Trimipramine* | >400 ng/mL |
| Vancomycin (Trough) | >40.0 mcg/mL |
| Valproic Acid (VPA) | >200 mcg/mL |
*Testing performed by Mayo Medical Laboratory
Critical values last reviewed: March 7, 2012. Revised March 4, 2011; November 14, 2011; March 30, 2012