Lab Values and Their Clinical Significance

Introduction

• Miss Melendez introduces the session, noting the absence of power and plans to review lab values.

• Urges students to check emails for updates the next morning before doing anything else.

Review of Lab Values

• Focus on the significance and interpretation of various lab values, especially in relation to clinical cases.

Kidney Laboratory Tests

1. Creatinine

   • Normal Values: $0.6 ext{ to } 1.2 ext{ mg/dl}$

   • Description: Waste product from meat protein metabolism and normal muscle wear.

   • Significance: More specific for renal dysfunction than blood urea nitrogen levels.

   • Elevated Levels: Indicate renal failure, chronic nephritis, urinary obstruction due to tumors or kidney stones.

2. Blood Urea Nitrogen (BUN)

   • Normal Values: $11 ext{ to } 23 ext{ mg/dl}$

   • Description: Product of food protein breakdown.

   • Elevated Levels: Associated with acute or chronic renal disease, renal damage, urinary stasis, GI bleeding, congestive heart failure, shock, and starvation.

   • Low Levels: May indicate overhydration, pregnancy, liver failure, low protein intake, or smoking.

3. Hematuria

   • Definition: Presence of red blood cells in urine visible on microscopy.

   • Associated Conditions: Early renal disease, renal tumors.

4. Proteinuria

   • Definition: Presence of normal amounts of protein in urine.

   • Associated Conditions: Nephritis, nephrolithiasis (kidney stones), renal carcinoma, polycystic kidney disease, hypertension, diabetes.

   • Implications: Increased risk for progressive renal dysfunction.

5. Urinalysis

   • Usage: Used to detect chronic renal disease.

   • Considerations: Distinguish between inflammatory conditions and those caused by obstruction or calculus of the kidney.

   • Categories: Benign vs. malignant pathology.

Renal Transplant Complications

• Importance of understanding renal transplant and its complications in clinical assessments.

Spleen Laboratory Tests

1. Erythrocytes (Red Blood Cells)

   • Function: Carry oxygen from lungs to tissues and carbon dioxide back to lungs; lifespan of 120 days.

   • Elevation: Associated with polycythemia vera and severe diarrhea.

   • Decrease: Linked to internal bleeding, hemolytic anemia, Hodgkin's disease, and hemangiosarcomas.

2. Leukocytes (White Blood Cells)

   • Normal Count: $4500 ext{ to } 11000$ cells per µL.

   • Function: Defend body against infections.

   • Elevation: Associated with acute inflammation, infection, leukemia, polycythemia vera, malignancy.

   • Decrease: Associated with viral infections, leukemia, aplastic anemia, diabetes.

3. Hematocrit

   • Normal Values: Female: 37 ext{ to } 47 ext{ %}, Male: 40 ext{ to } 54 ext{ %}.

   • Definition: Percentage of red blood cells in blood.

   • Elevation: Linked to severe dehydration, shock, polycythemia vera, COPD, and infections.

   • Decrease: Associated with hemorrhage, anemia, leukemia, cirrhosis.

4. Hemoglobin

   • Normal Values: Male: $13 ext{ to } 18$ g/dL, Female: $12 ext{ to } 16$ g/dL.

   • Function: Oxygen-carrying pigment.

   • Production and Recycling: Developed in bone marrow, recycled by the spleen into iron and bilirubin.

Spleen Pathologies

• Blood disorders, splenic pathologies, trauma, malformations of the spleen.

Adrenal Gland Laboratory Tests

1. Adrenocorticotropic Hormone (ACTH)

   • Function: Regulates cortisol production.

   • Elevation: Associated with adrenal tumors, Cushing's disease, lung tumors.

   • Measurement: Varies but is secreted by the cortex.

2. Aldosterone

   • Function: Regulates sodium and water balance affecting blood volume and pressure.

   • Elevation: Associated with hyperaldosteronism.

   • Decrease: Linked to hypoaldosteronism and Addison's disease.

3. Potassium

   • Function: Essential for organ functioning and maintaining cellular nutrient concentrations.

   • Elevation: Associated with Addison's disease.

   • Decrease: Linked to Cushing's disease and hyperaldosteronism.

4. Sodium

   • Normal Range: $135 ext{ to } 145 ext{ mEq/L}$.

   • Function: Major determinant of blood volume.

   • Decrease: Associated with Addison's disease.

5. Serum Cortisol

   • Usage: Measures adrenal hormone levels; ideally taken at 8AM and 4PM.

   • Expected Values: Level at 4PM ideally half of that at 8AM.

Adrenal Disorders

• Benign and malignant adrenal pathologies, Addison’s disease, adrenocortical syndrome, Cushing’s disease.

Clinical Case Examples

1. Case 1: Acute pancreatitis.

2. Case 2: Splenic infarction.

3. Case 3: Chronic pancreatitis.

4. Case 4: Splenic cyst.

5. Case 5: Hemolytic anemia with splenomegaly.

Conclusion

• Final thoughts encouraging continued study and organization of materials in a comprehensible manner.

• Miss Melendez promises to notify students of any updates in the communication platform, Teams.