Answer: C—Internet service purchase cipro line homeopathic antibiotics for acne, utilized for multiple purposes in the laboratory discount cipro uk bacteria urinalysis, is considered overhead or an indirect expense. Answer: C—Platelets are the blood products that have the highest rate of bacterial contamination. However, the fatality rate is higher when the platelet unit is contaminated with Gram negative bacteria. Answer: C—Interview questions that could potentially discriminate against age, sex, religion, or other factors are not allowed. Answer: A—An Ishikawa diagram, also known as a fshbone or cause and effect diagram would be most appropriate to investigate the various causes contributing to the error, such as methods, people, equipment, and environment. Basic prin- ciples include regulatory requirements and economical evaluation of new assays. They should also be able to interpret statistical tests/analyses, as an integral part of method comparison and assay validation. This chapter provides a review of laboratory principles and statistical methods, as well as a brief discussion on different study designs. Of note, this may be an advanced chapter for some students and you may wish to cover this chapter later on in your test preparation. Attention: Some diseases and scoring systems are used as examples in this chapter; however, intimate knowledge of these diseases and systems is not required to answer the questions. They are used to provide a reference for the statistical or laboratory management concepts. Further, the data used for the questions in this chapter are only for illustration—they are not actual data, and thus, the conclusions (i. Please answer Questions 1–9 based on the following scenario: You were recently appointed as the Medical Director for the Hemostasis Laboratory at your hospital. You would like to evaluate the possibility of perform- ing the assay in your laboratory. You have several options for this assay, including several commercially available kits, as well as an in-house developed assay. Waived tests (Answer A) are defned as “simple laboratory examinations and procedures that have an insignifcant risk of an erroneous result. It is also responsible to promote healthy and safe behaviors and to train the public health workforce, including disease investigators. Based on the information, at what point (A,B,C,D or E) will the commercial assay give you the most diagnostic accuracy (i. Cutoff point with the most diagnostic Cutoff point that gives the in-house developed accuracy for commercial assay assay more sensitivity than commercial one A. Point B is just the cutoff that the sensitivity and specifcity of your in-house assay is the same as the commercial one. Based on the fgure and the above explanation, all the other choices (Answers A, B, C, and E) are incorrect. On the other hand, confrmation tests should be very specifc because it is used to rule in or confrm the disease. Of course, with most of the testing we perform in the laboratory, we would prefer that a test has high sensitivity and specifcity, so we are able to both detect and confrm a disease with a single test. Answer: A—screening test should have high sensitivity to rule out patients with disease. On the other hand, confrmation test should have high specifcity to rule in patients with disease. All other choices (Answers B, C, D, and E) are incorrect based on the discussion above. Since you do not currently own a platform to detect fuorescent signals, you plan to lease it for $5,000 monthly. Assuming that there are no additional costs to consider, how many tests do you have to perform each month to break-even? This analysis takes into account all costs associated with performing the test and the expected proft. In the question above, we only take into account the reagent cost and the reimbursement. However, in real life, you may need to account for technologist time/salary, maintenance contracts, the cost of test tubes, etc. If the expected proft does not exceed the cost, then you may need to reconsider bringing the test in-house and consider the cost-beneft of sending the sample to a reference laboratory. In those cases, you may take a fnancial loss on this test and make up the difference on another, more commonly ordered test. Based on the defnition, technologist salary (Answer C) or maintenance of the contract (Answer D) is example of fxed direct cost. Internet service and electricity are examples of indirect costs since they are required to run more than one test in a laboratory. However, further evaluation reveals that performing the result in-house will result in a quicker turn-around-time. This will also enhance patient safety and quality of care since they would not be exposed to unnecessary procedures or transfusion. You are interviewing a technologist whose partial responsibility will be running this test Monday through Friday, 8:00 a. However, it is perfectly acceptable to ask questions about the capacity of the potential employees to perform the job. Answer: E—This question assesses the ability of this applicant to perform the job and is thus, a legally acceptable question. Questions that involve an applicant’s marital status, sexual orientation, religion, current or future plans to have children, and age are illegal (Answers A, B, and C) Asking about the applicant’s origin (Answer D) is also illegal; however, the employer can ask if the applicant is authorized to work in the United States. If the employer concerns about the possibility of an applicant to work during holidays and weekends, then instead of asking about marriage and religion, it is acceptable to ask if the applicant is willing to work during holidays and weekends, if necessary. From your analysis (Question #5 above), running the test in-house is costing you $50 just to buy the reagents, without considering other direct and indirect costs. Agree to send all samples to him because he offers a good price and turnaround time B. Only send the samples to him if his laboratory information system can interface with your hospital system D. Negotiate the price and only send the samples if the price is less than $25 per test E. Do not send any sample to him Concept: Stark’s law governs the physician self-referral to Medicare and Medicaid patients. This law prohibits physicians from making patient or laboratory referral for services payable by Medicare and Medicaid to an organization that they or their immediate family has a fnancial relationship. Though defnitions vary, immediate family usually includes spouses, children, parents, siblings, and frst cousins. Answer: E—Since your father owns this private laboratory, you cannot send the samples to him based on Stark’s law. Answers A, B, C, and D are incorrect because they would involve sending samples to your father’s laboratory. Which of the following provides the best interpretation of both the plot and Deming regression?
T—Trauma should bring to mind fecal impactions and foreign bodies or introduction of the male organ into the rectum discount cipro 250mg antimicrobial resistance surveillance. E—Endocrine disorders suggest nothing other than the ovarian cysts and ectopic pregnancy already mentioned purchase cipro in united states online xarelto antibiotics. Approach to the Diagnosis The cause of rectal pain is usually obvious on examination with an anoscope or proctoscope. Careful palpation may be necessary to discover a perirectal abscess, coccydynia, or an ectopic pregnancy. Anal fissures may be missed unless all quadrants of the anus are examined with the slit anoscope. Lateral anal fissures (3 o’clock or 9 o’clock) suggest syphilis, tuberculosis, or other serious underlying causes. If these are all the causes you can remember, you will be sadly mistaken in some cases. Most of the causes can be quickly recalled by simply considering the anatomy of the eye, because trauma or inflammation is the usual cause. The cornea may be involved by a foreign body or keratitis; corneal ulcers should also be looked for. Proceeding to deeper layers, the physician should consider iritis, scleritis, or injury to these structures. Finally, between the cornea and iris is the canal of Schlemm, which recalls glaucoma. Approach to the Diagnosis Pinning down the diagnosis of a red eye is usually not difficult because most causes will be evident to the naked eye. Even when conjunctivitis is likely, always check the visual acuity in the affected eye to rule out a more serious condition. However, a careful search for a foreign body with a magnifying glass and for a corneal abrasion using fluorescein will be necessary in some cases. Diffuse erythema of the eye usually indicates trauma, conjunctivitis, or scleritis, whereas circumcorneal injection suggests iritis or glaucoma. Episcleritis is a focal erythema that fails to blanch with one drop of phenylephrine 2. A dilated pupil suggests glaucoma, whereas a constricted or distorted pupil suggests iritis. Acute closed angle glaucoma is associated with nausea, vomiting, and halos and is a medical emergency. A smear and culture will help differentiate infectious conjunctivitis from allergic conjunctivitis, but the latter is usually bilateral whereas the former is usually unilateral. An ophthalmologist should be 726 consulted immediately if there is any doubt about the diagnosis. Chest x-ray (sarcoidosis) Case Presentation #78 A 17-year-old black boy presents to the emergency room with redness of his left eye. Utilizing your knowledge of anatomy, what is your differential diagnosis at this point? Further questioning reveals that he has had intermittent bloody diarrhea for several months. N—Neurologic disorders associated with restless leg syndrome include uremic or diabetic neuropathy, Parkinson disease, and multiple sclerosis. T—Toxic causes of this disorder include barbiturates, benzodiazepines, caffeine, and tricyclic antidepressants. A neurologist should be consulted before ordering these expensive diagnostic tests. It is almost invariably due to a wound infection with tetanus but may also give the appearance of a fixed grin. Approach to the Diagnosis Careful examination of the trunk and extremities for a wound infection is extremely important. If the patient is not stripped down, the clinician can miss a tetanus infection caused by dirty needles in drug addicts. A history of mental illness should alert one to attempted suicide with strychnine. M—Mental disorders such as pseudoneurosis can be associated with diffuse scalp tenderness. I—Inflammation would bring to mind herpes zoster, pediculosis, tinea capitis, cellulitis, an infected sebaceous cyst, and impetigo. N—Neurologic disorders associated with a tender scalp include temporal arteritis, occipital nerve entrapment, trigeminal neuralgia, and neoplasms that involve the cranium and meninges (i. Approach to the Diagnosis Most skin conditions should be easily diagnosed by inspection. A sedimentation rate and biopsy of the superficial temporal artery will diagnose temporal arteritis. If occipital nerve entrapment is suspected, a nerve block should be done to confirm the diagnosis. M—Malformation prompts the recall of osteogenesis imperfecta, congenital hemivertebra, Marfan syndrome, and arthrogryposis. The I should also remind one of idiopathic scoliosis, responsible for 80% of the cases. T—Trauma should facilitate the recall of thoracolumbar sprain, compression, fracture, and herniated disk. S—Systemic diseases associated with scoliosis include Paget disease, pulmonary fibrosis, and Ehlers–Danlos syndrome. Approach to the Diagnosis To diagnose scoliosis, have the patient bend over, and there will be asymmetry in the height of the scapulae (Adam test). Most causes of scoliosis will require only an x-ray of the spine to clarify the diagnosis. Tracing the nerve endings in the face or extremities to the brain we have the peripheral nerves, nerve plexus, nerve roots, spinal cord, brain stem, and cerebrum. Now cross-index these structures with the various etiologies (vascular, inflammatory, neoplastic, etc. Peripheral nerve—This structure should prompt the recall of carpal tunnel syndrome, ulnar entrapment in the hand or elbow, 730 and diffuse peripheral neuropathy (diabetes, nutritional disorders, etc. Nerve plexus—This structure should suggest brachial plexus neuritis, sciatic neuritis, brachial plexus compression by a Pancoast tumor or thoracic outlet syndrome, or lumbosacral plexus compression by a pelvic tumor. Nerve roots—This would facilitate the recall of space-occupying lesions of the spinal cord (e. It would also help to recall tabes dorsalis, herniated disk disease, osteoarthritis, cervical spondylosis, spinal stenosis, and spondylolisthesis. Spinal cord—Lesions in the spinal cord that cause sensory loss include space-occupying lesions, syringomyelia, pernicious anemia, multiple sclerosis, and Friedreich ataxia, acute traumatic or viral transverse myelitis, and anterior spinal artery occlusion may also cause sensory loss.
Atropine should be used with caution in patients that have glaucoma or benign prostatic hypertrophy purchase cipro 1000mg amex best antibiotics for sinus infection in adults. Isometric handgrip may be performed at the peak infusion rate to help achieve target heart rate generic cipro 1000 mg mastercard antibiotic creams, as well. Less serious side effects include tremor, nervousness, and marked hypertensive and hypotensive responses. The most common minor complication is hypotension, which usually responds to supportive therapy including intravenous fluids. Like dobutamine, esmolol has a very short half-life and, therefore, may be the preferred agent. A typical protocol starts at a low dose of 80 µg/kg/min and is increased every 3 minutes by 30 µg/kg/min to a peak dose of 170 to 200 µg/kg/min. Symptoms usually start to resolve within 60 seconds after medication administration. Modern technology allows digital image acquisition of multiple cardiac cycles and side-by-side comparison in a split screen display, enabling easy comparison of regional wall motion at rest and peak stress or after stress. Detailed frame- by-frame evaluation of wall thickening or excursion is possible, which helps in the evaluation of regional myocardial function. Harmonic imaging has improved endocardial definition, which can be further optimized with microbubble contrast agents. Microbubble contrast agents provide improved echocardiographic resolution and allow real-time assessment of intracardiac blood flow. Intravenous agitated saline improves visualization of the right atrium and ventricle and enables visualization of intracardiac shunts. However, intravenous agitated saline is not able to cross the pulmonary circulation and opacify the left ventricle. Second-generation microbubble contrast agents, such as Optison and Definity incorporate perfluoropropane gas encased in an albumin-based or phospholipid shell, are more durable and are able to cross the pulmonary circulation and opacify the left ventricle. Absolute contraindications to administration include previous hypersensitivity reaction and fixed right-to-left, bidirectional, or transient right-to-left cardiac shunts. Administration is relatively contraindicated in patients who are pregnant or nursing, although data are limited in these populations, and guidelines indicate that contrast should be given if needed. Significant advances have been made in 3D data acquisition without the need for off-line reconstruction. Each myocardial segment is visually assessed for wall thickening, rather than just wall motion, which may be influenced by myocardial tethering and translation. Examples of quantitative analysis methods include Doppler assessment of global systolic and diastolic function; automated endocardial border detection using integrated backscatter; and tissue Doppler assessment of myocardial displacement, velocity, strain, and strain rate. Tissue Doppler assessment along the long axis using apical views allows quantification of regional longitudinal myocardial function. Tissue Doppler is thought to be a potentially sensitive marker of subendocardial ischemia because abnormalities in regional contraction occur earlier in longitudinal than radial segments. The optimal cutoff for strain rate that gives the best sensitivity and specificity has been reported to be an increment of <0. It may be difficult to acquire technically adequate images at rest and especially at higher heart rates following stress, which limits its applicability. If digital clips include diastole, there is an increased likelihood positive wall motion abnormality 6. Compare the wall motion of individual segments from rest to stress in the four-screen display compare segments in the poststress images to identify differences in contraction and in the development of “hinge points” 8. Avoid calling a new wall motion abnormality if it is limited to only one myocardial segment; th contiguous segments B. The individual myocardial segments can be assigned to coronary artery territories, as illustrated in Figure 47. For instance, the left anterior descending coronary artery does not always supply the entire apex and the posterior wall is not always supplied by the left circumflex coronary artery. The system may also be problematic if multivessel disease is present, in which case the territory with the most ischemia is identified and less severe lesions may not be apparent. Wall motion is subjectively graded as normal, mildly hypokinetic, severely hypokinetic, akinetic, or dyskinetic and may be assigned a wall motion score of 1 to 4 (normal, hypokinetic, akinetic, or dyskinetic, respectively). A normal response to exercise stress includes a global increase in contractility, the development of hyperdynamic wall motion, and a gradual rise in the heart rate. This is manifested by increased wall thickness and increased endocardial excursion with stress. Akinesia and dyskinesia usually indicate transmural infarction, whereas hypokinetic segments may be partially infarcted or viable. An abnormal response to exercise is defined by the development or worsening of regional myocardial function. Regional myocardial dysfunction, as manifested by decreased endocardial excursion and wall thickening, is specific for myocardial ischemia. Decreased excursion alone is less specific and can occur with conduction abnormalities, with paced rhythms, and in the normal basal inferior myocardial segments. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: a statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. False-negative findings may occur with a delay in capturing postexercise images, low workload, or inadequate heart rate response (i. Additional causes of false-positive and false-negative findings are outlined in Table 47. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: a statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: a statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. The typical ischemic response to dobutamine is characterized by normal resting wall motion and an initial hyperdynamic response at low doses followed by a decline in function at higher doses. Ischemia may also be identified on the basis of deterioration of normal wall motion without any transient hyperdynamic response. The person who interprets the images must be well trained in order to develop an acceptable level of accuracy and must interpret an adequate number of studies on a regular basis to maintain accuracy. The ability to interpret stress echocardiograms is mitigated by image quality, the presence of arrhythmias, conduction abnormalities, respiratory interference from hyperventilation, and difficulty in reproducing the translational and rotational motion of the heart. Reported sensitivities and specificities (using coronary arteriography as the gold standard) vary between studies, depending on the prevalence of disease in the study population, the angiographic definition of significant disease, and the criteria used for a positive test. As with other imaging methods, the sensitivity is less for the detection of single-vessel disease and greater for the detection of multivessel disease. Myocardial perfusion scintigraphy is based on the detection of a perfusion defect during maximal hyperemia, with reduced perfusion of areas subtended by significant coronary artery stenosis (>50% stenosis). It may also be slightly superior for patients on antianginal therapy when it is necessary to induce ischemia.
CoA usually consists of a narrowing in the region of the ligamentum arteriosum proven 500 mg cipro antibiotic green capsule, the remnant of the ductus arteriosus cipro 750 mg free shipping can antibiotics cure acne for good, just distal to the origin of the left subclavian artery. The exact anatomy, however, varies, and the coarctation may include a long segment, the transverse arch, or the abdominal aorta. The main anatomic substrate is a prominent posterior shelf of the aorta, composed predominantly of thickened media. The first suggests that the narrowing is caused by aberrant ductal tissue that constricts the aorta at the time of ductal closure. The second proposes that aortic hypoplasia develops as a consequence of reduced blood flow in utero. Multiple left-sided heart lesions may be associated with CoA and are often referred to as the Shone complex. Associated extracardiac defects include intracranial aneurysms, especially within the circle of Willis (3% to 5% of cases), hemangiomas, hypospadias, and ocular defects. For patients with CoA who survive to adulthood, symptoms are usually negligible and nonspecific. Patients may complain of headaches, nosebleeds, cool extremities, leg weakness, or claudication with exertion. A thorough cardiovascular examination may identify a systolic ejection murmur at the left upper sternal border that radiates to the intrascapular area located immediately anterior or posterior to the CoA. The murmur may be longer in systole and even continue into diastole, depending on the degree of obstruction. Increased flow through the collateral intercostal arteries can produce a continuous murmur appreciated diffusely over the precordium. Upper extremity hypertension is often present, usually in conjunction with diminished and delayed femoral pulsations. CoA should always be considered in the differential diagnosis of refractory hypertension, especially in younger patients. Funduscopic examination may demonstrate a “corkscrew” tortuosity of the retinal arterioles. Cardiomegaly, dilated ascending aorta, and prominent pulmonary vasculature are common. Rib notching usually develops by 4 to 12 years of age and is caused by enlarged intercostal collaterals. The classic “3” or inverted-E sign is pathognomonic for CoA and is created by a dilated left subclavian artery above the CoA and poststenotic dilation of the aorta below the CoA. In adults, the suprasternal notch view is most helpful; color Doppler can be used to localize the site of turbulence. If severe narrowing is present, persistence of flow in diastole (widening of the flow profile from systole into diastole) is seen by continuous wave Doppler in the aorta below the coarctation, such as in the abdominal aorta. This is a useful method to ascertain the presence of significant coarctation, even if imaging the direct site of the obstruction is impossible. A complete study should measure left ventricular size and ascending aortic size, determine aortic valve anatomy and function, and identify any potential associated congenital anomalies. This enables the precise anatomy to be delineated and helps in the decision making regarding surgery or catheterization as treatment options. It is also useful in evaluating the intracranial vessels for associated berry aneurysms. Cardiac catheterization provides excellent image data and pressure information and is often more reliable than echocardiography in adults. An aortic angiogram in left anterior–oblique or caudal and direct lateral projections usually best defines the lesion. Pressures should be obtained in the left ventricle and the ascending aorta, and the gradient across the lesion should be measured. A pullback pressure of >20 mm Hg signifies hemodynamic significance and usually warrants intervention if concomitant clinical factors allow. Several factors need to be taken into account when deciding on optimal therapy for CoA, including the age of the patient, the anatomy of the coarctation, any prior CoA operations, and the local surgical expertise. Whatever mode of treatment is chosen, the presence of postprocedural upper extremity hypertension influences survival. In general, medical therapy for CoA has very limited utility, but it may be useful in a supportive role along with mechanical treatment. Hypertension should be medically treated, with the goal of controlling blood pressure and preventing end-organ damage. Percutaneous balloon angioplasty is generally less effective than surgery for treatment of primary coarctation. Neonates and infants treated with angioplasty experience high rates of recurrent CoA (about 50% to 60%) and aneurysm formations (5% to 20%); therefore, surgical repair is preferred in this patient population. Likewise, balloon angioplasty of the unoperated coarctation in adults is controversial, with data suggesting higher rates of restenosis and aneurysm formation compared with surgical repair. Procedural complications can include acute aortic rupture (rare), aortic dissection, femoral artery trauma, recurrent coarctation (8%), and aneurysm formation (8% to 35%). The suspected mechanism for late aneurysm formation is intimal tear at the site of cystic medial necrosis within the coarctation site. It should be noted that the clinical impact of aneurysm formation is unclear, as most defects are small and have a low risk of rupture. Percutaneous angioplasty, however, is the preferred therapy for recurrent postsurgical coarctation. The procedure is successful in reducing the gradient to <20 mm Hg in approximately 80% of interventions, with only a 1. Theoretically, stent implantation may mitigate the development of aneurysm or dissection for a few reasons. By apposing the torn intima to the media and through dispersion of force, stenting may limit vascular trauma. It can also oppose the vascular recoil of the coarcted segment and avoid overdilation. By allowing the use of smaller balloons and graded inflations in staged procedures, stents may also reduce rates of aneurysm formation. Early and intermediate outcomes are promising, with a good safety and efficacy profile as well as lower rates of restenosis and aneurysm formation compared with balloon angioplasty. Despite the lack of long-term outcome data, stenting has become the preferred treatment modality in adults and adult-sized adolescents with native CoA. For recoarctation, balloon angioplasty with or without stenting is preferred in adults as well, as long as the anatomy is suitable. Three types of surgical repair have been used for correction of CoA: resection of the stenosed segment with end-to-end anastomosis, use of a subclavian flap, and patch aortoplasty.