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Critical Values for Adults and Pediatrics (≥ 12 Month)

Laboratory values in the critical range will be reported by telephone immediately. On inpatients, the laboratory will attempt to phone the physician first; however, if the physician listed as the ordering physician is incorrect or does not respond within 10 minutes, the patient’s nurse will be notified. 

Results will be reported only to a physician or nurse unless the location of the patient is in the recovery room, operating room, or labor & delivery and a physician or nurse cannot come to the phone. 

Critical value laboratory test results will be phoned immediately to non-UC Irvine pathology referral services clients. These results can be released to a clinical laboratory scientist at the referral client location when the ordering physician is unavailable.

The urgency of the contact will be emphasized to the individual accepting the phoned report, as well as the importance of contacting the appropriate physician.

Inability to contact the requesting physician, clinic, or office after two attempts will be followed up with an attempt to reach the pathology resident on call, the clinical pathology attending on call, or the director of the specific laboratory section in which the laboratory results occurred.


Test Critical Low Value Critical High Value

Acid fast stain

 -----  First positive smear

Amniotic fluid, culture or Gram stain

 -----  Positive

Blood culture

 -----  Positive
Calcium  ≤6.0 mg/dL  ≥13.0 mg/dL
Carbon dioxide (CO2)  -----  ≥50 mEq/L
COVID-19 (SARS-CoV-2)  -----  Detected
C-Reactive Protein (for Ophthalmology only) TOPHT, TEYES, ZOPHT  >0.7 mg/dL
CSF, Cryptococcal antigen  -----  Positive
CSF, culture or Gram stain  -----  Positive
ESR (for Ophthalmology only) TOPHT, TEYES, ZOPHT. Ages >14 years  -----  Male >15 mm/hr
 Female >20 mm/hr
ESR (for Ophthalmology only) TOPHT, TEYES, ZOPHT. Ages 0 to 14 years  -----  Male >10 mm/hr
 Female >10 mm/hr
Glucose (1 hour post glucola)
OB patients only
 -----  >200 mg/dL
Glucose (blood)  ≤54 mg/dL  ≥400 mg/dL
Glucose (CSF)  ≤40 mg/dL  ≥300 mg/dL
Hematocrit  <21%  ≥62%
Hemoglobin  <7.0 gm/dL  ≥21 gm/dL

Low Molecular Weight Heparin (LMWH)

 -----  ≥2.0 IU/mL
 ≤1.0 mg/dL  
 ≥5.0 mg/dL   
 [≥8.0 mg/dL]
Malaria Smear  -----  Any Plasmodium species
Nucleated cells (CSF)  -----  >5 cells present
Partial Thromboplastin Time (PTT)  -----  ≥95.0 seconds
pH   ≤7.2  ≥7.6
Platelet Count   ≤20,000 /mm3  >106 /mm3
Potassium  ≤2.8 mEq/L  ≥6.0 mEq/L
Prothrombin Time (PT)  -----  >4.0 INR
Sodium  ≤120 mEq/L  ≥160 mEq/L
Unfractionaed Heparin  -----  ≥0.8 IU/mL
WBC (blood)   ≤1,000 /mm3  ≥50,000 /mm3
Therapeutic Drug Levels
Acetaminophen  -----  >150 mcg/mL
Amikacin  -----

 Peak:  >35.0 mcg/mL
 Trough: ≥8.0 mcg/mL

Carbamazepine  -----  >15.0 mcg/mL
Cyclosporin  -----  >450 ng/mL
Digoxin  -----  >2.1 ng/mL
Dilantin  -----  >20.0 mcg/mL
Everolimus  >15 ng/mL
Gentamicin  -----  Peak:  >12.0 mcg/mL
 Trough: >2.0 mcg/mL
Lead  -----  ≥10 mcg/dL (for <16 years old)
 ≥20 mcg/dL (for ≥16 years old)
Lithium  -----  ≥1.5 mEq/L
Pentobarbital  >5 mcg/dL
Phenobarbital  -----  >50 mcg/mL
Salicylate  -----  >30 mg/dL
Sirolimus  -----  >25 ng/mL: Liver Transplantation
 >15 ng/mL: Renal Transplantation
Tacrolimus  -----  >20 ng/mL
Theophylline  -----  >20.0 mcg/mL
Tobramycin  -----  Peak:  >12.0 mcg/mL
 Trough: >2.0 mcg/mL
Valproic acid  -----  >120 mcg/mL
Vancomycin  -----  Peak: >60.0 mcg/mL
 Trough: >20.0 mcg/mL


Critical Values for Transfusion Medicine

Notification of the following outcomes are documented according to Blood Bank policy and held on file in the Blood Bank.

  1. Incompatible crossmatch on issued unit (emergency release)
  2. Positive Transfusion Reaction work-up results

For more information, call us toll free at 1-888-UCI-LABS