Chronic Respiratory Infection Flashcards
describe diagnosis of chronic respiratory infection and the differential diagnosis
shadow on CXR weight loss persistent sputum production chest pain increasing shortness of breath low levels of albumin in liver
similar to lung cancer (shadow on CXR and weight loss)
shadow on CXR in upper quadrant indicates TB (returning travelers, immunosuppressed patients - HIV)
persistent sputum production indicates infection;
intrapulmonary abscess
empyema
bronchiectasis
cystic fibrosis
describe symptoms of chronic respiratory infection
weight loss
cachexia - weakness and wasting of body due to chronic illness
clubbing
lethargy
describe the risk factors for developing chronic pulmonary infection
not normal to develop chronic lung infection;
abnormal host response - immunodeficiency (congenital, acquired), immunosuppression (drugs, malignancy)
abnormal innate host defence - damaged bronchial mucosa, abnormal cilia, abnormal secretions (CF)
repeated insult - aspiration, indwelling material
describe immunodeficiency
an abnormal host response
primary immunodeficiency is not common, patients present with lung infection, sinusitis
immunoglobin deficiency;
IgA deficiency - common, increased risk of acute infections but rarely chronic
hypogammaglobulinaemia - rare, increased risk of acute and chronic infections
common variable immune deficiency (CVID) - most common cause of immunodeficiency, recurrent (ear) infections
specific polysacchardie antibody defiency (SPAD) - strepococcal infections
hypo-splenism
immune paresis - most common, myeloma, lymphoma, metastatic malignancy
HIV
describe immunosuppression
an abnormal host response
increasingly common therapy for more and more disease processes;
steroids
azathioprine
methotrexate
cyclophosphamide
monoclonal antibodies - TNFa, CD20, leflunamide
chemotherapy - causes neutropenia (low level of neutrophils), exposing patients to bacterial and fungal infections (especially in the lung)
describe the defective innate host defence
damaged bronchial mucosa - smoking, recent pneumonia or viral infection, malignancy
abnormal cilia - Kartenager’s syndrome, Young’s syndrome
abnormal secretions - CF, channelopathies
describe Kartenager’s syndrome
rare, autosomal recessive genetic ciliary disorder comprising the triad of situs inversus, chronic sinusitis, and bronchiectasis. The basic problem lies in the defective movement of cilia, leading to recurrent chest infections, ear/nose/throat symptoms, and infertility
describe young’s syndrome
combination of syndromes such as bronchiectasis, rhinosinusitis and reduced fertility
describe repeated insult
recurrent aspiration - NG feeding, poor swallow, pharyngeal pouch
indwelling material - NG tube in wrong place, chest drain, inhaled foreign body (e.g. peanut, chicken bone)
describe the different forms of chronic infection
intrapulmonary abscess empyema chronic bronchial sepsis bronchiectasis cystic fibrosis and other oddities
describe intrapulmonary abscess
indolent presentation weight loss common lethargy, tiredness, weakness cough +/- sputum high mortality if not treated usually a preceding illness of some sort - pneumonic infection, post viral, foreign body mortality is 10%
multiple abscess indicates the infection is from elsewhere circulating in the blood
describe preceding illnesses of an intrapulmonary abscess
pneumonia;
influenza - staph pneumonia - cavitating pneumonia - abscess
aspiration pneumonia;
vomiting, lowered conscious level, pharyngeal pouch
poor host immune response;
hypogammaglobulinaemia
describe the pathogens of intrapulmonary abscess
bacteria - strepoccous, staphylococcus, E-Coli, gram negative (worst kind)
fungi - aspergillus
describe septic emboli
type of embolism that is infected with bacteria, resulting in the formation of pus causes; right sided endocardits (infection in endocardium) infected DVT septicaemia intravenous drug users; inject into groin DVT infection PE and abscesses
describe empyema
pus in the pleural space
57% of all patients with pneumonia develop pleural fluid, the remainder are primary empyema - often iatrogenic, many idiopathic
high mortality - as high as severe pneumonia, >20% of all patients with empyema die
describe the progression of pleural effusion to empyema
simple parapneumonic effusion; clear fluid pH>7.2 LDH<1000 glucose>2.2
complicated parapneumonic effusion; pH<7.2 LDH>1000 glucose<2.2 requires chest tube drainage
empyema
frank pus
no other tests required
requires chest tube drainage
describe bacteriology of empyema
aerobic organisms most frequently gram positive; step milleri staph aureus (usually post operative, or nosocomial) immunocompromised gram negative; E-Coli psedudomonas haemophilus influenzae kelbsiellae anaerobes in 13% of cases ln severe pneumonia or door dental hygiene
describe diagnosis of empyema
clinical suspicion; slow to resolve pneumonia lateral chest film CXR; persisting effusion, particularly if loculations visible 'D' sign USS; preferred investigation, bed side test targeted sampling CT; differentiation between empyema and abscess
describe treatment of empyema
IV antibiotics; broad spectrum amoxicillin and metronidazole initially oral antibiotics; directly towards cultured bacteria co-amoxiclav
describe bronchiectasis
(wide airway) localised, irreversible dilation of the bronchial tree
involved bronchi are dilated, inflamed and easily collapsible
airflow obstruction
impaired clearance of secretions - cilia does not work properly, failure of muscociliary escalator
describe presentation of bronchiectasis
recurrent chest infections
recurrent antibiotic prescriptions
no response to antibiotics
short lived response to antibiotics
describe diagnosis of bronchiectasis
radiological;
CT - dilation of airways, thickening of bronchial walls,, tapering of airways
in normal lung, the artery should be bigger than airway (other way round in bronchiectasis)
describe pathophysiology of bronchiectasis
bronchial obstruction CF young's syndrome kartanager's syndrome ABPA immunodeficiency rheumatoid arthitis bronchopulmonary sequestration mounier-khun syndrome yellow nail syndrome traction bronchiectasis associated with pulmonary fibrosis
describe chronic bronchial sepsis
all hallmarks of bronchiectasis but no bronchiectasis on the high resolution CT
confirmed positive sputum results
common in younger patients, mainly woman, involved in childcare
others are older, with COPD, or airways disease
same work up as bronchiectasis
sinuses - reservoir of infection
describe treatment options for chronic bronchial sepsis
stop smoking influenza vaccine pneumococcal vaccine reactive antibiotics; send sputum sample give antibiotics appropriate to most recent positive culture
if colonised with persistent bacteria; oral macrolide antibiotics nebulised gentamicin, colomycin pulsed IV abx alternating oral antibiotics
anti-inflammatory;
low dose macrolide antibiotics reduce exacerbation rates in bronchiectasis - clarithromysin, azithromycin
not effective in current smokers
describe treatment of acute exacerbations of chronic bronchial sepsis
2 weeks of antibiotics appropriate to most recent positive sputum sample
send sputum every time
alter antibiotics if the sputum culture shows resistant organisms
aggressively eradicate pseudomonas aeriginosa
