Chapter IX Select Diagnostic TestsHISTOLOGY, CYTOLOGY, AND CYTOGENIC TESTINGImproved technology in histologic, cytologic, and cytogenic testing has greatly aided identification of abnormal cells. This has special significance in the detection of malignancy and genetic abnormalities. HISTOLOGY Histology is the study of the microscopic structure of tissues and cells. Histology is vital to confirm malignant disease and has made biopsy-extraction of a living tissue specimen-a common procedure. New tissue preparation techniques and needle designs allow rapid specimen removal from even deep tissue without surgery. Biopsies: Biopsies may be incisional or excisional. In incisional biopsy, a scalpel, cutting or aspiration needle, or punch is used to remove a portion of tissue from large, multiple, hidden lesions. Fine needle aspiration differs slightly from traditional needle biopsy. Although the procedure is the same, it provides a smaller specimen, requires cytologic (not histologic) studies, and is usually performed on outpatients for breast biopsies. Incision of a hidden lesion is called a closed, or blind, biopsy. In excisio9nal biopsy, a scalpel is used to remove abnormal tissue from the skin or subcutaneous tissue. When such tissue can be easily and completely removed, excisional biopsy is preferred, because it combines diagnosis and treatment. Biopsies commonly take place in the hospital, but they may also take place in clinics and physicians’ offices. Open biopsy performed in the operating room, usually requires general anesthesia. Open biopsy is required when the results of a closed biopsy or other diagnostic tests (i.e., CT scan) suggest the need for complete excision of a tissue mass. Tissue Preparation and Tissue Classification: Tissue preparation involves several time-consuming steps in the fixation of specimens on slides for examination by pathologist. Even a state tissue preparation can take 24 hours. The exception to this normal method of fixation of slides is a frozen section. Frozen sections may provide results in 10-15 minutes in emergency situations. However, frozen section results are not reliable and will usually be confirmed by the standard process. After standard analysis, tissue classification takes place. The pathologist’s report provides both gross and microscopic description, which result in histopathological classification of the tumor. Typically, results of this analysis are expressed on a scale of our grades:
A staging system is then used to direct the treatment and predict the prognosis when biopsy results confirm malignancy. CYTOLOGY Cytology is the study of cells, including their formation, origin, structure, function, biochemical activities, and pathology. Cytologic tests are generally inexpensive, useful screening tests that help detect suspected malignant or premalignant conditions and assess the effectiveness of therapy. However, they fail to determine the location and size of a malignancy and may require further histologic confirmation. Tissue scraping is a type of cytologic test. One of the most common tissue scrapings is the Papanicolaou (PAP) test, in which cervical scrapings are evaluated. Cytologic specimens may also be obtained by aspiration or by cell washing. Fine-needle (19G to 23G) aspiration of body fluids permits evaluation of a palpable mass, a lymph node, or a lesion that has been localized by x-rays. Cell washing is performed by instilling a solution into the bronchial tree, esophagus, stomach or uterine cavity and subsequently aspirating it out. This procedure loosens exfoliated cells from crevices and suspends them in the solution. Thereby increasing the number of cells collected for cytologic examination. The procedure also increases the probability of finding recently exfoliated cells. CYTOGENICS Cytogenics is the branch of genetics that studies cellular components concerned with heredity; primarily the structure, function, and origin of the chromosomes. Cytogenic tests identify abnormal genetic factors or patterns seen in conditions such as Down’s syndrome and Turner’s syndrome. Common Cytologic Specimens: Sputum, bronchial washings, lung aspirate, breast mass aspirate, bone marrow aspirate, cul-de-sac of Douglas aspirate, solid tumor aspirate, pleural fluid, ascetic fluid, spinal fluid, bladder urine, vaginal pool scrapings, cervical scrapings, endometrial scrapings Nursing Implications:
Some Common Biopsy/Cytology Tests and Nursing Implications Test: Breast Biopsy The breast biopsy is performed confirm or rule out breast cancer after clinical examination, mammography, or thermography has identified a mass. Fine-needle aspiration is usually done on a mass that has been identified by ultrasonography as being fluid-filled. Solid masses are assessed by one of four methods: Ultrasound-guided core biopsy; needle or wire localization biopsy; or excisional biopsy. An incisional biopsy is seldom performed. Stereotactic breast biopsy immobilizes the breast and allows the computer to calculate the exact location of the mass, based on x-rays from two angles. Needle or wire localization biopsy is used to localize a nonpalpable lesion for excisional biopsy. All four techniques require only local anesthesia, although an excisional biopsy may be done under general anesthesia. If sufficient tissue is obtained and the mass is found to be a malignant tumor, specimens are sent for estrogen and progesterone receptor assays to assist in determining future therapy and the prognosis. Because breast cancer remains the most prevalent cancer in women, genetic researchers are continually working to identify women at risk. Procedure and Preparation: The nurse should be sure that the procedure has been explained to the patient and all questions answered. Explain any food, fluid, or medication restrictions (usually few restrictions if local anesthesia is used). Offer emotional support if the patient appears anxious or expresses concerns. Ultrasound-guided core biopsy:
Stereotactic breast biopsy:
Needle or Wire Localization Biopsy:
Excisional Biopsy:
All Procedures:
Normal breast tissue consists of cellular and noncellular connective tissue, fat lobules, and various lactiferous ducts. It’s pink, more fatty than fibrous, and shows no abnormal development of cells or tissue elements. Abnormal breast tissue may exhibit a wide range of malignant or benign pathology. Breast tumors are common in women and account for 32% of female cancers; such tumors are rare in men. Benign tumors include fibrocyctic disease, adenofibroma, intraductal papilloma, mammary fat necrosis, and plasma cell mastitis (mammary duct ectasia). Malignant tumors include adenocarcinoma, cystosarcoma, intraductal carcinoma, infiltrating carcinoma, inflammatory carcinoma, medullary or circumscribed carcinoma, colloid carcinoma, lobular carcinoma, sarcoma, and Paget’s disease. Test: Lung Biopsy The purpose of a lung biopsy is usually to confirm the diagnosis of diffuse parenchymal pulmonary disease and pulmonary lesions. Usually, a biopsy of the lung is recommended after chest x-rays, computed tomography scan, and bronchoscopy have failed to identify the cause of any diffuse parenchymal pulmonary disease or a pulmonary lesion. Closed Technique or Open Technique may be used b\for lung biopsy. Closed technique is performed under local anesthesia and includes both needle biopsy and transbronchial biopsy. Needle biopsy is appropriate for lesions that are readily accessible, originates in the lunch parenchyma and is confined to it, or is affixed to the chest wall. Needle biopsy provides a much smaller specimen than the open technique. Transbronchial biopsy is used for the removal of multiple tissue specimens through a bronchoscope. This technique may be used for patients with diffuse infiltrative pulmonary disease or tumors or when severe debilitation contraindicates open biopsy. Open technique is performed under general anesthesia and includes both limited and standard thoracotomies. Open biopsy is appropriate for the study of a well-circumscribed lesion that may require resection. In addition to general nursing considerations above, sedative may be administered and blood studies may also be performed. The nurse should check vital signs every 15 minutes for 1 hour, then every hour for four hours. Assess for any bleeding, dyspnea, elevated pulse rate, diminished breath sounds on the biopsy side, and eventually, cyanosis. Also, remember to keep the patient calm and quiet. Coughing and movement during biopsy may cause tearing of the lung by the biopsy needle. Findings: Normal lung biopsy tissue results show uniform texture of the alveolar ducts, alveolar walls, bronchioles, and small vessels. Histological examination of a pulmonary tissue specimen can reveal squamous cell or oat cell carcinoma and adenocarcinoma. These findings supplement the results of microbiological cultures, deep-cough sputum specimens, chest x-rays, and bronchoscopy and the patient’s physical exam history in confirming cancer or parenchymal pulmonary disease. The nurse should remember that several factors may influence these above findings. The nurse should always be sure to obtain a careful history from the patient. The patient’s medical history, medication history, and family history may influence these findings. The nurse must also remember to collect and store the tissue specimens according to procedure. Failure to handle and deliver specimens correctly may lead to inaccurate results. In addition to these potential problems, the specimen may also be flawed by failure to obtain a representative tissue specimen. Test: Lymph Node Biopsy Lymph node biopsy is the surgical excision of an active lymph node or the needle aspiration of a nodal specimen for histological examination. Lymph node biopsy is performed to determine the cause of lymph node enlargement, to distinguish between benign and malignant lymph node process, and to stage certain cancers or metastatic carcinoma. Both techniques usually use a local anesthetic and sample the superficial nodes in the cervical, supraclavicular, axillary, or inguinal region. Excision is preferred because it yields a larger specimen. Although lymph nodes swell during infection, biopsy is indicated when nodal enlargement is prolonged and accompanied by backache, leg edema, breathing and swallowing difficulties and, later, weight loss, weakness, severe itching, fever, night sweats, cough, hemoptysis, and hoarseness. Generalized or localized lymph node enlargement is typical of such diseases and chronic lymphatic leukemia, Hodgkin’s disease, infectious mononucleosis, and rheumatoid arthritis. Complete blood count, liver functions tests, liver and spleen scans, and ex-rays should precede this test. Procedure and Preparation: As with all procedures, be sure to fully explain the procedure and answer any question regarding the test. Of course, the physician has probably already explained the procedure. However, the nurse cannot assume this. Be sure that a complete history and physical exam has been done, noted, and available on the patient’s chart. Be sure that the consent form has been fully explained and legally signed. Also, be sure to explain any food restrictions and any other preparation. Usually no prep is required for the needle bi9opsy. However, there may be a complete surgical-type prep for the excisional biopsy. The prep depends upon many factors such as the patient’s history and the location of the node to be biopsied. Excisional Biopsy
Needle Biopsy
Both Procedures
The results of a normal lymph node biopsy show a normal lymph node encapsulated by collagenous connective tissue and divided into smaller lobes by tissue strands called trabeculae. It has an outer cortex composed of lymphoid cells and nodules or follicles containing lymphocytes, and an inner medulla, composed of reticular phagocytic cells that collect and drain fluid. Histological examination of the tissue specimen distinguishes between malignant and nonmalignant causes of lymph node enlargement. Lymphatic cancer accounts for up to 5% of all cancers and is slightly more prevalent in males than in females. Hodgkin’s disease, a lymphoma affecting the entire lymph system, is the leading cancer affecting adolescents and young adults. Lymph node cancer may also result from metastasizing carcinoma. When histological results are not clear or nodular material is not involved, mediastinoscopy or laparotomy can provide another nodal specimen. Occasionally, lymphangiography can furnish additional diagnostic information. Storing the tissue specimen in normal saline solution instead of formaldehyde solution allows part of the specimen to be used for cytological impression smears, which are studied along with the biopsy specimen. However, be sure to follow procedure at your facility and the MD’s orders for that patient. Test: Papanicolaou Smear (Pap Smear-cytology test for cervical cancer) The Pap Smear became nationally known and used in the 1950’s for detecting cervical cancer and precancerous tissues. Dr. George Papanicolaou developed the cytology test in 1928 after spending 18 years in research. Today, he is referred to as the father of modern cytology. As the result of his work, there are many cytology studies done on body tissues and secretions. Since malignant tissue changes usually take many years, yearly examination of the exfoliative cervical cells (cells that have sloughed off) allow detection of early precancerous conditions. It is suggested that women from age 18 to 40 have yearly Pap smears and that women over age 40, have twice a year, or yearly Pap smears. How often the pap smear test should be performed is determined by the woman’s physician. Pap Smear (cytology) results are reported on a 5-point scale: Grade (Class) I Absence of atypical or abnormal cells For suggestive or positive Pap Smears, colonoscopy and/or cervical biopsy are frequently ordered to confirm the smear results. Atypical cells may occur due to cervicitis and excessive or prolonged use of hormones. Nursing Implications:
Nuclear Medicine Procedures Nuclear medicine refers to the medical discipline that uses radioactive isotopes to aid in the diagnosis and treatment of certain disease conditions. The major fields of nuclear medicine are physiologic function studies, radionuclide imaging, and therapeutic techniques. In this text we have already presented several procedures that often use radioactive isotopes such as the MRI and certain organ scans. There will be overlap with some of these procedures. Nuclear medicine is used quite often and is an important tool for diagnosis of many conditions and is even used in the treatment of many medical conditions. Be sure you are aware of your facility’s “Radiation Precautions” procedure. Each facility has its own way of handling radioactive materials. In most cases, nurses will not have to be concerned with radioactive substances. Most radioactive substances on the nursing unit are harmless and no precautions are needed. However, occasionally, the nurse will have patients who are receiving higher doses of radiation. Be sure to follow precautions set by the nuclear medicine department. These precautions may include, but are not limited to: isolation of the patient, wearing lead aprons, collecting all body fluids, and other precautions. Test: Radioactive Iodine Uptake Test (RAIU) The radioactive iodine uptake test evaluates thyroid function by measuring the amount of orally ingested iodine 123 (123I) or iodine 131 (1333I) that accumulates in the thyroid gland after 6 and 24 hours. An external single counting probe measures the radioactivity in the thyroid as a percentage of the original dose, thus indicating its ability to trap and retain iodine. The RAIU test accurately diagnoses hyperthyroidism but is less accurate for hypothyroidism. Indications for this test include abnormal results of chemical tests used to evaluate thyroid function (thyroid function tests, T3, T4, etc.). Following is the BSIC preparation and procedure for the RAIU test. However, the nurse should remember that each facility has its own procedures. Some facilities will scan the patient at different intervals (2-hours, 6-hours, 24-hours). Some facilities may perform another test at the same time, for example, a thyroid scan. The Thyroid Scan test also uses 133I. Frequently a thyroid scan may be performed along with the RAIU. The thyroid scan involves the oral or intravenous administration of radioactive iodine (131I) and then a scan at 30 minutes and at 60 minutes. Therefore, be aware that the nursing implications may change according to hospital and/or laboratory procedures. Also keep in mind that outpatient procedures may be different as well. The best “policy” is to carefully follow your facility’s procedures and to be aware that this procedure below may be quite different at your facility. Preparation and Procedure: Explain the test and the purpose of the test to the patient. He will need to begin fasting at midnight the night before the test. Explain that he will receive the radioactive iodine in capsule or liquid form and then be scanned at the 6-hour interval and again at a 24-hour interval. If the patient is an inpatient, the nurse or a technician will administer the dose to him right on the nursing unit at the specified time. Be sure to note the exact time the dose is administered. If he is an outpatient, the patient will usually be given the capsule to take at home at a certain time. Be sure you instruct the patient to take the dose at the specified time. If he misses the exact time, be sure to have the patient write down the exact time he did take the dose. Be sure to explain that the test is painless. Be sure to explain that the radioactive material is very small and will not harm him.4 Check the patient’s history for IODINE EXPOSURE5, which may interfere with the test results. Note any prior radiological tests using contrast media, nuclear medicine procedures, or current use of iodine preparations or thyroid medications on the film request form. Substances containing iodine, such as dyes used for the intravenous pyelogram (IVP), gallbladder series, or bronchograms may cause incorrect test results. Iodine hypersensitivity (allergy) is not considered a contraindication for this test because the amount of iodine used is similar to the amount consumed in a normal diet. Radioactive iodine uptake testing is contraindicated during pregnancy and lactation because of possible teratogenic effects.
At 6 hours, 5% to 20% of the radioactive iodine should accumulate in the thyroid. At 24 hours, accumulation should be 15% to 40%. The balance of the radioactive iodine is excreted in the urine. Local variations in the normal range of iodine uptake may occur due to regional differences in dietary iodine intake and procedural differences among laboratories. Below-normal iodine uptake may indicate hypothyroidism, subacute thyroiditis, or iodine overload. Above-normal iodine uptake may indicate hyperthyroidism, early Hashimoto’s thyroiditis, hypoalbuminemia, lithium ingestion, or iodine-deficient goiter. However, in hyperthyroidism, the rate of turnover may be so rapid that a false normal measurement occurs at 24 hours. The following factors may decrease iodine uptake: Renal failure, dieresis, severe diarrhea, x-ray contrast media studies, ingestion of iodine preparations including iodized salt, cough syrups, and some multivitamins, thyroid hormones, thyroid hormone antagonists, salicylates, penicillins, antihistamines, anticoagulants, corticosteroids The following factors may increase iodine uptake: Pheothiazines, iodine-deficient diet. Some patients will have extreme anxiety over receiving radioactive materials. Be aware for any signs of anxiety in your patient. Some patients may have false concepts about radiation. Several of this author’s patients thought that the radioactive capsule will make them sterile. One patient thought that she would glow in the dark. So be aware that your patient may not verbalize his anxiety and be aware that some patients may need more reassurance and further explanations that the radioactive substance will not harm him. ”Iodine exposure” means that the patient has consumed iodine in any form. For example, some people take iodine supplements, some people take herbal supplements that contain iodine, some people use large amounts of iodized salt, some patients may have just had another test which uses iodine. Be very aware that today, many people use herbal supplements that may contain any number of substances. Also note if the patient has recently consumed a large amount of seafood (shellfish in particular). Be sure to take a complete history from the patient, including any vitamin or herbal supplements used and any other tests that have been performed recently. Test: Bone Scan A bone scan involves imaging the skeleton by scanning camera after an intravenous injection of a radioactive tracer compound. The tracer of choice, radioactive technetium, diphosphonate, collects in bone tissue in increased concentrations at sites of abnormal metabolism. When scanned, these sites appear as “hot spots” that are often detectable months before an x-ray can reveal any lesion. To promote early detection of lesions, this test may be performed with a gallium scan. Preparation and Procedure: Explain the procedure to the patient and reassure him that it will be painless and the radioactive substance involved is not dangerous. There will be no food or fluid restrictions prior to the test. However, most facilities will have the patient withhold fluids two hours prior to the test, simply because the patient will be required to drink (as part of the test) four to six glasses of water or tea during the test. Before the procedure, some patients may be administered a sedative or analgesic, not due to the procedure itself, but to anxiety.
Although a bone scan demonstrates hot spots that identify sites of bone formation, it doesn’t distinguish between normal and abnormal bone formation. But scan results can identify all types of bone malignancy, infection, fracture, and other disorders, if viewed in light of the patient’s medical and surgical history, ex-rays, and other laboratory tests. Test: Liver-Spleen Scanning In liver-spleen scanning, a gamma camera records the distribution of radioactivity within the liver and spleen after intravenous injection of a radioactive colloid. The colloid most commonly used, technetium sufide-99m (99mTc), concentrates in the reticuloendothelial cells through phagocytosis. About 80% to 90% of the injected colloid is taken up by Kupffer’s cells in the liver, 5% to 10% by the spleen, and 3% to 5% by bone marrow. The gamma camera images either organ instantaneously without moving. Although the indications for this test include the detection of focal disease, such as tumors, cysts, and abscesses, liver-spleen scanning demonstrates focal disease nonspecifically as a cold spot (a defect that fails to take up the colloid) and may fail to detect focal lesions smaller than ¾ inch (2 cm) in diameter. Although clinical signs and symptoms may aid diagnosis, liver-spleen scanning frequently requires confirmation by ultrasonography, computed tomography, gallium scanning, or biopsy. Test: Gallium Scanning The gallium scan is a total-body scan used to assess certain neoplasms and inflammatory lesions that attract gallium. It is usually performed 24 to 48 hours after the intravenous injection of radioactive gallium (67Ga) citrate. Occasionally, it is performed 72 hours after the injection or, in acute inflammatory disease, after four to six hours. Because gallium has an affinity for both benign and malignant neoplasms and inflammatory lesions, exact diagnosis requires an additional confirming test, such as ultrasonography or computerized tomography scanning. Also be aware that many neoplasms and a few inflammatory lesions may fail to demonstrate abnormal gallium activity. Preparation and Procedure: Explain the procedure to the patient and inform him that there will be no food or fluid restrictions before the test. Also reassure him that there will be no pain during the test and the radioactive material is very low-dose and is of no danger to him. The intravenous injection will be administered 24 to 48 hours prior to the actual scan (in most cases). There may be some transient pain or discomfort at the injection site.
Gallium scanning may reveal inflammatory lesions, discrete abscesses or diffuse infiltration. In pancreatic or perinephric abscess, gallium activity is relatively localized. In bacterial peritonitis, gallium activity is spread diffusely within the abdomen. Abnormally high gallium accumulation is characteristic in inflammatory bowel disease, such as ulcerative colitis, regional ileitis (Crohn’s disease), and in carcinoma of the colon. However, because gallium normally accumulates in the colon, the detection of inflammatory and neoplastic diseases is sometimes difficult. Abnormal gallium activity may be present in various sarcomas, Wilm’s tumor, aneuroblastomas; carcinoma of the kidney, uterus, vagina, and stomach; and testicular tumors such as seminoma, embryonal carcinoma, choriocarcinoma, and teratocarcinoma, which often metastasize via the lymphatic system. In Hodgkin’s disease and malignant lymphoma, gallium scanning can demonstrate abnormal activity in one or more lymph nodes or in extranodal locations. However, gallium scanning supported by results of lymphangiography can gauge the extent of metastases more accurately than either test alone because neither test consistently indentifies all neoplastic nodes. After chemotherapy or radiation therapy, gallium scanning may be used to detect new or recurrent tumors. However these forms of therapy tend to diminish tumor affinity for gallium without necessarily eliminating the tumor. In the differential diagnosis of focal hepatic defects, abnormal gallium activity may help narrow the diagnostic possibilities. Gallium localizes in hepatomas, but not in pseudotumors; in abscesses, but not in pleural effusions; and in tumors, but not in cysts or hepatomas. In examining patients with suspected bronchogenic carcinoma, abnormal activity confirms the presence of a tumor. However, because gallium also localizes in inflammatory pulmonary diseases, such as pneumonia and sarcoidosis, a chest x-ray should be performed to distinguish a tumor from an inflammatory lesion. Special Diagnostic Procedures Test: Angiography (angiogram) Angiography simply means the examination of blood vessels. Angiography and arteriography (examination of the arteries) are often used interchangeably. Angiography is performed through the use of an injected contrast dye which outlines the lumen of the vessels. Under surgical asepsis, a long catheter is inserted into the femoral, brachial, or carotid artery. The catheter is positioned under fluoroscopy and the contrast dye is injected. Angiography is useful for evaluating the patency of blood vessels and for identifying abnormal vascularization resulting from neoplasms (tumors). The most common forms of angiography are:
Nursing Implications: The nursing implication may be similar to those of the general surgery patient. Angiography is an invasive procedure and carries risks similar to those of the surgical patient. There are pretest preparations and posttest considerations; in addition to the nursing care given during the test.6 Preparation:
During the procedure the nurse will assist.7 The patient is usually in the supine position. A local anesthetic is usually administered to the catheter insertion site. Try to keep the patient warm while on the X-ray table. Try to keep the patient still while the X-rays are being taken or distortions may occur. Monitor EKG, if indicated; monitor vital signs; monitor IV fluids. After the angiogram: Many “routine” post-op observations apply to the angiogram patient. The nurse will monitor vital signs, temperature, bed rest, IV fluids, the EKG if indicated, the incision dressing (usually a pressure dressing), and monitor the level of consciousness. Preparation of the patient for angiography is similar to that of a surgical patient. However, the procedure will be different at many hospitals. Be familiar with the procedure at your facility and remember the basic concepts for preparation. You want to minimize risks to the patient and plan for the most effective visualization of the arteries in question. Always follow the procedure at your facility and be sure to understand the rationale for each procedure. This will allow you to make rational decisions that will affect your patient’s health. Again, the procedure will vary at each hospital. Many hospitals today have technicians trained in assisting with this procedure and the nurse does not assist. However, the general principles remain the same during angiography. In addition, the following care should be given after the procedure:
The angiogram today has become a “routine” procedure. However, it does carry a certain amount of risk. The nurse must still carefully observe the insertion site and observe for any adverse signs of symptoms of complications. In many cases the patients have no ill effects and the angiogram can be a very important diagnostic tool. Test: Cardiac Catheterization (Cardiac Angiography, Angiocardiography, Coronary Arteriography) Cardiac catheterization is a procedure used for visualizing the heart structures and/or coronary arteries. A long catheter is inserted into a vein or artery of the arm or leg, guided under fluoroscopy. Contrast dye is then injected into the catheter. During the injection of the dye, cineangiography is used for filming the heart. The terms Angiocardiography and Coronary Arteriography are usually interchangeable with Cardiac Catheterization. However, with Coronary Arteriography, dye is injected directly into the coronary arteries. With Angiocardiography, the dye is injected into the heart, coronary, and/or pulmonary vessels. There is also a distinction between right cardiac catheterization and left cardiac catheterization. With right cardiac catheterization, the catheter is inserted into the femoral vein or an antecubital vein and threaded through the inferior vena cava into the right atrium to the pulmonary artery. Pressures in the right atrium, right ventricle, and pulmonary artery are measured. Samples of blood from the right side of the heart can be taken. As the dye is injected, the functions of the tricuspid and pulmonary valves can be observed as they operated. Some of the problems that can be detected with this procedure are: tricuspid stenosis, pulmonary stenosis, pulmonary hypertension, and septal defect. With left cardiac catheterization, the catheter is inserted into the brachial or femoral artery and is advanced retrograde through the aorta to the coronary arteries and/or left ventricle. As dye is injected, the patency of the coronary arteries can be observed. The function of the aortic and mitral valves and the left ventricle can also be observed. Some of the problems that can be detected with this procedure are: coronary artery disease, partial or complete coronary occlusion, valvular heart disease—mitral stenosis, mitral regurgitation, aortic regurgitation, left ventricle hypertrophy; aneurysm—ventricle. There still today remain some rare complications with cardiac catheterization. However, the rate of complications is less than 2 percent. Some of the serious complications are: cardiac arrhythmias, myocardial infarction, cardiac tamponade, pulmonary embolism, and cerebral embolism. Nursing Implications:
Test: Electroencephalography, Electroencephalogram – EEG The EEG test measures the electrical impulses produced by the brain. Sensitive electrodes are attached to the surface of the scalp at predetermined locations in order to pick up those minute electrical impulses (“brain waves”). These recorded impulses (EEG tracings) show patterns of “normal” activity or abnormal activity which indicates that disease may be present in certain parts of the brain. Abnormal EEG tracings may indicate the presence of pathology such as: epilepsy or seizure disorder, brain tumors, brain abscesses, head (brain) injury, intracranial hemorrhage, encephalitis, unconsciousness, coma. Post procedure care will be different at each facility. Be sure to check the procedure at your facility. Standard post procedure care includes monitoring vital signs, and check the insertion site carefully. Bleeding from the insertion site can occur quickly, be observant and report any abnormalities quickly. Nursing Implications:
Gastric Acid Secretion (Gastric Acid Stimulation, Gastric Acid Analysis) The Gastric Acid Analysis test examines the acidity of the gastric secretions. An increased acidity level (hydrochloric acid) could mean that ulceration of the gastric lining is present, especially with clinical symptoms present. A lowered or absence of acid could indicate gastric atrophy or pernicious anemia. Gastric analysis is accomplished by a nasogastric tube inserted into the stomach. The following gastric analyses are the most common: Test: Basal Gastric Acid Analysis Gastric secretions are aspirated through the nasogastric (NG) tube after a period of fasting. Specimens are obtained of the gastric secretions to evaluate the acidity of those secretions. This is a “baseline” or Basal analysis. Test: Stimulation Gastric Acid Analysis The stimulation test is a continuation of the Basal test and is usually performed after the Basal test is performed. After obtaining the basal sample, sometimes immediately after, a gastric stimulant is administered. The stimulant is usually histology or pentagastrin. Gastric samples are aspirated every 15 to 20 minutes until three or four specimens are obtained. (This may vary from place to place). The samples are then analyzed for the response of gastric acid secretion to the stimulant. Test: Tubeless Gastric Analysis This test is for screening purposes only for the presence of hydrochloric acid in the stomach. This test will not be specific enough to give the amount of free acid in the stomach. The test is performed by administering a gastric stimulant such as caffeine or histology. An hour later a resin dye such as Azuresin, Diagnex Blue is taken orally by the patient. Free hydrochloric acid in the stomach will cause the release of the dye from the resin base. The dye is then absorbed by the gastrointestinal tract and is excreted in the urine. If there is no dye in the urine after two hours, it is indicative of no gastric acid in the stomach. This general screening test is not very accurate, but it might save the patient from the discomfort of the NG tube insertion. Test: Hollander Test This test is rarely performed today due to the patient risks involved. Intravenous injections of insulin are administered to the patient. IV insulin causes hypoglycemia, which increases vagal stimulation and acid secretion. This test may be performed after a Vagotomy in order to test the effect of the surgery. Again, it is very dangerous to the patient and rarely performed any more. Nursing Considerations for all Gastric Analysis Tests:
Pulmonary Function Tests - PFT’s Pulmonary function tests may be divided into two groups of tests; the ventilator function tests for differentiating between obstructive and restrictive lung diseases and the arterial blood gas (ABG) tests for evaluating the distribution and diffusion of gases across the alveolar capillary membrane. The ABG test is not always a part of pulmonary function tests. The ABG test was already presented in this text in greater detail. Ventilatory function tests that are performed with a spirometer and a recording device will be discussed in this section. Pulmonary function tests are ordered for a variety of different reasons. They may be ordered as baseline screening tests to compare with future pulmonary tests; to evaluate pulmonary disability (for insurance purposes); to evaluate pulmonary status prior to surgery; to determine the severity of lung disease (either obstructive or restrictive); to follow the course of pulmonary disease and treatment; or to detect early respiratory failure. They cannot identify the type of lung tumor or give its location. With the use of spirometry, a patient’s pulmonary volumes, capacities, and flow rates can be measured. The spirometer measures and records tidal volume, (Vt or TV), vital capacity (VC), forced expiratory volume (FEV), forced inspiratory volume (FIV), and many other ventilator parameters. Some of the important measures for detecting disease entities are as follows: Tidal Volume (TV, Vt): Normal breathing with approximately 500 ml of inspired and expired gas. Vital Capacity (VC): The VC is the maximal amount of air exhaled after a maximal inspiration. A forced vital capacity (FVC), is the greatest amount of air exhaled quickly and forcefully after a deep inspiration. With obstructive lung disease, the FVC and FEV1 are decreased, and with restrictive lung disease, they could be normal or decreased. Forced Expiratory Volume (FEV): This test is part of the forced vital capacity test, giving the total volume of exhaled air in one second (FEV1), two seconds (FEV2), three seconds (FEV3), and four seconds (FEV4). Expiratory Reserve Volume (ERV): This is the maximal amount of air that can be exhaled after normal breathing. Inspiratory Capacity (IC): This is the greatest amount of air inhaled after exhaling in normal breathing. Forced Inspiratory Volume (FIV): This is the greatest amount of air inhaled after a maximal expiration from a forced vital capacity (FVC). Residual Volume (RV): After a maximal expiration, the amount of air left in the lungs is referred to as the RV. Chronic air trapping fro COLD (Chronic Obstructive Lung Disease) will cause an increased RV. In restrictive lung disease, the residual volume may be decreased. Functional Residual Capacity (FRC): This gives the amount of air left in the lungs after normal expiration. It is calculated by adding expiratory reserve volume and residual volume (ERV + RV = FRC). With obstructive lung disease, FRC is increased due to hyperinflation of the lungs through air trapping. The FRC can be normal or decreased in restrictive lung disease. Maximal Voluntary Ventilation (MVV): This is the maximal rate and depth of respiration after breathing fast and deep for 10 – 15 seconds. It tests the air flow and airway resistance. Decreased MVV can indicate obstructive lung disease and normal or decreased MVV can suggest restrictive lung disease. Total Lung Capacity (TLC): This is the total amount of air in the lungs at the end of a maximal inspiration. The total lung capacity, TLC, can be measured by adding the vital capacity and the residual volume (VC + RC = TLC) or by adding the inspiratory capacity, tidal volume, expiratory reserve volume, and residual volume (IC + Vt + ERV + RV = TLC). Flow Volume Loop (F – V Loop): The F-V Loop is a forced expiratory volume and followed by a forced inspiratory volume (FEV = FIV = F-V Loop). This test is useful for detecting small airway obstructive disease such as emphysema or advanced restrictive disease. Nursing Implications:
Stress/Exercise Testing, Stress Testing, Exercise Electro cardiology (ECG) Stress testing is based on the theory that patients with coronary artery disease will have marked S-T segment depression on the ECG when exercising. Depression of the S-T segment and depression or inversion of the T-wave indicate myocardial ischemia. In 1928, Fiel and Siegel reported on the relationship of exercising and S-T segment depression in patients complaining of angina. Master used an exercise test (two-step) in 1929 to demonstrate ischemia but used only the pulse and blood pressure to note changes. In 1931, Wood and Wolferth felt exercise was a useful tool for diagnosing coronary disease but that it could be dangerous. Later it was discovered that S-T segment depression usually occurred before the onset of pain and was still present for some time after the pain subsided. Mild S-T segment depression after exercise can occur without CAD present. In 1956, R.A. Bruce established guidelines on performing stress testing on a treadmill. Master’s Step Test (1955) was also accepted as a method for stress testing. Another method used today is the bicycle ergometer test. How3ever, the treadmill seems to be the choice for testing cardiac status. With the treadmill stress test, the work rate is changed every 3 minutes for 15 minutes by increasing the speed slightly and the degree of incline (grade) by three percent each time (3 percent, 6 percent, 9 percent, etc.). The body muscles do not seem to tire with the treadmill method as much as leg muscles (quadriceps) tire with the bicycle ergometer. The uses for the stress/exercise test include: screening for coronary artery disease, evaluating the work capacity of cardiac patients, and developing a cardiac rehabilitation program. Nursing Implications:
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