Chapter 13 Flashcards
Diagnostic Procedures
What are some sources of patient data?
-Hx and physical examination (H&P) findings.
-Invasive and noninvasive diagnostic imaging studies.
-Lab and pathology results.
-Electrodiagnostic recordings.
-Endoscopic procedures.
-Pulmonary capacity and sufficiency measurements.
-Peripheral vascular assessments
What are some components of medical history?
First step in determining a pts condition. Can be routine or to assess symptoms. Pts fill out a questionnaire abt current symptoms and personal and family hx, treatments, allergies, meds, diet/exercise, previous sx, and pregnancies (medical info), ethnicity and religion (social info), and psychological info if pertinent.
What are some components of a physical examination?
Used to verify symptoms and look for additional signs. Dr looks at all body systems. Includes taking vitals, weight, and height. Dr may request more labs. Methods the doc will use are:
-Direct/Indirect visualization (pharyngeal mirror)
-Enhanced Visualization (scope)
-Palpation (Internal and external)
-Auscultation (stethoscope)
What is diagnostic imaging?
Techniques used to produce images of the human body
What is ionizing radiation (radiography)?
Uses high energy ionizing electromagnetic radiation. An image is produced by the collision of a beam of electrons w a metal target within an x-ray vacuum. Produced by Wilhelm Conrad Roentgen
What are some uses for radiography?
-Identify location of abnormalities and foreign bodies
-Locate retained foreign objects
-Discover fluid or air within body cavities.
-Verify the correct location for an operative procedure (scout film).
-Diagnose bone fractures and aid in bone realignment (reduction) and prosthesis placement (internal fixation).
-Verify placement of indwelling catheters, tubes, and drains.
What are some components of the portable machine used for radiography in the OR?
A cassette w unexposed x-ray film is positioned opposite of tube and under/beside areas of interest. After exposure, the film is removed from the cassette and developed in a dark room. The film is then ready by a surgeon or radiologist.
How is an AP (Anteroposterior) X-ray taken?
Image is taken front to back. The cassette is placed in between the pt and bed. Special assistive devices may be required such as a platform adaptor for the bed.
How is a lateral X-ray taken?
Image is taken side to side. The cassette is placed next to the pt. Special assistive devices such as a portable cassette holder may be required.
What are the responsibilities of the STSR wen it comes to radiography?
-Protect the sterile field.
-CST should cover the cassette if its within the field.
-The tube should be draped
-The wound can be covered w a sterile towel for protection.
What is mammography?
A type of x-ray which locates tumors in the breast. The breast is held tightly to decrease the density of the tissue for better visualization. Used in conjunction w a needle biopsy, a breast biopsy, and a breast biopsy w preop needle localization.
What are the three ways contrast medium can be administered?
- Injected
- Swallow
- Instilled
-Some can not be used rectally bc they can cause paralysis of peristalsis. A radioopaque powder (barium) can be used rectally for a barium study.
What is contrast medium?
Solutions that are injected to allow anatomical structures to stand out in contrast to the surrounding tissues. They are water-soluble organic molecules w bound iodine which determines the radiodensity. The brand name often reflects the area of use. They are also hypertonic viscid solutions which is safe in proper doses but can become toxic if overdosed of if the pt has low cardiac output or dehydration breakdown can be delayed. Can be diluted w NS to reduce the risk.
What is a Computed Axial Tomography (CAT) Scan and what are some components of it? aka CT
A specialized X-ray that produces images in slices for evaluation. (360 x-rays make a 3D image)
-Thickness of the slices can be adjusted (2-10mm thick)
-Uses ionizing electromagnetic radiation to create an image from 4000 different tissue densities sorted into 16 groups
-Can be enhanced w an iodine based contrast medium which can be given to pts allergic to iodine if given a steroid treatment of prednisone or diphenhydramine prior to CT
-Faster and less expensive than an MRI (5-15 mins)
-Detects fast bleeding, cerebral infarction, osteophytes (bony spurs), and intervertebral pathology
-Pt enters tubular scanning device where they can hear a “whirr”. Sedation can be given to children or pts w claustrophobia.
What is fluoroscopy and what are some components of it?
Uses ionizing radiation to project images on a monitor where amplification is achieved w an image intensifier. Allows for removal of background images
-Allows movement to be projected in real time which is controlled by the surgeon in real time
-The portable one is called the c-arm which allows intensifier and x-ray tube to always be in opposition. Comes in mini, large, and extra-large
What are some considerations to remember for fluoroscopy?
-There is a special drape for the c-arm which is dependent on the size
-You need leaded PPE
-Requires a radiolucent table
What are some uses for fluoroscopy?
-Angiography (including cardiac catheterization)
-Cholangiography
-Retrograde urography
-Aid in bone realignment and prosthesis placement
-Verification of catheter placement (epidural/central venous pressure) and lead (pacemaker) introduction
-To direct instrumentation (neurosurgery/orthopedics)
What is myelography?
A form of x-ray and CT that clearly outlines bone tissue, osteophytes (bone spurs), or disk extrusions.
-For evaluation of spine, neck, and leg pain.
-Can be used in conjunction w contract medium that is injected into the subarachnoid space to outline the spinal cord and nerve roots
-Useful for pts that can’t undergo MRI bc of metallic implants
What is angiography?
A form of x-ray and CT that is an invasive, sterile technique
-Assesses the cause and severity of of PV disease that uses digital subtraction angiography that allows visualization of veins and arteries following IV injection of contrast
-Preliminary diagnostic for endarterectomy, angioplasty, bypass grafting, aneurysm clipping, and embolectomy
-Done in cath labs or hybrid rooms
-Pressure injector is used for nonselective angiography where large amounts of contrast are injected rapidly
-Catheters (needle/cannula combos that may have guidewire). May be used to instill contrast. The smaller the catheter, the less the damage. Multiples holes are used for aortograms. Caths are flushed w NS/Heparin mixture
-Guidewires are used to protect the intima of the vessel. Most common is J wire.
What equipment is essential for angiography?
-X-ray unit that can make still images and fluoroscopy
-serial film changers
-pressure injectors
-catheters
-guidewires
-needle/cannula assemblies
What is cardiac catheterization used for?
Used with fluoroscopy to permit the evaluation of:
-Heart function
-Coronary arteries
-Cardiac chambers
-Measurement of pressure in chamber
Diagnoses:
-CAD
-Valvular disease
-Pulmonary disease
-CHF
What are common catheter site placements?
-femoral artery/vein (most common; percutaneously)
-brachial artery/vein (cut-down)
-right subclavian
-internal jugular vein
-radial (minimal blood loss)
What is an ejection fraction?
Percentage of blood pumped out a ventricle with each heartbeat. Indicator of hearts health and cardiomyopathy. Only measured in the left ventricle. Normal is 55-75%
What is a coronary artery anteriorgram?
Catheter inserted into the ostia of the left/right coronary system to check for coronary artery disease
What is the Seldinger Technique?
The easiest way to access the vessels. The general term for insertion of a guidewire for placement into ducts. A catheter is inserted into an artery (usually femoral) and positioned into the ostia of the L coronary system. Contrast is injected and x-rays are taken and lesions of the system are outlined. Catheters are exchanged and repeated for the R coronary system.
What are the supplies required for the Seldinger Technique?
-1% Xylocaine
-#11 Blade
-Needle/Cannula set (Deep enough to spam from skin to vessel and is inserted at a 45-60 degree angle)
-Guidewire
-Catheter
-Contrast Medium
What are the steps for the Seldinger Technique?
- Skin and Subq are injected w local (xylocaine)
- Small incision is made w an 11 blade
- Subq is spread w a kelly
- Needle/cannula is inserted into the artery at a 45-60 degree angle. Stylet is then slowly withdrawn until there is a spurt of blood.
- Guidewire is inserted into the cannula of the needle
- Needle cannula is removed by sliding off the guidewire and digital pressure is applied to prevent the loss of bleeding
- Distal tip of the catheter threaded over the guidewire and into the artery
- Catheter is positioned at the proper level and guidewire is removed
- Catheter is flushed w hepsaline to prevent clotting
- Contrast is injected
- X-rays are taken under fluoroscopy
What is a L Ventriculogram?
A pigtail catheter is positioned through the aortic valve and into the L ventricle. Chamber pressures are measured and recorded into and cath is hooked up to a pressure injector for injection of a large amount of contrast into the L ventricle. The L ventricular wall is outlined and examined. Ejection Fraction is calculated from this.
What is a R Ventriculogram used for?
A Swanz-Ganz pulmonary catheter is attached to a transducer and a monitor. Pressures are taken in the R atrium to r/o ventricular failure, hypovolemia, or embolism. Pressures are taken in R ventricle to r/o mitral valve insufficiency, L ventricular failure, and CHF. Pressures are taken in the pulmonary artery to r/o pulmonary artery resistance, hypoxemia, respiratory insufficiency, pulmonary edema, and pulmonary embolism.
What are the steps for a R Ventriculogram?
- Catheter is inserted into a vein and advanced into the superior vena cava and positioned into the R atrium for chamber pressure measurements.
2.When a R atrial waveform appears on the oscilloscope, the balloon is inflated to facilitate advancement through the tricuspid into the R ventricle where a waveform also appears. - Cath is advanced into the pulmonary semilunar valve where a waveform is noted and recorded.
- The flow of blood will carry the balloon into a smaller branch of the pulmonary artery branches where it wedges and occludes the vessels and pulmonary capillary wedge pressure is recorded.
- The balloon is deflated and the catheter slips back into the pulmonary artery where pressure is recorded.
What is a Pulmonary Capillary Wedge Pressure?
End-diastolic pressures and is an important determinant in the functioning of the left side of the heart
What is cholangiography?
Performed intraop during a lapchole for common bile duct exploration. A cholangiogram catheter is inserted through a small incision in the cystic duct. Contrast is injected into the biliary system to detect the presence of caliculi or obstruction under x-ray/fluoroscopy.
What is a urogram?
Used to outline the structures of the urinary system (usually in conjunction w a cystoscopy procedure). Contrast is used to outline the renal pelvises and ureter. Usually includes KUB.
What is the difference between an intravenous and retrograde pyelogram?
Intravenous Pyelogram (IVP): Contrast is delivered into a vessel. aka antegrade pyelogram.
Retrograde: Contrast is delivered into distal ureter
What is radioisotope imaging?
Uses radioactive meds to assist primarily in locating tumors, their size, and invasiveness. Two types are positron emission tomography (PET) scan and scintigraphy. Radiotracers are introduced to the body via IV, gas inhalation, or gas inhalation and will uptake to abnormalities. Time is dependent on the radiotracer and tagged biological chemical.
What is Positron Emission Tomography? (PET Scan)
Combines CT and radioisotope imaging. Uses radiotracers often, the radioactive drug FDG (fluorodeoxyglucose) which tags glucose bc malignant tissue use higher quantities of glucose. This lights up on the scan. PET scans are lengthy and expensive.
What is Scintigraphy? aka isotope scanning
A nuclear medicine study or radionuclide imaging where a radioactive isotope/radiotracer is instilled which are metabolized by a specific tissue type. The more active a cell is, the more of the isotope it will take up (hot spots). Gamma rays are then used to pick up gamma rays emitting from hot spots creating an image. Used for the brain, breast, cardiac, gastroesophageal, skeletal, and thyroid.
What are the two different forms of energy MRI uses to create an image?
- Magnetic field. A spinning hydrogen atom is placed into a magnetic field, forcing atoms to line up and “spin” at a particular frequency.
- Radio Waves. Applied radio waves force the hydrogen atoms to cycle in phase. As the radio waves shut down, the atoms release a radio wave of the characteristic frequency that is measured and transformed into an image.
What are some differences between MRI and CT?
-MRI slices can be taken from any direction
-Uses no ionizing radiation
-Good for imaging soft tissue, brain disorders, and herniated discs
What are some components about MRI?
-A non-iodine based contrast medium can be injected to enhance structures. Images are taken before and after contrast injection. Gadolinium is most commonly used and works by using a chelating process in which large organic molecules form a stable complex around the gadolinium ions and reduces the chances of toxicity. This should not be used for pts w kidney disease bc there is a risk for nephrogenic cystic fibrosis.
-Take longer than CTs (can provide sedation or open MRIs can be used)
-Makes loud noises (provide music)
-No magnets near MRI (pure titanium implants are okay)
How does ultrasonography work?
A crystal transducer is electrically stimulated and produces high frequency sound waves (1-10 million Hz). The waves are then directed at the body then variances in tissue density are reflected back to the transducer as echos.
What is ultrasonography used for?
Used to examine the hear, carotid artery stenosis, blood flow, solid organs, and the abdominopelvic cavity. The waves cannot be passed through air since the echo is reflected in too many directions so not used on the lungs and the bladder should be full.
What is Doppler Ultrasonography?rin
The Doppler monitor measures blood flow that transmits the sound of moving red blood cells to the transducer. The difference in pitch can be amplified by the machine. Used in the OR to determine the patency of arterial anastomosis. The probe must be covered by a sterile drape.
What is electrocardiography? (ECG)
A noninvasive ultrasound study of the heart through the chest wall where waves echo from the heart and surrounding structures to provide information about cardiac structural abnormalities. Color techniques can be used to map blood flow through the heart. Transesophageal echocardiography (TEE) can also be done where the transducer is attached to the end of a gastroscope and put into the esophagus to bring it closer to the heart. Used to asses valvular function, interventricular blood volume, cardiac chamber enlargements, and septal defects.
What is Plethysmography?
Used to determine and register variations in the volume of an extremity and the volume of blood passing through a vessel. A pulse volume recorder detects changes in the volume of an inflated air bladder that is expressed on a strip chart recorder. Measures diffuse small vessel arterial disease (Doppler may be used to compare volume v. velocity). Measure the amount of air in the lungs.
What is Phleborheography?
Notes changes in venous volume when associated w respiration. Measures and is used to diagnose DVT. Mostly replaced by MRI and ultrasound.
What are some electrodiagnostic studies and how do they work?
ECG, EEG, and EMG. The body had cells w polarized molecules and the systems communicate via bioelectrical or biochemical. These micro-electric impulses can be used to provide diagnostic info.
What is electrocardiography? (ECG, EKG)
Used to detect all forms of heart disease. Electrodes/leads are placed on the arms, legs, and torso (3-5 in OR) and a Holter monitor is worn by the pt to detect dysrhythmias. ECG is also useful for a stress test where HR, BP, and ECG are closely monitored for changes to measure delivery of coronary oxygen and myocardial ischemia for pts w angina.
What is electroencephalography? (EEG)
Records electrical activity of the brain by measuring changes in electric potential. Electrodes are placed on the scalp or on the surface of the brain interop and the signals are picked up, sent to an amplifier, and a wave signal is printed for review. Used to help diagnose seizure disorder, brain tumors, and interop to monitor neuro function.
What is Electromyography? (EMG)
Records the electrical activity of skeletal muscle. Probe is inserted through the skin and into the muscle. Provides info abt muscle contractility and innervation to diagnose ALS, myasthenia gravis, and carpel tunnel syndrome.
What is intraoperative neuromonitoring?
Used during cranial and spinal sx when there is a high risk for nerve injury. Provides immediate electrical nerve velocity feedback from electrodes on pt extremities which indicates if there was a disruption of nerve signals. Allows the surgeon to modify the angle of approach, lessen compression, and use other maneuvers that could reverse the effects on the area being operated on.
What is pulse oximetry?
Measures arterial sats of hemoglobin w oxygen by passing a light through tissues to determine the optical density of blood. Oxygen rich hemoglobin absorbs infrared light and oxygen deprived hemoglobin absorbs red light. Microprocessor calculates the difference and turns it into a percent. Should measure between 95-97%. Is noninvasive.
What is capnography? aka End-tidal CO2
Estimates arterial levels of CO2 during mechanical ventilation and measures CO2 that is exhaled. Sensor is located in anesthesia circuit and displays info on a monitor in wave form. Useful in detecting dislocated ET tubes and acidosis.
What is spirometry?
Obtains info on lung capacity, resistance, and ventilator pressure in numerical and graph form on a monitor. Measures the quantity and rate of inhaled and exhaled air. Useful in detecting asthma, COPD, ARDs, and leaks in the ventilatory system.
What are blood gases?
Blood is drawn from a pt and visually assessed.
Arterial Sats: 96-100%
Venous Sats: 60-85%
What does a high and low red blood cell count indicate?
High: Bone Marrow Disease
Low: Anemia, sorosis, or dehydration
What does a high and low hemoglobin level indicate?
High: Dehydration or bone disease
Low: Anemia
What does a high and low hematocrit indicate?
High: Dehydration
Low: Anemia, bleeding, and malignancy
What does a high and low platelet level indicate?
High: Too thick
Low: Disseminated Intravascular Coagulation (DIC)
What does a high and low white blood cell count indicate?
High: Leukemia, infection
Low: Immunosuppression
What does a high and low International Normalized Ratio (INR) indicate?
High: Increased bleeding
Low: Increased clotting
What does a high and low prothrombin time indicate?
High: Bleeding out
Low: Embolism
What is Partial Thromboplastin Time?
The relationship between PT and PTT indicates which clotting factors are missing.
What are normal hematocrit levels?
Adult Male: 42-54%
Adult Female: 38-46%
Pregnant Women: 30-34% (Low limits); 46% (Upper limits)
Adult Male (High Altitude): 45-61%
Adult Female (High Altitude): 41-56%
What is International Normalized Ratio? (INR)
Doctors measure a patient’s INR level during a PT-INR test. The PT stands for prothrombin time. The test measures how much time it takes for a patient’s blood to clot. This test ensures that patients are receiving the dosage of warfarin that is right for them. Typical score is between 2-3 but its different for everyone.
What are the different methods of collection for a urinalysis?
Simple void: pt voids into a clean container
Clean Catch: cleaning the urinary meatus prior to voiding and “catching” the sample midstream into a sterile collection device
Sterile: Perineal prep plus catharized specimen into sterile container
24hr sample: Used to measure electrolytes and nitrogenous waste
What is being analyzed during a UA?
-Color
-Appearance
-Odor
-pH
-Specific gravity
-Proteins
-Glucose
-Ketones
-Microscopic: RBC and WBC
-Drug screening
What is a Gram Stain Bacteriological Test?
A valuable tool in identifying bacteria. Used as a quick method for determining initial course of tx which may be changed after the culture and sensitivity. Bacteria is exposed to stains of crystal violet and iodine, rinsing with alcohol, and stained again. Bacteria that retain the blue dye are called Gram-positive and those that fade to pink are Gram-negative.
What is a Culture and Sensitivity bacteriologic test?
Determines the exact organism and which antibiotics are effective after a 24-hour incubation period. Sterile cotton-tipped applicators are used to swab tissue or fluid. Aerobic and Anaerobic studies may be ordered requiring separate containers. Cultures should immediately be sent to lab to preserve life.
What is the difference between aerobic and anaerobic bacteria?
Aerobic: Can grow in oxygen. Found in superficial wounds
Anaerobic: Bacteria that lives in the absence of oxygen. Destroyed when exposed to the atmosphere in 10 minutes.
What is a spinal tap? aka lumbar puncture
Needle aspiration of cerebrospinal fluid (CSF) from the lumbar area of the spinal column for analysis. Normally clear, if bloody, tx will start ASAP. A culture tests to find germs that can cause infection and a sensitivity test checks to see what antibiotic will work best.
What is thoracentesis?
Placement of a needle in the posterior pleural space for analysis of pleural effusion. Used to diagnose cancer or inflammation of the pleura/lung or to remove fluid accumulations. CT and ultrasound can help w placement.
What is a surgical biopsy?
Excision of tissue or aspiration of fluid taken to determine nature of disease. Will few exceptions, all tissue and objects removed from the pt are considered specimens and sent to pathology.
What are some ways of obtaining specimens?
-Percutaneous (core needle)
-Fluid washings
-Brush sampling
-Incisional/excisional
-Centesis
What is the difference between a cytological and histological exam?
Cytological: Study of tissue
Histological: Study of cells (aspirated cells)
What is a needle biopsy?
The removal of fluid through a needle w a syringe attached. Used for cysts, joints, lesions, cavities, and thyroid/lymph nodes. 2 different types: fine needle is less invasive but may not obtain sufficient specimen for examination, core uses a larger needle and can take sample from center of lesion
What are washing and brush specimens?
The collection of fluid with cells usually in the pelvic cavity or bronchi.
Washing: Obtained during irrigation and aspiration of fluid. The specimens are then spun down by a centrifuge to receive cells. The cells are then placed on a plate and sprayed w fixative. They are stained and examined under a microscope.
Brush: Long flexible wire w a brush is used to capture cells. The CST wipes the brush on a slide to create a smear and cuts off the tip of the brush, placing it in formalin.
What are incisional and excisional biopsies?
Incisional: Removal of a portion of a mass or lesion
Excisional: Removal of the entire mass or lesion
Both can be processed frozen or permanent
What is a permanent section?
Placed in preservative such as formalin, formaldehyde, NS, dry. The specimen is then placed in a machine that removes fluid and water, replacing it w paraffin. The specimen is then sliced into thin sections which are stained or placed on slides for viewing under a microscope
What is a frozen section?
Used to perform an immediate diagnosis, determine if more tissue needs to be excised, or initiate postop therapy. The tissue is kept dry and placed into a specimen container. Pathologist quick-freezes the tissue sample, cuts thin slices and stains the sections, and views the tissue under the microscope. Not 100% accurate so sent as a permanent section afterwards.
What is centesis?
Placement of a needle into a body cavity for removal of fluid for diagnostic or therapeutic purposes
What is paracentesis?
Removal of ascites fluid from the peritoneal cavity, which develops as a result of cirrhosis or cancer of the liver, pancreatitis, or ovarian cancer
What is amniocentesis?
Placement of a needle through the abdomen into the uterus and amniotic sac in pregnancy for sampling of the amniotic fluid, which surrounds the developing fetus. Performed around the sixteenth week of gestation, it can detect chromosomal anomalies and the gender of the fetus.
What is pericardiocentesis?
percutaneous insertion of a needle into the pericardial sac to treat cardiac tamponade or to sample pericardial effusion fluid for laboratory culture in cases of infective pericarditis.
What is endoscopy used for?
Used for direct visualization of internal structures and diagnostic purposes.
