Critical Values

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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 pH pCO2 pO2	<7.20 or >7.58 <9 or >65 mmHg <40 mmHg
Blood Gases, Newborn (under 30 days old) pH pCO2 pO2	<7.25 or >7.50 <30 or >50 mmHg <50 or >90 mmHg
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 Newborn (under 30 days old) Adult	<40 or >200 mg/dL <45 or >500 mg/dL
Glucose, CSF	<20 mg/dL
Glucose, POCT Newborn (under 30 days old) Adult	<50 or >200 mg/dL <50 or >500 mg/dL
Hematocrit	<20%
Hemoglobin by oximetry Newborn (under 30 days old) Adult	<8.1 g/dL or >21.1 g/dL <6.0 g/dL
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 Pediatric Range Infants (NICU only) Adults (non-Oncology)	<60 THOU/mcL <60 THOU/mcL <20 THOU/mcL
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 Newborns (under 30 days old) Adult	<3.5 or >18.0 mcg/dL >18.0 mcg/dL
Troponin I	≥0.40 ng/mL (first critical value per 24 hour period for each patient)

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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:

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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

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