Lab Value Interpretation

Original Editor - Ayelawa Samuel Top Contributors - Ayelawa Samuel, Lucinda hampton, Kim Jackson and Rachael Lowe

Introduction[edit | edit source]

Lab values.jpg

Laboratory testing involves the checking of blood, urine, and body tissue samples in order to see if the resulting lab values fall within the normal range. Lab values are used to determine a patient’s overall health and well-being.

There are many factors that can affect a patient’s result and lab values but some of the most common factors are gender, age, race, the medicines taken, and the presence of any underlying condition(s).[1]

The video below gives a good introduction to lab values and normal ranges.

[2]

Care Plan[edit | edit source]

The fundamental consideration when reviewing patient laboratory findings is toward determining an appropriate plan of care and weighing the anticipated benefit of a therapy intervention against the potential of the patient.

Physical therapists should:

  • Carefully anticipate the physiological changes that might have occurred whenever a laboratory value is out of range.
  • Be aware of the heightened risk level if a value should fall into the critical range.
  • Be aware of the importance of understanding pertinent lab values and the subsequent potential of adverse events when practicing in this kind of practice setting.

When commencing or continuing care of patients in the acute care setting, always use sound clinical decision making[3].  The Lab values alone may or may not determine whether you’re going to intervene with a patient, or whether you’re going to hold[4].

Be aware[edit | edit source]

Clinicians in Intensive Care Unit.jpg

Things to consider when looking at the patient’s condition

  • Potential drug interactions
  • Significant trends in the values over time
  • Electrolyte panels might change with intravenous infusions, medications, and diet
  • Chronic medical conditions (such as Anaemia) might be asymptomatic during exercise, while a patient with precipitous drop in hemoglobin and hematocrit might require urgent medical attention.

Complete Blood Count[edit | edit source]

Complete blood count is one of the most basic laboratory examinations to assess the overall health status of a patient. It can help diagnose infections, autoimmune disorders, anemia, and other blood diseases.[5][6]

Lab values Normal range Rehabilitation consideration
Hematocrit(%RBC) 43-49%(male)    

38-44%(female)

No exercise (<25%)

light exercise (25-30%)

Resistive exercise (>30%)

Platelets 150,000-350,000/µL No exercise (<20,000µL)

Light exercise (20,000-50,000µL)

Resistive exercise (>50,000µL)

Hemoglobin 14.4-16.6gm/dL (male)

12.2-14.7gm/dl (female)

No exercise (<8gm/dl)

light exercise (8-10gm/dl)

Resistive exercise (>10gm/dl)

White blood cell(WBC)    4,500-11,000 mm3 No exercise (<5,000 mm3 )

Light exercise (>5,000 mm3)

Resistive exercise (>5,000 mm3 as tolerated)

Electrolytes[edit | edit source]

Electrolytes are minerals that are involved in some of the important functions in our body. Serum electrolytes are routinely ordered for a patient admitted to a hospital as a screening test for electrolyte and acid-base imbalances.[7]

Lab values Normal range Rehabilitation consideration
Sodium  135-145mEq/L Reduction: Cramps, weakness, confusion

Elevation: Fluid retention, Swelling, Hypertension

Potassium  3.5-5.0mEq/L Reductions: Flattened T waves, arrthymias

Elevations: Peaked T waves, shortened QT interval

Calcium  8.5-10.5mg/dl     Reductions (Moderate to severe): parathesias, muscle spasms and seizure and

QT interval prolongation.

Elevations (severe only): Bradycardia, AV block, and short QT interval, coma

Magnesium         1.7 to 2.2mg/dl  Reductions: prolonged PR or QT intervals, T-Waves flattening or inversion, SVT.

Elevation: weakness, respiratory failure, coma, paralysis.

Chloride  95-105mEq/L       Reduction: often occur during metabolic alkalosis

Elevations: Metabolic acidosis[8]

Coagulation[edit | edit source]

Blood test.jpg

Clotting is what prevents excessive bleeding, the blood moving through your vessels shouldn’t clot. If such clots form, they can travel through the bloodstream to the heart, lungs, or brain. This can cause a heart attack, stroke, or even death.

Coagulation tests measure the blood’s ability to clot, and how long it takes to clot. Testing can help assess the risk of excessive bleeding or developing clots (thrombosis) somewhere in your blood vessels. Coagulation tests are useful in monitoring people who take medications that affect clotting ability. Coagulation tests are also sometimes recommended before surgery.

Conditions that can cause coagulation problems include:

  • Liver disease
  • Thrombophilia, which is excessive clotting
  • Hemophilia, which is an inability to clot normally

There are many types of coagulation tests. Some of the more common are listed below.[9]

Lab values Normal range Rehabilitation consideration
Prothrombin time(PTT) 11-12.5sec Assesses extrinsic pathway (fast system)

Therapeutic range: 1-2 times normal

Risk of bleeding: >2-3 times normal

International normalized

Ratio (INR)

0.9-1.1   normalized ratio PT, used to assess effect of warfarin

therapeutic range: Afib/DVT/PE (2-3)

Valve replacement (2.5-3.5)

Risk of bleeding: >4.0 light exercise only

>5.0 hold exercise, PT eval only

>6.0 PT contraindication

The above outline was created to assist the clinician with lab value considerations for the general population.

  • Be aware that “norm” are created for the healthy adult, and each patient’s lab value should be interpreted within the context of the patient’s current medical status[3].
  • Pediatrics population lab values range is not included above[8].

General Chemistry[edit | edit source]

Blood chemistry set is used to measure the amount of substances in the body. Glucose measures blood sugar and determines if the patient is within the criterion for diabetes. Uric acid is often an indication of kidney stones and a high BUN and creatinine suggest impairment in our kidney. In general, the basic chemistry helps us assess many conditions and give light to how the body’s organs are working[1].

Normal Range:

  • Albumin: 3.5-5.5 g/dL
  • Alkaline Phosphate (ALP): L32 – 110 IU/L
  • Aminotransferase, alanine (ALT): 0-35 U/L
  • Aminotransferase, aspartate (AST): 0-35 U/L
  • Ammonia, plasma: 40-80 μg/dL
  • Amylase, serum: 0-130 U/L
  • Bilirubin: <1.0 mg/dL
  • Bicarbonate (CO2): 23-29 mEq/L
  • Blood Urea Nitrogen (BUN): 7-2 mg/dL
  • Ferritin: 10 – 350 NG/ML
  • Chloride (Cl): 96-112 mEq/L
  • Glucose: 65-99 mg/dL

Immunoglobulins[edit | edit source]

Innate Immune cells.jpg

Immunoglobulins or antibodies are molecules produced by white blood cells. They function as the primary part of the immune response by determining and binding to antigens, such as viruses and bacteria.[1] eg:

Globulins, total: 2.5-3.5 g/dL

  • IgG: 640-1430 mg/dL
  • IgA: 70-300 mg/dL
  • IgM: 20-140 mg/dL
  • IgD: less than 8 mg/dL
  • IgE: 0-90 U/mL

Iron studies

  • Ferritin, serum: 15-200 ng/mL
  • Iron, serum: 60-160 μg/dL
  • Transferring saturation: 20%-50%

Urinalysis[edit | edit source]

Kidney anatomy.jpg

Urine is another commonly used fluid for lab testing. It’s the most suitable sample for evaluating kidney functions.

  • Urine analysis is the test used to evaluate urine samples. This diagnostic examination is important in diagnosing certain illnesses including diabetes mellitus and chronic nephritis.
  • Urinalysis often involves three stages, the first is the visual exam, followed by the dipstick test, and lastly the microscopic exam. When doing a urinalysis, best practice is to use the first morning urine sample of a patient[1].

Hemodynamic Parameters[edit | edit source]

Hemodynamic monitoring focuses on the measurement of blood pressure in veins, heart, and arteries. This test is conducted to determine a patient’s heart health through the flow of blood and the amount of oxygen present in the blood[1].eg:

Normal Range:

  • Arterial Blood Pressure (BP): 90 to 140 mmHg
  • Diastolic (DBP): 60 to 90 mmHg
  • Mean Arterial Pressure (MAP): 70 to 105 mmHg
  • Left Atrial Pressure (LAP): 4 to 12 mmHg
  • Right Atrial Pressure (RAP): 4 to 6 mmHg
  • Cardiac Output (CO) 4.0 to 8.0 l/min

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 Global Rx Ph Lab Values Available from:https://globalrph.com/2020/02/a-comprehensive-guide-to-normal-lab-values/ (accessed 29.5.2021)
  2. Khanacacemymedicine. Introduction to lab values and normal ranges | Health & Medicine | Khan Academy. Available from: https://www.youtube.com/watch?v=_mGszRbve9s (last accessed 26.4.2019)
  3. 3.0 3.1 1.   James T., Traci N., Kim L. Academy of Acute Care Physical Therapy-APTA Task Force on Lab Values. Laboratory values interpretation Resource. 2017
  4. Physicaltherapy.com. Available from: http://www.physicaltherapy.com/articles/essential-role-lab-values-and-3637
  5. Nurse Buff Laboratory Values and Interpretation – A Nurse’s Ultimate Guide Available :https://www.nursebuff.com/laboratory-values-for-nurses/ (accessed 29.5.2021)
  6. Flashcard Machine: available from: http://www.flashcardmachine.com/contraindications-to-ptinacutecaresetting.html
  7. Nurse labs Lab Values Available from:https://nurseslabs.com/normal-lab-values-nclex-nursing/#serum_electrolytes-2 (accessed 29.5.2021)
  8. 8.0 8.1 1.      Physical Therapy Reviewer. Available from: http://ptreviewer.com/lab-values-3/  
  9. Health line Coagulation tests Available from: https://www.healthline.com/health/coagulation-tests#purpose (accessed 29.5.2021)