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Reporting Critical Test Limits

Quick Links To Critical Test Limits
Chemistry Blood Gas Hematology Microbiology
Anatomic Pathology Transfusion Medicine Blood Donor Program Blood Bank/Cellular Therapy Center

All critical, Code Blue, Trauma and O.R. laboratory results must be called regardless of the ordering location's printer capability (See Dept. of Pathology Policy for Verbal Orders and Results). Each laboratory section determines its own critical value listing (See combined critical listing below). Non-critical stat results are reported in CIS without phone notification (See Dept. of Pathology Policy for Requesting Stat Orders and Reporting Stat Results).

When laboratory staff verbally communicates results they should include the following information:

  • Caller's name and lab section
  • The patient's full name
  • The patient's MRN
  • Critical or Code Blue laboratory results

    Laboratory staff will request this information to be read back to them in order to verify accuracy. The date, time and person they gave the results to should be recorded in the Laboratory Information System (LIS).

    Every effort should be made by laboratory staff to communicate critical results to a person to ensure they are enacted upon ASAP. For DHMC outpatient clinic locations the following process should occur in attempting to communicate critical lab results:

    1. The ordering provider will be paged with any outpatient critical results.
    2. During off-hours the resident covering the service will be paged. The name and pager # of the covering resident can be determined by asking the hospital operator.
    3. The pathology resident on call will be contacted in the event that the ordering or covering provider does not return their page or can not be reached.
    4. The clinic location will be called with outpatient critical results only if the ordering physician name is missing or can not be determined.

    Leaving a message on voice mail for an off-site ordering provider indicating that critical results are available on a patient should only be done when all reasonable efforts to contact the provider or covering provider are exhausted. Voice message should include the lab contact name, phone number, patient name, MRN, and name of test(s). The date and time of the call that the voice message was left should be recorded in the Laboratory Information System (LIS).


    Clinical Chemistry Laboratory: Guidelines for Reporting Critical Values
    Revised November 1, 2005

    ACETAMINOPHEN Greater than or Equal to 15 mg/L
    AMMONIA Greater than 150 mcmol/L (< 3 mos)
    BUN Greater than 150 mg/dl
    CALCIUM Less than 7.0 mg/dl, Greater than 13.0 mg/dl
    CARBAMAZEPINE (TEGRETOL) Greater than 12.0 mg/L
    CREATININE Greater than 10.0 mg/dl (Except for dialysis pts.)
    CO2 Less than 10 mmol/L
    DIGOXIN Greater than 2.0 mcg/L (6 mos-adult)
    Greater than 3.5 mcg/L (0-6 mos)
    FREE PHENYTOIN Greater than 3.00 mg/L
    GENTAMICIN Peak Greater than 14.0 mg/L
    Trough Greater than 2.0 mg/L
    GLUCOSE Less than 55, Greater than 500 mg/dl (3 mos-adult)
    Less than 40, Greater than 300 (0-3 mos)
    IGM Greater than 3,000 mg/dL (except for apheresis patients from BDP)
    LACTATE Greater than 3.9 mmol/L
    LITHIUM Greater than 1.5 mmol/L (chronic toxicity)
    Greater than 4.0 mmol/L (acute toxicity)
    MAGNESIUM Greater than 3.59 mmol/L for BP pts.
    OSMOLALITY-SERUM Less than 250 mOs/KgH20, Greater than 330 mOs/KgH20
    PHENOBARBITAL Greater than 50.0 mg/L
    PHENYTOIN (DILANTIN) Greater than 25.0 mg/L
    PHOSPHORUS Less 1.5 mg/dl, Greater than 9.0 mg/dl (Except for dialysis pts.)
    POTASSIUM Less than 3.1mmol/L, Greater than 6.0 mmol/L
    Less than 3.1 mmol/L for ICN and Newborn
    Greater than 8.0 mmol/L for ICN and Newborn
    SALICYLATE Greater than 350 mg/L
    SODIUM Less than 120, Greater than 160 mmol/L
    THEOPHYLLINE Greater than 25 mg/L
    TOBRAMYCIN Peak Greater than 14.0 mg/L
    Trough Greater than 2.0 mg/L
    URIC ACID Greater than 15.0 mg/dl
    VALPROIC ACID Greater than 125 mg/L
    VANCOMYCIN Peak Greater than 50 mg/L
    Trough Greater than 25 mg/L

    Only OR, ER,Code and critical Blood Gas Results will be called.

    Only ED Troponin T results greater than 0.01 ng/mL will be called.

    For BP only, call if the initial Cre greater than 1.09 mg/dL or any Cre value that has doubled within 24 hrs.

    For BP only, call if the initial AST greater than 59 U/L or any AST value that has doubled within 24 hrs.

    For BP only, call all HIV screens that are presumptive positive.


    pH Less than 7.30(pH less than 6.8 or greater than 7.8 are incompatible with life)

    Less than 25 mmHg (0-28 days old only)
    Greater than 50 mmHg

    pO2 Less than 50 mmHg
    iCa Less than 0.93 and Greater than 1.53 mmol/L
    Na Less than 120 mmol/L and Greater than 160 mmol/L
    K Less than 3.1 and Greater than 6.0 mmol/L
    Greater than 8.0 mmol/L for ICN
    Glucose Less than 55, Greater than 500 mg/dl (3 mos-adult)
    Less than 40, Greater than 300 (0-3 mos)
    Total Hemoglobin (tHb) See Hgb Reference Range chart below

    Total Hemoglobin (in gm/dL)
    Based on 06/29/08 DHMC Hematology Sysmex Ranges

    Age Reference Range Critical Value Range
    Less than 3 days 14.5 - 22.5 Less than 6.0, greater than 24.6
    3 days to 2 weeks 12.5 - 20.5 Less than 6.0, greater than 22.6
    2 weeks to 1 month 10.0 - 18.0 Less than 6.0, greater than 20.0
    1 to 6 months 9.4 - 14.0 Less than 6.0, greater than 20.0
    6 months to 2 years 10.5 - 13.5 Less than 6.0, greater than 20.0
    2 to 6 years 11.5 - 13.5 Less than 6.0, greater than 20.0
    6 to 12 years 11.5 - 15.5 Less than 6.0, greater than 20.0
    12 to 18 years (Female) 12.0 - 16.0 Less than 6.0, greater than 20.0
    12 to 18 years (Male) 13.0 - 16.0 Less than 6.0, greater than 20.0
    Greater than 18 years (Female) 11.2 - 15.7 Less than 6.0, greater than 20.0
    Greater than 18 years (Male) 13.7 - 17.5 Less than 6.0, greater than 20.0



    Prothrombin Time Greater than 49 seconds
    Partial Thromboplastin Time Greater than 130 seconds
    Fibrinogen Less than 100 mg/dl
    Platelet Counts Less than 20,000/cmm (Greater than or equal to 5,000 for HSCU/1WST patients)
    Urine Glucose Greater than 1,000mg/dl
    NOTE: Both Ketone and Glucose must exceed critical values.
    Urine Ketones

    Greater than 80 mg/dl
    NOTE: Both Ketone and Glucose must exceed critical values.

    Urine Clinitest

    Positive Clinitest on childeren when dipstick is negative

    Neutrophil Absolute, Body fluid

    Count of 250 or greater/ mcL (NOTE: ONLY Ascites, Paracentesis, Peritoneal, Peritoneal Dialysates)


    D-Dimer Greater than 20,000 ng/ml

    Less than 6.0gm/dl for all age groups
    Greater than 24.6 gm/dl for 0-3 days
    Greater than 22.6 gm/dl for 3 days to 2 weeks

    Greater than 20.0 gm/dl for greater than 2 weeks

    White Cell Count Less than 2,000/cmm (<1000 for HOC patients)
    Greater than 30,000/cmm
    [Do not call critical WBCs to HSCU/1WST]
    Absolute Granulocytes
    (Gran #)
    Less than 0.5 X 103 cells/ul
    [Do not call critical ABS granulocytes to HSCU/1WST]

    NOTE: All Platelet counts less than 20,000/cmm must be called to the attending physician or designee. Call HSCU (Hematology Special Care) platelets = 5,000/cmm.

    1. Kost, G.J., JAMA, 1990; 263:704
    2. Howanitz, P.J., et al., Archives of Pathology and Laboratory Medicine, 2002; 126:663
    3. ISLH Consensus rules.


    For optimum patient care, the following critical isolates and test results will be telephoned to the provider (Provider or nurse).
    • Positive blood cultures
    • Positive gram stains from CSF and joint fluids
    • Positive CSF PCR results
    • Positive Chlamydia and GC amplificiation tests
    • Positive PCR for B. pertussis
    • Positive culture with N. gonorrhoeae
    • Positive Acid Fast stains and isolates
    • Virus cultures, stains or EIA positive for respiratory viruses on in-patients
    • Entamoeba histolytica
    • Stronglyoides stercoralis
    • Positive blood parasite slides, i.e., Malaria, Babesia and Trypanosomes
    • Positive eye cultures (all sources) with P. aeruginosa and Bacillus speciesand filamentous fungi, and all positive cultures on vitreous fluid


    All frozen section surgical pathology specimens are considered critical and results are called regardless of the diagnosis. Please refer to the Anatomic Pathology Physician Guidelines for specifics.


    *The Transfusion Medicine Service does not produce laboratory test results that have the traditional critical test limits, however lisited below are specific procedures that are performed, or products that are issued, that are critical to the care of the patient and require immediate response.


    Pre- HPC collection Hemoglobin <8 gm
    WBC count >65,000
    Platelet count <30,000
    Post-HPC collection Platelet count <20,000
    Severe or sustained donor reactions  


    • All suspected adverse reactions to transfusion of blood components (or infusion of products prepared in the Cellular Therapy Center), including those suggestive of TRALI or hemolysis (symptoms of respiratory distress or hypotension)
    • Release of Block/Uncrossmatched red blood cell units
    • Release of untested or potentially incompatible blood components
    • Release of ABO-incompatible platelets
    • Requests for any blood component outside of standard indications
    • Positive antibody screen in pre-op or surgical patients
    • Positive bacterial culture of platelets or product prepared by the Cellular Therapy Center
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