Lower respiratory tract infection 964371 225131813 2008-07-12T01:20:48Z Michael Devore 44833 /* Complementary Therapies */ remove user sig {{citation style}} <br clear=all> {{DiseaseDisorder infobox | Name = Lower respiratory tract infection | ICD10 = J10-J22, J40-J47 | ICD9 = | Image = Illu_conducting_passages.jpg | Caption = Conducting passages. | }} While often used as a synonym for [[pneumonia]], the rubric of '''lower respiratory tract infection''' can also be applied to other types of infection including [[lung abscess]], [[acute bronchitis]], and [[emphysema]]. Symptoms include shortness of breath, weakness, high fever, coughing and fatigue. Lower respiratory tract infections place a considerable strain on the health budget and are generally more serious than upper respiratory infections. Since 1993 there has been a slight reduction in the total number of deaths from lower respiratory tract infection. However in 2002 they were still the leading cause of deaths among all [[Infectious disease#Mortality from infectious diseases|infectious diseases]], and they accounted for 3.9 million deaths worldwide and 6.9% of all deaths that year.<ref name="WHO-2004">{{cite book | authorlink=http://www.who.int/en/ | title=The World Health Report 2004 - Changing History | publisher=[[World Health Organization]] | date=2004 | pages=120-4 | format=[[PDF]] | url=http://www.who.int/entity/whr/2004/en/report04_en.pdf | id= ISBN 92-4-156265-X}}</ref> There are a number of acute and chronic infections that can affect the lower respiratory tract. The two most common infections are [[bronchitis]] and pneumonia.<ref name="TGAntibiotic13">Antibiotic Expert Group. Therapeutic guidelines: Antibiotic. 13th ed. North Melbourne: Therapeutic Guidelines; 2006.</ref> [[Influenza]] affects both the upper and lower respiratory tracts. Antibiotics are often thought to be the first line treatment in lower respiratory tract infections; however, these are not indicated in viral infections. It is important to use appropriate antibiotic selection based on the infecting organism and to ensure this therapy changes with the evolving nature of these infections and the emerging resistance to conventional therapies.<ref name="pmid11742937">{{cite journal |author=Guthrie R |title=Community-acquired lower respiratory tract infections: etiology and treatment |journal=[[Chest]] |volume=120 |issue=6 |pages=2021–34 |year=2001 |pmid=11742937 |doi= |url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=11742937}}</ref> H influenzae and M catarrhalis are of increasing importance in both community acquired pneumonia (CAP) and acute exacerbation of chronic bronchitis (AECB) while the importance of S pneumoniae is declining. It has also become apparent the importance of atypical pathogens such as C pneumoniae, M pneumoniae and L pneumophila, in CAP.<ref name="pmid11742937">{{cite journal |author=Guthrie R |title=Community-acquired lower respiratory tract infections: etiology and treatment |journal=Chest |volume=120 |issue=6 |pages=2021–34 |year=2001 |pmid=11742937 |doi= |url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=11742937}}</ref> == Bronchitis == [[Bronchitis]] can be classified as either acute or chronic. Acute bronchitis can be defined as acute bacterial or viral infection of the larger airways in healthy patients with no history of recurrent disease.<ref name="TGAntibiotic13" /> It affects over 40 adults per 1000 each year and consists of transient inflammation of the major bronchi and trachea. <ref name="oldRef6">BJM Clinical evidence: London, United Kingdom: BMJ, 1999-2007 : Accessed 29/3/7 at : http://0-www.clinicalevidence.com.library.newcastle.edu.au/ceweb/index.jsp.</ref> Most often it is caused by viral infection and hence antibiotic therapy is not indicated in immunocompetent individuals. <ref name="oldRef7">Therapeutic guidelines : respiratory. 2nd ed ed: North Melbourne : Therapeutic Guidelines Limited, 2000.</ref><ref name="oldRef9" /> There are no effective therapies for viral bronchitis. <ref name="oldRef9" /><ref name="oldRef10" /> Treatment of acute bronchitis with antibiotics is common but controversial as their use has only moderate benefit weighted against potential side effects (nausea and vomiting), increased resistance, and cost of treatment in a self-limiting condition. <ref name="oldRef6" /><ref name="oldRef11">Fahey T SJ, Becker L, Glazier R. . Antibiotics for acute bronchitis. Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD000245. DOI: 10.1002/14651858.CD000245.pub2. </ref> Beta2 agonists are sometimes used to relieve the cough associated with acute bronchitis. In a recent systematic review it was found there was no evidence to support their use. <ref name="oldRef9">Smucny J BL, Glazier R. . Beta2-agonists for acute bronchitis. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD001726. DOI: 10.1002/14651858.CD001726.pub3.</ref> AECB are frequently due to non-infective causes along with viral ones. 50% of patients are colonised with Hemophilus Influenzae Streptococcus pneumoniae or Moraxella catarrhalis.<ref name="TGAntibiotic13" /> Antibiotics have only been shown to be effective if all three of the following symptoms are present:- increased [[dyspnoea]], increased sputum volume and [[purulence]]. In these cases 500mg of Amoxycillin orally, 8 hourly for 5 days or 100mg doxycycline orally for 5 days should be used.<ref name="TGAntibiotic13" /> == Pneumonia == Pneumonia is a serious infection of the small bronchioles and alveoli that can involve the pleura. It occurs in a variety of situations and treatment must vary according to the situation. <ref name="oldRef10">Integrated pharmacology / Clive Page ... [et al.]. 2nd ed ed: Edinburgh : Mosby, 2002.</ref> It is classified as either community or hospital acquired depending on where the patient contracted the infection. It is very life-threatening in the elderly or people with illnesses that affect the immune system (diabetes). <ref name="oldRef12" /><ref name="oldRef13" /> The most common treatment is antibiotics and these vary in their adverse effects and their effectiveness. <ref name="oldRef12">Bjerre LM VT, Kochen MM. . Antibiotics for community acquired pneumonia in adult outpatients. Cochrane Database of Systematic Reviews 2004, Issue 2. Art. No.: CD002109. DOI: 10.1002/14651858.CD002109.pub2.</ref> Pneumonia is also the leading cause of death in children less than fives years of age. <ref name="oldRef14">Kabra SK LR, Pandey RM. . Antibiotics for community acquired pneumonia in children. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD004874. DOI: 10.1002/14651858.CD004874.pub2.</ref> The most common cause of pneumonia is pneumococcal bacteria, Streptococcus pneumoniae accounts for 2/3 of bacteremic pneumonias. <ref name="oldRef15">The Merck manual of diagnosis and therapy. 17th ed / Mark H. Beers and Robert Berkow ed: Whitehouse Station, N.J. : Merck Research Laboratories, 1999.</ref> A dangerous type of lung infection with a mortality rate of around 25%. <ref name="oldRef13">Dear KB G AR, Holden J, Tatham DP. . Vaccines for preventing pneumococcal infection in adults. Cochrane Database of Systematic Reviews 2003, Issue 4. Art. No.: CD000422. DOI: 10.1002/14651858.CD000422.</ref> For optimal management of a pneumonia patient the following must be assessed;- pneumonia severity (including where to treat eg. Home, hospital or intensive care), identification of causative organism, analgesia of chest pain, the need for supplemental oxygen, physiotherapy, Hydration, bronchodilators and possible complications of emphysema or lung abscess. <ref name="oldRef16">eTG complete [electronic resource] http://0-www.etg.hcn.net.au.library.newcastle.edu.au/. [cited; Available from: http://0-www.etg.hcn.net.au.library.newcastle.edu.au/</ref> For community acquired respiratory infections the appropriate use of fluoroquinolones is a therapeutic option. These have been demonstrated to have targeted ''in vitro'' activity against both the typical and atypical pathogens of interest.<ref name="pmid1662900">{{cite journal |author=Chodosh S |title=Use of quinolones for the treatment of acute exacerbations of chronic bronchitis |journal=[[Am. J. Med.]] |volume=91 |issue=6A |pages=93S–100S |year=1991 |pmid=1662900 |doi=}}</ref><ref name="pmid9559818">{{cite journal |author=Roblin PM, Hammerschlag MR |title=In vitro activity of a new 8-methoxyquinolone, BAY 12-8039, against Chlamydia pneumoniae |journal=[[Antimicrob. Agents Chemother.]] |volume=42 |issue=4 |pages=951–2 |year=1998 |pmid=9559818 |doi= |url=http://aac.asm.org/cgi/pmidlookup?view=long&pmid=9559818}}</ref> The newer fluoroquinolones (eg, moxifloxacin or gatifloxacin) have extended gram +ve activity and once daily dosing and hence are potential first line in the treatment of lower respiratory tract infections.<ref name="pmid11742937" /> However it is clinical response that is the best indicators of efficacy and moxifloxacin or gatifloxacin have been proven to be effective against community acquired respiratory tract infections clinically.<ref name="pmid10714475">{{cite journal |author=Chodosh S, DeAbate CA, Haverstock D, Aneiro L, Church D |title=Short-course moxifloxacin therapy for treatment of acute bacterial exacerbations of chronic bronchitis. The Bronchitis Study Group |journal=[[Respir Med]] |volume=94 |issue=1 |pages=18–27 |year=2000 |pmid=10714475 |doi=}}</ref><ref name="pmid10588312">{{cite journal |author=Wilson R, Kubin R, Ballin I, ''et al'' |title=Five day moxifloxacin therapy compared with 7 day clarithromycin therapy for the treatment of acute exacerbations of chronic bronchitis |journal=[[J. Antimicrob. Chemother.]] |volume=44 |issue=4 |pages=501–13 |year=1999 |pmid=10588312 |doi= |url=http://jac.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=10588312}}</ref> == Antibiotic Choice == With increased development of drug resistance, traditional empirical treatments are becoming less effective, hence it is important to base antibiotic choice on isolated bacteria and sensitivity tests. According to the Cochrane review of antibiotic use in CAP in adults, the current evidence from RCTs is insufficient in order to make evidenced based decisions on the antibiotic of choice. Further studies are required to make these decisions. <ref name="oldRef12" /> For children they found amoxicillin or procaine penicillin to have greater effect than co-trimoxazole for the treatment of CAP. In hospital settings, penicillin and [[gentamicin]] was found to be more effective than chloramphenicol, with oral amoxicillin giving similar results to injectable penicillins. <ref name="oldRef14" /> In another review of children with severe pneumonia, oral antibiotics were found to be as effective as injectable ones without the side effects of pain, risk of infection, or high cost. <ref name="oldRef21">Rojas MX GC. Oral antibiotics versus parenteral antibiotics for severe pneumonia in children. Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD004979. DOI: 10.1002/14651858.CD004979.pub2.</ref> Also in a Cochrane review azithromycin has been shown to be no better than Amoxycillin or Amoxycillin with clavulanic acid in the treatment of lower respiratory infections. <ref name="oldRef22">Panpanich R LP, Laopaiboon M. Azithromycin for acute lower respiratory tract infections. Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD001954. DOI: 10.1002/14651858.CD001954.pub2.</ref> The AMH list Amoxycillin as first line of AECB and community acquired pneumonia where as IV azithromycin is first line if high risk of death. If severe hospital acquired pneumonia it recommends IV gentamicin and ticarcillin with clavulanic acid. <ref name="oldRef23">AMH 2006 : Australian medicines handbook. [7th ed.] ed: Adelaide, South Australia : Australian Medicines Handbook, 2006.</ref> == Non-Pharmacological Treatments == The main stay of non pharmacological treatment for many years has been rest and increased fluid intake. Although it is common for doctors and other health professional to recommend extra fluid intake a Cochrane systematic review could find no evidence for or against increased fluid intake. Although the idea of replacing fluids lost through fever and rapid breathing was sound, some observational studies reported harmful effects such as dilution of blood sodium concentration leading to headache, confusion or possibly seizures. <ref name="oldRef24">Guppy MPB MS, Del Mar CB. . Advising patients to increase fluid intake for treating acute respiratory infections. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD004419. DOI: 10.1002/14651858.CD004419.pub2.</ref> Rest will allow the body to conserve energy to fight off the infection. Physiotherapy is indicated in some types of pneumonia and should be encouraged where appropriate. ref name="oldRef16" /> == Complementary Therapies == Chickweed taken orally has been used for many years to reduce fever and phlegm associated with bronchitis. It is believed to act as an expectorant and although the pharmacological actions of several constituents suggest it may be useful, controlled studies are not available to confirm its effectiveness. <ref name="oldRef25">Braun L. Herbs & natural supplements : an evidence-based guide / authors Lesley Braun, Marc Cohen. 2nd ed ed: Marrickville, N.S.W. : Elsevier Australia, 2006. </ref> A systematic review of Chinese herbs used in the treatment of acute bronchitis found that there was weak evidence for their use, but there was insufficient quality data to recommend them. The benefit found may be due to study design or publication bias. Hence they should be used carefully because their safety is largely unknown. <ref name="oldRef26">Wei J JN, Wu T, Chen X, Duan X, Liu G, Qiao J, Wang Q, Zhen J, Zhou L. . Chinese medicinal herbs for acute bronchitis. Cochrane Database of Systematic Reviews 2005, Issue 3. Art. No.: CD004560. DOI: 10.1002/14651858.CD004560.pub2.</ref> Thyme is approved by commission E in the treatment of bronchitis and there is encouraging data for its use in chronic bronchitis when used in combination with other herbs, however there is no stand-alone data. <ref name="oldRef25" /> The use of Vitamin C is commonly thought to act to prevent colds and other respiratory infections. However according to a recent Cochrane review the evidence is too weak to support its widespread use as a prophylactic in preventing pneumonia in the general population. It may be reasonable to use in high risk patients with low plasma levels of vitamin C due to its low cost and risk associated with is use. <ref name="oldRef27">Hemilä H LP. Vitamin C for preventing and treating pneumonia. Cochrane Database of Systematic Reviews 2007, Issue 1. Art. No.: CD005532. DOI: 10.1002/14651858.CD005532.pub2.</ref> Vitamin C used as an orthomolecular antibiotic, is most effective when used in the same way; i.e., on timetable dosages. Dr. Linus Pauling took 10 grams of vitamin C daily (to prevent colds). Vitamin A has been successfully used to reduce the mortality and severity of respiratory infection with measles. However in a review of non-measles pneumonia it was not found to have any benefit or harmful effects. <ref name="oldRef28">Ni J WJ, Wu T. . Vitamin A for non-measles pneumonia in children. Cochrane Database of Systematic Reviews 2005, Issue 3. Art. No.: CD003700. DOI: 10.1002/14651858.CD003700.pub2.</ref> Used by native healers for millennia, garlic contains allicin, a powerful anti-fungal and antibiotic compound. Native American tribes have used garlic to treat coughs and croup. British herbalists use garlic for hoarseness and coughs. Louis Pasteur studied garlic's antibacterial properties. During both World Wars, ''Allium sativum'' was used as an antiseptic. In general, it is ignored as unprofitable by Big Pharma. For the treatment of pneumonia baical skullcap was shown to be as effective as piperacillin after one treatment. The piperacillin group resulted in 4 of 30 patients with fungal infections while there were none in the baical skullcap group. <ref name="oldRef25" /> == The Future == It is likely that the future treatment of lower respiratory tract infections will consist of new antibiotics aimed at facing the problems associated with the constant emergence of antibiotic resistance. With resistance evolving so rapidly future treatments may include the use of vaccines to prevent these infections. Although a Cochrane systematic review of a polysaccharide pneumococcal vaccine didn’t reduce the pneumonia or their related deaths in adults, but was able to reduce incidence of more specific outcomes such as pneumococcal disease in the elderly. <ref name="oldRef13" /> So it is hoped with further developments these will become more effective against pneumonia. Vaccination of patients with AECB in the autumn months is thought to have a positive effect in reducing the severity and number of exacerbations over winter. The oral vaccine described in this review was able to decrease the carriage or non-typeable Haemophilus influenzae that is a common cause of exacerbations to chronic bronchitis. <ref>Foxwell AR CA, Dear KBG. . Haemophilus influenzae oral whole cell vaccination for preventing acute exacerbations of chronic bronchitis. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD001958. DOI: 10.1002/14651858.CD001958.pub2.</ref> With good planing and further research these types of vaccines may reduce the burden associated with lower respiratory diseases. There are few treatments available for viral forms of bronchitis and pneumonia. Respiratory syncytial virus (RSV), the main cause of these in children, could be potentially treated using a new monoclonal antibody (mAb) Motavizumab. In animal trials it reduced antibody titres 100 lower than the only drug currently available to treat the condition.<ref name="pmid17362988">{{cite journal |author=Wu H, Pfarr DS, Johnson S, ''et al'' |title=Development of motavizumab, an ultra-potent antibody for the prevention of respiratory syncytial virus infection in the upper and lower respiratory tract |journal=[[J. Mol. Biol.]] |volume=368 |issue=3 |pages=652–65 |year=2007 |pmid=17362988 |doi=10.1016/j.jmb.2007.02.024 |url=http://linkinghub.elsevier.com/retrieve/pii/S0022-2836(07)00205-7}}</ref> This holds great promise for future treatments of LRTI. == References == {{reflist}} ==See also== * [[Upper respiratory tract infection]] [[Category:Diseases]] [[Category:Infectious diseases]]