Critical Values

Clinical Biochemistry: CLS and CRL

Biochemistry CLS and Calgary Rural Labs (CRL)	Critical Values To be called as soon as the result is available 24 hours per day. All Patients, Unless Otherwise Noted
Acetaminophen	Greater than 330 µmol/L
Acetone	Greater than 6 mmol/L
Amikacin	Pre: greater than 17.0 mg/L Post: greater than 60.0 mg/L
Amiodarone	Greater than 5.4 µmol/L
Ammonia	0-16 years: greater than 109 µmol/L
BHCG, Quantitative - Blood	Greater than 5 IU/L on females less than 16 years
BHCG, Qualitative - Urine	Positive on females less than 16 years
Bilirubin, Total	0-365 days: greater than 300 µmol/L
Blood Gases	CRL only - EXCEPTION Strathmore & Didsbury: pH: less than 7.30, Greater than 7.51 pCO₂: less than 20 mm Hg, Greater than 70 mm Hg pO₂: less than 60 mm Hg CO: greater than or equal to 10.0% Strathmore and Didsbury: no critical values apply.
Calcium, Total	Less than 1.65 mmol/L Greater than 3.25 mmol/L
Calcium, Free or Ionized	Less than 0.85 mmol/L Greater than 1.50 mmol/L
Carbamazepine	Greater than 55 µmol/L
Creatinine - Blood	CLS only: 0-31 days: greater than 150 µmol/L
Desethylamiodarone	Greater than 4.9 µmol/L
Digoxin	Greater than 2.6 nmol/L
Ethanol	Greater than 65.0 mmol/L
Ethylene Glycol	Greater than 2.0 mmol/L
Gentamicin	Pre: greater than 2.0 mg/L Post: greater than 10.0 mg/L
Glucose	Less than 30 days: - Critical low less than 2.0 mmol/L - Critical high greater than 24.9 mmol/L 30 days - 150 years: - Critical low: less than 2.6 mmol/L - Critical high: greater than 24.9 mmol/L
Isopropanol	Greater than 2.0 mmol/L
Lactate	Greater than 4.0 mmol/L
Lithium	Greater than 1.50 mmol/L
Magnesium	Less than 0.50 mmol/L Greater than 1.50 mmol/L
Methanol	Greater than 2.0 mmol/L
Oncology Cortisol	Oncology patients only: Less than 50 nmol/L
Osmolality	Acute care patients only: Less than 250 mmol/kg Greater than 320 mmol/kg
Overdose Iron	Less than 12 years: greater than 54 µmol/L
Phenobarbital	Greater than 190 µmol/L
Phenytoin (Dilantin)	0-3 months: greater than 55 µmol/L 4 months-150 years: greater than 80 µmol/L
Phenytoin, Free (Dilantin, Free)	Greater than 16.0 µmol/L
Phosphate	Less than 0.40 mmol/L
Potassium	All: Less than 2.5 mmol/L 4 months - 150 years: greater than 6.0 mmol/L 0-3 months (venous): greater than 6.4 mmol/L 0-3 months (capillary): greater than 7.3 mmol/L
Primidone (Mysoline)	Greater than 65 µmol/L
Salicylate	Greater than 2.00 mmol/L
Sirolimus	Greater than 30 µg/L
Sodium	Less than 120 mmol/L Greater than 155 mmol/L
Spermatozoa - Urine	Female less than 16 years
Tacrolimus	Greater than 30 µg/L
Theophylline	Greater than 110.0 µmol/L
Tobramycin	Pre: greater than 2.0 mg/L Post: greater than 10.0 mg/L ACH CF patients: greater than 25.0 mg/L
Troponin I Stratus CLH CMGH DDHS HRH OGH SDHS VCH	Greater than 0.50 µg/L
Troponin I Vidas HCTL BMSH OHWC	Greater than or equal to 0.11 µg/L
Troponin T High Sensitivity	Greater than 110 ng/L
Tricyclic Screen	Greater than 1600 nmol/L
Urate	ACH only: greater than 713 µmol/L
Valproic Acid	Greater than 750 µmol/L
Vancomycin	Pre: greater than 25.0 mg/L Random: greater than 60.0 mg/L

Hematology: CLS and CRL

Hematology CLS and Calgary Rural Labs (CRL)	Critical Values *To be called as soon as result is available 24 hours per day*
Hemoglobin	Adults: equal to or less than 60 g/L 0-6 days: less than 100 g/L
Platelet Count	Equal to or less than 20 x 10E9/L
Absolute Neutrophil Count	Less than 0.5 x 10E9/L (* See note)
Prothrombin Time (PT)	INR greater than 5.0
Activated Partial Thromboplastin Time (APTT)	Equal to or greater than 120 seconds
Fibrinogen	Less than or equal to 1.0 g/L

*Note: All the differential results are phoned, not just the neutrophil count.

Microbiology

Appropriate medical staff will be notified by fax or phone of the following results:

1. Positive blood cultures

2. Positive central nervous system specimens (CSF, brain, etc.) cultures and gram stains

3. Positive tissue cultures (liver, bone biopsies, etc.)

4. Beta-hemolytic Streptococci, Group A from sterile sites

5. Neisseria gonorrhoeae from eyes

6. Clostridium botulinum, Clostridium perfringens, Clostridium tetanus

7. Corynebacterium diptheriae

8. Legionella species

9. Listeria species

10. Positive Modified Acid Fast and Ziehl-Neelsen stains

11. Unusually resistant organisms including:

Vancomycin resistant Enterococci (VRE)
Methicillin resistant Staphylococcus aureus (MRSA)
Multiply resistant gram negative or any other highly resistant organism with unusual suscetibility pattern. On Blood/Sterile fluids/Wound/AN0₂/Screening swabs, BAL, tracheal aspirates
Extended spectrum beta lactamases (ESBLs)
Glycopeptide intermediate Staphylococcus aureus (GISA), Borderline oxacillin resistant Staphylococcus aureus (BORSA)

12. All Notifiable Diseases isolates http://www.health.gov.ab.ca/professionals/notifiablediseases.html

13. Cryptococcus neoformans

14. Zygomycetes from sinus/eye specimens

15. Vitreous fluids from eyes (positive and negative reports from slide preparations)

16. Blastomyces dermatitidis, Histoplasma capsulatum, Coccidioides immitis, Paracoccidioides brasiliensis, Sporothrix schenkii, Penicillium marneffi

17.Level III organisms: Bacillus anthracis, Brucella spp., Francisella spp., Yersinia pestis

18. Stenotrophomonas maltophilia: non-sterile sites

19. Stool pathogens including Salmonella, Shigella, Yersinia, Campylobacter spp., Clostridium difficile, E-coli 0157:H7, Vibrio spp., Rotavirus

20. All positive and/or STAT Malaria tests

21. PCP - Pneumocystis jirovecii (carinii)

22. RSV, Influenzae A; all positive results

23. Varicella Zoster Virus: all positive results

24. Parasites:Cyclospora spp.,Giardia, Entamoeba histolytica, Cryptosporidium spp., Acanthamoeba, Parasitic ova, worm, proglottid, and larvae

Notes:

Critical values are test results that are so abnormal that they generally indicate severe illness and require immediate medical intervention. For this reason, these values must be communicated to the attending physian immediately.
While critical values are generally indicative of acute disease requiring intervention, there are some patients with marked metabolic derangements that are physiologically fairly well compensated. For example, renal patients can have chronically elevated potassium levels that are surprisingly well tolerated. A general rule of thumb is that chronic changes in physiological status are much better tolerated than rapid alterations.
Some physicians or units may decline communication of critical values. In these cases, written documentation must be produced for the laboratory to comply with this request.

Some testing areas may wish to phone some abnormal results, and these discretionary decisions have not been built into the critical value list.