Friday, 25 May 2012

Cigarette Smoking

Cigarette smoking

Cigarette smoking remains the most important cause of preventable morbidity and early mortality. In 2000, there were an estimated 4.8 million premature deaths in the world attributable to smoking, 2.4 million in developing countries and 2 million in industrialized countries. More than three-quarters (3.8 million) of these deaths were in men. The leading causes of death from smoking were cardiovascular diseases (1.7 million deaths), chronic obstructive pulmonary disease (COPD) (1 million deaths), and lung cancer (0.9 million deaths). Nicotine is highly addictive, raises brain levels of dopamine, and produces withdrawal symptoms on discontinuation. Cigar smoking has also increased; there is also continued use of smokeless tobacco (chewing tobacco and snuff), particularly among young people. Tobacco dependence may have a genetic component.

Cigarettes are responsible for one in every five deaths in the United States, yet smoking prevalence rates have been increasing among high school and college students. Currently, 23% of US adults and 26% of US young adults are smokers.

Smokers have twice the risk of fatal heart disease, 10 times the risk of lung cancer, and several times the risk of cancers of the mouth, throat, esophagus, pancreas, kidney, bladder, and cervix; a twofold to threefold higher incidence of stroke and peptic ulcers (which heal less well than in nonsmokers); a twofold to fourfold greater risk of fractures of the hip, wrist, and vertebrae; four times the risk of invasive pneumococcal disease; and a twofold increase in cataracts. In the United States, over 90% of cases of COPD occur among current or former smokers. Both active smoking and passive smoking are associated with deterioration of the elastic properties of the aorta (increasing the risk of aortic aneurysm) and with progression of carotid artery atherosclerosis. Smoking has also been associated with increased risks of leukemia, of colon and prostate cancers, of breast cancer among postmenopausal women who are slow acetylators of N-acetyltransferase-2 enzymes, osteoporosis, and Alzheimer's disease. In cancers of the head and neck, lung, esophagus, and bladder, smoking is linked to mutations of the P53 gene, the most common genetic change in human cancer. Patients with head and neck cancer who continue to smoke during radiation therapy have lower rates of response than those who do not smoke. Olfaction and taste are impaired in smokers, and facial wrinkles are increased. Heavy smokers have a 2.5 greater risk of age-related macular degeneration. Smokers die 5–8 years earlier than never-smokers.

The children of smokers have lower birth weights, are more likely to be mentally retarded, have more frequent respiratory infections and less efficient pulmonary function, have a higher incidence of chronic ear infections than children of nonsmokers, and are more likely to become smokers themselves.

In addition, exposure to environmental tobacco smoke has been shown to increase the risk of cervical cancer, lung cancer, invasive pneumococcal disease, and heart disease; to promote endothelial damage and platelet aggregation; and to increase urinary excretion of tobacco-specific lung carcinogens. The incidence of breast cancer may be increased as well. Of approximately 450,000 smoking-related deaths in the United States annually, as many as 53,000 are attributable to environmental tobacco smoke.

Smoking cessation reduces the risks of death and of myocardial infarction in people with coronary artery disease; reduces the rate of death and acute myocardial infarction in patients who have undergone percutaneous coronary revascularization; lessens the risk of stroke; slows the rate of progression of carotid atherosclerosis; and is associated with improvement of COPD symptoms. On average, women smokers who quit smoking by age 35 add about 3 years to their life expectancy, and men add more than 2 years to theirs. Smoking cessation can increase life expectancy even for those who stop after the age of 65.
Although tobacco use constitutes the most serious common medical problem, it is undertreated. Almost 40% of smokers attempt to quit each year, but only 4% are successful. Factors associated with successful cessation include having a rule against smoking in the home, being older, and having greater education. Persons whose physicians advise them to quit are 1.6 times as likely to attempt quitting. Over 70% of smokers see a physician each year, but only 20% of them receive any medical quitting advice or assistance.

Several effective interventions are available to promote smoking cessation, including counseling, pharmacotherapy, and combinations of the two. The five steps for helping smokers quit are summarized in Table 1–3. Common elements of supportive smoking cessation treatments are reviewed in Table 1–4. A system should be implemented to identify smokers, and advice to quit should be tailored to the patient's level of readiness to change. Pharmacotherapy to reduce cigarette consumption is ineffective in smokers who are unwilling or not ready to quit. Conversely, all patients trying to quit should be offered pharmacotherapy except those with medical contraindications, women who are pregnant or breast-feeding, and adolescents.

 Actions and strategies for the primary care clinician to help patients quit smoking.
Action Strategies for Implementation
Step 1. Ask—Systematically Identify All Tobacco Users at Every Visit 
Implement an officewide system that ensures that for every patient at every clinic visit, tobacco-use status is queried and documented1
Expand the vital signs to include tobacco use.
  Data should be collected by the health care team.
  The action should be implemented using preprinted progress note paper that includes the expanded vital signs, a vital signs stamp or, for computerized records, an item assessing tobacco-use status.
Alternatives to the vital signs stamp are to place tobacco-use status stickers on all patients' charts or to indicate smoking status using computerized reminder systems.
Step 2. Advise—Strongly Urge All Smokers to Quit 
In a clear, strong, and personalized manner, urge every smoker to quit  Advice should be
  Clear:"I think it is important for you to quit smoking now, and I will help you. Cutting down while you are ill is not enough." 
  Strong:"As your clinician, I need you to know that quitting smoking is the most important thing you can do to protect your current and future health." 
   Personalized: Tie smoking to current health or illness and/or the social and economic costs of tobacco use, motivational level/readiness to quit, and the impact of smoking on children and others in the household.  
Encourage clinic staff to reinforce the cessation message and support the patient's quit attempt.
Step 3. Attempt—Identify Smokers Willing to Make a Quit Attempt 
Ask every smoker if he or she is willing to make a quit attempt at this time If the patient is willing to make a quit attempt at this time, provide assistance (see step 4).
If the patient prefers a more intensive treatment or the clinician believes more intensive treatment is appropriate, refer the patient to interventions administered by a smoking cessation specialist and follow up with him or her regarding quitting (see step 5).
If the patient clearly states he or she is not willing to make a quit attempt at this time, provide a motivational intervention.
Step 4. Assist—Aid the Patient in Quitting 
A. Help the patient with a quit plan Set a quit date. Ideally, the quit date should be within 2 weeks, taking patient preference into account.  
Help the patient prepare for quitting. The patient must:  
  Inform family, friends, and coworkers of quitting and request understanding and support.  
  Prepare the environment by removing cigarettes from it. Prior to quitting, the patient should avoid smoking in places where he or she spends a lot of time (eg, home, car).  
  Review previous quit attempts. What helped? What led to relapse?  
  Anticipate challenges to the planned quit attempt, particularly during the critical first few weeks.  
B. Encourage nicotine replacement therapy except in special circumstances Encourage the use of the nicotine patch or nicotine gum therapy for smoking cessation (see Table 1–5, Table 1–6, and Table 1–7 for specific instructions and precautions).
C. Give key advice on successful quitting Abstinence: Total abstinence is essential. Not even a single puff after the quit date.  
Alcohol: Drinking alcohol is highly associated with relapse. Those who stop smoking should review their alcohol use and consider limiting or abstaining from alcohol use during the quit process.  
Other smokers in the household: The presence of other smokers in the household, particularly a spouse, is associated with lower success rates. Patients should consider quitting with their significant others and/or developing specific plans to maintain abstinence in a household where others still smoke.  
D. Provide supplementary materials Source: Federal agencies, including the National Cancer Institute and the Agency for Health Care Policy and Research; nonprofit agencies (American Cancer Society, American Lung Association, American Heart Association); or local or state health departments. 
Selection concerns: The material must be culturally, racially, educationally, and age appropriate for the patient.  
Location: Readily available in every clinic office. 
Step 5. Arrange—Schedule Follow-Up Contact 
Schedule follow-up contact, either in person or via telephone1
Timing: Follow-up contact should occur soon after the quit date, preferably during the first week. A second follow-up contact is recommended within the first month. Schedule further follow-up contacts as indicated. 
Actions during follow-up: Congratulate success. If smoking occurred, review the circumstances and elicit recommitment to total abstinence. Remind the patient that a lapse can be used as a learning experience and is not a sign of failure. Identify the problems already encountered and anticipate challenges in the immediate future. Assess nicotine replacement therapy use and problems. Consider referral to a more intense or specialized program.

Thursday, 17 May 2012

Abdominal Aortic Aneurysm

Abdominal Aortic Aneurysm : 
Screening  for abdominal aortic aneurysm in men aged 65-75 years is associated with a significant reduction in condition-specific mortality (odds ratio, 0.57 [95% CI, 0.45 to 0.74]). This benefit is sustained through 7 years of followup. Women do not appear to benefit, and the most of the benefit in men appears to accrue among current or former smokers.

Friday, 11 May 2012

Cardiovascular Disease prevention

Cardiovascular Disease :
Cardiovascular diseases, including coronary heart disease (CHD) and stroke, represent two of the most important causes of morbidity and mortality in developed countries.

Several risk factors increase the risk for coronary disease and stroke. They can be divided into those that are modifiable (eg, lipid disorders, hypertension, cigarette smoking) and those that are not (eg, gender, age, family history of early coronary disease). This section considers the role of screening for and treating modifiable risk factors.

Impressive declines in age-specific mortality rates from heart disease and stroke have been achieved in all age groups in North America during the past 2 decades. The chief reasons for this favorable trend appear to be modification of risk factors, especially cigarette smoking and hypercholesterolemia, plus more aggressive detection and treatment of hypertension and better care for patients with heart disease. African-Americans appear to have a greater proportion of risk attributable to these key risk factors, suggesting that focusing on better control could help reduce disparities in health outcomes.

Sunday, 6 May 2012

Infectious Disease Prevention

Infectious Disease :

Much of the decline in the incidence and fatality rates of infectious diseases is attributable to public health measures—especially immunization, improved sanitation, and better nutrition.
Immunization remains the best means of preventing many infectious diseases. In the United States, childhood immunization has resulted in near elimination of measles, mumps, rubella, poliomyelitis, diphtheria, pertussis, and tetanus. Haemophilus influenzae type b invasive disease has been reduced by more than 9500 since the introduction of the first conjugate vaccines.
However, substantial vaccine-preventable morbidity and mortality continue to occur among adults from vac-cine-preventable diseases, such as hepatitis A, hepatitis B, influenza, and pneumococcal infections. For example, in adults in the United States, there are an estimated 50,000– 70,000 deaths annually from influenza, hepatitis B, and nVasiVe pneumococcal disease. Influenza vaccination is recommended for adults age 50 and older, and it has been documented that annual influenza immunization with Inactivated vaccine (administered intramuscularly) pre¬vents cardiovascular morbidity and all-cause mortality in persons with coronary and other atherosclerotic vascular disease. Rates of influenza vaccination have increased. Self- reported rates of influenza vaccine coverage in adults older than 65 years increased from 300o in 1989 to 70% in 2004. However, vaccination rates were higher for non-Hispanic whites compared with other ethnic minority groups.
The American College of Physicians recommends that clinicians should review each adult's immunization status at age 50; assess risk factors that would indicate a need for pneumococcal vaccination and annual influenza immuni-zations; reimmunize at age 65 those who received an immunization against pneumococcus more than 6 years before; ensure that all adults have completed a primary diphtheria-tetanus immunization series, and administer a single booster at age 50; and assess the postvaccination serologic response to hepatitis B vaccination in all recipi¬ents who have ongoing risks of exposure to blood or body fluids (eg, sharp in)uries, blood splashes).
Strategies have also been proposed to improve influenza, pneumococcal polysaccharide, and hepatitis B vaccination. Strategies to enhance vaccinations in general include increasing community demand for vaccinations; enhancing access to vaccination services; and provider- or system based interventions, such as reminder systems. Increasing reports of pertussis among US adolescents, adults, and their infant contacts have stimulated vaccine development for older age groups. A safe and effective tetanus-diphthena 5- component acellular pertussis vaccine (Tdap) is available for use in adolescents and in adUltS younger than age 65. The Advisory Committee on Immunization Practices (AC.11') I e, int mends routine use 01 a single dose of Tdap for adults aged 19-64 years to replace the next booster dose of tetanus and diphtheria tmoids vaccine (Td). Further research is needed to elucidate the role of vaccination in persons older than 65 years and to determine whether future booster doses of Tdap are needed.
A new recombinant protein hepatitis E vaccine has been developed that has proven safe and efficacious in preventing hepatitis E among high risk populations (such as those in Nepal). Both hepatitis A vaccine and immune globulin provide protection against hepatitis A; however, administration of immune globulin may provide a modest benefit over vaccination in some settings.
Recommended immunization schedules for children and adolescents and adults are set forth in Tables 30-12 and 30-13. Thimerosal-free hepatitis B vaccination is available for newborns and infants, and despite the dis¬proved relationship between vaccines and autism, thime¬rosal-free vaccines are available for pregnant women.
Human papillomavirus (HPV) virus-like particle (VLP) vaccines have demonstrated effectiveness in preventing per¬sistent HPV infections, and thus may impact the rate of cervical intraepithelial neoplasia (CIN) 11-11I. The Ameri¬can Cancer Society and the American Academy of Pediat¬rics (AAP) recommends routine HPV vaccination for girls aged 11-12 years. The AAP also recommends that all unvaccinated girls and women ages 13-26 years receive the HPV vaccine. Trials demonstrate efficacy of bivalent HPV (16/18) or quadrivalent HPV (6/11/16/18)L1 virus-like par-ticle vaccines in preventing new HPV infection and cervical lesions but not in women with preexisting infection. It is estimated that routine use of HPV vaccination of females at 11 to 12 years of age and catch-up vaccination of females at age 13-16 (with vaccination of girls age 9 and 10 at the discretion of the physician) could prevent 95% to 100% of CIN and adenocarcinoma in situ, 99% of genital warts and approximately 70% of cervical cancer cases worldwide; thus, the role of HPV testing will need redefinition. Despite the effectiveness of the vaccine, rates of immunization are low. Interventions addressing personal beliefs and system barriers to vaccinations may help address the slow adoption of this vaccine.
Persons traveling to countries where infections are endemic should take precautions described in Chapter 30. Immunization registries—confidential, population-based, computerized information systems that collect vaccination data about all residents of a geographic area—can be used to increase and sustain high vaccination coverage.

Skin testing for tuberculosis and treating selected patients reduce the risk of reactivation tuberculosis . Two blood tests, which are not confounded by prior BCG (bacille Calmette-Guerin) vaccination, have been developed to detect tuberculosis infection by measur¬ing in vitro T-cell interferon-gamma release in response to two antigens (the enzyme-linked immunospot [ELISPOT], [T-SPOT.TB] and the other, a quatitative ELISA [Quantiferon- TBGlod] test ) . These T-Cell-based assays have an excellent specificity that is higher than tuberculin skin testing in BCG-vaccinated populations. The rate of tuberculosis in thc United States has been declining since 1992, although this decline has slowed in recent years. In 2007 the tuberculosis rate was the lowest recorded since national reporting began in 1953. The Advisory Council for rhe Elimination of Tuberculosis has called for a renewed corn. rnitment to eliminating tuberculosis in the United States, and the Institute of Medicine has published a detailed plan for achieving that goal. Patients with HIV infection are at an especially high risk for tuberculosis, and tuberculosis preventive therapy in the era of HIV will require further work to overcome implementation barriers and to identify optimal duration of preventive therapy and treatment approach for individuals receiving highly active antiretro¬viral therapy (HAART).
Treatment of tuberculosis poses a risk of hepatotoxicity and thus requires close monitoring of liver transaminases. Alanine aminotransferase (ALT) monitoring during the treatment of latent tuberculosis infection is recommended for certain individuals (preexisting liver disease, pregnancy, chronic alcohol consumption). ALT should be monitored in HIV-infected patients during treatment of tuberculosis disease and should be considered in patients over the age of 35. Symptomatic patients with an ALT elevation three times the upper limit of normal (ULN) or asymptomatic patients with an elevation five times the ULN should be treated with a modified or alternative regimen.
HIV infection is now the major infectious disease prob-lem in the world, and it affects 850,000-950,000 persons in the United States. Since sexual contact is a common mode of transmission, primary prevention relies on eliminating unsafe sexual behavior by promoting abstinence, later onset of first sexual activity, decreased number of partners, and use of latex condoms. Appropriately used, condoms can reduce the rate of HIV transmission by nearly 700/0. In one study, couples with one infected partner who used condoms incon¬sistently had a considerable risk of infection: the rate of seroconversion was estimated to be IPA, after 24 months. No seroconversions were noted with consistent condom use Unfortunately, as many as one-third of HIV-positive per¬sons continue unprotected sexual practices after learning that they are HIV-infected. Tailored group educational intervention focused on practicing "safer sex" can red.' their transmission-risk behaviors with partners who are not HIV-positive. Other approaches to prevent HIV infection include treatment of sexually transmitted diseases, develop¬ment of vaginal microbicides, and vaccine developriT. Increasingly, cases of HIV infection are transmitted by 111/e0" tion drug use. HIV prevention activities should include provision of sterile injection equipment for these individuals.

With regard to secondary prevention, many HIV- infected persons in the United States receive the diagnosis advanced stages of immunosuppression, and almost all will progress to AIDS if untreated. On the other hand. HAAR' substantially reduces the risk of clinical progression or death in patients with advanced immtmosuppression. SreenthrT tests for HIV are extremely (> 99%)  Accurate.While the benifits of HIV screening appear to outweigh its harms,current screening is generally based on individual pattient risk factors. Such screening can identify persons at risk  for AIDS but misses a substantial proportion of those infected.

Nonetheless, the yield from screening higher prevalence populations is substantially greater than that from screening the general population, and more widespread screening of the population remains controversial.
In immunocompromised patients, live vaccines are con¬traindicated but many killed or component vaccines are safe and recommended. Asymptomatic HIV infectedpatients have not shown adverse consequences when given live MMR and influenza vaccinations as well as tetanus, hepatitis B, H influenzae type b, and pneumococcal vaccinations—all should be given. However, if poliomyelitis immunization is required, the inactivated poliomyelitis vaccine is indicated. In symptomatic HIV-infected patients, live virus vaccines such as MMR should generally be avoided, but annual influenza vaccination is safe.
Whenever possible, immunizations should be com-pleted before procedures that require or induce immuno¬suppression (organ transplantation or chemotherapy), or that reduce immunogenic responses (splenectomy). How¬ever, if this is not possible, the patient may mount only a partial immune response, yet even this partial response can be beneficial. Patients who undergo allogeneic bone mar¬row transplantation lose preexisting immunities and should be revaccinated. In many situations, family mem¬bers should also be vaccinated to protect the immunocom¬promised patient, although oral live polio vaccine should be avoided because of the risk of infecting the patient.
New cases of poliomyelitis have been reported in the United States, Haiti, and the Dominican Republic recently, slowing its eradication in the Western Hemisphere. Worldwide eradication of poliovirus, including endemic areas such as India, remains challenging.
The current epidemic of highly pathogenic H5N1 avian influenza within duck and poultry populations in Southeast Asia raises serious concerns that genetic reassortment will result in a human influenza pandemic. In 2003 through 2005, there were 138 confirmed cases of human infection with H5N1 avian influenza in Vietnam, Thailand, Indonesia, China, and Cambodia, with a mortality rate of > 50./o. To Prevent and prepare for an increase in human cases, public health officials are working to improve detection methods and to stockpile effective antivirals, such as oseltamivir. The development of an H5N1 vaccine is underway. Two trials have demonstrated development of neutralizing antibodies using a vaccine with varying doses of hemagglutinin antigen.
Herpes zoster, caused by reactivation from previous varicella zoster virus (VZV) infection, affects many older adults and people with immune system dysfunction. Whites are at higher risk than other ethnic groups and the incidence in adults age 65 and older may be higher than previously described. It can cause postherpetic neuralgia, a potentially debilitating chronic pain syndrome. A varicella vaccine is available for the prevention of herpes zoster. Several clinical trials have shown that this vaccine (Zostavax) is safe, elevates VZV-specific cell-mediated immunity, and significantly reduces the incidence of herpes zoster and postherpetic neuralgia in persons older than 60 years. In one randomized, double-blind, placebo-controlled trial among more than 38,000 older adults, the vaccine reduced the incidence of N.herpetic neuralgia by 66% and the incidence of herpes zoster by 51%. The vaccine is administered as a one-time subcutaneous dose (0.65 mL) and is approved for adults 60 years of age and older. However, durability of vaccine response and whether any booster vaccination is needed are still uncertain. The cost effectiveness of the vaccine varies substantially, and the patient's age should be considered in vaccine recommendations. One study reported a cost-effec¬tiveness exceeding $100,000 per quality-adjusted life year saved.
In 2008, the United States Preventive Services Task Force (USPSTF) reviewed evidence to reaffirm its recom-mendation on screening for asymptomatic bacteriuria in adults. New evidence was reviewed, which continues to support routine screening in pregnant women but not in other groups of adults.

Tuesday, 1 May 2012

Disease Prevention And Health Maintenance

Disease Prevention And Health Maintenance : 
Preventive medicine can be categorized as primary, second-ary, or tertiary. Primary prevention aims to remove or reduce disease risk factors (eg, immunization, giving up or not starting smoking). Secondary prevention techniques promote early detection of disease or precursor states (eg, routine cervical Papanicolaou screening to detect carcinoma or dysplasia of the cervix). Tertiary prevention measures are aimed at limiting the impact of established disease (eg, partial mastectomy and radiation therapy to remove and control localized breast cancer). Table 1-1 gives data for deaths from preventable causes in the United States. Table 1-2 compares recommendations for periodic health examinations as developed by the United States Preventive Services Task Force, the American College of Physicians, and the Canadian Task Force on the Periodic Health Examination. Despite emerging consensus on many of the services, controversy persists for others. Many effective preventive services are underutilized. and few adults receive all of the most strongly recommended services. In 2006, the National Commission on Prevention Priorities ranked clinical preventive service recommendations up to December 2004. The three highest-ranking services were discussing aspirin use with high-risk adults, tobacco-use screening and brief interventions, and immunizing children. Other high-ranking services with data indicating low current utilization rates (< 50%) included screening adults aged 50 and older for colorectal cancer, iminunizing adults aged 65 and older against pneumococcal disease' and screening young women for Chlarnydia. Several methods, including the use of reminder systems or financial incentives, can increase utilization of preventive services, but such methods have not been widely adopted.

Table: 1-2