Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Electroencephalography

Background An electroencephalography is a test to measure the electrical activities of the brain, allowing for the detection of abnormal brain activity. It is often abbreviated as EEG. The suffix “-graphy” (“G”) refers to the presentation of the results found from the electrical (“E”) impulses measured in the brain (encephalo – “E”). You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy…

Electrocardiography

Background An electrocardiogram (EKG) is a noninvasive test that provides a visual representation of the electrical conduction of the heart. It is called EKG because the test produces a “-gram” (something written or drawn—e.g., telegram, diagram—the “G”) of the electrical (the “E”) conduction through the heart (cardio—the “K” or “C”). The abbreviation ECG can be used interchangeably with the more common EKG, a reflection of the…

Echocardiography

Background Echocardiography uses ultrasound imaging to visualize the structures of the heart. An ultrasound machine uses an electrical pulse that causes a sound wave that courses through tissue and results in an image based on the variable conductance through different parts of the body. There are two ways to obtain images in echocardiography, noninvasively and invasively. For the noninvasive approach, an ultrasound is placed externally on…

Dexamethasone Suppression Test

Background The dexamethasone suppression test (DST), low-dose DST, overnight DST, or 1-mg DST is a dynamic endocrine test in which hormone levels are evaluated based on the principles of biofeedback regulation. , A suppression test, in general, involves giving the patient a substance that would normally cause the inhibition of the release of the hormone. However, due to the excessive amounts of hormone or hyperfunction of…

Culture – Urine

Background Urinary tract infections (UTIs) have been around for as long as humans have had urinary tracts. Hippocrates believed that symptoms were caused by an imbalance of four humors. Ancient treatment regimens in the pre-antibiotic era ranged from bed rest to narcotics, and also included various herbs, enemas, and, in the heroic era of medical treatments, “judicious bleeding.” While medicine has advanced a great deal since…

Culture – Sputum

Background A sputum culture is often a noninvasive and most useful test in the assessment of lower respiratory tract infections. Sputum samples can be useful in other disease states such as certain cancers; however, sampling is predominately useful for infectious diseases. Obtained sputum can be tested and evaluated via Gram stain, microbiologic culture, and sensitivity testing. These procedures are most frequently performed simultaneously and interpreted together…

Culture – Blood

Background Blood culture is the most efficient way of identifying organisms in the blood. For someone who does not have an infection, blood should always be sterile. The most common organisms identified in the blood are bacteria and fungi, and their presence is called bacteremia and fungemia, respectively. Despite their possible presence in the blood, viruses are not typically identified through traditional blood culture technique because…

Coronary Artery Bypass Grafting

Background Cardiovascular disease is the leading cause of death in the United States. An American suffers from a myocardial infarction approximately every 40 seconds. On average, men are 65 years old and women are 72 years old at the time of the first myocardial infarction. The death rate for coronary artery disease (CAD) has decreased by 31.8% over the 10-year period from 2006 to 2016. This…

Continuous Renal Replacement Therapy

Background Continuous renal replacement therapy (CRRT) is commonly used in the intensive care unit (ICU) setting and can consist of continuous venovenous hemodialysis (CVVHD), continuous venovenous hemofiltration (CVVH), or continuous venovenous hemodiafiltration (CVVHDF). Each of these procedures involves the slow passage of blood, continuously (24 hours a day), through a filter to remove various waste products and/or fluid. You’re Reading a Preview Become a Clinical Tree…

Continuous Glucose Monitoring

Background Continuous glucose monitoring devices provide a way for patients to approximate their blood glucose by testing the interstitial fluid via the chemical reaction of fluorescence, every 1 to 5 minutes, with minimal “fingerstick” point-of-care glucose testing. These devices are frequently referred to by the abbreviation “CGMs.” There are two major types of CGMs called “real-time CGMs” or “intermittently scanning CGMs.” The major difference between the…

Computed Tomography Scan

Background A computed tomography (CT) scan is a noninvasive imaging modality that uses rotating X-ray beams and detectors to produce high-quality cross-sectional imaging of anatomic structures. The word “tomography” comes from the words “tomos” meaning “slice” and “graph” meaning “recording,” referring to the cross-sectional image slices recorded with CT imaging. A CT scan may also be referred to as a computerized axial tomography (CAT) scan. You’re…

Chest X-Ray

Background A chest X-ray (CXR) is a noninvasive imaging procedure that uses ionizing radiation to produce a shadow image of the anatomic structures in the thoracic cavity. The term “X-ray” refers to the type of high-energy electromagnetic radiation used in the imaging procedure, which was discovered by the German physicist, Dr. Wilhelm Roentgen. A CXR is also known as a plain chest roentgenogram, a plain (chest)…

Chest Tube

Background A thoracostomy tube is a hollow plastic tube or catheter that is used to drain air, fluid, pus, or blood from the intrathoracic space ( Fig. 15.1 ). The word “thoracostomy” combines the prefix “thoraco” meaning “chest wall” and the suffix “stomy” meaning “opening.” Thoracostomy tube may sometimes be referred to as a chest tube (the term that will be used throughout this chapter), intrapleural…

Carotid Endarterectomy

Background Carotid endarterectomy (CEA) is a surgical procedure that involves the removal of plaque from the carotid arteries. Carotid arteries are the two major arteries located in the neck, which branch off from the aorta and supply blood to the brain. Plaque formation in the carotid arteries can result in stroke or transient ischemic attack (TIA). This extracranial atherosclerosis, or blockage in the arteries that supply…

Bronchoscopy

Background Bronchoscopy is an endoscopic technique used to visualize the tracheobronchial tree for diagnostic and therapeutic purposes. The word “bronchoscopy” is derived from Greek words by combining the prefix “broncho” meaning “bronchus” and the verb “skopía” meaning “to view.” Rigid bronchoscopy, which was first used in the 1920s, is less commonly used now, as it uses a more rigid piece of equipment that can only access…

Bladder Scan

Background A bladder scan is a portable noninvasive ultrasound device that measures the volume of urine in the bladder by using ultrasound waves measured in three dimensions. The machine calculates a volume measurement of urine in the bladder without displaying an image on the screen. Bladder scans are used mostly during inpatient encounters to evaluate patients for urinary retention. Acute urinary retention (AUR) is defined as…

Bariatric Surgery

Background Bariatric surgery, or weight loss surgery, is any procedure intended to reduce weight in patients with morbid obesity. Bariatric, translated from Greek, literally means “weight medicine.” Bariatric surgery procedures are classified as restrictive (reduced stomach size; limiting the amount a patient may comfortably eat at any given time) or malabsorptive (alterations to the small intestine length to inhibit caloric absorption). Procedures may be restrictive (e.g.,…

Atrial Fibrillation Ablation

Background An atrial fibrillation (AF) ablation is an invasive procedure that is intended to treat AF. AF is the most common cardiac arrhythmia and is caused by disorganized and rapid electrical impulses in the atria of the heart. In an untreated patient, the ventricular rate also tends to be rapid and variable, between 120 and 160 beats/minute, but in some patients it may exceed 200 beats…

Ankle-Brachial Index Test

Background The ankle-brachial index (ABI) is a common noninvasive test used to determine if there is occlusive disease of the peripheral vasculature. It uses the brachial arterial systolic blood pressure as the control, assuming it to be nonocclusive, and compares it to either that of the posterior tibial (PT) or dorsalis pedis (DP) arteries. The ABI is calculated in each foot by dividing the higher systolic…

Adrenocorticotropic Hormone Stimulation Test

Background The adrenocorticotropic hormone (ACTH) stimulation test is a relatively noninvasive laboratory assessment that involves the administration of a medication followed by the collection of blood samples. ACTH is a naturally occurring hormone released from the pituitary gland that stimulates the secretion of cortisol from the adrenal glands. Cortisol is a glucocorticoid that is responsible for the regulation of fat, carbohydrate, and protein metabolism. The test…