Common Lab Tests for Cardiovascular Disorders

1. Serum chemistry
2. Serum Electrolytes
3. Alanine Aminotransferases (AST) 
4. Creatine Kinase (CK)
5. CK-MB (isoenzyme)
6. Lactic Dehydrogenase
7. Complete Blood Count
8. Lipid Levels
9. Prothrombin Time
10. Alkaline Phosphatase
11. ESR
12. Arterial Blood Gases
13. Troponin

Complete Blood Count

• basic screening test and one of the most frequently ordered laboratory procedure
• findings may give valuable diagnostic information about the hematologic  and body systems, prognosis and response to treatment and recovery of a patient

• Hemoglobin : main component of RBCs which transports Oxygen (O2) and Carbon Dioxide (CO2) all over the body
• MEN : 13.5-18.0 g/dL
• WOMEN : 12-16 g/dL (PREGNANCY : >11 g/dL)
• CHILDREN : 11-16 g/dL
• INFANTS : 10-15 g/dL
• NEWBORNS : 12-24 g/dL
• Red Blood Cell Count : main blood cells of the body that carries O2 from lungs to blood tissues and CO2 from tissues to the lungs
• MEN : 4.7-6.1 million/mm3
• WOMEN : 4.2-5.4 million/mm3
• INFANTS and CHILDREN : 3.8-5.5 million/mm3
• NEWBORNS : 4.8-7.1 million/mm3
• Red Blood Cell Indices
• MEAN CORPUSCULAR VOLUME (MCV) : 86-98 m3/cell
• MEAN CORPUSCULAR HEMOGLOBIN (MCH) : 27-32 pg/rbc
• MEAN CORPUSCULAR HEMOGLOBIN CONCENTRATION : 32-36%
• Hematocrit : measures the RBC mass separating the solute from the solvent
• MEN : 42-52%
• WOMEN : 37-47%
• CHILDREN : 31-43%
• INFANTS : 30-40%
• NEWBORNS : 44-64%
• White Blood Cell Count : main blood cells of the body that fights infection
• ADULTS and CHILDREN more than 2 YEARS : 5,000-10,000 mm3
• CHILDREN less than 2 years : 6,200-17,000/mm^3
• NEWBORNS : 9,000-30,000 mm3
• Differential White Cell Count : specific patterns of WBC
• NEUTROPHILS : 55-70%
• LYMPHOCYTES : 20-40%
• MONOCYTES : 2-8%
• EOSINOPHILS : 1-4%
• BASOPHILS : 0.5-1.0%
• Platelet Count : blood component necessary for clotting and control of bleeding
• 140-450

Nursing Interventions:

Pretest

1. Explain test procedure. Explain that slight discomfort may be felt when the skin is punctured.
2. Avoid stress if possible. Altered physiologic status influences and changes normal hemogram values
3. Select hemogram components ordered at regular intervals. Drawing of blood should be done as consistent as possible, if possible at the same time of the day for reasons of accurate comparisons. Natural body rhythms cause fluctuations in laboratory values at certain times of the day.
4. Dehydration or overhydration can dramatically alter values. For example, largerl volumes of IV fluids can dilute the blood and values will appear as lower counts.
5. Fasting is NOT necessary.  However, high fat meals may alter some test results as a result of lipidemia.

Posttest

1. Apply manual pressure to the puncture site upon removal of the needle for about 30-60 seconds.
2. Monitor the puncture site for bleeding or hematoma formation. Maintain pressure at the puncture site if necessary. Notify a physician of unusual problems.
3. Resume normal activities and diet.
4. Bruising at the puncture site is not uncommon. Signs of inflammation are unusual and should be reported if the inflamed area appears larger, if red streaks develop, or if drainage occurs.

TESTS OF WHITE BLOOD CELLS

White Blood Cells (WBCs) or Leukocytes are divided into 2 main groups: Granulocytes and Agranulocytes.

Granulocytes are named from the distinctive granules present in the cytoplasm of neutrophils, basophils and eosinophils. However, each of these cells also contains a multilobed nucleus, accounting for their name as polymorphonuclear leukocytes or 'polys' or PMNs.

Agranulocytes, consists of the lymphocytes and monocytes, do not contain distinctive granules and have nonlobular nuclei that are not necessarily spherical. They are also called MonoNuclear Leukocytes. 

The life span of leukocytes varies from 13-20 days, after which the cells are destroyed in the lymphatic system; many are excreted from the body in fecal matter. 

Leukocytes fight infection and defend the body by a process called phagocytosis, in which the leukocytes actually encapsulates the foreign organism and destroy them. Leukocytes also produce , transport and distribute antibodies as part of the immune response to a foreign substance.

WBCs serve as useful guide to the severity of the disease process. Leukocytes and differential counts, by themselves, are of little value as aids to diagnosis unless the results are related to the clinical condition of the patient.

Clinical Implications

• Leukocytosis: WBC >11,000/mm^3 or >11.0 x 10^3/mm^3 or >11 x 10^9/L
• Occurs in acute infection, in which the degree of increase of leukocytes depends on severity of the infection, patient's resistance, patient's age and marrow efficiency and reserve
• Possible causes of leukocytosis include:
• Leukemia, myeloproliferative disorders
• Trauma or tissue injury (Surgeries)
• Malignant neoplasms, especially bronchogenic carcinoma
• Toxins, uremia, coma, eclampsia, thyroid storm
• Drugs, especially ether, chloroform, quinine, epinephrine (adrenaline), colony-stimulating factors
• Acute hemolysis
• Hemorrhage (Acute)
• After splenectomy
• Polycythemia vera
• Tissue necrosis
• Occasionally, leukocytosis is found when there is no evidence of clinical disease. These findings may suggest the presence of:
• Sunlight, ultraviolet irradiation
• Physiologic leukocytosis resulting from excitement, stress, exercise, pain, cold or heat, anesthesia
• Nausea, vomiting, seizures
• Steroid Therapy modifies the leukocyte response
• When corticotropin (adrenocorticotropic hormone or ACTH) is given to a patient, leukocytosis happens
• When ACTH is given to a patient with severe infection, the infection can spread rapidly without producing the expected leukocytosis; therefore, what would normally be an important sign is obscured

Leukopenia: WBC <4000 mm="" sup=""> 

or <4 .0="" mm="" nbsp="" sup="" x=""> or <4 .0="" 10="" 4="" cells="" nbsp="" sup="" x="">9/L occurs during and following:

• Viral Infections, some bacterial infections, overwhelming bacterial infections
• Hypersplenism
• Bone Marrow Depression caused by heavy-metal intoxication, ionizing radiation, drugs:
• Antimetabolites
• Barbiturates
• Benzene
• Antibiotics
• Antihistamines
• Anticonvulsives
• Antithyroid drugs
• Arsenicals
• Cancer chemotherapy
• Cardiovascular drugs
• Diuretics
• Analgesic and antiinflammatory drugs
• Primary Bone Marrow Disorders
• Leukemia (aleukemic)
• Pernicious anemia
• Aplastic anemia
• Myelodysplastic syndromes
• Congenital disorders
• Kostmann's Syndrome
• Reticular agenesis
• Cartilage-hair hypoplasia
• Shwachman-Diamond syndrome
• Chediak-Higashi syndrome
• Immune-associated Neutropenia
• Marrow-Occupying Diseases (fungal infection, metastatic tumor)
• Pernicious Anemia