Defination PATHOLOGICAL:- Infection of alveoli, distalairways and interstitium of the lung that ismanifested by increased weight of thelungs, replacement of the normal lung’ssponginess by consolidation and alveolifilled withWBC, RBC and fibrin. CLINICAL:- Pneumonia is a constellation ofsymptoms and signs in combination with atleast one opacity on chest radiography.
Classification BY SOURCE : Community acquired Noscomial Aspiration Immunocompromised host Pathological Lobar bronchopneumonia
By Infectious Agents Bacterial Atypical Viral Fungi Others On basis of previous health status Primary Secondary
HOST DEFENCES IN LUNGSUpper airway:- Nasal turbinates and angulation of pharynx Mucociliary transport system Mucins Decreased mucosal pH Natural bacterial & epithelial cell bindinganalogues Secretory IgA Constant desquamation of epithelial cells Nonpathogenic bacteria
ROUTES OF INFECTIONMicroaspiration of oropharyngeal secretionscolonized with pathogenic microorganisms(e.g., S. pneumoniae, H. influenzae) is themost common route.Gross aspiration –More common in patients with impaired level of consciousness:alcoholics, IVDA, seizures, stroke, anesthesia, swallowing disorders,NG tubes, ETTGram positive and anaerobes: Strep pneumo, H flu, Mycoplasma,Moraxella,ActinomycesGram negatives: more likely with hospitalization, debility, alcoholism, DM, andadvanced age Source may be stomach which can become colonized with theseorganisms with use of H2blockers
Aerosolization –TB, fungi, Legionella,CoxiellaHematogenous spread –Staph aureusFusobacterium infections of the retropharyngeal tissuesDirect spreadstab wound, ETT
DEFINATION Community-acquired pneumonia (CAP) is aninfection of the alveoli, distal airways, andinterstitium of the lungs that occurs outsidethe hospital setting in ambulatory patients orpreviously ambulatory patients within 48hrsafter admission in hospital.
Etiology Most cases of CAP are caused by a fewcommon respiratory pathogens, including: Streptococcus pneumoniae Accounts for ~50% of all cases of CAPrequiring hospital admission
Condition OrganismAlcoholismStreptococcus pneumoniae, oralanaerobes, Klebsiella pneumoniae,Acinetobacter species, MycobacteriumtuberculosisCOPD and/or smokingHaemophilus influenzae, Pseudomonasaeruginosa, Legionella species, S.pneumoniae, Moraxella catarrhalis,Chlamydophila pneumoniaeLung abscessCA-MRSA, oral anaerobes, endemicfungal pneumonia, M. tuberculosis,atypical mycobacteriaExposure to bat or bird droppings Histoplasma capsulatumExposure to birdsChlamydophila psittaci (if poultry: avianinfluenza)
Exposure to birdsChlamydophila psittaci (if poultry:avian influenza)Exposure to rabbits Francisella tularensisExposure to farm animals or parturientcatsCoxiella burnetti (Q fever)HIV infection (early)S. pneumoniae, H. influenzae, M.tuberculosisHIV infection (late)Pneumocystis jirovecii, Cryptococcus,Histoplasma, Aspergillus, atypicalmycobacteria (especiallyMycobacterium kansasii), P. aeruginosa,H. influenzaeHotel or cruise ship stay in previous 2weeksLegionella speciesInjection drug useS. aureus, anaerobes, M. tuberculosis, S.pneumoniae
Bacteria are the most common cause of CAP andhave traditionally been divided into two groups,"typical" and "atypical" agents: "Typical" organisms include S. pneumoniae,Haemophilus influenzae (H. influenzae), S.aureus, Group A streptococci, Moraxellacatarrhalis, anaerobes, and aerobic gram-negative bacteria. "Atypical pneumonia” refers to pneumoniacaused by Legionella spp, M. pneumoniae,Chlamydophila (formerly Chlamydia)pneumoniae, and C. psittaci, and is a term thatshould no longer be used.
Diagnostic Approach Assess pneumonia severity. Pay attention to vital signs, including oxygensaturation. Always count the respiratory rate yourself for1 min. The single most useful clinical sign of severityis a respiratory rate of > 30/min in a personwithout underlying lung disease. Ensure adequate oxygenation and support ofcirculation during the evaluation
Consider possible etiologies. Carefully collect information on: Travel Occupational and other exposures Underlying illnesses Prior infections Never forget tuberculosis and Pneumocystisinfection as possible etiologies. Consider pulmonary embolus in all patientswith pleuritic chest pain.
Perform etiologic workup. Chest x-ray Sputum stains and cultures Blood cultures, if bacteremia is likely Urine antigen tests for S. pneumoniae andLegionella pneumophila type 1 can be helpful. Serology can be helpful in identifying certainpathogens.
Laboratory Tests Assessment of the severity of pneumonia andcoexisting disease Arterial blood gas Complete blood count Serum electrolyte and glucose measurements Blood urea nitrogen (BUN) and creatininemeasurements Sputum stains and culture Gram’s stain
All patients admitted to the hospital for CAPshould have 2 sets of blood cultures donebefore initiation of antibiotic therapy Detection of antigens of pulmonarypathogens in urine for Legionella pneumophilia S pneumoniae
Serology Detection of IgM antibody or demonstration of a 4-fold risein titer of antibody to a particular agent between acute-and convalescent-phase serum samples. M. pneumoniae C. pneumoniae Chlamydia psittaci Legionella spp. Coxiella burnetii Adenovirus Parainfluenza viruses Influenza virus A
ImagingChest x-ray Diagnostic test of choice for pneumonia May show lobar consolidation, interstitial infiltrates,cavitation, associated pleural fluid, etc. Occasionally, an etiologic diagnosis is suggested bychest radiography findings. A cavitating upper-lobe lesion raises the likelihood oftuberculosis. Pneumatoceles suggest S. aureus pneumonia. An air-fluid level suggests a pulmonary abscess,which often is polymicrobial. In the immunocompromised host, a crescent(meniscus) sign suggests aspergillosis.
If pneumonia is strongly suspected on clinicalgrounds and no opacity is seen on the initialchest radiograph, it is useful to repeat theradiograph in 24–48 hours or to perform CT. High-resolution CT Occasionally detects pulmonary opacities inpatients with symptoms and signs suggestiveof pneumonia and negative chest x-ray
Special Examinations DiagnosticThoracocentesisthe fluid should be sampled for studiesincluding Gram’s stain, culture, cell counts,and measurements of protein, lactatedehydrogenase (LDH), glucose, and pH. SPUTUM INDUCTION AND FIBEROPTICBRONCHOSCOPY PROCALCITONIN PCR
INDICATIONS FOR ADMISSION PSI CURB 65 Confusion (based upon a specific mental test or disorientation to person, place,or time) Urea (blood urea nitrogen in the United States) >7 mmol/L Respiratory rate >30 breaths/minute Blood pressure [BP] (systolic <90 mmHg or diastolic <60 mmHg) Age >65 yearsCURB-65 report suggested that patients with a CURB-65 score of 0 to 1 were at low risk and could probablybe treated as outpatients; those with a score of 2should be admitted to the hospital, and those with ascore of 3 or more should be assessed for ICU care,particularly if the score was 4 or 5.
ATS/IDSA Criteria for ICU Rx Minor criteriaa Respiratory rateb 30 breaths/min PaO2/FiO2 ratio less then 250 Multilobar infiltrates Confusion/disorientation Uremia (BUN level more then 7mmol/l) Leukopeniac (WBC count, less then 4000 cells/mm3) Thrombocytopenia (platelet count, less 100,000 cells/mm3) Hypothermia (core temperature, less then 36C) Hypotension requiring aggressive fluid resuscitation Major criteria Invasive mechanical ventilation Septic shock with the need for vasopressors
Empiric Therapy Outpatient treatment 1. Previously healthy and no use of antimicrobials within the previous 3months: A macrolide (azithromycin, clarithromycin, or erythromycin)OR Doxycyline 2. Presence of comorbidities such as chronic heart, lung, liver or renaldisease; diabetes mellitus; alcoholism; malignancies; asplenia;immunosuppressing conditions or use of immunosuppressing drugs; oruse of antimicrobials within the previous 3 months (in which case analternative from a different class should be selected): A respiratoryfluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin [750 mg]) OR A beta-lactam (first-line agents: high-dose amoxicillin, amoxicillin-clavulanate; alternative agents: ceftriaxone, cefpodoxime, orcefuroxime) PLUS a macrolide (azithromycin, clarithromycin, orerythromycin)* 3. In regions with a high rate (>25 percent) of infection with high-level(MIC ≥16 µg/mL) macrolide-resistant Streptococcus pneumoniae,consider use of alternative agents listed in (2) above.
Inpatients, non-ICU treatment A respiratory fluoroquinolone (moxifloxacin,gemifloxacin, or levofloxacin [750 mg]) OR An antipneumococcal beta-lactam (preferredagents: cefotaxime, ceftriaxone, orampicillin-sulbactam; or ertapenem forselected patients)• PLUS a macrolide(azithromycin, clarithromycin, orerythromycin)*Δ
Inpatients, ICU treatment An antipneumococcal beta-lactam (cefotaxime,ceftriaxone, or ampicillin-sulbactam) PLUSazithromycin OR An antipneumococcal beta-lactam (cefotaxime,ceftriaxone, or ampicillin-sulbactam) PLUS arespiratory fluoroquinolone (moxifloxacin,gemifloxacin, or levofloxacin [750 mg]) OR For penicillin-allergic patients, a respiratoryfluoroquinolone (moxifloxacin, gemifloxacin, orlevofloxacin [750 mg]) PLUS aztreonam
Special concerns If Pseudomonas is a consideration: An antipneumococcal,antipseudomonal beta-lactam (piperacillin-tazobactam,cefepime, imipenem, or meropenem) PLUS eitherciprofloxacin or levofloxacin (750 mg) OR The above beta-lactam PLUS an aminoglycoside PLUSazithromycin OR The above beta-lactam PLUS an aminoglycoside PLUS arespiratory fluoroquinolone (moxifloxacin, gemifloxacin, orlevofloxacin [750 mg]); for penicillin-allergic patients,substitute aztreonam for above beta-lactam IfCA-MRSA is a consideration: Add vancomycin or linezolid
Clinical Response Most patients with CAP will have an adequateresponse within 3 days. Switch to oral antibioticsafter Resolution of fever for >24 hrs. Resolution of tachypnoea Pulse < 100 beats /min Resolution of hypotension Hydrated and taking oral fluidsAbsence of hypoxia Improving white cell count Non-bacteremic infection No concern over GI absorption
Duration of therapy Patients managed in community and admittednon-severe uncomplicated pneumonia:07 DAYSTHERAPY IS ENOUGH Patients with severe microbiologically undefinedpneumonia:10 DAYSTHERAPY IS PROPOSED Patients suffering from legionella, staphylococcal, orGram negative enteric bacilli pneumonia: 14-21 DAYSTHERAPY IS RECOMMENDED
COMPLICATIONS Usually result of direct spread of bacterialinfection within thoracic cavity.(pleural effusion- empyema- pericarditis) bacteremia and hematologic spreadmeningitis suppurative arthritis osteomyelitis
Non Resolving PneumoniaConsider other diagnosis TB Lung Cancer Fungal pneumonia Foreign body inhalation Eosinophilic pneumonias, Sarcoidosis Pulmonary embolism Pulmonary hemorrhage Heart failure
Correct Diagnosis but Failto Respond Host: Obstruction, Foreign body,Superinfection, Empyema Drug: Error in drug selection, dose or route,Compliance, Drug interaction Pathogen: Nonbacterial, Resistant
SOME FACTS ABOUT CAP The etiologic agent causing CAP cannot beaccurately predicted from clinical orradiological features The term ‘atypical pneumonia’ should beabandoned Elderly patients with CAP more frequentlypresent with non specific symptoms and areless likely to have fever Radiological resolution may take upto 6weeks Radiological resolution is slow in the elderlyand cases of multilobar involvement.
The 2005 AmericanThoracic Society/Infectious Diseases Societyof America (ATS/IDSA) guidelines: Hospital-acquired (or nosocomial) pneumonia (HAP) ispneumonia that occurs 48 hours or more after admission and didnot appear to be incubating at the time of admission. Ventilator-associated pneumonia (VAP) is a type of HAPthat develops more than 48 to 72 hours after endotrachealintubation. Healthcare-associated pneumonia (HCAP) is defined aspneumonia that occurs in a non-hospitalized patient withextensive healthcare contact, as defined by one or more of thefollowing: - Intravenous therapy, wound care, or intravenouschemotherapy within the prior 30 days - Residence in a nursing home or other long-term care facility - Hospitalization in an acute care hospital for two or more dayswithin the prior 90 days - Attendance at a hospital or hemodialysis clinic within theprior 30 days
DIFFERENCE B/W CAP & NP DIFFERENT INFECTIOUS CAUSES DIFFERENTANTIBIOTIC SUSCEPTIBILITYPATTERNS PATIENTS UNDERLYING HEALTH STATUS
PNEUMONIA ORGANISMHAP SAUREUS,MRSA,PAERUGINOSA,GRAM –VE RODSVAP ACTINOBACTER,HCAP S PNEUMONIAE, H INFLUENZACommon pathogens include aerobic gram-negative bacilli(eg, Escherichia coli, Klebsiella pneumoniae, Enterobacterspp, Pseudomonas aeruginosa, Acinetobacter spp) andgram-positive cocci (eg, Staphylococcus aureus, includingmethicillin-resistant S. aureus [MRSA], Streptococcus spp).Nosocomial pneumonia due to viruses or fungi issignificantly less common, except in theimmunocompromised patient.
S/S The clinical diagnosis of HAP,VAP, and HCAP is difficult in partbecause the clinical findings are nonspecific.The 2005 ATS/IDSAguidelines concluded that HAP,VAP, or HCAP should besuspected in patients with a new or progressive infiltrate on lungimaging as well as clinical characteristics such as Fever Purulent sputum Leukocytosis Decline in oxygenation The presence of a new or progressive radiographic infiltrate plusat least two of the three clinical features (fever >38ºC,leukocytosis or leukopenia, and purulent secretions) represents aclinically relevant combination of criteria for starting empiricantimicrobial therapy.
SPECIAL EXAMINATION ENDOTRACHEALASPIRATION FIBEROPTIC BRONCHOSCOPYWITH BAL PROCALCITONIN
Risk factor for MDR• Antimicrobial therapy in preceding 90 d• Current hospitalization of 5 d or more• High frequency of antibiotic resistance in the community orin the specific hospital unit • Presence of risk factors for HCAP: Hospitalization for 2 d or more in the preceding 90 d Residence in a nursing home or extended care facility Home infusion therapy (including antibiotics) Chronic dialysis within 30 d Home wound care Family member with multidrug-resistant pathogen • Immunosuppressive disease and/or therapy
High risk use 1 frm each 1) anti pseudomonal Cefepime,imipenem,tanzo,aztreonam 2)2nd anti pseudomonal Levofloxocin,ciprofloxocin,aminoglycosides 3) coverage for MRSA with either Vancomycin or linezolid