ex1 lab values

Note the location of each component on a Fishbone diagram (BMP)

Differentiate between quantitative and qualitative, screening and confirmation laboratory tests

Qualitative vs. quantitative test

- Yes/No answer or numerical value?

- Quantitative: frequently provided with reference range

Understand influences that may impact interpretation of values

- Free vs. protein bound assays - albumin
- Drug-assay interactions
- Timing of day
- Fasting status
- Source
- Gender
- Age

TRUE POSITIVE RATE VS. TRUE NEGATIVE RATE

BMP labs

CBC labs

Hyperglycemia/sodium relationship

Hyperglycemia causes pseudohyponatremia

Hemoglobin A1C (reference range: ?)

(reference range: 4 - 5.6%)

- 3 month average
- Glucose irreversibly binds to hemoglobin proportionally to average serum glucose
- Useful for assessing diabetes therapy, adherence
- Fasting state not important in assessing A1C

Serum creatinine

Kidney damage likely - renal function

Creatine is decomposed to creatinine

Sodium

body water homeostasis by kidneys

influences serum osmolarity

Chloride

High Na typically = High Cl, visa versa

Bicarbonate

Used to assess acid-base disorders

Blood urea nitrogen (BUN)

BUN - renal

Waste product from protein decomposition
- Formed in liver
- Marker for hydration status, renal function, protein tolerance

Phopshorus

Several roles
- Metabolism of proteins, lipids, carbohydrates
- Co-factors
- Cellular energy

Corrected calcium equation

[(4 - albumin) * 0.8] + Total Serum Calcium

Looking at albumin levels

Hypomagnesemia - what syndrome is associated with it?

Low magnesium levels

Refeeding syndrome

Liver function tests

Acute vs Chronic

abnormal labs do not indicate symptoms present

Hepatocellular injury (LFT)

ACUTE

- Aspartate aminotransferase (AST)
- Alanine aminotransferase (ALT)
- Indirect and direct bilirubin
- Alkaline phosphatase (ALP)
- Gamma glutamyl transferase (GGT)
- Amylase
- Lipase

Synthetic tests (LFT)

CHRONIC - LIVER ISNT WORKING

- Albumin
- Coagulation studies

AST AND ALT

Hepatocyte injury

>2:1 AST:ALT ratio, marker for potential alcoholic liver disease

BILIRUBIN

Hepatocyte injury

-Indirect (aka unconjugated)
- NOT water soluble
- Elevated with hepatic impairment, certain medications

- Direct (aka conjugated)
- Water soluble
- Excreted through bile, feces, urine
- Elevated possibly due to biliary obstruction

ALBUMIN

Synthetic tests

anything bound to albumin is physiologically inactive

COAGULATION STUDIES

Synthetic test for liver function

Monitor anticoagulants (warfarin)

Assess syntheitc hepatic impairment

ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT)

another marker of synthetic liver impairment

FASTING LIPID PANEL (FLP)

Total cholesterol (impacted by both HDL - good and LDL - bad)

Triglycerides (TG, <150 mg/dL)
- Potential for false elevation if not fasting
- Elevated with:
- Diabetes
- Alcohol ingestion
- Liver disease
- High carbohydrate diet

THERAPEUTIC DRUG MONITORING (TDM)

- Therapeutic confirmation
- Avoidance of inefficacy
- Dosage optimization
- Suspected toxicity
- Avoidance of toxicity
- Assess adherence
- Concern for drug interactions impacting level

IDEAL AGENT FOCUS - PHENYTOIN

- Seizures
- Toxicity
- Numerous drug interactions
- Narrow therapeutic window
- Assess adherence
- Unpredictable dose/response (aka level) relationship

COMPLETE BLOOD COUNT (CBC) fishbone diagram

CBC’s

Measure different values involving blood

White blood cells

Common marker of infection

Red blood cells

carry O2 to tissues

URINE ANALYSIS (UA)

illicit drug use/infection

Urine drug screen

Qualitative tests (different illicit drugs)

Urine analysis

Seeing different cells/proteins in the urine

NEVER SHOULD BE PROTEIN IN THE URINE (kidney damage)