Today our topic of discussion is Potential Complications of Ultrasonography.
Potential Complications of Ultrasonography
Potential Complications
- Allergic reaction to iodinated dye
- Hypoglycemia or acidosis or acidosis may occur in clients who are taking metformin (glucophage) and receive iodine dye
- Cardiac arrhythmia-premature ventricular contra- ctions during right-sided heart catheterization may lead to ventricular tachycardia and ventricular fibrillation.
Contraindication: CT pulmonary angiogram (CTPA) is less desirable in pregnancy due to the amount of ionizing radiation required, which may damage the breasts, which are particularly sensitive during pregnancy, and because of concerns of the effects of iodine on the fetus’ thyroid gland. Nevertheless, CTPA is generally preferred to isotope studies in pregnancy, due to the lower radiation dose to the fetus.
Diagnostic algorithms for pulmonary embolism in pregnancy vary; however, a common compromise is to perform ultrasound testing for deep vein thrombosis of the legs, and if this is positive, make the diagnosis of pulmonary embolism on the basis of symptoms and presence of the DVT. CTPA would then only be performed if exhaustive non- radiation based testing could not make a positive diagnosis.
COMPUTERIZED TOMOGRAPHY
Computed tomography (CT) scan provides cross-sectional views of the chest by passing and X-ray beam from a computerized scanner through the body at different angles and depths. The CT scan provides a three-dimensional image of the lungs, allowing the doctor to visualize the abnormalities.
Contrast agents sometimes used to highlight blood vessels and to allow greater visual discrimination. By using computer to regulate the layers or slices of tissue examined, the camera rotates in a circular pattern and three-dimensional assessment of the thorax (or other body area) is possible. Still photographs are taken at each level. CT is able to visualize most abnormalities but small early lesions may be missed.
Reference Values
Normal size, position, and shape of chest organ tissue and structures; no tumors, cysts, infection or inflammation, aneurysm, enlarged lymph nodes or fluid accumulation.
Purposes
- Often CT studies are done before and after the intravenous administration of a contrast containing a radioactively
- CT scans are particularly helpful in identifying peripheral (pleural) or mediastinal disorders
- Spiral or helical CT scan of the chest is an alternative to the lung scan for identifying pulmonary emboli.
Indications (Fig. 29.33)
- Configuration of the trachea or major bronchi and evaluate masses or lesions
- Tumors and abscesses Abnormal lung shadows.
General Instructions
- Computerized tomography scans highlight differences in bone and soft tissue
- The images are generated by computerized synthesis of X-ray data obtained in many different directions in a cross-sectional plane or slice
- The computerized data are assembled as three- dimensional images
- CT is used to identify space-occupying lesions (masses) and shifts of structures caused by neoplasm’s, cysts, focal inflammatory lesions and abscesses of chest distinguish normal tissue from abnormal masses, a contrast medium (dye) may be administered
- The CT-scan can be performed quickly, within 20 minutes
Nursing Considerations
- Before a CT-scan, make sure that the client has given informed consent and answer any questions about the procedures
- Explain the fasting usually is not required for a CT scan of the chest, but ask whether or not the client becomes nauseated easily; if so, adjust foot and fluid intake accordingly Inform the client, placed in supine.
- The technician moves the table from a control room to direct the study to different areas
- Inform the client, he can expect to hear mechanical noises coming from scanner
- Some clients may feel claustrophobic during the test. but assure them that it is possible to communicate with the technician (Fig. 29.34)
- Emphasize that the client must remain still during the scan.
- Unable to comply, sedation is needed
- After the test, assess the client for reactions to the contrast agent, and the quality of pulses in the limb used for injection of the contrast agent
- The client may be resume normal activities unless additional diagnostic tests are planned.
Nursing Care Before the Procedure
- Inform the client that the study takes about 30 minutes to 1 hour
- Obtain a history that includes cardiac and pulmonary assessment findings, known or suspected pulmonary conditions, and results of associated laboratory tests and diagnostic procedures.
Procedure (Fig. 29.34)
- The scanner takes images at different levels and angles of the chest region, from the neck to the waist instead of the whole body
- Contrast-enhanced studies are performed by the IV administration of an iodinated contrast medium for vessel evaluation or by oral administration of a contras medium for esophageal evaluation.
- Nursing Care After the Procedure
- Monitor vital signs if the client has an acute or chronic cardiac or pulmonary condition.
Interfering Factors
- Inability of client to remain still during procedure
- Metal objects such as jewelry within the examination field.
Contraindications
- Pregnancy, unless the benefits of performing the study greatly outweigh the risks to the fetus
- Allergy to iodine, if an iodinated contrast medium s be used
- Extreme obesity
- Unstable medical status, i.e. vital signs or dehydration
- Extreme claustrophobic response that prevents the client from remaining still during procedure, unless medications are given before the study.
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