Diagnostic Test

• Nurse's responsibilities

  1. Collaborate with laboratory personnel in proper collection and transport of samples

  2. Prepare patient mentally, explain procedure

  3. Proper labeling and documentation
• Invasive diagnostic testing


  Accessing the body's tissue, organ, or cavity through some type of instrumentation procedure
• Invasive diagnostic testing

  • Most of Laboratory Exams
  • Biopsy (Excisional and Incisional)
  • Lumbar puncture
• Visualization procedures


  Endoscopic Procedures like Arthroscopy, Bronchoscopy, Colonoscopy, Cystourethroscopy, Laparoscopy
• Non-invasive diagnostic testing


  Body is not entered with any type of instrument
• Non-invasive diagnostic testing

  • EEG
  • ECG
  • Stress Test
  • Holter ECG (24 hrs)
  • Chest X-ray
  • Sputum exam
  • Urine and Stool examinations
• Phases of diagnostic testing


  • Pretest phase: client preparation
  • Intra-test phase: specimen collection, standard precautions and aseptic technique in collection of samples
  • Post-test phase: nursing care of the client and follow-up activities and observation
• How doctors reach a diagnosis

  1. Initial Diagnostic Assessment – Patient history, physical exam, evaluation of the patient's chief complaint and symptoms

  2. Differential diagnosis, and ordering of diagnostic tests

  3. Referral, Consultation, Treatment & Follow-Up
• Preparing for the diagnostic testing

  1. Assessment

  2. Client teaching

  3. Documentation
• Assessment


  • Verify patient identification
  • Check medical history
  • Assess for presence, location, and characteristics of physical and communicative limitations or preexisting conditions
  • Monitor the client's knowledge of why the test is being performed
  • Obtain vital to establish baseline data
  • Monitor level of hydration and weakness for clients who are NPO
  • Check general patient condition, preparedness for the test, anxiety level
• Client teaching


  • Explain reason for test and what to expect, how long it will take
  • Restrictions (activities, food, etc.)
  • Provide proper instruction on specimen collection
  • Explain if dyes are to be ingested or injected
  • Provide post test instructions
• Documentation


  • Who performed the procedure
  • Reason for the procedure
  • Type of anesthesia, dye, or other medications administered
  • Type of specimen obtained and where it was delivered
  • Vital signs and other assessment data
  • Any symptoms of complications
  • Who transported the client to another area
• Different samples for diagnostic testing


  • Blood
  • Semen
  • Urine
  • Gastric lavage
  • Stool
  • Swabs
  • Sputum
  • Secretions
  • Tissue biopsy
  • CSF
• Guidelines for specimen collection


  • Consider the patient's need and ability to participate
  • Recognize that the collection may provoke anxiety, embarrassment, or discomfort
  • Provide support for patients who are fearful about the results
  • Recognize that children require clear explanation and support
  • Obtain specimen in accordance with specific prerequisite conditions
• Complete blood count (CBC)


  Provides information about the types and numbers of cells in the blood

  obtained thru: capillary prick, venipuncture, arterial sampling

  
• Purpose of CBC

  • Preoperative to determine oxygen carrying capacity and hemostasis
  • Infection to monitor anemia and progress of treatment
  • Chronic illness or blood disorders
  • Monitor effects of chemotherapy
• There are 250 million red blood cells in one drop of blood
• The life cycle of a normal red blood cell is 120 days
• The spleen helps remove old red blood cells
• Techniques for blood collection

  • Prepare the materials prior to drawing blood
  • Check lab request prior to extraction
  • Use purple top (EDTA) tube for CBC
  • Use capillary prick for babies, finger prick for glucometer
  • Avoid prolonged tourniquet, IV site, small gauge needle, hematoma or bruises, over or under-sampling, introducing air, contamination
• Red blood cell (RBC) count

  • Male: 4.5–5.5 x 10^12/L
  • Female: 4.0–5.0 x 10^12/L
  • Children: 3.8–6.0 x 10^12/L
  • Newborn: 4.1–6.1 x 10^12/L
• High RBC count

  Dehydration, cigarette smoking, congenital heart disease, pulmonary fibrosis, renal cell carcinoma, polycythemia vera, COPD
• Low RBC count

  Bleeding, anemia, malnutrition, overhydration, hemolysis, erythropoietin deficiency, leukemia, multiple myeloma, porphyria, thalassemia, sickle cell anemia, hemorrhage, bleeding, renal disease
• Drugs that may increase RBC count

  Methyldopa, Gentamycin
• Drugs that may decrease RBC count

  Quinidine, hydantoins, chloramphenicol, chemotherapeutic drugs
• Polycythemia makes blood viscous
• Hemoglobin (Hb or Hgb)

  • Males: 13.5-16.5 g/dl
  • Females: 12-15 g/dl
  • Pregnant: 10-15 g/dl
• High hemoglobin

  Dehydration, cigarette smoking, polycythemia vera, tumors, erythropoietin abuse, lung diseases
• Low hemoglobin


  Nutritional deficiencies, blood loss, renal problems, sickle cell anemia, bone marrow suppression, leukemia, lead poisoning, Hodgkin's lymphoma
• High hemoglobin levels in high altitude locations and among smokers (compensatory)
• Low hemoglobin levels in blood diseases, like sickle cell disease and thalassemia
• Drugs that may increase hemoglobin


  Erythropoietin, iron supplements
• Drugs that may decrease hemoglobin

  Aspirin, antibiotics, sulfonamides, trimethadione, anti-neoplastic drugs, indomethacin, doxapram, rifampin, and primaquine
• Hematocrit (Hct)

  • Males: 41-50%
  • Females: 36-44%
  • Children: 36-40%
  • Newborn: 55-68%
• High hematocrit

  Dehydration, hypoxia, cigarette smoking, polycythemia vera, tumors, erythropoietin abuse, lung diseases, blood doping, erythrocytosis
• Low hematocrit

  Overhydration, nutritional deficiencies, blood loss, bone marrow suppression, leukemia, lead poisoning, Hodgkin's lymphoma, chemotherapy treatment, anemia, bone marrow disorder
• Hematocrit is helpful in diagnosing and assessing blood diseases, nutritional deficiencies, and hydration status
• Mean corpuscular volume (MCV)

  76-100 mm3
• Macrocytic MCV


  Vitamin B1 or Folic acid deficiency, hypothyroidism, alcoholism
• Microcytic MCV

  Iron-deficiency anemia, thalassemia