Laboratory Test Critical values, Which need immediate action
Critical values
There are values of various tests that need immediate action or immediate communication of the result to the hospital or referring doctors.
Critical values: Laboratory critical value and its protocol
- These values should be conveyed to the concerned person without any delay.
The tests and their critical values:
| Test | Critical value>(more than) | Critical value < (less than) |
| Biochemical tests | ||
| Amylase | Three times the normal value | No value |
| Ammonia | >40 µmol/L | No value |
| Bilirubin level |
adult= > 12 mg/dL newborn= >15 mg/dL |
No value |
| Blood glucose level |
Adult male = > 400 mg/dL Adult female = >400 mg/dL Newborn = >300 mg/dL |
|
| Serum sodium (Na+) | > 160 meq/L | < 120 meq/L |
| Serum potassium (K+) |
Adult = > 6.5 meq/L Newborn = >8 meq/L |
Adult = < 2.5 meq/L Newborn = <2.5 meq/L |
| Serum calcium (Ca++) | >13 mg/dL (3.25 mmol/L) | <6.5 mg/dL (1.5 mmol/L) |
| Ionized calcium | >7 mg/dL (1.58 mmol/L) | <2.2 (0.78 mmol/L) |
| Serum phosphate (PO4)3- | < 1 mg/dL | |
| Magnesium (Mg++) | >3 meq/L | <0.5 meq/L |
| Serum bicarbonate (HCO3–) | >40 meq/L | <10 meq/L |
| Chloride (Cl–) | >115 meq/L | <80 meq/L |
| Creatinine | >4 mg/dL (>5.0 mg/dL) | No value |
| Blood urea nitrogen (BUN) | >100 mg/dL | 2 mg/dL |
| Phosphorus | No value | <1.1 mg/dL |
| Uric acid | >12 mg/dL | |
| Triglyceride | >400 mg/dL | |
| HDL |
Male = <35 mg/dl. Female = <40 mg/dl. |
|
| Ethanol | >300 mg/dL (>65 mmol/L) | |
| Haptoglobin | No value | <40 mg/dL |
| Insulin assay | >30 µU/mL | |
| Arterial pH | > 7.6 | < 7.2 |
| pCO2 | >60 mm Hg | <20 mm Hg |
| pO2 (arterial) | No value | <40 |
| O saturation | 75% or lower | |
| CO2 content | <6 meq/L | |
| Osmolality | >320 mOsm /Kg H2O (>600) | <265 mOsm /Kg H2O |
| Haptoglobin | <40 mg/dL | |
| Prealbumin | <10.7 mg/dL = Severe nutritional deficiency | |
| Cardiac troponin T | >0.1 µg/L | No value |
| Cardiac troponin I | >1.6 µg/L | No value |
| Ck-MB | >5% or >10 µg/L | No value |
| Cerebrospinal fluid (CSF) | Critical value>(more than) | Critical value < (less than) |
| Glucose | <80% of the blood level | |
| Protein | >45 mg/dL | No value |
| White blood cells (WBCs) | >1000/cmm | No value |
| Gram stain | Positive | |
| AFB stain | Positive | |
| Malignant cells | Positive | |
| Blast cells | Positive | |
| Amniotic fluid | ||
| Bilirubin level | Increased in Hemolytic anemia of the newborn | |
| Color | Red, green, yellow, or brown | |
| Lecithin/sphingomyelin ratio | <2.0 | |
| Chromosomal abnormalities | Positive | |
| Hematology | Critical value>(more than) | Critical value < (less than) |
| Hemoglobin | >20 g/dL | <5 g/dL |
| Methemoglobin | >40% of the total Hb | |
| Hematocrit (Hct) | >60% | <14% |
| Reticulocytes | > 20 % | |
| Platelets | >one million/cmm | <20,000/cmm |
| Total leucocyte count (TLC) | >50,000 /cmm | <2000 /cmm |
| Carboxyhemoglobin (COHb) | 20% | |
| Prothrombin time | >20 seconds | No value |
| Partial thromboplastin time (PTT) | >100 seconds | No value |
| Activated partial thromboplastin (APTT) | >70 seconds | |
| INR | >5.5 | |
| Fibrinogen | >700 mg/dL | <100 mg/dL |
| Fibrinogen degradation factor (FDP) | >40 mcg/mL | |
| Bone marrow | Positive for malignant cells | |
| Urine | Result | |
| Glucose | Strongly positive | |
| Ketones | Strongly positive | |
| Pathologic crystals | Cysteine, leucine, and tyrosine | |
| WBCs | Increased number >15/HPF | |
| RBCs | Increased number >10/HPF | |
| Protein | Positive 2+ | |
| Urine colony culture numbers | >50,000 colonies/mL | |
| Microbiology | Result |
|
| CSF gram stain | Positive | |
| Pleural fluid gram stain |
Positive | |
| Synovial fluid gram stain |
Positive | |
| Peritoneal fluid gram stain |
Positive | |
| AFB stain | Positive | |
| Blood culture | Positive | |
| C. Diphtheria culture | Positive | |
| Peripheral blood smear |
|
|
| Respiratory area culture | Positive growth for pathogens | |
| Hormones | Critical value>(more than) | Critical value < (less than) |
| TSH | > 7 mIU/L (hypothyroidism) | < 0.5 mIU/L (hyperthyroidism) |
| Thyroxin (T4) |
|
Adult <2 mcg/dL if myxedema comma Newborn = <7 mcg/dL |
| Estriol | <40% below the average of two previous values, demand immediate evaluation of fetal well-being during pregnancy | |
| Growth hormone | ||
| Surgical pathology | Result | |
| Fine needle aspiration | Positive for malignant cells | |
| Cervical biopsy or PAP smear | Positive for malignant cells | |
| Serology | Result | |
| HBV (Hepatitis B virus) | Positive | |
| HCV (Hepatitis C virus) | Positive | |
| Test for syphilis | Positive | |
| Coomb’s test direct /indirect | Positive | |
| Therapeutic drugs level | Result | |
| Acetaminophen | >150 µg/mL | |
| Salicylates | >700 µg/mL | |
| Gentamicin | >12 µg/mL | |
| Chloramphenicol | >50 µg/mL | |
| Tobramycin | >12 µg/mL | |
| Quinidine | >10 µg/mL | |
| Primidone | >24 µg/mL | |
| Theophylline | >25 µg/mL | |
| Phenytoin | >40 µg/mL | |
| Digoxin | >2.5 ng/mL | |
| Digitoxin | >35 ng/mL | |
| Lithium | 2 meq/L | |
| Lidocain | 9 µg/mL | |
Very informatve
Thanks.
Very informatve
Thanks.