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By G. Sobota. University of Maryland at College Park.
Speciﬁc Conditions Tumors Malignant Esophageal Tumors Overview: The majority of esophageal neoplasms are malignant order lady era 100mg without a prescription. Esophageal cancer is among the top 10 leading causes of cancer deaths in the United States and is increasing in incidence lady era 100mg on line. Although squa- mous cell carcinoma previously accounted for 90% to 95% of reported esophageal malignancies discount lady era 100 mg amex, the incidence of adenocarcinoma has increased dramatically in the past two decades and now accounts for at least 40% of all malignancies. This relative change may reﬂect the increased use of ﬂexible endoscopy and closer surveillance of asymp- tomatic patients who are at risk of developing esophageal carcinoma. Squamous cell carcinomas are distributed equally among the upper, middle, and lower thirds of the esophagus. Alcohol consumption and tobacco use are well-established factors for the development of esophageal carcinoma. Other risk factors for esophageal cancer include achalasia, radiation esophagitis, caustic esophageal injury, infection (human papilloma virus), Plummer– Vinson syndrome, leukoplakia, esophageal diverticula, ectopic gastric mucosa, and the inherited condition of familial keratosis palmaris et plantaris (tylosis). Diagnosis: The vast majority of esophageal carcinomas are clinically occult and present well after disease progression prevents cure. Most patients experience dysphagia an average of 2 to 4 months before presentation. Unfortunately, dysphagia almost uniformly indicates extensive disease and incurability. The initial study should be a barium swallow; this most frequently reveals distinct mucosal irregularity, stricture, a shelf in the lower esophagus, or rigidity. Upper esophageal endoscopy allows visualiza- tion of the affected area and biopsy to conﬁrm the diagnosis. Staging: The stage of esophageal cancer is determined by the depth of penetration of the primary tumor (T) and the presence of lymph node (N0, N1) and distant organ metastasis (M0, M1). Bronchoscopy is indicated for midesophageal tumors because of their propensity to invade the trachea and left mainstem bronchus. Weight loss greater than 10% has been shown to be associated with a signiﬁcantly poorer outcome in patients with operable esophageal cancer. Clinical staging categorizes patients into two groups: those with potentially curable disease and those with metastatic disease (disease outside of the local or regional area) in whom palliation is currently the only treatment option. An overall 5-year survival for esophageal cancer patients was reported in only 4% after surgical resection (surgical mortality, 29%) and in only 6% after radiation therapy. The treatment of esophageal cancer is gen- erally a palliative practice, and cure is a chance occurrence. However, precise clinical staging allows treatment modiﬁcation of patients with carcinoma of the esophagus. Surgical, radiation, and chemotherapy therapies are possible, with optimal outcomes often utilizing a combi- nation approach. Based on reviews of current literature available on the multimodal- ity management of patients with esophageal carcinoma, treatment pro- 212 J. Management of technically resectable esophageal cancer, 5-Fu, 5-ﬂuorouracil; mets, metastases. Value of Nissen fun- doplication in patients with gastro-oesophageal reﬂux judged by long-term symptom control. Outcome 5 years after 360 degree fundoplication for gastro-oesophageal reﬂux disease. Collis- Nissen gastrooplasty fundoplication for complicated gastrooesophageal reﬂux disease. Once symptoms appear, most esophageal cancers have invaded adjacent structures or have spread to distant organs. In those cases in which signiﬁcant obstructive symptoms exist, operative management often is the most effective means of relieving dysphagia and providing long-term palliation. In general, because esophageal cancer can have extensive and unpredictable spread longi- tudinally, it seems prudent to perform total esophagectomy, especially for those proximal- and middle-third lesions. Distal small lesions may be approached through the abdomen only, or resection for palliation alone can avoid total esophagectomy and its associated morbidity. Long-term follow-up of these patients reported a 5-year survival of 26% for combined therapy, while no patient receiv- ing radiation alone survived 5 years. Author Cell type R1 R2 Survival Positive ﬁndings Cooper et ala Both Rad Che/Rad 0% vs. Preoperative chemotherapy versus surgery alone for squamous cell carcinoma of the esophagus: a prospective randomized trial. Chemotherapy followed by surgery compared to surgery alone for local- ized esophageal cancer. Chemoradiotherapy followed by surgery compared with surgery alone in squamous cell cancer of the esophagus. A randomized trial of surgery with and without chemotherapy for localized squamous cell carcinoma of the thoracic esophagus. Local and regional treatment modalities are the corner- stones of symptomatic control. Palliative radiation therapy is a key component and is associated with signiﬁcant, albeit short-term, suc- cess in maintaining adequate swallowing. Concurrent chemotherapy and radiation have been used in the palliation of patients with metastatic tumors. Preoperative chemotherapy versus surgery alone for squamous cell carcinoma of the esophagus: a prospective ran- domized trial. Chemotherapy followed by surgery compared to surgery alone for localized esophageal cancer. A comparison of multimodality therapy and surgery for esophageal adenocarci- noma. Chemora- diotherapy followed by surgery compared with surgery alone in squamous cell cancer of the esophagus. A randomized trial of surgery with and without chemotherapy for localized squamous cell carcinoma of the thoracic esophagus. Swallowing Difﬁculty and Pain 215 While efﬁcacious in improving local and regional control, this treat- ment comes with a signiﬁcantly increased risk of toxicity and may not be appropriate in most patients. A number of local measures can preserve swallowing and avoid the toxicity of chemotherapy and radiotherapy. Dilation of malignant strictures with bougies or endoscopic balloon dilators temporarily can relieve dysphagia. Dilation is typically performed not as a sole therapy but as a prelude to other, more deﬁnitive measures. Injection with alcohol causes tumor necrosis and a decrease in the exophytic portion of the tumor. Laser therapy is reserved for patients with severe obstruction of the esophagus requiring palliation until chemotherapy and radiotherapy take effect. It also is used in patients who are not candidates for prosthesis placement because of an anticipated short life expectancy. This is not a desirable method of palliation for patients whose life expectancy is measured in weeks or months. Newer, self-expanding metal stents are easier to place and require much less tumor dilation before placement. Silicone-covered stents prevent tumor ingrowth but are more apt to migrate than noncovered stents; they are the pros- theses of choice in the treatment of malignant ﬁstula between the airway and esophagus. Stent placement after chemotherapy or radio- therapy may be associated with increased complications. Modern stents provide effective, long-lasting palliation with little morbidity and are the ﬁrst mode of palliation considered for patients with esophageal carcinoma. Benign Esophageal Tumors Leiomyomas, Cysts, and Polyps: Benign tumors of the esophagus are uncommon, with three histologic types accounting for 87% of benign esophageal tumors: leiomyomas, cysts, and polyps. These three tumors have distinct locations in the esophagus that reﬂect their cells of origin. Polyps occur almost exclusively in the cervical esophagus, while leiomyomas and cysts tend to occur in the distal two thirds. Leiomyomas constitute 50% of benign tumors of the esophagus, with an average patient age at presentation of 38 years, in contrast to esophageal malignancy, which typically presents at a more advanced age. Esophageal cysts are commonly congenital and are lined by colum- nar epithelium of the respiratory type, glandular epithelium of the gastric type, squamous epithelium, or transitional epithelium. Treatment is similar to that for leiomyoma, with resection for large or symptomatic lesions. Sutyak to the respiratory tract should be carried out, especially in patients who have had recurrent respiratory tract infections. These abnormalities result in a spectrum of symptoms and diseases ranging from “heartburn” to esophageal tissue damage with subsequent complications of ulceration and stricture for- mation. Gastroesophageal reﬂux is an extremely common condition, accounting for nearly 75% of all esophageal pathology. Lower esophageal sphincter dysfunction may be either physiologic and transient or pathologic and permanent. Nearly everyone experiences physiologic reﬂux, most commonly related to gastric distention fol- lowing a meal. These transient episodes of reﬂux are relieved with gastric venting (belching) or when the stomach empties normally. Overeating exacerbates these episodes, and a high-fat Western diet may delay gastric emptying, thereby extending the dura- tion of these transient episodes. Evidence is accumulating that chronic, gastric-related, transient physiologic reﬂux leads to sufﬁ- cient esophageal injury to cause dysfunction of the antireﬂux barrier; this then progresses to more permanent and pathologic reﬂux.
Department of Health and Human Services endorsement of such derivative products may not be stated or implied generic 100mg lady era with mastercard. This document is in the public domain and may be used and reprinted without permission except those copyrighted materials noted for which further reproduction is prohibited without the specific permission of copyright holders best lady era 100mg. We would like to offer special thanks to Mary Gauld buy lady era 100mg on-line, Maureen Rice, and Roxanne Cheeseman for assistance and guidance with project management and editorial help. The project would not be complete without their wisdom, experience, good will, and sense of humor. We acknowledge the hard work of Nicholas Hobson, our computer programmer, for creating our evolving systematic review management software. Our Technical Expert Panel provided valuable insights and challenges as well as ways to meet them. Our technical experts were David Bates, Doug Bell, Ken Boockvar, Chris Gibbons, Joy Grossman, Jerry Gurwitz, Joe Hanlon, Kevin Johnson, John Poikonen, Gordon Schiff, Bimla Schwarz, and Dennis Tribble. They represent a broad range of expertise and experience and the report is stronger because of them. Another group of experts who have been extremely helpful at improving the analyses of our data were our technical reviewers. Other expert reviewers were Anne Bobb, Elizabeth Chrischilles, Alan Flynn, and Kevin Marvin. We searched peer-reviewed electronic databases, grey literature, and performed ® ® ® hand-searches. Grey literature searching involved Internet searching, reviewing relevant Web sites, and searching electronic databases of grey literatures. Randomized controlled trials and cohort, case-control, and case series studies were independently assessed for quality. All data were abstracted by one reviewer and examined by one of two different reviewers with content and methods expertise. After duplicates were removed, 32,785 articles were screened at the title and abstract phase. Of these, 361 met only content criteria and were listed without further abstraction. Substantially more studies, and studies with stronger comparative methods, evaluated prescribing and monitoring. Other health care professionals, patients, and families are important but not studied as thoroughly as physicians. Hospitals and ambulatory clinics were well-represented in the literature with less emphasis placed on long-term care facilities, communities, homes, and nonhospital pharmacies. Most studies evaluated changes in process and outcomes of use, usability, and knowledge, skills, and attitudes. We found little data on the effects of forms of medications, conformity, standards, and open source status. Much descriptive literature discusses implementation issues but little strong evidence exists. Discuss Gaps in Research, Including Specific Areas That Should Be Addressed and Suggest Possible Public and Private Organizational Types To Perform the Research and/or Analysis........................ To What Extent Does the Evidence Demonstrate That Health Care Settings (Inpatient, Ambulatory, Long-Term Care, etc. Research Design for studies across the Phases of Medication Management and Education and Reconciliation................................................................................................... Settings for the Phases of Medication Management and Reconciliation and Education............................................................................................................................ Clinicians Evaluated in Outcomes Studies of Medication Management Phases, Education, and Reconciliation.................................................................................................. Research Design for Studies Across the Phases of Medication Management and Education and Reconciliation....................................................................................................... Settings for the Phases of Medication Management and Reconciliation and Education................................................................................................................................ Clinicians Evaluated in Outcomes Studies of Medication Management Phases, Education, and Reconciliation...................................................................................................... Patients and Caregivers Studied by Phase of Medication Management and Education and Reconciliation........................................................................................................................ Summary of the Number of Studies Reporting Statistically Significant Process Changes in Studies of Prescribing by Process for Hospital and Ambulatory Based Studies...................... Summary of the Number of Statistically Significant Process Changes in Studies of Order Communication by Process for Hospital and Ambulatory Based Studies......................... Study Designs Used in Studies Measuring Intermediate Outcomes Across the Phases for Medication Management......................................................................................................... Clinician Study Participants in Studies Assessing Intermediate Outcomes Across the Phases of Medication Management.............................................................................................. Patient Study Participants in Studies Assessing Intermediate Outcomes Across the Phases of Medication Management.............................................................................................. Research Design for Studies Across the Phases of Medication Management and Education and Reconciliation That Address Clinical Outcomes as Their Main Outcomes......... Summary of the Number of Studies Reporting Statistically Significant Differences in Clinical Primary Endpoints Between Study Groups for Hospital and Ambulatory Based Studies........................................................................................................................................... Frequency of Medication Management Phases Studies Plus Reconciliation and Education................................................................................................................................ List of Articles Addressing Various Features That Were Instrumental in the Decision To Purchase, Implement, and Use................................................................................................ Frequency of Core Informatics Journal Articles That Mention Sustainability to the End of 2009.......................................................................................................................................... Study Design of Included Studies Across the Medication Management Phases (Plus Education and Reconciliation).................................................................................................... Trends in Publication of Articles Relating to the Phases of Medication Management Across Years Until Searching Was Completed in June 2010....................................................... Glossary of Terms xi Executive Summary Background Medication management is a continuum that covers all aspects of prescription medications. Medication management includes prescribing and ordering, order communication (or order transmission) between prescribers and pharmacists, dispensing, administering, and monitoring, 1 as well as reconciliation, adherence, and education. Medication management is complex and costly and enhances the health and well-being of more than half of the population in the developing world. For the purposes of this review, medication management includes the processes that encompass the five phases of the medication process (i. Medication management can also include procurement, storage, and reporting from the first assessment of patients to determine their need for drugs through to optimal care and monitoring after the drugs are prescribed. The organization of the information in this report is based on the Bell framework of the five phases across the continuum 1 of medication management and reconciliation and education. Many health professionals, support staff, patients, and patients’ families were involved in medication management in the studies assessed. Within reporting related to the questions, sections are based on phases of medication management. Reporting is done to address the multiple settings where medication management is important, the range of health care providers who deliver and support care using medications, and classes of medications, specific drugs, or a broad spectrum of medications. What evidence exists to demonstrate that health care settings (ambulatory, long-term care, etc. We supplemented these articles with other studies addressing values propositions by stakeholders. The evidence for this question comes from studies of all designs that measure implementation, use, and purchasing decisions. Their definition of sustainability was the ability of a health service to provide ongoing access to appropriate quality care in a cost- and health- effective manner. Because our interest was in all study designs, we did not limit based on methodology. We also put no limits on language or time to capture the global literature and early studies. Once we tagged the articles for content, we assessed whether those that passed our inclusion criteria were pertinent to specific key questions. Many articles were analyzed in several phases of medication management and sections of the report. The quality of included studies was assessed using the same criteria employed by Jimison et al. Observational studies with before–after, time series, surveys, or qualitative methods were not assessed for quality because few well-validated instruments exist. Bibliographies of systematic and narrative reviews were examined to identify studies, and select reviews were integrated into sections of the report. Data were abstracted from relevant articles and tagged for applicability to the various key questions. Given the range of questions addressed, data abstraction was performed by a core group of staff and entered into online data abstraction forms. One reviewer did the abstraction, and a second, senior reviewer checked its accuracy. The reviewers were not blinded to the identity of the article authors, institutions, or journal. Definitions for medication errors and related terms were often inconsistently used. To make data abstraction easier, we established working definitions, which can be found in Appendix F of the full report. Meta-analysis was not performed on any data because of the heterogeneity of the studies in terms of interventions, populations, technologies used, and outcomes measured, as well as the presence of mostly descriptive and observational studies. After duplicates were removed, 32,785 articles were screened at title and abstract stage.
Rinse millet in vitamin C water before cooking purchase lady era 100 mg free shipping, or add vitamin C to the cooking water cheap lady era 100mg without a prescription. Elderly people are more easily poisoned than others; their hemorrhages show up as strokes and purple blotches on the skin quality 100 mg lady era. It is particularly hazardous since the mold that produces it can actually grow in your intestine in patches. Mix it with home made preserves, honey, marmalade, not very homogene- ously so the bright colors and individual flavors stand out in contrast. Having three or four such spreads in the refrigerator will give your children the right perspective on food— homemade is better. Store bought jams are sweeter and brighter in color but strangely low in flavor and often indistinguishable from each other. Let your children eat the polluted foods that friends and restaurants serve (but not rare-cooked meats) so they can experience the difference. Although I used to recommend single herb teas (tea mixtures have solvents), I can now only recommend single herb teas from fresh sources in bulk (see Sources). This also gets you away from the benzalkonium chloride and possibly other antiseptics in the bag itself. It comes as a surprise that pure, genuine maple syrup has the deadly aflatoxin and other molds. You can often see mold yourself, as a thin scum on the surface or an opaque spot on the inside of the glass after the syrup has stood some time, even in the refrigerator. In my testing, aflatoxin can be cleared with vitamin C but sterig and others need to be treated with a high temperature as well. Artificial maple flavor did not have benzene, propyl alcohol or wood alcohol, nor molds. Rolled oats never showed molds in my testing, although they have their characteristic fungi, too. As soon as you open a cereal grain, put the whole box in a plastic bag to keep moisture out. Anything that is put in the refrigerator or freezer and then taken out develops moisture inside. Simply sending inspectors out to look into the bins at grain elevators is not sufficient. Crusts of mold, sometimes several feet thick, that form on top of grain bins can be simply shoveled away before the inspector arrives. The humidity and temperature of stored grain should be regulated, requiring automated controls. This would soon be cost effective, too, in terms of reduced spoilage losses and higher quality prices earned. Getting Away From Grains In view of the many molds that are grain-related, and because these cannot be seen or smelled in pastas, breads, cold cereals, it would be wise to steer away from grain consumption. Always choose potatoes, because it is a vegetable instead of a grain, if you have a choice. Whereas grain was hulled, stored for quite a long time, perhaps degerminated (the bran and germ picks up Fig. Then it was mixed with assorted chemicals (fumigation, anti oxidants), each polluted in its own way, pack- aged again and stored again. But we can trick them into eating corn and soybeans by adding the flavors they like and thereby defeat their wisdom the same way we defeat ours. A concoction is made for them that is called “complete nutrition” and we feed this meal after meal, day after day, a most unnatural situation. The liver is deluged with the same set of pollutants time after time and never gets a rest. This gives the liver a chance to catch up with detoxifying one pollutant while the new one builds up. If the liver is absolutely unable to handle something, you are informed quite quickly with an allergic reaction to the food. Cats and dogs with their monolithic diet get no opportunity to reject food (except by vomiting or starvation). It is not surprising they are getting cancer with increasing frequency, a situation where the liver can no longer detoxify isopropyl alcohol, a common pollutant in their food. But what if they like and prefer their monolithic “scientific”, “complete”, polluted diet? All change should be brought about slowly and with kindness for animals and humans alike. After your pets have stopped eating propyl alcohol polluted food and are not getting propyl alcohol in their shampoos, there is no way they can get cancer. Whatever cancer they have will clear up by this change in diet and by giving them the pet parasite program. By selecting wise habits your improved lifestyle pays you back for the rest of your life. After using the bathroom and washing your hands, treat your fingernails with alcohol. Add ½ cup 95% alcohol to ½ cup cold tap water or buy plain vodka, 80 to 100 proof. Ask your pharmacist to make it from scratch for you (there are only two ingredients and water, see Recipes). In long-ago days, all sheets, towels, table cloths, and underwear were separated and boiled. With the convenience of our electric washing machine, we tend to overlook the fact that underwear is always contaminated by fecal matter and urogenital secretions and excretions. Lime water (calcium hydroxide) or iodine based antiseptics seem obviously simple methods to accomplish this. Besides, your skin absorbs it from clothing, it is quite toxic to you, and can cause mental effects. They do not clean quite as well as modern detergents, but there is less static cling, eliminating the need to put more chemicals in your dryer. Better Kitchen Habits Once a day, sterilize the sponge or cloth you use to wipe up the table, counter tops and sink. This little piece of contami- nated cloth is the most infectious thing in the house, besides the toilet. Sometimes it has a slight odor at first, which may warn you, but most pathogens do not have an odor! As we wipe up droplets of milk, we give the milk bacteria, Salmonellas and Shigellas, a new home to multiply and thrive in. The cloth or sponge recolonizes the kitchen and dining room table several times a day. No doubt, the last thing you do before leaving the kitchen is squeeze it dry with your hands. In two hours they are already multiplying in the greatest culture system of all: your body! To sterilize the sponge: drop it into a 50% solution of grain alcohol at the end of each day. Another way to sterilize the sponge or cloth is to microwave it, after wetting it, for 3 minutes. Another strategy is to use a fresh cloth or sponge each day, putting the used one to dry until laundry day. The counter and table top have on them whatever is in the kitchen dust and on the wipe cloth. Vacuuming sends up a hurricane of dust and distributes bathroom dust to the kitchen and kitchen dust to the bedrooms. So if one person has brought in a new infection, the whole family is exposed to it in hours via the dust. The newly contaminated dust drops into your ready and waiting glasses on the table and the open foods. Teach children to cough and sneeze into a suitable col- lecting place like a tissue, not their hands. If you must cough or sneeze and a tissue is not within reach fast enough, use your clothing! Never, never your hands unless you are free to immediately dash into the washroom and clean the contamination off your hands. Teach children this old rearranged verse: If you cough or sneeze or sniff Grab a tissue, quick-quick-quick! Better Housekeeping Throw out as much of the wall to wall carpeting as you can bear to part with. Modern shoes, with their deep treads, bring in huge amounts of outdoor filth which settles deep down into the carpets. When you see how much filth is in the water and realize how much dirt you were living with, you might be willing to trade in the “beauty” of carpets for the cleaner living of smooth floors. Cobalt, which adds “lustre” to carpets, causes skin and heart disease after it has built up in your organs. Nothing controls fleas reliably, except getting rid of the carpets and cloth furniture (keep pets out of bedrooms). Fleas and other vermin in the carpet simply crawl below the wetness level when you wash the carpet. Spraying a grain alco- hol solution with lemon peel in it (it needs to extract for a half hour) on the damp carpet will reach and kill a lot of these, to- gether with the residual bacteria. Molds and bacteria that grow right on the air conditioning unit get blown about for all to inhale. Never, never use fiberglass as a filter or to insulate your air conditioner around the sides.
Which measurement principle is employed in a Answers to Questions 52–57 vapor pressure osmometer? When sample is cooled to its dew point buy cheap lady era 100 mg on line, the Chemistry/Apply principles of special procedures/ voltage change across the thermocouple is directly Osmometry/1 proportional to osmolality buy generic lady era 100mg online. B Alcohol enters the vapor phase so rapidly that it vapor pressure osmometer in that only the freezing evaporates before the dew point of the sample is point osmometer: reached generic 100mg lady era overnight delivery. Requires a thermoelectric module alcohol and can be used in emergency department D. Requires calibration with aqueous standards settings to estimate ethanol toxicity. Te method for measuring iron or lead by plating mercury cathode by applying a negative charge. The the metal and then oxidizing it is called: voltage of this electrode is reversed until the plated A. C An isocratic separation uses a single mobile phase of Chemistry/Apply principles of special procedures/ constant composition, pH, and polarity, and requires Instrumentation/1 a single pump. Te term isocratic is used in high-performance mobile phase to increase distance between peaks. Mobile phase is at constant temperature using a controller to change the proportions of B. Mobile phase consists of a constant solvent using a nonpolar sorbent (stationary phase) such as composition octadecylsilane (C18). Most clinical Chemistry/Apply principles of special procedures/ separations of drugs, hormones, and metabolites High-performance liquid chromatography/1 use reverse phase because aqueous mobile phases 56. Organic and the stationary phase is aqueous the mobile phase and stationary phase is most D. A stronger solvent than the stationary phase important and depends upon solvent polarity, pH, Chemistry/Apply principles of special procedures/ and ionic strength. Cation exchange Chemistry/Apply principles of special procedures/ High-performance liquid chromatography/1 184 Chapter 5 | Clinical Chemistry 58. Termal conductance from a ﬂame is used to excite the analytes as they elute from the column. The ﬂame is made by igniting Chemistry/Apply principles of special procedures/ a mixture of hydrogen, carrier gas, and air. Current is Gas chromatography/1 produced when an outer shell electron is ejected 59. A The order of elution is dependent upon the velocity volatiles is usually based upon the: of the analyte. The Kd is the partition Chemistry/Apply principles of special procedures/ coeﬃcient, and is a measure of the relative aﬃnity Biochemical/2 of solutes for the stationary phase. The pK is the the solute migrates divided by the distance the negative logarithm of K, the ionization constant, and solvent migrates is the: is a measure of ionization. More than a High-performance liquid chromatography/1 90% of the drug will be nonionized and will extract in ethyl acetate or another organic solvent. Neutral solution of ethyl acetate Chemistry/Apply principles of special procedures/ Biochemical/2 5. A Internal standards should have the same aﬃnity as injection the analyte for the extraction reagents. To correct for background absorbance peak height (or area) of all samples (standards and C. To compensate for changes in ﬂow rate unknowns) by the peak height (or area) of the D. To correct for coelution of solutes internal standard reduces error caused by variation in extraction recovery and injection volume. What is the conﬁrmatory method for measuring substance has a unique and characteristic spectrum drugs of abuse? Cations can be formed by various Chemistry/Select instruments to perform test/Drugs of methods, the most common of which is electron abuse/2 bombardment (electron ionization). Cations caused by electron loss or proton a nitrogen laser causes transfer of a proton from the attachment matrix (an acid) to the protein. Chemistry/Deﬁne fundamental characteristics/ Instrumentation/1 186 Chapter 5 | Clinical Chemistry 68. Electrospray ionization uses a small-bore tube that forms a 1–4 μ nozzle at the mass Chemistry/Identify basic principle(s)/Mass spectroscopy/1 ﬁlter inlet and which is charged by several kilovolts. In mass spectroscopy, the term base peak typically The sample enters the tube along with inert drying refers to: gas. A natural isotope of the molecular ion reaches the nozzle, it becomes highly charged. Te ﬁrst peak to reach the mass detector size of the droplet is decreased owing to evaporation. Chemistry/Deﬁne fundamental characteristics/ This causes the charge density to become excessive, Instrumentation/1 and the droplets break apart. These particles are drawn into the for errors of amino and organic acid metabolism? Electrospray ionization tandem-mass parent or “molecular” ion, a process called soft spectroscopy ionization. B The base peak is typically the “molecular ion” or Chemistry/Select instruments to perform test/Newborn parent ion, meaning that it is the initial fragment screening/2 made by releasing an electron. The cation thus formed has a charge of +1, and therefore, its m/z ratio is equal to its mass. It is the most abundant and most stable ion, and gives the best sensitivity for quantitative analysis. C While two-dimensional thin-layer chromatography can separate both amino and organic acids, it is not suﬃciently sensitive for newborn screening. Electrospray ionization allows a small alcohol-extracted whole-blood sample to be analyzed by two mass spectrometers without prior separation by liquid or gas chromatography. Disorders of both organic and fatty acid metabolism are identiﬁed by the speciﬁc pattern of acylcarnitine ions produced. Amino acids are detected as amino species that have lost a carboxyl group during ionization, a process called neutral loss. In tandem-mass spectroscopy, the ﬁrst mass ﬁlter Answers to Questions 71–73 performs the same function as: A. Te vacuum system molecular or parent ions of interest by excluding ions outside a speciﬁed size range. Therefore, it eﬀectively Chemistry/Apply principles of special procedures/ separates the analyte(s) of interest from unwanted Instrumentation/1 compounds. Results of an Autotune test are drawn into a second mass ﬁlter where they are showed the appearance of a base peak at 16 with bombarded by argon atoms. Te carrier gas is contaminated The process can be repeated in a third mass ﬁlter C. Why is vacuum necessary in the mass ﬁlter of a acid, amino acid, and organic acid metabolism. It removes electrons from the ion source atmosphere also contains small quantities of two D. It prevents contamination isotopes with molecular weights of 17 and 18 owing to one and two extra neutrons, respectively. What method is used to introduce the sample into Answers to Questions 74–76 a mass spectrometer for analysis of a trace element? This is done by introducing the sample into a very hot plasma (6,000–10,000°K) called a torch. The Chemistry/Apply principles of special procedures/ torch is made by circulating argon through inner and Instrumentation/2 outer quartz tubes. Which component is needed for a thermal cycler coil of wire that receives a radio frequency. Sealed airtight constant-temperature chamber argon is ignited by a spark, it forms the plasma. Temperature-controlled ionization chamber sample is mixed with argon at the other end to create Chemistry/Deﬁne fundamental characteristics/ an aerosol. When it reaches the torch, the solvent is Instrumentation/1 evaporated and the energy from the torch and collisions with argon ions cause ejection of outer- 76. Annealing requires a Instrumentation/1 temperature between 40°C–65°C and allows the primers to bind to the target base sequence. Extension requires a temperature of 72°C and allows the heat-stable polymerase to add complementary bases to the primer in the 5’ to 3’ direction. Rapid heating and cooling is usually achieved using a thermoelectric block that is cooled by forced air ﬂow. They are used to correct the measurements from each well so that the same concentration of ﬂuorescent dye gives the same signal intensity regardless of the well. A line is drawn from the threshold value on the y-axis through the curve, and a perpendicular dropped to the x-axis. A The relative centrifugal force (number times the force of gravity) is proportional to the square of the rotor speed in revolutions per minute and the radius in centimeters of the head (distance from the shaft to A. B Electronic balances do not use substitution weights needed to calculate the relative centrifugal force or knife edges to balance the weight on the pan. Diameter of the centrifuge tube type of balance used, all need to be located on a D.
The origins of this reversal are many and complex: human behavior has changed generic lady era 100 mg mastercard, particularly in terms of mobility and nutrition generic 100mg lady era amex. Further contributory factors were the in- troduction of invasive and aggressive medical therapies purchase 100mg lady era with mastercard, neglect of estab- lished methods of infection control and, of course, the ability of pathogens to make full use of their specific genetic variability to adapt to changing con- ditions. The upshot is that physicians in particular, as well as other medical professionals and staff, urgently require a basic knowledge of the pathogens involved and the genesis of infectious diseases if they are to respond effec- tively to this dynamism in the field of infectiology. Prokaryotic and Eukaryotic Microorganisms According to a proposal by Woese that has been gaining general acceptance in recent years, the world of living things is classified in the three domains bac- teria, archaea, and eucarya. In this system, each domain is subdivided into Kayser, Medical Microbiology © 2005 Thieme All rights reserved. This domain includes the kingdom of the heterotrophic eubacteria and includes all human pathogen bacteria. The other kingdoms, for instance that of the photosynthetic cyanobacteria, are notpathogenic. It is estimated that bacterial spe- cies on Earth number in the hundreds of thousands, of which only about 5500 have been discovered and described in detail. This domain includes forms that live under extreme environmental con- ditions, including thermophilic, hyperthermophilic, halophilic, and methanogenic microorganisms. The earlier term for the archaea was archaebacteria (ancient bac- teria), and they are indeed a kind of living fossil. Thermophilic archaea thrive mainly in warm, moist biotopes such as the hot springs at the top of geothermal vents. The hyperthermophilic archaea, a more recent discovery, live near deep-sea volcanic plumes at temperatures exceeding 1008C. The plant and animal kingdoms (animales and plantales) are all eukaryotic life forms. These organisms are obligate intracellular parasites that are able to reproduce in certain human cells only and are found in two stages: the infectious, nonreproductive particles called elementary bodies (0. These organisms are obligate intracellular parasites, rod- shaped to coccoid, that reproduce by binary transverse fission. Theyare found in a wide variety of forms, the most common being the coccoid cell (0. Fungi (Mycophyta) are nonmotile eukaryotes with rigid cell walls and a classic cell nucleus. They contain no photosynthetic pigments and are carbon heterotrophic, that is, they utilize various organic nutrient substrates (in contrast to carbon autotrophic plants). Of more than 50 000 fungal spe- cies, only about 300 are known to be human pathogens. Protozoa are microorganisms in various sizes and forms that may be free-living or parasitic. They possess a nucleus containing chromo- somes and organelles such as mitochondria (lacking in some cases), an en- Kayser, Medical Microbiology © 2005 Thieme All rights reserved. Host–Pathogen Interactions 7 doplasmic reticulum, pseudopods, flagella, cilia, kinetoplasts, etc. Many para- sitic protozoa are transmitted by arthropods, whereby multiplication and 1 transformation into the infectious stage take place in the vector. Medically signif- icant groups include the trematodes (flukes or flatworms), cestodes (tape- worms), and nematodes (roundworms). These animals are characterized by an external chitin skele- ton, segmented bodies, jointed legs, special mouthparts, and other specific features. Their role as direct causative agents of diseases is a minor one (mites, for instance, cause scabies) as compared to their role as vectors trans- mitting viruses, bacteria, protozoa, and helminths. Host–Pathogen Interactions & The factors determining the genesis, clinical picture and outcome of an infection include complex relationships between the host and invading or- ganisms that differ widely depending on the pathogen involved. Despite this variability, a number of general principles apply to the interactions be- tween the invading pathogen with its aggression factors and the host with its defenses. Since the pathogenesis of bacterial infectious diseases has been re- searched very thoroughly, the following summary is based on the host–in- vader interactions seen in this type of infection. The determinants of bacterial pathogenicity and virulence can be outlined as follows: & Adhesion to host cells (adhesins). The above bacterial pathogenicity factors are confronted by the following host defense mechanisms: & Nonspecific defenses including mechanical, humoral, and cellular sys- tems. The response of these defenses to infection thus involves the correlation of a number of different mechanisms. Primary, innate defects are rare, whereas acquired, sec- ondary immune defects occur frequently, paving the way for infections by microorganisms known as “facultative pathogens” (opportunists). The terms pathogenicity and virulence are not clearly defined in their relevance to microorganisms. It has been proposed that pathogenicity be used to characterize a particular species and that virulence be used to describe the sum of the disease-causing properties of a population (strain) of a pathogenic species (Fig. Determinants of Bacterial Pathogenicity and Virulence Relatively little is known about the factors determining the pathogenicity and virulence of microorganisms, and most of what we do know concerns the disease-causing mechanisms of bacteria. Host–Pathogen Interactions 11 Virulence, Pathogenicity, Susceptibility, Disposition 1 virulent strain avirulent type or var (e. The terms disposi- tion and resistance are used to characterize the status of individuals of a suscep- tible host species. There are five groups of potential bacterial contributors to the pathogen- esis of infectious diseases: 1. Adhesion When pathogenic bacteria come into contact with intact human surface tis- sues (e. This is a specific process, meaning that the adhesion structure (or ligand) and the receptor must fit together like a key in a keyhole. Bacteria may invade a host passively through microtraumata or macrotraumata in the skin or mucosa. On the other hand, bacteria that invade through intact mucosa first adhere to this anatomical barrier, then actively breach it. Different bacterial species deploy a variety of mechanisms to reach this end: — Production of tissue-damaging exoenzymes that destroy anatomical bar- riers. Bacteria translocated into the intracellular space by endocytosis cause actin to condense into filaments, which then array at one end of the bacterium and push up against the inner side of the cell membrane. This is followed by fusion with the membrane of the neighboring tissue cell, whereupon the bacterium enters the new cell (typical of Listeria and Shigella). Strategies against Nonspecific Immunity Establishment of a bacterial infection in a host presupposes the capacity of the invaders to overcome the host’s nonspecific immune defenses. The most important mechanisms used by pathogenic bacteria are: Kayser, Medical Microbiology © 2005 Thieme All rights reserved. Capsule components may 1 block alternative activation of complement so that C3b is lacking (ligand for C3b receptor of phagocytes) on the surface of encapsulated bacteria. Microorganisms that use this strategy include Streptococcus pneumoniae and Haemophilus influenzae. A lipopolysaccharide in the outer membrane is modified in such a way that it cannot initiate alternative activation of the complement system. As a result, the membrane attack complex (C5b6789), which would otherwise lyse holes in the outer membrane, is no longer produced (see p. They complex with iron, thereby stealing this element from proteins containing iron (transferrin, lactoferrin). The intricate iron transport system is localized in the cytoplasmic membrane, and in Gram- negative bacteria in the outer membrane as well. The free availability of only about 10–20 mol/l iron in human body fluids thus presents a challenge to them. At this stage of development, the immune system is un- able to recognize bacterial immunogens as foreign. Molecular mimicry refers to the presence of molecules on the surface of bacteria that are not recognized as foreign by the im- mune system. Examples of this strategy are the hyaluronic acid capsule of Streptococcus pyogenes or the neuraminic acid capsule of Escherichia coli K1 and serotype B Neisseria meningitidis. Mucosal immunity to gonococci depends on antibodies in the secretions of the urogenital mucosa that attach to the immunodominant seg- ment of the pilin, thus blocking adhesion of gonococci to the target cells. The gonococcal genome has many other pil genes besides the pilE without promoters, i. Intracellular homologous recombination of conserved regions of silent pil genes and corre- sponding sequences of the expressed gene results in pilE genes with changed cas- settes. Some bacteria are characterized by a pronounced variability of their immunogens (= immune antigens) due to the genetic variability of the structural genes coding the antigen proteins. This results in production of a series of antigen variants in the course of an infection that no longer “match” with the antibodies to the “old” antigen. Examples: gonococci can modify the primary structure of the pilin of their attachment Kayser, Medical Microbiology © 2005 Thieme All rights reserved. The borreliae that cause relapsing fevers have the capacity to change the structure of one of the adhesion proteins in their outer 1 membrane (vmp = variable major protein), resulting in the typical “recur- rences” of fever. Similarly, meningococci can change the chemistry of their capsule polysaccharides (“capsule switching”). Mucosal secretions contain the secretory antibodies of the sIgA1 class responsible for the specific local immunity of the mucosa. Classic mucosal parasites such as gonococci, meningococci and Haemophilus influ- enzae produce proteases that destroy this immunoglobulin. Clinical Disease The clinical symptoms of a bacterial infection arise from the effects of dama- ging noxae produced by the bacteria as well as from excessive host immune responses, both nonspecific and specific.
Fracture of the scaphoid is another injury that occurs as a result of a fall onto an outstretched hand cheap lady era 100 mg free shipping. However purchase lady era 100 mg on line, the patient tends to have ten- derness in the anatomic snuffbox to palpation buy lady era 100mg with amex. If a scaphoid fracture is suspected, radiographs should be inspected carefully, since up to 20% of these injuries are not diagnosed at the initial evaluation. If the clinical examination is consistent with a scaphoid fracture and the initial radiographs do not demonstrate a fracture, the patient should be immobilized in a thumb spica splint and follow-up should be arranged, since radiographic evidence of the injury may not be present until 2 to 3 weeks after the injury. This injury does have a high incidence of nonunion, especially if the injury is not immobilized in the early stages or if there is displacement of the fracture. A fracture of the ﬁfth metacarpal neck is referred to as a boxer’s fracture and usually occurs as a result of the patient’s striking a hard object with a clenched ﬁst. This particular injury should be inspected carefully for a laceration over the head of the metacarpal. The laceration can be the result of the clenched ﬁst hitting the tooth of another person. Consequently, this par- ticular injury is at signiﬁcant risk for infection and requires thorough 33. This injury presents with apex dorsal angulation at the level of the metacarpal neck distally, and this almost always can be successfully reduced and held in good position with cast immobilization. In the poste- rior aspect, the sacrum, which contains the distal spinal nerve roots, articulates with the ilium on either side. The hip joint is formed by the articulation between the head of the proximal femur and the acetabulum. In con- trast to the “ball and socket” joint of the shoulder, the round head of the femur is well contained in the deep socket of the acetabulum. In sports events, high-energy direct blows to the anterior thigh can lead to quadriceps contusions and hematomas. This particular injury can be very painful and lead to a very tense-appearing thigh. The size of the hematoma formation can be controlled by early splinting of the leg with the knee held in hyperﬂexion, putting the quadriceps muscle on stretch. Since myositis ossiﬁcans at the site of the quadriceps injury is a troublesome sequela, minimizing the size of the hematoma formation is beneﬁcial. Another sports-related injury that often has a dramatic presentation is avulsion of the sartorius muscle from the anterosuperior iliac spine or avulsion of the rectus femoris from the anteroinferior iliac spine. In either of these injuries, patients report feeling a pop in their hip and present with signiﬁcant pain with ambulation. However, palpation over the appropriate iliac spine helps diagnose the site of the injury. Dislocations of the hip joint usually are caused by high-energy trauma, such as a motor vehicle accident or a fall from a height, although they can occur in sporting injuries. The most common dis- location is a posterior dislocation of the femoral head from the acetabulum. In this case, the patient presents with the hip ﬂexed, adducted, and internally rotated. When the dislocation is anterior, the patient presents with the hip held in abduction, ﬂexion, and external rotation. Prior to reduction, a neurovascular examination should be performed with attention paid to sciatic nerve function, since this nerve can be injured, especially with posterior dislocations. Radiographs should be evaluated for other associated injuries, such as acetabular wall fractures, femoral head fractures, or fractures of the femur. Reduction of hip dislocation usually requires some form of sedation, followed by application of longitudinal traction in line with the defor- mity. Once reduced, a repeat neurologic examination should be per- formed, again paying attention to the function of the sciatic nerve. Avascular necrosis of the femoral head can occur in up to 40% of patients who sustain dislocations of the hip and may present as late as 18 months after the injury. Protection from early weight bearing has not been shown to change the incidence of avascular necrosis. Low-energy fractures of the pelvis occur commonly as a result of a fall in elderly patients. Fractures usually occur through the superior or inferior pubic ramus, and patients present complaining with groin pain and painful ambulation. However, in cases of signiﬁcant osteoporosis with minimal displacement, the fracture can be difﬁcult to detect, and a bone scan may be necessary to conﬁrm the diagnosis. Most notable is the “open-book” fracture of the pelvis as a result of anterior-posterior compression of the pelvis (Fig. In this case, the pubic symphysis is disrupted, allowing the opening of the pelvic ring anteriorly, and, in the posterior aspect of the pelvic ring, the sacroiliac joint usually is disrupted. As a consequence, the venous plexus that lies anterior to the sacroiliac joint is damaged, and excessive bleeding can occur. Since the pelvis volume is increased as a result of the pubic symphysis diastasis, signiﬁcant blood loss can occur. Physical examination demonstrates the instabil- ity of the pelvis as obvious motion is detected with compression of the iliac wings together. The situation can be temporized in the emergency room setting either with straps or percutaneous tongs. Once cleared, the patient should be brought to the operating room for application of an external ﬁxator that closes down the pelvis and prevents excessive Figure 33. This can be a lifesaving procedure and should not be delayed unless absolutely necessary. High-energy lateral compression injuries to the pelvis also result either in disruption of the pubic sym- physis of the pubic rami on the anterior aspect of the pelvis and dis- ruption of the sacroiliac joint or a crush injury of the sacral body on the posterior aspect of the pelvis. Although blood loss is expected with this injury, the pelvic volume is not expanding, and, consequently, urgent stabilization of the pelvis rarely is required. Fractures of the hip are divided into two categories: intracapsular and extracapsular. In elderly patients, a fracture of the femoral neck can result in an impacted valgus position of the fracture fragments, and this is treated routinely with screw ﬁxation. When a fracture of the femoral neck is displaced, the blood supply to the femoral head usually is disrupted, and there is a signiﬁcant risk of avascular necrosis of the femoral head. Consequently, many of these injuries are treated with primary hemi- arthroplasty in the elderly patient. However, in the younger patient, a displaced femoral neck fracture should be treated with more aggres- sive attempts to achieve a reduction of the fracture to a near-anatomic position and ﬁxation with screws. Extracapsular or peritrochanteric fractures of the femur can result in signiﬁcant blood loss into the thigh. This needs to be recognized, especially in the elderly patient with a low cardiac reserve. These injuries generally require surgical treatment with screw and side plate ﬁxation or intermedullary ﬁxation. Fractures in the intertrochanteric region heal readily while fractures to the sub- trochanteric region of the femur have a much higher signiﬁcance of nonunion and hardware failure. In cases of peritrochanteric fractures of the hip, avascular necrosis is not a concern. Fractures of the femoral shaft are the result of high-energy injuries, such as motor vehicle accidents or falls from a signiﬁcant height. Phys- ical examination of the thigh should be thorough to be sure that there is not an open wound associated with the femoral shaft fracture. These injuries require surgical ﬁxation, and this usually is done in an inter- medullary fashion. Knee and Lower Leg The osseous anatomy of the knee consists of the distal femur, the prox- imal tibia, and the proximal ﬁbula. This often is considered a hinged joint, although rotations do occur about the longitudinal axis and in the coronal plane. The proximal ﬁbula articulates with the proximal tibia, but this occurs distal to the femorotibial articulation. Its deep surface is covered with artic- ular cartilage, and the patella articulates with the femur. The primary role of the patella is to increase the length of the extensor moment arm. Since very little muscle tissue overlies the knee joint, muscle contu- sions are not common. In general, signiﬁcant contusions tend to occur in the posterior aspect of the lower leg as a result of direct blows to the gastrosoleus complex. These injuries can lead to signiﬁcant swelling, and neurovascular status should be assessed in association with these injuries. The most dramatic muscle injuries around the knee are disruptions of the extensor mechanism. In the younger population, patellar tendon ruptures can occur while jumping or while landing from a jump. These injuries present with a high-riding patella, referred to as patella alta, and a palpable defect at the inferior pole of the patella. The majority of these injuries are avulsions of the patellar tendon from the distal pole of the patella. Ruptures of the quadriceps tendon tend to occur in the middle-aged and elderly population. These often are low- energy injuries and can occur with an activity as simple as ascending or descending the stairs. In these cases, the patient presents with a swollen knee, a low-riding patella referred to as patella baja, and a pal- pable defect at the superior pole of the patella.
To earn that trust order lady era 100mg with visa, surgeons must be well trained buy lady era 100mg without prescription, exhibit good judgment generic lady era 100 mg online, understand the limitations of their patients based on their comorbidities, and understand the limitations of their own ability. Development and validation of a multifactorial risk index for predicting postoperative pneumonia after major noncardiac surgery. Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). History of present illness: Three days ago, when lifting a very large pine tree that blew over in a recent windstorm, the patient felt a sudden pain in his left groin. The acute pain resolved, but he continues to feel a “dragging” sensation in same area. Review of systems: Noncontributory: • Gastrointestinal: Denies change in bowel habits; no history of con- stipation; no hematochezia; no nausea and vomiting. Nackman Pertinent social/family history: Non–union worker who loads and unloads delivery trucks. Upon standing, a bulge observed in left inguinal region: no erythema, nontender, easily reduced. The Relevance of Evidence-Based Medicine Many of the issues involved in the care of patients include “age-old” traditions that may be based on empiricism. Until several decades ago, drainage of the gall- bladder bed following cholecystectomy was the standard of care and was based on the belief that drainage of the affected area would promote healing and reduce postoperative complications. Through the 1970s, students and residents heard from their instructors and super- visors: “This is how my mentor taught me to drain the gallbladder bed, so you should do it this way, too. Even though the traditional dogma had been rebuked by demonstrating no need for routine drainage, the clinical practice took decades to change. A signiﬁcant challenge in medicine is to maintain the learning process throughout one’s career, to keep current with the most recent evidence and practice guidelines, to understand the science behind the evidence and the guidelines, and thereby to continue providing optimal patient care. Even seasoned clinicians, when faced with the need to make a complex clinical decision, ask: “What are the practice guidelines for treating patients with this disease? It is important to understand the studies that resulted in the practice guidelines and the implications of these ﬁndings for your speciﬁc patient. Remaining current with important developments and thoughtfully integrating new information into your patient’s care are essential elements of the practice of surgery, whether one is a student, resident, or an experi- enced attending physician. Evidence-based medicine is the purpose- ful integration of the most recent, best evidence into the daily practice of medicine (See Algorithm 2. The practice of evidence-based medicine means integrating individual clinical expertise with the best avail- able clinical evidence from systematic research. Practicing Evidence-Based Surgery 21 Begin Here: Proceed Determine to Next Diagnosis Patient Problem Provide Care of Review Estimate Highest Quality the Prognosis Evidence Determine Decide Harm Best Therapy Algorithm 2. Without clinical expertise, practice risks becoming tyrannized by external evidence, for even excellent external evidence may be inapplicable to or inappropriate for an individual patient. Without current best external evidence, practice risks becoming rapidly out of date, to the detriment of the patients. Further, “best evidence” refers to the data and the conclusions derived from systematic research, such as infor- mation provided through the Cochrane Library (http://www. However, current best evidence must be integrated with clinical acumen (derived from experience, expert opinion, and anecdotal evidence) and with the preferences and values of the patient. Nackman Patients with a similar disease process may vary in their presenta- tion and in their response to treatment. Therefore, it is essential to realize that, even with the best evidence, the application of that evi- dence must be considered in the context of the unique attributes of each patient. Further, patient autonomy, as expressed in differences in expec- tations and preferences, must be considered when developing a patient management plan. First, a common characteristic of physicians is their desire and obligation to provide optimal care for their patients and, as much as is possible, to facilitate the patients’ return to their previous state of health. Since optimal medical care for patients changes over time with progress in technology and improved understanding of patient outcomes, it is necessary to have the tools that ensure your ability to remain current. Evidence-based medicine provides a framework to allow the physician lifelong learning opportunities. Second, today’s patients are better educated and often seek a collab- orative relationship with their physician. Current knowledge and critical appraisal of the professional literature is a vital component of your skill set as a physician. Through critical appraisal of the literature, you can provide the appropriate context for the information obtained by patients. Your clinical acumen, combined with your knowledge of the scientiﬁc method and levels of evidence, allows you to respond pro- fessionally and meaningfully to your patient’s questions about his or her care. Third, physicians must play an increasingly high-proﬁle role in the development of public policy. The best evidence and an understand- ing of why it is the best are necessary if medicine, as a profession, is going to be the ﬁnal arbiter of its practice. The Practice of Evidence-Based Surgery The practice of evidence-based surgery integrates the art of surgery (well-honed clinical acumen, “good hands,” and interpersonal aware- ness) with use of the best information provided by contemporary science. The clinical problem, not the physician’s habits or institutional protocols, should determine the type of evidence to be sought. It has been recognized that “clinical pathways” or “optimaps” aid in the care of patients, streamlining cost-effective care. The correct application of the evidence-based approach to patient care demands that, in follow- ing clinical protocols, one always must be mindful that the quality of the evidence being used to develop a treatment plan meets the speciﬁc needs of the individual patient. Clinical decision making should be based on the clinical data obtained by the practitioner and application of the best available scientiﬁc evidence. Data obtained from conducting a history and physical examination provide the foundation for clinical decision making. Clinical decision making is the result of applying the best that science and clinical acumen have to offer in the unique context of the individual patient. It frequently has been stated that the literature is complex and often contradictory. The challenge is for the physician to be able to judge the validity of a study and the applicability of the ﬁndings for guiding the care of the speciﬁc patient. Identifying the best evidence refers to reading the literature critically with a basic understanding of epidemiologic and biostatistical methods. Without an understand- ing of the basic concepts of research design and statistics, one is unable to critically review the relevance and validity of a study. Conclusions derived from identifying and critically appraising evidence are useful only if they are put into the context of the indi- vidual patient’s needs and then put into action in managing patients or making healthcare decisions. Physicians need to be able to obtain meaningful information in real time to improve clinical decision making. It is important to monitor the outcome of your care and communicate with colleagues the success and failures of treatment, as demonstrated in the classic morbidity and mortality conference. Understanding the relationship between care and outcomes has been the hallmark of surgical care since the days of Billroth in the 19th century. Being accountable for one’s actions and taking action to eliminate untoward outcomes are hallmarks of the excellent surgeon. The practice of evidence-based surgery begins with gathering data to understand what brings the patient to the surgeon’s ofﬁce. As with the traditional practice of surgery, it is necessary to ask meaningful questions about the patient’s problem. The answers to the questions are obtained from a focused history and physical examination of the patient. The information that is obtained is organized into a differen- tial diagnosis list. The process of asking questions then shifts from posing questions designed to elicit accurate data about the patient to posing questions about the available evidence regarding how to best care for the patient. This additional step of systematically obtaining relevant, current, scientiﬁc evidence to guide clinical decision making is what differentiates evidence-based practice from tradi- tional practice. How to Use the Current Best Evidence The most effective way of using evidence to provide clinical care is with a “bottom-up” “approach. Nackman posing of relevant questions and the obtaining of useful information to better characterize the patient’s problem. The questions posed in the process of clinical decision making are answered by using the best evidence available. For example, a properly randomized controlled trial is rated as more scientiﬁc and, therefore, as more reliable and valid than clinical wisdom and acumen or published expert opinion. Finally, the question is put into context by integrating the best external evi- dence with individual clinical expertise and patient choice. Study designs also include less rigorous experimental designs and quasi-experimental designs, such as case series, case-control studies, and cohort studies. Quasi-experimental methods, meta-analyses, outcome studies, and practice guidelines provide an overall assessment of a topic by analyzing multiple studies that used various research designs. The study designs and the elements of randomized controlled trials are summarized in Tables 2. The levels of evidence refer to a grading system for assessing medical studies by classifying them according to the scientiﬁc rigor or the quality of the evidence (outcomes). The levels of evidence are ordered to give the best rating to studies in which the risk of bias is reduced, as reﬂected by the a priori design of the study (its scientiﬁc rigor) and the actual quality of the study. In addition to reviewing the outcomes of speciﬁc, randomized, clin- ical trials, systematic reviews, meta-analyses, and practice guidelines can be extremely useful in dealing with speciﬁc patient problems or in updating of knowledge. Systematic reviews follow a deﬁned protocol for the purpose of integrating the results of multiple studies when methodologic differences preclude conducting a meta-analysis. Guide- lines for evaluating the quality of systematic reviews are presented in Table 2. Nackman A review conducted using the meta-analysis process differs from the typical techniques used in the creation of a review article.