1. Clinical Laboratory Review for Toxicology

2. Objectives
List the common lab tests used in the evaluation of poisoned patients
Normal values
Describe common calculations based on these tests
Interpret the findings of common tests

3. Electrolytes Basic Metabolic Panel Sodium (135-148)
Potassium ( )
Bicarbonate (22-28)
Chloride (95-105)
Calcium ( mg/dl)
Other electrolytes
Magnesium ( )
Phosphorous ( )
Units are millieqivilant/L except Ca

4. Renal function Creatinine (0.8-1.2 mg/dl)
Blood Urea Nitrogen (8-18 mg/dl)

5. Shorthand for Basic Metabolic Panel

6. Liver function Alananine aminotransferase- ALT SGPT (12-40 IU/L)
Aspartate aminotransferase AST SGOT (12-40 IU/L)
AST and ALT increase with hepatocyte death
Acetaminophen (and most acute toxic causes) produce fold elevation while viral/ethanol cause 5-10 fold elevation

7. Liver function Alkaline phosphatase (39-117) Bilirubin (0.5 to 2.0)
Elevation= billiary obstruction
Bilirubin (0.5 to 2.0)
Measures ability of liver to clear toxins
INR (1-1.2)
Measures ability of liver to produce coagulation proteins
Elevation of transaminsase with change in INR= significant liver injury

8. Blood gas Shorthand: pH/CO2/O2 pH 7.35 to 7.42
<7.3= acidosis
>7.45= alkalosis
Partial pressure of CO2 (38-42 torr)
<36=respiratory alkalosis
>42= respiratory acidosis
Low serum bicarbonate= metabolic acidosis
High serum bicarbonate= metabolic alkalosis

9. Anion Gap = Sodium-bicarbonate+ chloride Normal= 10 to 14 meq/L
Increase anion gap in the setting of metabolic acidosis consider
MUDPILES etc

10. 2xNa+(Glucose/18)+ (BUN/2.8)+ (EtOH/4.6)
Osmolar gap
Serum osmolality is measured by the lab
You estimate serum osmolality from other values
2xNa+(Glucose/18)+ (BUN/2.8)+ (EtOH/4.6)
Calculate the difference (“Osmolar Gap”)
Measured-estimated (normal<10)
If the osmolar gap> 10 suspect toxic alcohol