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PneumoniaDefintiionCommunity acquired: those who haven’t been in hospital / long term care facility for >14/7; 5-15% aspirationHospital acquired: occuring >48hrs after hospital admission; G-ive account for 50%Ventilator acquired: 48-72hrs after ETTHealth care associated: acquired in health care enviro, but not hospitalEpidemiology8% 3/12 mortality if admitted, 28% if ICU admit, <1% if OPAssoc with severe: Strep pneumoniae, Staph aureus H influenzae, anaerobes, G-ives, legionella, M pneumoniae, PCP viralAssoc with death: strep pneumoniae, staph aureus (esp MRSA) legionella, pseudomonasAssoc with lung abscess: staph, anaerobes, G-iveCauses2 pathogens in 10%; unknown cause in 30-50%Strep pneumoniae: 30% overall; most common cause of CAP worldwide; esp in children, chronic illness, elderly; nasopharynx colonised in 50% healthy patients Cause in up to 10% OP patients, up to 45% hospitalised patients, up to 40% ICU patients RF = dementia, seizures, CCF, CVD, COPD, HIV, black, overcrowding, smoking, ETOH Acute onset high fever, rigors, pleurisy CXR: Lobar / segmental / multilobular / round; pleural effusion 10%, empyema <20%, air bronchograms Mortality 30% untreated; resistance to penicillins and macrolides emergingH influenzae: <5% overall Cause in up to 10% OP patients, up to 10% hospitalised patients, up to 20% RH patients RF = debilitated, COPD, recent Abx/steroids CXR: Alveolar infiltratesStaph aureus: Cause in up to 5% hospitalised patients, up to 25% RH residents; more common superadded on viral RF = IVDU, hospitalised, old, debilitated, underlying lung disease, prev Abx, OT, virus CXR: Lung abscess, empyema, pleural effusions, round pneumonia, lobular changes High mortality, bacteraemia and septic shockG –ives: eg. Klebsiella, pseudomonas, serratia Cause in up to 7% hospitalised patients, up to 25% RH residents RF = alcoholics, NH residents, major comorbidity (eg. Ca, CF, bronchiectasis) CXR: Lung abscess, klebsiella esp in upper zones, empyema, effusion High mortality (esp pseudomonas)Atypicals: Mycoplasma pneumoniae: 10-25% CAP overall; usually young adults or children Cause in up to 35% OP patients, up to 33% hospitalised patients, up to 20% RH residents Insiduous onset, prodromal period of general malaise, URTI Sx, N+V+D Rash, 5-10% get SJS; rarely causes meningitis, transverse myelitis, CCF, arrhythmias, pericarditis, hepatitis, haemolytic anaemia; rusty coloured sputum Low mortality CXR: no consolidation despite severe cough, enlarged LN’s, maybe lung infiltratesChlamydia pneumoniae: cause in up to 10% OP patients, up to 20% hospitalised patients, 7% RH residents RF = old, multiple comorbitidies Sore throat, hoarse voice, headache; can be mild or serious Low mortalityChlamydia psittaci: RF = bird handlers, occupational High fever, chills, headache, pneumonia; epistaxis in 25%; N+V+APLegionella (G-ive): sporadic / epidemic (air conditioning); often in young healthy patients RF = long term steroids, recent travel, hot tubs, spas, plumbing, DM, Ca, smoking, immunosupp, DM, ARF/liver failure Relative brady, confusion, AP Multisystem illness (ARF, incr CK, NS, GI, incr LFTs, hypoNa, pericarditis, myocarditis, pancreatitis, coma) CXR: Rapidly progressive asymmetrical infiltrates, esp in lower zones High mortality (75% mortality untreated)Anaerobes: RF = aspiration, gingivitis, bronchopleural fistula; cause lung abscess and empyemaViral: flu A+B, adenovirus, RSV, parainfluenza ( staph aureus)Immunocomp: M TB, PCP (RF = prolonged Abx, bronchiectasis, HIV, immunosupp; can be treated with PO cotrimoxazole if mild), fungalOthers: nocardia coxiella burnetti (animal handlers) moraxella catarrhalis (1-5% healthy adults are colonised, higher if chronic lung disease; RF = old, RH resident, COPD, bronchiectasis, steroids, DM, Ca; causes fulminant pneumonia) aspiration is cause of 5-15% CAP (20% in elderly, most RH residents; 40% those who aspirate develop pneumonia; usually staph aureus, pseudomonas, enterobacter, anaerobes, klebsiella, E coli, G-ives, H influenza, Strep pneumoniae; usually post upper or sup lower lobes if recumbent, basal lower lobes if erect)Risk factorsAsthma, COPD, smoking, O2, INH, alcoholism, institutionalisation, immunosuppAssessmentHistory: LR 2 = cough; LR 1.5 = SOBOE: LR 6 = egophony; LR 3.5 = bronchial BS; LR 3 = dullness, T >38; LR 2.5 = RR >25, crackles, decr BS Auscultation is 10% sens, 95% specInvestigationCXR: 70% sens, 95% spec; improvements lag behind clinical (pneumococcal will clear in 8-12/52, legionella by 12-20/52 with scarring and fibrosis, mycoplasma by 2-4/52 without scarring; in general findings clear quicker in atypicals)Lobar: usually strep pneumoniae; uniform opacity confined to one lobe; air bronchograms seen; may be ill defined if not adjacent to one of the fissures; may be small assoc pleural effusionLobular: often staph; multifocal, patchyBronchial: ill defined areas of patchy opacity (eg. Post-op, aspiration)Lower zones: legionellaUpper zones: klebsiellaRound pneumonia: C Burnetti, S pneumoniae, L pneumophilia, S aureusMiliary pattern / intersitital: TB, varicella pneumonia; air bronchogram not seenAbscesses: staph aureus, Klebsiella, anaerobes, G-ives, TB, aspiration pneumonia; 90% have predispostion to aspiration or dental probs; needs Abx for up to 2/12USS: 90% sens, 95% spec; more accurate for peripheral diseaseBloods: L shift; decr WBC assoc with poor outcome; do ABG if severe distress; markers of severity (CRP - <100 has high NPV for serious illness and mortality; procalcitonin – low levels have high NPV; cortisol)Blood culture: do if admitting / immunocomp / signficiant co-morbidities / pleural effusion / cavitation; 1-16% +ive; rarely result in change of mngSputum: 40% positive (counts if single MO grown); similar indications and usefulness as blood cultureUrinary antigens: legionella (if ICU, alcoholic, recent travel), pneumococcalSerology: mycoplasma Igm, legionella, chlamydia, influenzaScoring systemsGoals: identify low risk patients, guide need for admission, recognise severe and need for ICU, guide ABxPros: provide decision support info; scores which predict clinical deterioration are preferredCons: less accurate in elderly, fail to consider social factors, fail to consider some common co-morbiditiesSMART-COP: SBP <90, multi-lobar, alb <35, RR, Tachy >125, confusion, O2, pH <7.35 Predicts: clinical deterioration; need for ICU / vasopressorsResults: 0-2 = low risk; 3-4 = mod risk (1/8); 5-6 = high risk (1/3); >7 = ? riskAccuracy: If >3, 92% sens, 62% spec, 22% PPV, 99% NPVPros: determines needs for ICU / vasopressors; detemines severity; more variables than CORB; incr sens to CORB; some validationCons: needs more validation; complex variables and cut offs; doesn’t predict mortalityCORB: confusion, O2 <90%, RR >30, BP <95Predicts: clinical deterioration; need for ICU / vasopressorsResults: Severe if 2+ factorsAccuracy: 80% sens, 68% spec, 18% PPV, 98% NPVPros: determines needs for ICU / vasopressors; detemines severity; simple; no labs needed; no age biasCons: needs more validation; age not included; co-morbidities not included; less sens than SMART-COPCURB-65: confusion, Ur >7, RR >30, BP <90 (DBP <60), age >65yrsPredicts: 30 day mortalityResults: 0 = 0% 30 day mortality; 1 = 1%; 2 = 7.5%; 3 = 20%; 4 = 40%; 5 = 60%Pros: well validated; simple; can be used without labs as belowCons: doesn’t account for comorbidities or hypoxia; performs less well in severe; less good at determining who can be trted as OP; overestimates in elderly, underestimates in young; doesn’t identify ICU candidates wellCRB-65: as above without Ur; better for GP’s and shows who can be safely mnged as OP; performs as well as CURB65 and PSIPSI: history (NH res, CCF/CVA/CRF, Ca, liver) OE (T, HR >125, RR >30, BP <90) investigations (BSL >14, Hct <30, PaO2 <60, Ur >11, Na <130, pH <7.35, pleural effusion)Predicts: mortalityResults: Class I: 0 score from Hx and OE + <50yrs mortality 0.1-0.5% discharge (5% readmission) Class II: score <70 morality 0.6-0.7% probable discharge (8% readmission) Class III: score 71-90 mortality 2% short admission (17% readmission) Class IV: score 91-130 mortality 9% admit (20% readmission) Class V: score >130 mortality 30% admitPros: well validated; identifies those at low risk (ie. Candidates for OP); good in research; high sens and spec for mortality and ICU admissionCons: complex; needs lab results; heavily influenced by age and co-morbidities (but doesn’t include DM, COPD, immuncomp); overestimates severity in elderly; underestimates severity in young hypoxic patients; doesn’t account for social history or unusual comorbidities; CXR not includedPrognosisBad if: PaO2/FiO2 ratio >250; multilobular infiltrates on CXR; Ur >7; WBC <4; plt <100; T <36; decr Na, BSL, pHComplicationsParapneumonic effusion (50%, small, if >5cm high on lateral, need to exclude empyema); empyema (<5%), lung abscess, pericardial extension, AMIMngA:B: maintain SaO2 >95%; bronchoD if asthma/COPD; NIV helps if COPD, but better to do early ETT if needs itC: ensure adequate hydrationAntibiotics: cover typical and atypicals as decr mortality; cannot tell atypicals from H, OE and CXR aloneMild: amoxillin 1g PO TDS for 5-7/7If think atypical MO / allergy / failure to improve + doxycycline 100mg OD / clarithromycin 250mg BD 5/7Mod: benpen 1.2g IV QID ( amox for 7/7) + doxy 100mg BD or clari 500mg BD for 7/7 Don’t use cef’s routinely, as resistance uncommon If allergy, change to ceftriaxone 1g IV OD or cefotaxime 1g TDS ( cefuroxime 500mg PO BD 7/7) If anaphylaxis, change to moxifloxacin 400mg PO OD 7/7 If G-ive add gent, or change penicillin to ceftriaxone / cefotaxime; 2nd line is cipro 400mg IV BD or meropenem If tropical regions, ceftriaxone 2g IV OD + gent 5mg/kgSevere: benpen 1.2g IV QID or ceftriaxone 1g IV OD or cefotaxime 1g IV TDS + azithyromycin 500mg IV OD / cipro 400mg IV BD + gent If ?Staph aureus, fluclox 2g IV QID (cephazolin 2g IV TDS if allergy, vanc if anaphylaxis or MRSA) augmentin If tropical regions, meropenem 1g IV TDS or imipenem 1g IV QID + azithromycinAspiration: benpen (clindamycin if allergy) + metronidazole 500mg IV BD (or 400mg PO BD)Admit ifSaO2 <90% OA, CV instability, old, significant co-morbidities, can’t take PO’s, psych, SHAdmit ICU ifRequiring vasopressors / ETT; CORB/SMARTCOP suggest vasopressors/ETT may be needed; need for NIVICU admit required in 10%Discharge ifStable obs for 24hrs (T <37.8, RR <25, HR <100, BP >90, SaO2 >90%), taking PO’s, food and drinkFollow upReview within 48hrs; if severe, repeat CXR at 8-12/52, or earlier if clinical worseningAtypical pneumoniaCan vaccinate against coxielle burnettiAtypical pneumonia assoc with: abnormal LFT’s, hypoPhos, bilateral patchy infiltrates on CXR, incr cold agglutininsIn paedsEpidemiology: up to 40% are mixed; viral more common than bacterial; strep pneumoniae most common bacterial cause (esp <5yrs); mycoplasma up to 30%History: if neonate, ask about mother’s pre- and peri-natal health inc infections and fever, PROM, peri-partum complications, meconium; wheeze in young infant = bronchiolitis, in child = mycoplasma Staph rapidly progressive Sx high fever, toxic, abscesses, cavitations, pleural effusions C trachomatis staccato cough, diffuse rales, no fever, sore throat Mycoplasma hacking dry cough, arthralgia, rash (in 10%), indolent course, Kawasaki syndrome, erythema multiforme, GBS B pertussis paroxysmal coughing, gasping, colour change, URTI If severely unwell: ?staph aureus, grp B strep If underlying lung disease: ?Hib In neonates: strep agalactiae (grp B strep), listeria, G-ives (eg, klebsiella, E coli) Apnoeas: more common in RSV, chlamydia, B pertussis Effusions: strep pneumoniae most common cause; also mycoplasma, Hib Empyema, pneumatocoele, cavitation: staph aureusExamination: toxic appearance has better sens than other parts of exam; SaO2 <90% OA incr risk of trt failure with PO amox; fever + incr RR / decr BS / fine crackles predicts XR positive pneumonia with 93-96% sens; fever + all 3 = 98% sens; absence of incr RR, resp distress, rales and decr BS excludes pneumonia in 100%; SOB is best sign to rule outBloods: blood culture +ive in <5%; NPA helpful to identify virus in younger, mycoplasma in older; mycoplasma cold agglutinins 72-92% sensCXR: cons: may be false –ive / +ive; may be poor quality image; cost; delay; exposure to radiation; can’t distinguish between bacterial and viral Indications for CXR: toxic appearance with resp findings; <3/12 as part of septic screen; <5yrs with T >39, WCC >20 and no source; ambiguous clinical findings; ?complication; not responding to Abx; ?congenital lung malformation; FU of round pneumonia; specific exam findings suggesting pneumoniaAdmission criteria: <6-12/12, toxic, altered LOC, complicated pneumonia, hypoxia, unrelieved resp distress; inability to feed; co-morbidities, dehydration, not tolerating PO Abx, social issues<3/12: amoxicillin/ampicillin 50mg/kg QID (TDS if <1/52) + cefotaxime 100mg/kg loading dose 50mg/kg QID (BD if <1/52) (or gent)>3/12: amoxicillin 30-50mg/kg TDS (can do PO for 5-7/7 if well)>3/12, complicated: augmentin 30mg/kg TDS-QID (?staph, lung abscess, pleural effusion) or cefuroxime 30mg/kg TDS + erythromycin 12.5mg/kg QID PO / roxi 4mg/kg BD PO if severe (for atypicals) 7-10/7>3/12, unwell ++: fluclox 50mg/kg QID IV (to cover staph) (unwell, post-viral, abscesses) + cefotaxime 50mg/kg QID IV Notes from: PNEUMOCYSTIS JIROVECII (formerly Pneumocystis carinii):? Pneumocystis pneumonia (PCP) is a potentially life threatening infection that occurs in immunocompromised individuals with HIV-infected patients with a low CD4 count at highest risk.? Others at risk include transplant recipients, caner patients (particularly hematologic malignancies) and those on immunosuppressive medications.? In patients without HIV PCP typically presents as fulminant respiratory failure associated with fever and dry cough.? The presentation is usually indolent in HIV-infected patients.? The typical Radiographic features of PCP are diffuse bilateral interstitial infiltrates.? Diagnosis of PCP requires documentation of the organism in respiratory specimens? seen by microscopy with staining (pneumocystis cannot be cultured), alternatively PCR assays may help in non-HIV patients with lower sensitivity of microscopy and staining.LEGIONELLA PNEUMONIA:? Legionella pneumophilia is a commonly identified pathogen in community-acquired pneumonia in immunocompetent patients.? Respiratory symptoms are not prominent initially with the cough at first mild and only slightly productive.? The sputum may be blood streaked.? Chest pain can occur.? Gastrointestinal symptoms are often prominent with diarrhoea, nausea, vomiting and abdominal pain.? Patients are usually lethargic with headache and occasionally stupor.? Fever is virtually always present and oral temperature > 39 degrees Celsius suggests the possibility of legionnaires’ disease.? Laboratory abnormalities are common but non-specific including renal and hepatic dysfunction, thrombocytopaenia, and leukocytosis.? Hyponatremia (Serum Sodium <130mmol/L) occurs more frequently than other pneumonias.? Hematuria and proteinuria are also common.? Radiologically the most common pattern is a patchy unilobar infiltrate that progresses to consolidation however all types of infiltrates have been reported including diffuse, interstitial infiltrates. Pleural effusions are common.? Culture of a respiratory specimen and urinary antigen testing are key to securing a diagnosis.MYCOBACTERIUM TUBERCULOSIS:? The lungs are the major site for Mycobacterium tuberculosis infection.? Clinical manifestations include primary TB, reactivation TB, laryngeal TB, endobronchial TB, lower lung field TB, and tuberculoma.? The clinical manifestations of primary TB include fever generally gradual in onset and low grade.? A quarter of patients will have pleuritic or retrosternal pain (and of these one half will have a pleural effusion).? Rarer symptoms include fatigue, cough, arthralgias and pharyngitis.? In primary TB the chest radiograph is often normal.? Abnormalities in primary TB include hilar adenopathy (65% of cases), pleural effusion (one third of patients), pulmonary infultrates (27% of patients with perihilar and right sided infiltrates most common).? Reactivation TB refers to reactivation of a previously dormant focus seeded at the time of primary infection.? The apical posterior segments of the lung are frequently involved.? Typically symptoms are insidious and may include cough, weight loss, fatigue, fever, night sweats, chest pain, dyspnoea and or haemoptysis.MYCOPLASMA PNEMONIAE:? Mycoplasma pneumoniae is one of the most common causes of atypical pneumonia.? It can occur at any age but is most common among school aged children.? Many infections are asymptomatic.? The onset of the illness is gradual and is usually heralded by headache, malaise and low grade fever.? Chills are frequent but rigors are rare.? Only 10% of patients develop pneumonia.? Respiratory symptoms can include non productive to mildly productive cough, wheezing and dyspnoea (though dyspnoea is not a common complaint).? Pharyngitis, rhinorrhoea and ear pain may also be present.? There may be no findings on chest auscultation however scattered rales, wheezes or both may be present later.? Occasionally extrapulmonary abnormalities occur including haemolysis, rash, joint involvement, hepatitis and rarely encephalitis.? The most common radiographic findings include reticulnodular pattern and / or patchy areas of consolidation.? Infiltrates can be unilateral or bilateral and airspace consolidation is more common in the lower lobes.? Diagnostic testing for M. pneumoniae remains inadequate thus most treatment is empiric.? Serology remains the mainstay of diagnosis.STREPTOCOCCUS PNEUMONIAE:? Pneumococcus (Streptococcus pneumoniae) is the leading cause of pneumonia requiring hospitalisation in all age groups.? The classic presentation of pneumococcal pneumonia is an abrupt onset of fever, chills, cough and side pain.? Physical exam typically reveals signs of consolidation.? Complications of infection include empyema, necrotising pneumonia and lung abscess.? Chest x-ray typically reveals a classic lobar consolidation.? Sputum gram stain can suggest pneumococcal infection however the diagnosis is usually confirmed with blood culture. ................
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