Community-Acquired Pneumonia Treatment - Essay Example

? Community Acquired Pneumonia (CAP) Introduction Community Acquired Pneumonia refers to a type of pneumonia acquired infectiously through normal social contacts as opposed to acquisition through hospitalization. It is an acute infection of pulmonary parenchyma in patients with such infection in the community. The improvement of care for patients suffering from CAP has been the focus by many organizations. CAP is a major health concern in various parts of the world. It is the seventh leading course of mortality rate worldwide, with an approximate of 1.7 million annual hospital admissions, and annual economic costs of approximately $9 billion. The CAP carries an adjusted mortality rate of over 22 percent. Despite the increased clinical advances, the CAP mortality rates have decreased insignificantly since the introduction of penicillin (Nakou & Woodhead 2009, p. 1015). Given the significance associated with CAP, improvement of pneumonia care has been determined as the primary focus in most organizations like joint commissions. There have been several cases of patients diagnosed of CAP and core measures are being established to identify the appropriate antibiotic and propose relevant care for CAP patients. This is faced by challenges like use of antibiotics before confirmation of diagnosis, and this ay negatively affect the drug resistance. Therefore, disposition for CAP patients remain a major decision for the physicians to impact the patient outcome. The prognostic tools like Pneumonia Severity Index (PSI) and the severity of illness index stratifies the patients based on mortality risks. However, the treatment of CAP faces various challenges. This paper explains the different causes of CAP and the current challenges involved in treatment of the disease (Wu & Rs 2006, p. 21). 1.0. Causes of Community Acquired Pneumonia Most pathogens responsible for CAP in children are prominently bacteria and viruses. Researchers have used various laboratory tests to establish microbial etiology of CAP. In most children with LRTI, the diagnostic testing may identify more than three pathogens, and at time may include combinations of both viruses and bacteria. This makes it difficult to determine significance of any pathogen in CAP (Freitas 2006, p. 779). There are more than one hundred microorganisms that can cause CAP. The different types of microorganisms vary among the different groups of people. The newborn infants, adults and children are affected by different spectrums of CAP causing microorganisms. Furthermore, adults experiencing chronic illnesses and living in specific parts of the world, or even living near nursing homes have high risks of getting infected. Despite taking aggressive measures, the definite cause of CAP is only identifiable under limited cases (Carrie 2005, p. 49). 1.1. Etiological Classification of CAP in children and infants In most children, identification of causative organism may not be critical. The childhood CAP results from various infective agents. Table 1.0: Etiological Classification of CAP in children and infants Common Causes of CAP in Children Etiology Types Virus Influenza virus A/B, Respiratory syncytial virus (RSV), measles virus and adenovirus Atypical Bacteria C. trachimatis, M. pneumonia and C. pneumoniae Typical bactreia H. Influenza type b*, S. aureus and S. pneumoniae Uncommon Causes of CAP in children Viruses Corona virus, cytomegalovirus, herpes simplex virus, mumps virus, Epstein-Barr virus (EBV) and Varicella-zoster virus (VZV) Chlamydia C. pittaci Coxiella C. burnetii and S. pyogenes Bacteria Legionella, Brucella abortus, F. tularensis and Pseudomonas pseudomallei Fungi Coccidioides immitis, blasmomyces dermatitidis and Histiplasma Capsulatam A significant proportion of the CAP occurs as a result of mixed infections where a number of pathogen is involved. 1.1.1. Viral causes The viral etiology accounts for over 35 percent of the causal agents in children and infants. However, that percentage of CAP resulting from bacteria remains difficult. The viral CAP is among the children in both developed and developing nations. The virus that is mostly associated with CAP is respiratory syncytial virus (RSV). Other causal viruses results in isolated CAP cases (Low 2008, p. 1245). 1.1.2. Human Metapneumovirus (hMPV) The hMPV is an infectious agent recognized recently among the children suffering from CAP. This has been successfully witnessed in other parts worldwide. The hMPV infection occurs during infancy, and is characterized by seropositivity that increases with age. Retrospective studies establish that some specific antibodies against the virus existed since 1958. The hMPV virus shares with RSV in many dimensions, including use of human beings as a host, and posses identical laboratory and clinical features. The serotype A and B are the major hMPV types, and the heterogeneity of their viral genome causes repeated infections and incomplete infections. The hMPV virus causes respiratory infection among the hospitalized children, and this may also affect the elderly and immune-compromised patients. Studies indicate that children below the age five are the most susceptible to hMPV infections, while those under the age of two are severely infected (Lee & David 2011, p. 981). The hMPV infection can be clinically present in several ways; from mild upper respiratory to moderate tract infections characterized by the flu-like symptoms and high fever. Most of infections caused by hMPV are subclinical and acquired infection neither may nor protect from re-infection. Currently, relationship between hMPV and bacterial infections has not yet been established. Studies indicate that hMPV causes CAP more frequently than RSV (Ko 2002, p. 162). 1.1.3. Human Bocavirus (HBoV) The HBoV has been identified through analysis of biological samples from blood, stool and nasopharynx evidencing the possibility of inducing intestinal, respiratory and systematic diseases. The high HBoV load in respiratory track results, in acute infection, while low viral load results in viral carrier condition. The respiratory infections resulting from HBoV can be serologically diagnosed. 1.1.4. Bacteria etiology The S. pneumonia is the most prevalent bacterium causing CAP in children. The co-infections of both typical and atypical bacteria are common; hence, S. pneumoniae and M. pneumoniae must be accounted for when diagnosing CAP in children. The S. negevensis bacterium is intracellular in nature and is associated with LRTI in children (Grant & Edward 2005,p. 262). 1.2. Etiology in Adults The adults are affected by both pathogen and etiology based on medical history like bad on environmental, travel history, occupational history and host factors. Table 2.0: Etiological Classification of CAP in Adults Usual Pathogens Outpatients Pathogen No comorbid factors S. pneumoniae M. pneumoniae C. pneumoniae Comorbid factors S. pneumoniae H. pneumoniae S. aureus M. catarrhalis Enterobacteriaceae C. pneumoniae Hospitalized Moderate/ severe patients S. pneumoniae H. influenza S.aureus Group A streptococci Enterobacteriaceae C. pneumonia Legionella app (rare) Etiology Based on Medical History Cause Etiologic Agent Environmental Continued exposure to contaminated air like in hot pub, cooling towers, mist machines in grocery store, contaminated drinking water by L. pneumophila, exposure to sheep, goats or cats or windstorm in an area with endemnicity. Legionella pneumophila Coxiella burnetti S. pneumonia Mycobacterium tuberculosis Histoplama capsulatam Occupational history The healthcare work Tick bite M. tuberculosis and Ehrlichia species Hot factor Alcoholism Diabetic ketoacidosis Chronic lung disease S. pneumonia, Haemophilus influenza and Legionella species The true incidence of atypical infections in adults still remains uncertain. Infections with C. pneumaniae and M. pneumoniae organisms are cynical. However, there is geographical variation in infection incidence with the Legionella spp. Studies indicate that Legionella infection remains low. Patients suffering from chronic obstructive pulmonary disease (COPD) are more vulnerable to H. Influenza infections. In adults, more infections from Gram-negative are prevalent. The severely infected adult patients are frequently affected by K. pneumoniae and S. aureus. The polymicrobial infections are common in elderly and other severely ill patients, while infections from anaerobic organisms occur to patients with increased aspiration risks such as epilepsy, alcoholism and cerebrovascular accident (Freitas 2006, p. 780). The HIV-seropositive patients experience inverse relationship between CD4 cells and CAP frequency, with CAP occurring in any stage of HIV infection especially when CD4 count decreases below 200 cells/ ?l. Organisms responsible for CAP among the HIV-seropositive patients are similar to those in HIV-seronegative cases. However, the most common cause of bacterial CAP infections is S. pneumonia and H. influenza (Wu & Rs 2006, p. 21). Figure 1: Percentage of Influenza Cases Other relatively common infections are S.aureus and the aerobic Gram-negative bacilli. Such infections may occur alone or may be in combination with other bacterial pathogens. The risks associated with reduced CD4 increase the risk of opportunistic infections. The prevalence of risks to CAP infections increase when patients suffer from structural lung diseases, especially the cystic fibriosis and bronchiectasis, as well as in patients with broad-spectrum antibiotic therapy for more than seven days in previous months(Nakou & Woodhead 2009, p. 1013). The virus types A and B may present as moderate or severe flu illness. The Avian influenza results upon contact with infected poultry, with occasional human-human transmission. Possibility of infection by Mycobacterium tuberculosis must be carefully considered as it is common among patients with concomitant HIV infection and may be present as acute infection. Also, tuberculosis may be considered as possible cause of pneumonia among the immune-competent individuals, especially among those who are resistant to conventional antibiotic therapy. Most antibiotics used in CAP therapy contain antituberculosis activity, especially the fluoroquinolones. When used frequently among CAP patients suffering from tuberculosis, the resulting diagnosis for tuberculosis may be complicated and may enhance development of mycobacteria (Nakou & Woodhead 2009, p. 1014). Figure 2.0: Comparison of the Prevalence of Pathogens 1.0. Current Challenges In Treatment of Community Acquired Pneumonia The CAP treatment experiences several challenges, ranging from accurate diagnosis decision to the choice of appropriate antibiotic. There has been extensive literature review and empirical studies to determine the most appropriate treatment for CAP and associated infections. Other empirical antimicrobial elements are still under investigation, with adjunctive therapies and new antibiotics proposed. Nevertheless, effective management of CAP and associated infections requires the stratification of the risks to patients and severity of the infection. The increased innovation in antibiotics and therapeutic interventions may enhance the improvement of outcomes in CAP patients (Nakamura 2005, p. 932). Some of the major challenges affecting CAP treatment include determination of severity of the disease. For instance, 80 percent of CAP patients are outpatient while the rest are inpatients. Out of the 80 percent, 1 percent succumb to the CAP while for inpatients, 14 percent normally die. Figure 3.0: Effects of CAP to Outpatients and Inpatients Despite the advances in development of more-potent and new antibiotics, the community acquired pneumonia (CAP) is still the leading cause of mortality and morbidity among most people in the world. The multi-drug and drug resistant bacteria, particularly the Streptococcus pneumonia, continue hindering effective treatment of the respiratory tract infections. Therefore, empirical antimicrobial therapy must be performed to ensure sufficient coverage of both typical (S. penumaniae) and atypical pathogens. The judicious use of the antimicrobials is advocated for in order to prevent further increase in resistant. Currently, phycisians must identify optimal therapeutic regimen which effectively eradicates respiratory infections and minimizes risks for build-up of resistance without compromising the safety of the patient (Lynch 2005, p. 541). The improvements made in patient care decreases the necessity for hospitalization among most CAP patients. Nevertheless, for patients requiring hospital admissions, mortality rate remains high, especially one year after discharge. This is most common among elderly patients and patients with underlying disease. Studies indicate that 25 percent of people discharged from hospitals die one year down the line, with a higher percentage, about 33 percent, among the elderly than in hospitalized controls (Low 2008, p. 1245). The aforementioned research indicates that CAP results in long-term consequences among certain populations. Comprehensive understanding of CAP necessitates improved outcomes among severely ill and elderly patients. The increased prevalence of the drug-resistant strains, particularly the S. penumoniae, remains a primary concern in CAP treatment. The rate of increase of penicillin resistance increased by 13 percent from 1987 to 2002, with additional 16 percent isolation cases that recorded intermediate resistance to penicillin. In the same period, the resistance to microlides increased by 27.4 percent. Nevertheless, the clinical relevance of the drug-resistant bacteria in CAP treatment is not clear and relates to correlation with specific MIC breakpoints than just the susceptible outcomes of R (resistant) and S (susceptible). Despite the increased resistance to respiratory fluoroquinolones in most parts of the world, the resistance rate remains fairly low in most area (Lee & David 2011, p. 979). The sporadic cases of fluoroquinolone failure result from previous uses of the drug. In general, patients with treatment failure after administration of fluoroquinolone should not be prescribed for more fluoroquinolone. Instead, different class of antibiotics may be necessary to avoid risks associated with resistance to fluoroquinolone. The increased tests for S. pneumonia isolate in order to determine the susceptibility to fluoroquinolones and decrease the risks of treatment failure among the at-risk patients. Fluoroquinolones facilitate treatment of the respiratory tract infections. Introduction of fluoroquinolones in respiratory infections have increased resistance against S. pneumonia and this allows for opportunity of antimicrobial class to remain an effective option in CAP treatment. The levofloxacin was the first fluoroquinolone invention which has been followed by gatifloxacin introduction in CAP treatment. Each of the fluoroquinolones provides an excellent activity against common respiratory CAP pathogens. Currently, levofloxacin is marketed more than seven years and contains over 250 prescriptions. During this period, safety profile has been established for levofloxacin (Ko 2002, p. 160). The post-marketing surveillance is described as trial establishing efficacy and safety of levofloxacin used in real world. This used the radio-logically supported clinical CAP diagnoses. Studies on efficacy of the agent reveal that levofloxacin presents an increased efficiency in CAP treatment caused by S. pneumonia, non-susceptible to penicillin (Heiskanen-Kosma et al. 2008, p. 127).The levofloxacin effectiveness has been compared with that of ?-lactam–macrolide in empirical treatment of the seriously ill CAP patients. The patients in the experiments required hospitalization with mechanical ventilation and serious derangements in the vital signs. The levofloxacin remained clinically equivalent to the combination regimen of ?-lactam–macrolide. The range of pathogens identifiable through specimen culture from patients suffering from Staphylococcus aureus and Pseudomonas aeruginosa indicates a gram-negative species. This reinforces significance of continued surveillance of microbiological etiology of the CAP infections (Heiskanen-Kosma et al. 2008, p. 128). Issues relating to effective CAP treatments for the macrolide-resistant infections by S. pneumonia (MRSP) have been addressed in various studies. Despite the increased prevalence of the macrolide-resistant strains in the past decade, it still remains important choice for empirical CAP treatment. The macrolides have been recommended in empirical treatment of CAP patients. Research indicates that MRSP must be considered carefully in determining the type of antibiotic to use (Grant & Edward 2005,p. 261). Fluoroquinolones have been used in effective treatment of CAP patients with MRSP as the causal agents. The CAP patients can also be treated using the levofloxacin due to the macrolide resistant pathogens. The bacteremia deals with moderate to severe CAP instances with associated mortality rate of approximately 20 percent, and can be higher as the patient increases in age and comorbidities. The S. pneumoniae in most cases causes the bacteremic pneumonia, hence the need for use of ?-lactam-macrolide combination instead of monotherapy regimen in CAP treatment, subsequently associated with the pneumococcal bacteremia. This calls for careful assessment of clinical efficacy associated with monotherapy with fluoroquinolone in infections (Freitas 2006, p. 779). The study on determination of clinical experience with the levofloxacin in treatment of CAP related with pneumonia bacteremia using cases for macrolide and penicillin resistant strains revealed the microbiological and clinical success of the levofloxacin treatment. Most clinical trials reveal and support effectiveness in use of levofloxacin in treatment of the CAP and other CAP-associated infections. The levofloxacin 500mg appears to be very effective against most pathogens, including the macrolide and penicillin-resistant strains. Nevertheless, the new trends within the antimicrobial therapy support use of high doses and short durations in effective eradication of pathogen and minimizing the risks for resistance development. The patient must be effectively treated until a febrile of 72hr since average fever duration after the initiation of treatment among young adults suffering from pneumococcal pneumonia remains between 2 and 3 days. However, a 5-day course may be adequate when the potent has the potential of fighting against the causative pathogens (File & Thomas 2004, p. S1). The clinical trials used recently compared the efficacy of the short-course high-dose levofloxacin regimens with the traditional approach. The preliminary results indicated the treatments have comparable microbiological and clinical results. Nevertheless, faster resolutions for the symptoms for the short-course remained exceptional. The high-dose therapy may provide different benefits in future treatment of the respiratory infections without compromising the safety of the patient. The high doses remain advantageous, especially in concentration-dependent antimicrobials like fluoroquinolones. The high doses increase probability of achieving the target pharmacodynamic and pharmacokinetic goals for successful outcomes. This is important in treatment of infections resulting from less-susceptible organisms. The short duration for therapy decreases the total use of antibiotic and lessens the risk of resistance development. Furthermore, short-course reduces incidences of adverse events and increases the compliance of the patient. The new strategies in CAP treatment like the high-dose short-term regimen can be critical in limiting previous prevalence of multi-drug and drug-resistant pathogens within the community. Nevertheless, judicious and responsible antibiotic usage is required in reversing the trends in bacterial resistance (Carrie 2005, p. 49). References List Carrie, A. (2005). Use of Intravenous Antibiotics for the Treatment of Community-acquired Pneumonia in the Emergency Department. Therapeutics and Clinical Risk Management 1(1), pp. 49-54. File, J., & Thomas, M. (2004). Current Challenges in the Treatment of Community?Acquired Pneumonia. Clinical Infectious Diseases 38(S1), pp. S1-S4. Freitas, M. (2006). Viridans Streptococci Causing Community Acquired Pneumonia. Archives of Disease in Childhood 91(9), pp. 779-80. Grant, H., & Edward, P. (2005). Economic and Outcomes Assessment of First-line Monotherapy in the Treatment of Community-acquired Pneumonia within Managed Care. Current Medical Research and Opinion 21 (2), pp. 261-70. Heiskanen-Kosma, T., Mika, P., & Matti, K. (2008). Simkania Negevensis May Be a True Cause of Community Acquired Pneumonia in Children. Scandinavian Journal of Infectious Diseases 40(2), pp. 127-30. Ko, W. (2002). Community-Acquired Klebsiella Pneumoniae Bacteremia: Global Differences in Clinical Patterns. Emerging Infectious Diseases 8(2), pp. 160-66. Lee, N., & David, S. (2011). Dexamethasone in Community-acquired Pneumonia. The Lancet 378(9795), pp. 979-80. Low, D. E. (2008). Treatment of Community-acquired Pneumonia. Canadian Medical Association Journal 179(12), pp. 1245-246. Lynch, J. (2005). Community-Acquired Pneumonia. Seminars in Respiratory and Critical Care Medicine 26(06), pp. 541-42. Nakamura, S. (2005). Community Acquired Pneumonia (CAP) Caused by Cryptococcus Neoformans in a healthy Individual. Scandinavian Journal of Infectious Disease 37 (11-12), pp. 932-35. Nakou, A., & Woodhead, M. (2009). MRSA as a Cause of Community-acquired Pneumonia . European Respiratory Journal 34(5), pp. 1013-014. Wu, J., & Rs, T. (2006). Id4 Compliance With Antibiotic Treatment Guidelines In Medicare Managed Care Patients With Community-Acquired Pneumonia (Cap) In Ambulatory Settings. Value in Health 9(3), pp. 21-22. Read More