General Pathology 601 for Dental Students

Lab Values & Cases
 

Richard McPherson, MDRichard McPherson, MD
Chair of the Division of Clinical Pathology
CSC Building
Office: (804) 828-5389
FAX: (804) 828-6156 
ramcpher@hsc.vcu.edu

 

A. Red top/gold sleeve (clot tube): serum chemistries

Panels

Electrolytes

Basic Metab

Comp Metab

Hepatic

Renal

Tests

          

Na

X

X

X

  

X

K

X

X

X

  

X

Cl

X

X

X

  

X

CO2

X

X

X

  

X

Glucose

  

X

X

  

X

Urea

  

X

X

  

X

Creatinine

  

X

X

  

X

Calcium

  

X

X

  

X

Bilirubin, Dir

      

X

  

Bilirubin, Tot

    

X

X

  

Albumin

    

X

X

X

Total Protein

    

X

X

  

AST (SGOT)

    

X

X

  

ALT (SGPT)

    

X

X

  

ALP

    

X

X

  

Phosphorus

        

X

B. Lavender top (EDTA anticoagulant): whole blood for cell counts

  • CBC (complete blood cell count) = RBC + WBC + Platelets
  • Erythrocyte Sedimentation Rate (ESR)
C. Blue top (citrate anticoagulant): plasma for coagulation tests
  • Prothrombin Time (PT)
  • Activated Partial Thromboplastin Time (APTT; PTT)
  • Thrombin Time
  • Fibrinogen
  • Factor assays
D. Gray top (fluoride inhibits cellular glycolysis): for accurate glucose measurements to diagnose diabetes mellitus

E. Green top (heparin): plasma for stat chemistries (electrolytes, basic metabolic panel, cardiac injury markers)

F. Other body fluid containers: urine, cerebrospinal fluid, ascites fluid, pleural fluid

Case 1

A 47-year-old man experienced acute onset of intense chest pain radiating from midsternum into his left arm and left jaw. The pain began about 30 minutes earlier. He had had many episodes of epigastric pain over the last few years that responded to antacids; however, this pain was much more severe and crushing. He was 30 pounds overweight and smoked two packs of cigarettes per day. Earlier in the day he had worked strenuously digging in his garden. His mother was alive and well, as were three siblings. His father had died suddenly on a business trip at 49 years of age.

Differential Diagnosis

  • Acute Myocardial Infarction (AMI)
  • Pulmonary Embolus (PE)
  • Intercostal muscle spasm
  • Vascular accident (e.g., aneurysm)
  • Broken rib
  • Pulmonary abnormality

Tests to be performed in the ER

  • Myoglobin
  • CK-MB
  • Cardiac Troponin I (or T)

Treatment for AMI

  • Fibrinolysis (TPA)
  • Angioplasty
  • Heparinization

Tests to be performed to monitor acute therapy

  • PT 
  • APTT
  • Basic Metabolic Panel

Tests to be performed to assess cardiac risk

  • Total cholesterol
  • HDL cholesterol
  • Triglycerides
  • LDL cholesterol
  • Maybe homocysteine in the future

Case 2

A 35-year-old man drove straight through from Miami to Richmond during which time his right calf became progressively more tender and swollen. After a brisk walk the next morning, he had sudden onset of chest pain that persisted, and a few hours later he coughed up some blood.

Differential Diagnosis

  • Thrombophlebitis and pulmonary embolus

  • Leg muscle injury/fasciitis/cramp

  • Pneumonia/lung infection

  • Traumatic injury

Tests

  • Ventilation-perfusion scan of lungs--decreased flow due to embolus

  • Doppler study of blood flow in leg--obstruction (clot) to flow can be detected

Treatment: heparin converting to coumadin after a few days

Lab Monitoring

  • APTT for heparin

  • PT for coumadin; reported as the INR = (PTpatient/PTcontrol)ISI

Labs for Risk Assessment

  • Protein C

  • Protein S

  • Activated protein C resistance (APCR)

  • Lupus anticoagulant

How long should he stay on coumadin? Does coumadin affect what his dentist does?

Case 3

A 3-year-old girl had a fever of 104°F, complained of ear ache, and was extremely lethargic. She had had a cold for the last week.

Differential Diagnosis

  • Upper respiratory infection (URI)

  • Otitis media

  • Other infectious source--urinary tract, intestine, CNS

Lab tests

  • CBC showed WBC 13.5 x 109 cells/L (elevated) with 38% granulocytes, 12% bands, 40% lymphocytes, 10% monocytes

  • Urinalysis--dipstick positive for nitrite, positive for leukocyte esterase microscopic showed numerous WBC, loaded with bacteria

  • Throat smear--negative for bacterial antigens (Streptococcus); sent for culture

  • Neurological exam--normal

  • GI--no diarrhea; abdomen soft and non-tender except in lower region near bladder

Case 4

A 39-year-old woman complained of "not feeling very good" for the last year. She gave a history of heavy menstrual periods. Her oral mucosa and nail beds were very pale.

Differential Diagnosis

  • Iron deficiency anemia

  • Diabetes mellitus

  • Electrolyte abnormality

  • Occult malignancy

  • Pregnancy

Lab tests

 Patient Results Reference Ranges

CBC

 RBC 2.4 x 1012 cells/L 3.6-5.8 x 1012 cells/L
  Hematocrit 14% 32-52%
  Hemoglobin 4.7 g/dL 11.0-17.4 g/dL
  Mean Cell Volume 58. fL 82-97 fL microcytic
  MCHC 33.6 g/dL 32-35 g/dL hypochromic
  MCH 19.6 pg 27-33 pg
  WBC 7.1 x 109 cells/L 3.7-9.4 x 109 cells/L
  Platelets 170 x 109 cells/L 134-357 x 109 cells/L
  Glucose 115 mg/dL 65-110 mg/dL
  serum iron 15 µg/dL 30-190 µg/dL
  IBC 410 µg/dL 100-300 µg/dL
  Transferrin saturation 3.6% 20-40%
  Stool negative for blood (hemoccult)  

The anemia responded to oral Fe. She was found to have enlarging fibroid tumors of the uterus that were eventually removed surgically. She had three units of packed RBCs transfused. She did well post-operatively. At age 52 she again reported "not feeling good" for at least a year. Physical exam showed yellow skin and sclerae of the eyes.

Lab Tests

 Results Reference Ranges
Bilirubin:    

direct

 2.5 mg/dL 0.0-0.3

 total

 6.1 mg/dL 0.2-1.5
AST 475 U 0-50
ALT 630 U 0-50
ALP 175 U 0-100
Hepatitis serologies:    

Hepatitis A antibody

 negative  

Hepatitis B surface antigen

 negative  

Hepatitis B core antibody

 negative   

Hepatitis C antibody

 positive  

Liver Biopsy

Hepatitis C RNA in serum by quantitative RT-PCR

Treatment

  • Alpha interferon

  • ribavirin

  • liver transplant

Digital Legends for Labs
Lab 1 | Lab 2 | Lab 3 | Lab 4 | Lab 5 | Lab 6 | Lab 7 | Lab 8 | Lab 9 | Lab10 |
Lab11 | Lab 12 | Lab 13 | Lab 14 | Lab 15 | Lab 16 | Lab 17 |

Lab 18

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Medical II

Updated April 7, 2009