Hematocrit (Hct) Lab Values

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Chance Reaves
MSN-Ed,RN
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Included In This Lesson

Study Tools For Hematocrit (Hct) Lab Values

63 Must Know Lab Values (Cheatsheet)
Types of Anemia (Cheatsheet)
Symptoms of Anemia (Image)
Severe Pallor (Image)
Sickle Cell Anemia (Image)
Sickled Blood Cells (Image)
B12 Supplement for Pernicious Anemia (Image)
Cardiovascular Changes in Pregnancy (Image)
63 Must Know Lab Values (Book)
Hematocrit (Hct) Lab Values (Picmonic)

Outline

Overview

  1. Hematocrit
    1. Normal Value Range
    2. Pathophysiology
    3. Special considerations
    4. Elevations in lab results
    5. Decreased HCT levels

Nursing Points

General

  1. Normal value range
    1. HCT measured in percentage
    2. Males – 41-50%
    3. Females – 36-44%
  2. Pathophysiology
    1. Measurement of total pRBCs compared to rest of blood volume
    2. Helps to indicate anemia
    3. Often measured with HGB (hemoglobin)
  3. Special considerations
    1. Lavender top tube (EDTA)
    2. Be cautious with technique
      1. Do not force sample into tube
      2. Can cause hemolysis
      3. Alters results
  4. Causes of HCT elevation
    1. Dehydration
      1. Change in % compared to total blood volume
    2. Respiratory disease
      1. COPD
      2. Pulmonary fibrosis
        1. Increased need for oxygen -> increased need for RBC production
    3. Polycythemia vera
      1. RBC overproduction due to bone marrow cancer
      2. Treatment includes bloodletting and increasing water consumption (also some medications)
  5. Causes of decreased HCT
    1. Blood loss
      1. Trauma
      2. Hemorrhage
      3. Treatment
        1. Stop bleeding
        2. Transfuse blood
    2. Anemia
      1. Kidney disease
        1. Decrease in EPO production
        2. Treatment
          1. Supplement with EPO
      2. Pregnancy
        1. Relative to increase total blood volume
    3. Leukemia
      1. Decreased bone marrow production causes ↓ RBC
      2. Treat leukemia via oncology pathways
        1. Chemotherapy
        2. Radiation
        3. Bone marrow transplant

Assessment

  1. Assess for signs of anemia
    1. Tachycardia
    2. Fatigue
    3. Shortness of breath
    4. Decreased SaO2
    5. Pallor

Therapeutic Management

  1. Blood transfusions as necessary
  2. Treat primary cause of anemia
  3. Use oncologic methods to treat leukemia
  4. Bloodletting (phlebotomy) for polycythemia patients

Nursing Concepts

  1. Lab Values
  2. Oxygenation

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Transcript

For this lesson we’re going to talk about hematocrit.

Now before we get started the thing that you need to know about hematocrit is that it’s measured in percentages, which will get into in a minute. But for our male patients this is really going to be similar to the red blood cells and the hemoglobin in that the male percentages are going to be slightly higher than the female. So 41 to 50% is normal for a male patient and a female patient is normal hematocrit is going to be right between 36 to 44%.

Like I said the important thing to know about hematocrit is that it is measured in a percentage. And when I say percentage what I’m talking about is that it’s a measuring the actual packed red blood cells compared to the total blood volume. So if you look at this tube we’re looking at the percentage of the erythrocytes, are the red blood cells in relation to the whole volume of the blood. So in this tube, 45% of the volume is erythrocytes, and the other 55% is plasma and other types of cells in the blood. So this says that the hematocrit of this patient is 45%.

One of the benefits to hematocrit is it it helps to quickly indicate certain conditions like anemia, or other conditions where you have really high hematocrit levels. It gives a quick reference into what’s going on with the patient in terms of their overall blood volume, and any other problems. It’s often measured with hemoglobin, and you need to be mindful of what the red blood cell count is because all of these things typically Trend together.

I definitely recommend that you check out both the lessons on hemoglobin and red blood cells so that you can get a better understanding of how these three lab values all play together.

What do we need to be mindful of when we are submitting hematocrit levels to the lab?

So the first thing you’re going to want to do is it’s typically submitted in a lavender top tube, that has a EDTA in it. EDTA is going to keep the blood from clotting, and it also helps to get an accurate measurement of percentages.

Just like with hemoglobin and red blood cells, how you get the blood and how you put it into the tube is vitally important. What we don’t want to do is cause hemolysis, or breakdown of those red blood cells, because we both forced those red blood cells through a tiny opening or with too much pressure and it breaks them down, and then you’re not going to get accurate measurements. So make sure that you were introducing them slowly, pay attention to facility policy and terms of putting blood into blood tubing, and also consider the size of the gauge of the needle is that you’re drawing with. If you are drawing blood to a really small needle, or a small amount of tubing, or you’re applying too much pressure, it could cause a breakdown in those red blood cells, and then the measurements are going to be off, not only in the hematocrit, but also theoretically in the red blood cells and the hemoglobin.

Now let’s take a look at some abnormal lab values for hematocrit.

With increased hematocrit, just like with red blood cells, and hemoglobin, dehydration can cause a change in the percentage of the total blood volume, and that can actually increase the amount of red blood cells, and in theory the Hematocrit. Also think about respiratory disease. If you have a disease that is requiring an increase in oxygen, the body compensates by kicking out more red blood cells, and therefore will cause an increase in the hematocrit. These are diseases like pulmonary fibrosis and COPD. Because there is a higher need for oxygen, the body is going to respond by producing more red blood cells because it thinks that it can get more oxygen delivered to the tissues by that pathway.

Polycythemia vera is another one that you’ll need to pay attention to when you see an increase hematocrit and it’s probably going to be the one that’s going to knock your socks off, because the hematocrit is usually extremely high. Polycythemia vera is an illness where you have a major overproduction of red blood cell counts, and it’s going to cause the hematocrit to jump excessively high. The way the providers typically treat this is through bloodletting, so literally pulling off large quantities of blood, in order to decrease that hematocrit level, in Austin you can use to increase water intake and also by some medications.

What if the hematocrit is low? Decreased hematocrit levels are often caused by some sort of blood loss, whether this is through some sort of surgery, or trauma, or some other sort of hemorrhage. You’re going to want to make sure that you stop deleting your patient and you may typically also do blood transfusions if they’re at dangerous levels. Other reasons why you may see decreased hematocrit are through types of anemia, like sickle cell anemia or aplastic anemia. You also may see relative anemia that’s associated with pregnancy because the increased total volume of plasma. Another time that you may see and anemia is from the decrease in the hormone erythropoietin, that’s caused by kidney disease. The kidneys are where EPO is produced, so if they’re damaged they’re not going to produce it, and therefore you’re going to have no stimulation from the kidneys to tell the bone marrow to secrete red blood cells.

You may also see decreased red blood cell production with diseases like leukemia, because the bone marrow production is so vastly affected by the cancer. You can either do chemotherapy, radiation, bone marrow transplants, or other methods of treating leukemia to help bring that hematocrit level back up.

For nursing concepts for this lesson, we really focused online values, and oxygenation, since hematocrit is in direct relation to the red blood cells would carry oxygen to all of our tissues.
So let’s recap.

Hematocrit is a percentage, and it’s related to the total volume of blood.

When you’re looking at hematocrit, also consider your red blood cells or hemoglobin counts, because they’re almost always tested together.

You always want to send hematocrit samples in the lavender top tube, and be careful not to cause hemolysis with technique.

When you have elevated hematocrit counts, it’s because there’s an increased need for oxygen and the body is responding by over producing it, or you actually have an overproduction of those red blood cells causing the hematocrit to be increased.

And finally when you have a decreased hematocrit, often look to blood loss or decrease red blood cell production as the call Britt.

That’s our lesson on hematocrit. Make sure you check out all the resources attached to this lesson. Now, go out and be the best selves today. And, as always, happy nursing!!

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Lab Values

The Lab Values Course will help you understand how to interpret some of the most common and most important laboratory values you might see in your patients. We’ll break them down by body system and help you understand how the numbers you see in the chart relate to what’s actually happening to your patient. We’ll even walk you through how to draw blood in the right order and how to easily document lab values on your patient.

Course Lessons

Lab Values Course Introduction
Lab Values Course Introduction
Lab Basics
Lab Panels
Order of Lab Draws
Shorthand Lab Values
Cardiovascular Labs
Troponin I (cTNL) Lab Values
Brain Natriuretic Peptide (BNP) Lab Values
Cardiac (Heart) Enzymes
Hematology Labs
Red Blood Cell (RBC) Lab Values
Hemoglobin (Hbg) Lab Values
Hematocrit (Hct) Lab Values
White Blood Cell (WBC) Lab Values
Platelets (PLT) Lab Values
Coagulation Studies (PT, PTT, INR)
Cultures
Cyclic Citrullinated Peptide (CCP) Lab Values
Absolute Neutrophil Count (ANC) Lab Values
Mean Platelet Volume (MPV) Lab Values
Total Iron Binding Capacity (TIBC) Lab Values
Red Cell Distribution Width (RDW) Lab Values
Absolute Reticulocyte Count (ARC) Lab Values
Carboxyhemoglobin Lab Values
Methemoglobin (MHGB) Lab Values
Mean Corpuscular Volume (MCV) Lab Values
D-Dimer (DDI) Lab Values
Iron (Fe) Lab Values
Fibrin Degradation Products (FDP) Lab Values
Fibrinogen Lab Values
GI and Hepatic Labs
Albumin Lab Values
Cholesterol (Chol) Lab Values
Ammonia (NH3) Lab Values
Total Bilirubin (T. Billi) Lab Values
Liver Function Tests
Gamma Glutamyl Transferase (GGT) Lab Values
Alanine Aminotransferase (ALT) Lab Values
Alkaline Phosphatase (ALK PHOS) Lab Values
Lipase Lab Values
Prealbumin (PAB) Lab Values
Protein (PROT) Lab Values
Renal Labs
Blood Urea Nitrogen (BUN) Lab Values
Creatinine (Cr) Lab Values
Glomerular Filtration Rate (GFR)
Urinalysis (UA)
Protein in Urine Lab Values
Creatinine Clearance Lab Values
Endocrine Labs
Glucose Lab Values
Hemoglobin A1c (HbA1C)
Anion Gap
Free T4 (Thyroxine) Lab Values
Thyroid Stimulating Hormone (TSH) Lab Values
Cortisol Lab Vales
Glucagon Lab Values
Glucose Tolerance Test (GTT) Lab Values
Growth Hormone (GH) Lab Values
Triiodothyronine (T3) Lab Values
Thyroxine (T4) Lab Values
Metabolic Labs
Carbon Dioxide (Co2) Lab Values
Vitamin B12 Lab Values
Vitamin D Lab Values
Phosphorus (PO4) Blood Test Lab Values
Bicarbonate (HCO3) Lab Values
Lactate Dehydrogenase (LDH) Lab Values
Direct Bilirubin (Conjugated) Lab Values
Homocysteine (HCY) Lab Values
Beta Hydroxy (BHB) Lab Values
Ionized Calcium Lab Values
Myoglobin (MB) Lab Values
Immunology and Inflammatory Labs
Cyclic Citrullinated Peptide (CCP) Lab Values
Hepatitis B Virus (HBV) Lab Values
Creatine Phosphokinase (CPK) Lab Values
Erythrocyte Sedimentation Rate (ESR) Lab Values
C-Reactive Protein (CRP) Lab Values
Prostate Specific Antigen (PSA) Lab Values
Procalcitonin (PCT) Lab Values
Urine Culture and Sensitivity Lab Values
Antinuclear Antibody Lab Values
Perinatal Labs
Alpha-fetoprotein (AFP) Lab Values
Pharmacology Labs
Lithium Lab Values
Lab Values By Diagnosis
Pregnancy Labs
Pneumonia Labs
Dysrhythmias Labs
Sepsis Labs
Congestive Heart Failure (CHF) Labs
COPD (Chronic Obstructive Pulmonary Disease) Labs
Renal (Kidney) Failure Labs
Pediatric Bronchiolitis Labs
Ischemic (CVA) Stroke Labs