Diagnostic Testing and Procedures: Lab Values

• Diagnostic testing and procedures involve lab values for patient assessment.
• Golda Widawski, PT, DPT presented this information in February 2025.

Basic Labs

• Serum Enzymes
• Blood lipids
• Complete Blood Count (CBC)
• Coagulation profile
• Electrolytes
• Blood Urea Nitrogen (BUN)
• Creatinine (Cr)
• Serum glucose

Serum Enzymes

• Used to determine if someone had myocardial necrosis/injury.
• Troponin is the "Gold Standard", normal levels are 0.02-0.04, and typically 3 draws are done to "trend troponins".
• Troponin is released earlier and remains in blood up to 7 days, and high sensitivity troponin may trend 2 over a shorter time period.
• CPK-MB is also frequently used and conclusive for myocardial damage.
• Normal levels for CPK-MB are 0-3%, so greater than 3% is abnormal.

Blood Lipids

• A major risk factor for CAD.
• Total cholesterol >240 mg/100ml of blood is considered high, ideal level is <200.
• LDL >130 mg/100ml is borderline high/high, ideal level is <100.
• HDL <40 in men and <50 in women is low, the ideal level to be high in HDLs is above 60.
• Triglycerides >150 mg/100ml is considered borderline high.

Complete Blood Count (CBC)

• Hemoglobin (Hgb) normal value is 12-16 g/100ml.
• Hematocrit (Hct) normal value: 36-44 g/100ml.
• White blood cell (WBC) normal value: 4-12; leukocytosis and leukopenia indicate abnormal levels.
• Platelets are also measured in a CBC.

Low Hemoglobin (Hgb) - Anemia

• Not always a sign of illness, and can be normal for some pregnancies.
• It is associated with diseases and conditions that cause the body to have too few red blood cells.
• At NYP, Hgb is used as a guide where < 7, usually defer until post transfusion, sometimes use 8, and the case would have to be discussed with MD.

Hematocrit (Hct)

• Percentage of the blood that consists of RBCs.
• Low hematocrit = anemia for reasons such as loss of blood, nutritional deficiency, bone marrow problems, and sickle cell anemia.
• High hematocrit may be attributed to high altitudes, chronic smokers, dehydration, and blood doping.

White Blood Cells

• A low number of WBCs = leukopenia, possibly due to bone marrow deficiency or failure, collagen-vascular diseases, disease of the liver or spleen or radiation therapy or exposure
• A high number of WBCs = leukocytosis, possibly due to anemia, bone marrow tumors, infectious diseases, inflammatory disease, leukemia, severe emotional or physical stress, or tissue damage.

Platelets

• Normal level is 150-450 x 10^3 cells/uL
• Low = thrombocytopenia, increasing risk of bleeding, so consider limiting activity.
• High = thromobocytosis and increases risk of clotting.
• Platelet precautions vary from hospital to hospital, MD to MD.
• At NYPH greater than 50,000 = ok for some resistance, 20-30,000 = very light resistance (if any), <20,000 = no resistance, +ADLs, walking, etc. and <10,000 = likely to get transfusion, may hold PT and be sure to speak with medical team

Coagulation Profiles

• Measures clotting times.
• Partial thromboplastin time (PTT)/Activated PTT (aPTT) normal range: 25-39 sec, may be elevated for patients on __________
• Prothrombin time (PT) normal: 12-16 sec, and May be elevated for patients on __________
• International Normalized Ratio (INR) is the Method of standardizing PT results, normal range is 1.0-1.5.
  • INR 2.0-3.0: for afib, DVT/PE, and/or valve replacement pts
  • Lower INR: risk of clot
  • Higher INR: risk of bleed
• Factor Xa reflects patients on _______________

Normal Blood Values

• White Blood Cells norm is 3.4-11.2 K/ul.
  • High levels indicate parasitic/bacterial infection, leukemia, lymphoma.
  • Low levels indicate viral infection, leukemia, chemotherapy, BMT.
  • High or Low: indicates bodily compromise and to Utilize standard precautions
• Hemoglobin norm is 12-16 g/dl (M=12-16, F=12-15)
  • Increase level indicates dehydration, polycythemia, high altitudes
  • Decrease level indicates anemia, and to avoid strenuous aerobic exercise.
• Hematocrit (packed RBC Volume/whole blood volume) norm is 35-47%
  • High: Polycythemia-Increased viscosity to 10x H2O which impedes flow (norm viscosity is 3x H2O)
• Platelets norm is 150-450 k/dl, and to avoid activites that can cause trauma to tissues (ie: ROM, muscle stretching/strengthening, massage, blunt trauma) with low platelet counts.
• Prothrombin Time (PT) norm >4 above norm: investigate
• Partial Thrombin Time (PTT) norm: 21-38 sec.
• International Normalization Ratio (INR) norm is 1.0.
• 2.0-3.0 for A Fib; 4.0 Mechanical Valve Replacement

Electrolytes

• Involved with managing cell membrane potential.
• Sodium (Na+) normal Levels 135-147 mEq/L
• Potassium (K+) normal Levels 3.5-5.0 mEq/L
• BUN (Blood Urea Nitrogen) normal Levels 8-23 mg/dL
• Creatinine normal Levels 0.5-1.5 mg/dL
• Serum Glucose normal Levels 80-110mg/100 mL blood

Electrolytes: Sodium & Potassium

• Sodium Helps regulates H2O levels in the body and Helps with nerve conduction.
  • Too high sodium (hypernatremia) is commonly caused by unreplaced water loss in the body
  • Too low sodium (hyponatremia) is One of most common electrolyte disorders in US
• Potassium Works with Na+, Essential for normal cell function, Involved in contraction of heart & other muscles of the body, and Helps with nerve conduction.
  • Too high potassium (hyperkalemia) Decreases contractility of the heart.
  • Too low potassium (hypokalemia).

Electrolytes: BUN, Cr, Glucose

• BUN forms when protein breaks down: can indicate Heart or Renal failure.
  • Too high BUN can indicate CHF, kidney disease/failure, GIB, hypovolemia, uremia, MI
  • Too low BUN may be due to liver failure, starvation, malnutrition, low protein diet, high-carb diet
• Creatinine measures effectiveness of the kidneys
  • Too high Creatinine:renal failure, eclampsia/pre-eclampsia, dehydration,decreased kidney blood flow , rhabdomyololysis,urinary tract obstruction
• Glucose:
  • Too low Glucose (hypoglycemia)may become drowsy, unconscious, potential death
  • Too high Glucose (hyperglycemia): chronically can kick kidneys into working harder, potential for dehydration, coma, death

Electolytes: Glucose-PT Considerations

• LOW Glucose levels
  • Below 70mg/dL do NOT exercise, and treat hypoglycemia
  • If less than 100mg/dL wait until glucose is at least 100 before initiating exercise, and eat additional carbohydrate
• HIGH Glucose levels
  • For Type 1 DM: If greater than 250 mg/dL (fasting glucose level) -Most sources say to test urine for ketones, and if ketones present in urine, then avoid exercise
  • For Type 2 DM: If greater than 300 mg/dL
  • Some sources say to avoid exercise -Others say to use caution with exercise

Electrolytes Reference Levels

• Sodium (Na): Norm: 135-147 mEq/L

  • Hypernatremia: Intense thirst,fatigue, agitation, coma
    • Cause: Dehydration, excess intake
  • Hyponatremia: Muscle weakness, dizziness, headache,hypotension, tachycardia -Cause:Decreased intake, diuretics, burns, diarrhea, increased H2O, increased ADH

• Potassium (K) Normal: 4.5-5.2 mEq/l

  • Hyperkalemia: Irritability,anxiety, weakness, paresthesia,heart fibrillation
    • Cause: Renal Failure,dehydration Muscle tissue damage -Hypokalemia: Cramps, fatigue,flaccid paralysis, nausea,confusion, lengthened p-r- interval, flattened T wave
  • Cause: diuretics, vomiting, diarrhea, metabolic acidosis

• Chloride (Cl) Norm: 94-110 mEq/l -High: Hyperchloremia: Sx similar to increased Na , b/c Cl follows Na via electrical attraction - Cause: diarrhea, meds -Low: Hypochloremia: similar to increased Na - Cause: Vomiting, DM,ketoacidosis, renal Dz, increased RR

• Carbon Dioxide (CO2) Norm: 22-32 mmol/l

  • High: Hypercapnea; Compensation for respiratory acidosis,metabolic alkalosis,emphysema, severe vomiting,

• Muscle tissue damage Low: Hypocapnea; Compensation for respiratory acidosis, starvation, severe diarrhea

• Creatine Norm: 0.5- 1.5 mg/dl

  • Low: Pregnancy, decreased muscle mass (aging), severe liver disease
  • High: Renal failure, false positive ketoacidosis, urinary obstruction,dehydration, hyperthyroidism, muscle disease

• Blood Urea Nitrogen (BUN) Norm: 5-25 mg/dl (measures renal function)

  • High BUN: Renal failure,GI bleeding, stress, drugs, heart failure
  • Low BUN: starvation, liver function, pregnancy

• Glucose Norm:70-105 mg/dl (fasting) 80-120 mg/dl (diabetics)

  • Hyperglycemia: diabetic,epinephrine (stress, burns), acute pancreatitis,elderliness, glucosteroids,blood draws above dextrose IV site
  • Hypoglycemia: dizziness PT: Avoid vigorous exercise or ambulation after insulin and before

• BNP >300 pg/mL  Mild heart failure

• BNP >600 pg/mL  Moderate heart failure

• BNP >900 pg/mL  Severe heart failure

• BNP accurately detects heart failure 83% of the time which compared to 74% for clinical decision making alone Reduces clinical indecision from 43% to 11% (JACC 2002)

• May provide protective effect , and contributes to sodium and water excretion by kidneys along with relaxing them .