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 | |
| Lidocaine | 9 µg/mL | |
Very informatve
Thanks.
Very informatve
Thanks.