IM 3A- Pulmonology- Pneumonia

IM 3A: PULMONOLOGY PNEUMONIA SOURCE: PPT 2016 + Castillo trans OCTOBER 2016

PNEUMONIA - There are an estimated 4 million cases of CAP/yr in the US - Approximately 10 million physician visits, 1 million hospitalizations, 45,000 deaths - Mortality of CAP - In hospitalized patients: 14% - Require ICU care: 20-50% - In the Philippines, it’s the 3rd leading cause of morbidity and mortally based on Phil Health Statistics of

DO NOT REQUIRE HOSPITALIZATION Mycoplasma pneumoniae
 Streptococcus pneumoniae
 Chlamydophila pneumoniae
 Haemophilus influenzae
 Respiratory viruses

DOH

PATHOPHYSIOLOGY Inhalation pneumonia is most often due to microorganisms that: - Survive long enough while suspended in the air to be transported far from the initial source - Have a size less than 5 um and carry a high inoculum - Evade local host defenses Aspiration of oropharyngeal secretions: - Main mechanism of contamination of lower airways by large bacteria— MOST COMMON MECHANISM - Awake - normal glottal reflexes prevent aspiration - Asleep - 50% of normal persons aspirate small volumes of pharyngeal secretions - Healthy adults - 10 to 100 million bacteria/mL of secretions - 100- to 1000-fold increase in patients with periodontal disease - Aspiration of 0.001 mL = inoculum of >100,000 microorganisms - Normal oropharynx is predominated by a mixed flora of low virulence. - The ability of virulent microorganisms to colonize the oropharynx is determined by the interaction of specific microbial adhesins with cellular receptors: • Streptococcus pneumoniae • Staphylococcus aureus • Pseudomonas aeruginosa • Klebsiella pneumoniae Glycoproteins (fibronectin) in oral mucus - Promote the adherence of viridans streptococci and prevent colonization of the oropharynx by gramnegative bacilli - Colonization is increased in persons with lower levels of salivary fibronectin consequent to alcoholism, diabetes, malnutrition, other severe comorbidities Gram-negative bacillus colonization also occurs when new receptors appear in the surface of epithelial cells. This occurs following influenza infection or in chronic obstructive pulmonary disease (COPD). Aerosolization is the route of infection by intracellular bacteria such as Mycoplasma pneumoniae, Chlamydophila spp., and Coxiella burnetii Aspiration: S. pneumoniae, Haemophilus influenzae, gram-negative bacilli, and related organisms HAP: - Inhalational pneumonia due to Legionella - Contaminated medical aerosols - Aspiration especially in intubated patients— Biofilms are a well-recognized reservoir of bacteria that facilitate the development of HAP.

EPIDEMIOLOGY CAP - True incidence : uncertain - Only 20% to 50% of patients require hospitalization. - Estimates : 2 to 15 cases/1000 persons/yr higher rates in the elderly - Severity of disease is largely determined by: subject's age, presence and type of any coexisting illness

IM 3A:Pulmonology- Pneumonia

COMON CAUSES OF CAP REQUIRE HOSPITALIZATION SEVERE CAP (listed in general order of frequency) Streptococcus pneumoniae: Streptococcus pneumoniae
 MC etiologic agent in admitted Enteric gram-negative bacilli
 patients with pneumonia
 Staphylococcus aureus
 Mycoplasma pneumoniae
 Legionella spp.
 Chlamydophila pneumoniae
 Mycoplasma pneumoniae
 Haemophilus influenzae
 Respiratory viruses
 Mixed infections
 Pseudomonas aeruginosa (determined by Enteric gram-negative bacilli
 the presence or absence of specific risk Aspiration (anaerobes)
 factors: previous antibiotic treatment, Respiratory viruses
 structural lung disease like bronchiectasis, Legionella spp. cystic fibrosis) *Severity of disease warranting treatment in an intensive care unit.

FACTORS 1. AGE RELATED FACTORS Children younger than 2 years Older children and young adult Elderly

Older than 80 years old

S. pneumoniae and RSV M. pneumoniae At risk for: - pneumococcal pneumonia - M. catarrhalis - H. influenzae - L. pneumophila - gram negative bacilli - C. pneumoniae - polymicrobial infections Higher incidence of aspiration pneumonia Lower incidence of Legionella spp.

2. PERSONAL HABITS - Alcohol consumption: Important risk factor for CAP - Immunosuppressive effects - Potential to lower consciousness level—> ↑ risk of aspiration pneumonia - Independent risk factor for an increased rate and severity of pneumonia, especially that due to S. pneumoniae - Persists several months after cessation of alcohol consumption - Smoking - Associated with CAP due to S. pneumoniae, L. pneumophila, and influenza - Alters mucociliary transport and humoral and cellular defenses, affects epithelial cells - Increases adhesion of S. pneumonia and H. influenzae to the oropharyngeal epithelium. 3. COMORBIDITIES - COPD: Most frequent comorbidity associated with CAP - Microorganisms frequently colonize the lower airways of patients with COPD such patients have important alterations in mechanical and cellular defenses - Severe COPD (FEV1< 30% of predicted) and bronchiectasis: increased risk for pneumonias caused by H. influenzae and P. aeruginosa - Patients treated with oral corticosteroids for long periods: risk for Aspergillus spp. is increased - Bronchitis and pneumonia - major causes of morbidity and mortality in patients with cystic fibrosis. - Other comorbidities : congestive heart PATHOGENS PRESENT IN PATIENTS WITH CF failure, chronic kidney or liver disease, Infants P. aeurginosa cancer, diabetes, dementia, cerebrovascular diseases, and First decade of life S. aureus and nontypeable H. influenza immunodeficiency states 18 years of age 80% P. aeruginosa - Malnutrition-related phenomena: ↓ 3.5 % non fermenters: - Burkholderia cepacia secretory IgA, failure of macrophage - Stenotrophomonas maltophilia recruitment, alterations in cellular immunity - Stenotrophomonas maltophilia —> colonization by gram-negative bacilli is - Achromobacter xylososidans increased - Nontubercuolos mycobacteria

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4. GEOGRAPHICAL AND OCCUPATIONAL CONSIDERATIONS Etiologic agent Occupations/Exposure S. pneumoniae Soldier, painters, South African gold miners Burkholderia pseudomallei (melioidosis) Rural tropics Animal exposure: Zoonotic Psittacosis Birds Rhodococcis Horses Yersinia pestis Rodent Francisella tularensis(tularemia) Sheep, dogs, cats C. burnetti Australia, Basque region of Spain, Nova Scotia S. pneumonia and H. influenzae Winter months

EPIDEMIOLOGY HAP Early onset HAP (5 days of hospitalization)

S. pneumoniae H. influenza Anaerobes MRSA enteric gram-negative bacilli P. aeruginosa Nonfermenters: Acinetobacter baumanii S. maltophilia

FACTORS INCREASING THE RISK OF HAP - Antibiotic exposure - Old age - Severe comorbidities - Immunosuppression - Colonization of the oropharynx by virulent microorganisms - Conditions that promote pulmonary aspiration or inhibit coughing (thoracoabdominal surgery, endotracheal intubation, insertion of nasogastric tube, supine position)

- Exposure to contaminated respiratory equipment HEALTH CARE-ASSOCIATED PNEUMONIA - S. aureus (both methicillin-sensitive and -resistant) and P. aeruginosa - Were the most frequent microorganisms - More severe disease, higher mortality, greater length of stay - Common in nursing homes, lengthy stay in the hospital, dialysis patients

Etiology

Onset Cough Sputum Pulmonary signs and symptom

Extrapulmo nary symptoms CBC CXR

EPIDEMIOLOGY OF TYPICAL AND ATYPICAL PNEUMONIA Atypical Pneumonia Syndrome Typical Pneumonia Syndrome M. pneumonia Mycoplasma S. pneumonia Legionella sp. Coxiella H. influenza Chlamydophila viruses Klebsiella sp pneumoniae Mixed aerobic & anaerobic oral flora Gradual Acute Dry cough Productive cough Scanty Purulent or bloody - Shortness of breath Shortness of breath - Pleuritic chest pain (very specific of S. pneumoniae) - Sign of pulmonary consolidation - Rales Prominent (headache, myalgia, fatigue, Not prominent nausea, vomiting, diarrhea) Intense and unique chill *Typically more prominent than pulmonary signs and symptoms Normal WBC count Leukocytosis with neutrophilic with band forms Diffuse interstitial infiltrates Lobar condensation with air bronchograms

IM 3A:Pulmonology- Pneumonia

PATIENT EVALUATION • Clinical Evaluation - Best differentiate CAP from other acute respiratory tract infection - Cough, fever, tachypnea, tachycardia, and pulmonary crackles - CAP is present in 20% to 50% of persons who have all four factors Clues to the etiologic diagnosis outside the respiratory tract: Legionella Chlamydophilia psitacci Mycoplasma pneumoniae Mycoplasma P. aeruginosa Mycoplasma Tularemia - Arthralgia - Myocarditis - Erythema - Ecthyma Bradycardia (in relation to - Cervical LAD - Hepatitis amount of fever) multiforme gangrenosum - Bulls myringitis - Nausea - Erythema - Diarrhea - Pericarditis nodosum - Myalgia - Vomiting • Laboratory Evaluation - Blood cell counts, serum glucose and electrolyte measurements, and pulse oximetry or ABG assays S. pneumoniae Marked Leukocytosis with H. influenza leftward shift Gram-negative bacilli Leukopenia Overwhelming pneumococcal or gram-negative bacillary pneumonia

• Procalcitonin - A precursor of calcitonin released into the blood of persons with bacterial infections. - Useful to evaluate the severity and prognosis of the patients and to deescalate antibiotic treatments. - Routine use in the initial evaluation of CAP needs further evaluation. - Measured when we are thinking of shifting the antibiotic, from IV to oral because of septic to no septic conditions of the patients

• Radiographic Evaluation - Necessary to establish the presence of pneumonia - the sensitivity of the chest radiograph is decreased: - patients with emphysema, bullae, or structural abnormalities of the lung - Obese patients - Patients with: - Very early infection (labeled as “radiologic lag”) - Severe dehydration(causes blood vessels to collapse —> infiltrates less apparent) - Profound granulocytopenia (immune system response is less —> less infiltrates)

Unilobar typical pneumonia

Downward bulging of interlobar septum due to excess secretions usually caused by Klebsiella

- CXR: new parenchymal infiltrates confirms the diagnosis, assess the severity/prognostication, may suggest the etiology ETIOLOGIC AGENT/TYPE Typical pneumoniae Atypical pneumonia Pneumonia complicating aspiration

Infections from hematogenous seeding (MC: S. aureus)

RADIOGRAPHIC FINDINGS + air bronchograms and a lobar/segmental pattern Mixed pattern (alveolar and interstitial) - Superior segment of RLL - Posterior segment of RUL as well as corresponding segments on the left - multiple rounded shadows sometimes with cavities in the greatest distribution of blood flow

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• Microbiologic Evaluation - Serves to verify the clinical diagnosis of infection - Facilitates the use of specific therapy instead of unnecessarily broad-spectrum antimicrobial agents. - Although the utility of sputum examination is much debated, pleural fluid (if present) and two sets of blood cultures should be obtained in patients hospitalized for CAP. RECOMMENDED MICROBIOLOGIC EVALUATION IN PATIENTS WITH CAP PATIENTS WHO REQUIRE HOSPITALIZATION PATIENTS WHO REQUIRE TREATMENT IN ICU - Two sets of blood cultures Gram stain and culture of : - valid sputum sample - Gram stain and culture of a valid sputum sample - Urinary antigen test for detection of Legionella pneumophila (in - endotracheal aspirate - bronchoscopically obtained endemic areas) specimens using a protected - Stain for AFB and culture of sputum (if TB is suggested by history specimen brush or BAL or radiologic findings)

- Fungal stain and culture of sputum, and fungal serologies (if -

infection by an endemic mycosis is suggested by the clinical history or radiologic findings) Sputum examination for Pneumocystis jirovecii (if suggested by clinical history or radiologic findings) Serologies for M. pneumoniae, C. pneumoniae, C psittaci, Coxiella burnetii, Legionella spp., and respiratory viruses (in endemic areas or during outbreaks) Culture and microscopic evaluation of pleural fluid (if significant fluid is present)

OTHER PROCEDURES AS FOR OTHER HOSPITALIZED PATIENTS: - Examination of the Sputum - Microscopic examination of expectorated sputum is the easiest and most rapidly available method of evaluating the microbiology of lower respiratory tract infections. - Ideal sputum sample: - Few or no squamous cells (25 cells/LPF) - Excessive oropharyngeal contamination (not a good sample) - >10 squamous epithelial cells/LPF CLINICAL INDICATIONS FOR MORE EXTENSIVE TESTING IN CAP: - Intensive care unit admission - Severe obstructive/structural lung disease - Failure of outpatient antibiotic therapy - Asplenia - Radiographic cavities - Recent travel (within past 2 week) - Leukopenia - Positive Legionella Urinary Ag Test result - Active alcohol abuse - Positive pneumococcal Urinary Ag Test result - Chronic severe liver disease - Pleural effusion Blood and Pleural Fluid Cultures - Although the overall yield of blood cultures is probably less than 20% in patients hospitalized for CAP, a positive culture of blood or pleural fluid definitively establishes the etiologic diagnosis of pneumonia Antigen Detection - Commercial assays can be used to rapidly detect capsular polysaccharide antigens of S. pneumonia or L. pneumophila serogroup 1 in urine - L. pneumophila serogroup 1, the sensitivity is 60% to 80%, and the specificity is >95%. - S. pneumoniae sensitivity is 50% to 80% and the specificity 90 % Serologic techniques - are often the most practical means to establish a microbiologic diagnosis for pneumonia caused by pathogens that cannot be readily cultured - M. pneumoniae, C. pneumoniae, and L. pneumophila; less common causes of pneumonia such as those caused by the agents of tularemia, brucellosis, and psittacosis; and viral infections. - Diagnosis requires that a convalescent specimen demonstrate a fourfold rise in IgG titer above that present in an acute specimen.

IM 3A:Pulmonology- Pneumonia

Invasive Diagnostic Techniques a. Bronchoscopic Samples b. Transthoracic Lung Aspiration: injecting 30 ml liquid into the thoracic cavity then aspirate - Obtains specimens suitable for microbiologic and cytologic examination directly from lung parenchyma - Diagnostic yield is approximately 50% - With a sensitivity of 35% to 82% - Serious complications : pneumothorax (2%–5%) and hemoptysis (2%–5%)— hence, not usually done

THERAPEUTIC APPROACH

- Once the diagnosis of pneumonia has been made, the -

clinician must decide whether the patient can be managed in the outpatient setting. The second key decision is selection of the initial antimicrobial therapy. Assessment of Severity

The PSI (Pneumonia Severity Index) - Point scoring system - From a retrospective analysis of a cohort of 14,199 patients with CAP in 1989 and prospectively validated in a separate cohort of 38,039 patients with CAP in 1991. - Age is the most significant risk factor, with 1 point given for each year of age (−10 points in women). - Patients with a score < 50 are candidates for outpatient treatment, whereas those with scores > 90 warrant hospitalization. - Proper management of patients with scores of 70–90 requires careful application of clinical judgment. - A risk score is obtained by summing the patient's age in years (age −10 for females) and the points for each applicable patient characteristic.

Demographics Men Women

Points Comorbities

Age(yrs):__ +30 Age (yrs)-10:__ +20

Nursing +10 home resident

Neoplasm Liver disease

+15

+10

- Altered mental status - RR > 30 bpm - SBP 125 bpm

- Glucose >250 mg/ dL

- Hct 48 hours after intubation. TREATMENT: - Antibiotic regimens recommended for the empirical treatment of HAP typically include expanded-spectrum β-lactam agents, often given in combination with aminoglycosides or vancomycin. - If aspiration is likely, specific treatment for anaerobes (metronidazole, clindamycin) must be strongly considered. HIGH RISK CRITERIA: - age ≥ 65 years - Pancreatitis - chronic obstructive pulmonary disease - central nervous system dysfunction (stroke, drug overdose, coma, status epilepticus) - congestive heart failure * all other patients not listed are considered low risk

-

Malnutrition Diabetes mellitus Endotracheal intubation Renal failure Complicated thoracoabdominal surgery Alcoholism

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NURSING HOME ACQUIRED PNEUMONIA - The etiology of bacterial pneumonia in nursing home residents is diverse - HAP-associated pathogens - aerobic gram-negative rods, S. aureus - CAP-associated pathogens - S. pneumoniae, H. influenzae, “atypicals”, and anaerobes (due to the aspiration risk in these patients)

- Particular attention should be paid to providing adequate treatment for S. pneumoniae in all patients and to gram-negative bacilli, especially in patients with severe CAP in the setting of significant medical comorbidities or recent antimicrobial therapy.

ADJUSTMENT IN ANTIMICROBIAL THERAPY - Organisms recovered from normally sterile sites (blood, pleural fluid, CSF, or transthoracic lung aspiration specimens) are presumed to be pathogens.

- Expectorated sputum culture results must be interpreted in light of the quality of the specimen, correlation with pathogens identified by Gram stain, and the clinical impression.

- Pathogen-based modification of therapy is particularly important in HAP because prolonged use of broadspectrum empirical agents promotes the emergence of pathogens with multidrug resistance.

- If a pathogen is not identified, reevaluation of the initial therapeutic regimen must take into account the patient's response to therapy

- The change from parenteral to oral antimicrobial therapy can safely be made in CAP patients who are -

clinically stable and able to absorb effective oral antimicrobials (often achieved within 3 days of the initiation of parenteral therapy in hospitalized patients.) Pathogen-based modification of therapy is particularly important in HAP because prolonged use of broadspectrum empirical agents promotes the emergence of pathogens with multidrug resistance If a pathogen is not identified, reevaluation of the initial therapeutic regimen must take into account the patient’s response to therapy

Ideal drug for a known pathogen: - Has the narrowest spectrum of activity - Most efficacious - Least toxic - Least costly Indications for streamlining of antibiotic therapy: • Resolution of fever for >24 hours • No unstable comorbid condition or life-threatening complication such as MI, CHF, complete heart block, • Less cough and resolution of respiratory distress (normalization of RR new a-fib, SVT, etc. • Improving WBC count, no bacteremia • No sign of organ dysfunction such as hypotension, acute mental changes, BUN to creatinine ratio >10.1, • Etiologic agent is not a high-risk (virulenr/ resistant) pathogen e.g. Legionella, S. aureus hypoxemia, and metabolic acidosis or Gram-negative enteric bacilli • Patient is clinically hydrated, taking oral fluids and is able to take oral medication Recommended hospital discharge criteria: - Temperature of 36-37.5oC - SBP >90 mmHg - Pulse 90% - RR 16-24 cpm - Functioning GI tract If the patient’s conditions are not improving then it is recommended to do one of the following: Do Blood Culture (2 sets) Urine: Antigen test for detection of Legionella pneumophila Sputum: Legionella: GS, Giemsa stain, IF stains Mycobacteria spp. and Nocardia: Normal and modified Ziehl-Neelsen stain For conventional bacteria(Legionella, mycobacteria, fungi): Culture Bronchoscopy and Specimens Legionella and Pneumocystis jirovecii: GS, Giemsa stain, IF stains (Using PSB or BAL) Mycobacteria spp. and Nocardia: Normal and modified Ziehl-Neelsen stain Pleural Fluid For conventional bacteria(Legionella, mycobacteria, fungi): Culture LUNG ABSCESS - Pus-containing necrotic lesions of the lung parenchyma that often contain an air-fluid level.

IM 3A:Pulmonology- Pneumonia

- A similar process with multiple small cavities less than 2 cm in diameter has been designated necrotizing pneumonia by some clinicians.

- May be associated with infections caused by pyogenic bacteria, mycobacteria, fungi and parasites - May also complicate pulmonary infarction, primary and metastatic malignancies, and the necrotic conglomerate lesions of silicosis and coal miners’ pneumoconiosis

- May be a cause of nonresolving pneumonia

IMAGING STUDIES: - In nonresolving pneumonia, a simple chest radiograph may demonstrate pleural effusion, cavitation, or new changes. - In progressive pneumonia, clinical deterioration and the extension of the radiographic image may appear during the first 72 hours after the initiation of satisfactory treatment. - Pulmonary CT scans: more detailed study of the parenchyma, interstitium, pleura, and mediastinum. - Nodular images with the halo sign (i.e., a nodule surrounded by a halo of ground-glass attenuation, especially near the pleura) on CT scan is suggestive of pulmonary aspergillosis or mucormycosis. - Nodules of similar appearance have also been described in cytomegalovirus infection, Wegener's granulomatosis, Kaposi's sarcoma, and hemorrhagic metastasis. - Chest radiography of P. jirovecii pneumonia: characteristic ground-glass opacities consistent with interstitial pneumonia. Infection by Nocardia spp., M. tuberculosis, or Q fever may result in nodules or multiple masses with or without cavitation. - Diffuse or mixed interstitial and alveolar opacities may be due to viral infections or M. pneumoniae. - Other imaging studies, such as perfusion-ventilation scintigraphy, may be performed according to the clinical suspicion of pulmonary embolism. Spiral CT scans and pulmonary arteriography complement this diagnostic procedure. PREVENTION: - Vaccinations - Administering the pneumococcal and influenza (during flu season) vaccines for eligible patients. - The recommendations for administration of live, attenuated influenza vaccine are healthy persons from 5 to 49 years including health care providers and household contacts of high-risk patients. - We usually advise influenza vaccine in patients 60 years and above but high contact persons like the health care providers are given the flu vaccine - Vaccines are given every 5 years for high risk patients other clinicians prefer 1 dose 60 years old and 1 dose after 65 years old as it is more economical - Other conditions that indicate immediate administration of flu vaccine upon diagnosis: - COPD - CVD - DM - Bronchiectasis - Heart failure - Chronic alcoholism - Chronic TB - Cardiomyopathy - Liver, renal, neurologic disease - Asplenia Influenza Vaccine

Pneumococcal Vaccine - all persons >60 - Chronic illness: Pulmonary (COPD, cardiovascular (hypertension), renal, hepatic, bronchiectasis, PTB), neurological/neuromuscular, hematological or cardiovascular (CHF and metabolic (including DM) cardiomyopathies), DM, alcoholism, - Immunosuppression: HIV, malignancies, chronic liver disease, chronic renal immunosuppressive drug, RT, organ or BM failure or nephrotic syndrome, CSF transplantation leaks, functional or anatomic - Pregnancy: 2nd or 3rd trimester asplenia - Residents of nursing homes and other chronic care - Immunosuppression: HIV, facilities lymphoma, luekemia, multiple - Health care personnel myeloma, generalized malignancy, - Household contacts (including children) and immunosuppressive drug (chemo caregivers of children aged less than 5 years and or corticosteroids), solid organ or adults aged 50 and above BM transplantation - Household contacts (including children) and - Residents of nursing homes and caregivers of persons with medical conditions that other chronic care facilities put them at high risk for severe complications from - Smokers or asthmatic persons influenza 19-64 years old Adult dose 0.5 ml IM once a year Single 0.5 ml dose IM or SQ Indicaions

- all persons 50 and above - Chronic illness: Pulmonary (including asthma),

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Precaution s/ Contraindi cations

- Anaphylactic reaction to a previous dose of -

influenza vaccine Allergy to eggs or to a vaccine component Moderate or severe acute illness with or without a fever Active neurologic disorder or a history of developing neurologic symptoms or illness following a previous dose History of GBS

Potential Pathogens S. pneumoniae H. influenzae C. pneumoniae M. pneumoniae M. catarrhalis Enteric Gram-negative bacilli (among those with comorbidities)

- Immediate anaphylactic reaction to -

a previous dose Allergy to a vaccine component: anaphylaxis to phenol or thimerosal Moderate to severe illness with or without fever

LOW-RISK CAP Empiric treatment Drug Previously healthy: - B-lactams Amoxicillin - Extended Macrolides Aztihromycin (suspected atypical Clarithromycin pathogen) With stable comorbid illness: - B-lactam with BAmoxicillinlactamase inhibitor Clavulanic acid combination (BLIC) AmoxicillinSulbactam Sultamicillin - Second generation Cefaclor oral cephalosporins +/- extended Cefuroxime axetil macrolides Alternative: - Third generation oral cephalosporin +/extended macrolide

Dose 500 mg TID 500 mg OD 500 mg BID

625 mg TID or 1 gm BID 1 gm TID 750 mg BID 500 mg TID or 750 mg BID 500 mg BID

Cefdinir 300 mg BID Cefixime 200 mg BID Cefpodoxime proxetil 200 mg BID MODERATE RISK CAP S. pneumoniae IV non-antipseudomonal B-lactam (BLIC, cephalosporin or carbapenem) H. influenzae 1.2 g q8h BLIC AmoxicillinC. pneumoniae Clavulanic acid, IV M. pneumoniae Ampicillin1.5 g q8h M. catarrhalis Sulbactam, IV Enteric Gram-negative Cephalosporin 2nd generation: bacilli (among those with Cefotiam, IV 1 g q8h comorbidities) Cefoxition, IV (with 1-2 g q8h Legionella pneumophilia anaerobic activity) Anaerobes (among Cefuroxime Na, IV 1.5 g q8h those with risk of 3rd generation: aspiration) Cefotaxime, IV 1-2 g q8h Ceftizoxime, IV (with 1-2 g q8h anaerobic activity) Ceftriaxone, IV 1-2 g q24h 1 g q24h Carbapenem Ertapenem, IV 500 mg q24h + extended macrolide Azithromycin dihydrate, PO/IV Clarithromycin, PO/IV 500 mg q12h Erythromycin PO/IV 0.5-1 g q6h OR IV non-antipseudomonal B-lactam (BLIC, cephalosporin or carbapenem) + respiratory fluoroquinolones Respiratory Quinolones Levofloxacin PO/IV 500-700 mg q24h Moxifloxacin PO/IV 400 mg q24h IM 3A:Pulmonology- Pneumonia

S. pneumoniae H. influenzae C. pneumoniae M. pneumoniae M. catarrhalis Enteric Gram-negative bacilli (among those with comorbidities) Legionella pneumophilia Anaerobes (among those with risk of aspiration) S.Aureus P. aeruginosa

HIGH RISK CAP (all drugs given thru IV) No risk for P. aeruginosa: IV non-antipseudomonal B-lactam (BLIC, cephalosporin or carbapenem) + IV extended macrolide or IV respiratory FQ same dose with moderate BLIC same drugs with Cephalosporin moderate Carbapenem Macrolide Dose of levofloxacin 750 IV respiratory mg q24h, maxi same dose fluoroquinolone With risk for P. aeruginosa IV anti-pneumococcal antipseudomonal B-lactam (BLIC, cephalosporin or carbapenem) + IV extended macrolide + aminoglycoside Anti-pneumococcal, Cefoperazone1.5-3 gm q8-12h antipseudomonal Bsulbactam lactams (BLIC, Piperacillin2.25-4.5 g q6-8h cephalosporin, Tazobactam carbapenem) Ticarcillin-clavulanic 3.2 g q6h acid Cefepime 2 g q8-12h Cefpirome 2 g q12h Imipinem-cilastatin 0.5-1 g q6-8h Meropenem 1-2 g q8h Aminoglycosides Amikacin 15 mg/kg q24h Gentamicin 3 mg/kg q24h Netilmicin 7 mg/kg q24h Tobramycin 3 mg/kg q24h IV anti-pneumococcal antipseudomonal B-lactam (BLIC, cephalosporin or carbapenem) + IV ciprofloxacin/levofloxacin (high-dose) Anti-pseudomonal FQ Ciprofloxacin 400 mg q12h Levofloxacin 750 mg q24h Anti-pneumococcal FQ Moxifloxacin 400 mg q24h OTHERS: Oxacillin 1-2 g q4-6h (Staphylociccus) Clindamycin 600 mg q6-8h (Staphylococcus and anaerobes) Metronidazole 500 mg q6-8h (anaerobes) Linezolid (MRSA) 600 mg q12h Vancomycin (MRSA) 1 g q12h

KEY POINTS: - All patients with suspected pneumonia should have a chest radiograph. - Gram stains and cultures of blood, sputum, and other sites should be obtained in hospitalized patients prior to treatment. - Infection by the aerosolization route occurs with the intracellular bacteria - M. pneumoniae, Chlamydophila spp., and C. Burnetii - Infection occurs by aspiration with S. pneumoniae, H. influenzae, gram-negative bacilli - Aside from inhalational pneumonia due to Legionella or contaminated medical aerosols, aspiration is the cause of HAP, especially in intubated patients - In elderly and immunocompromised patients, the signs and symptoms of pneumonia may be muted and overshadowed by nonspecific complaints. Elderly patients with pneumonia who present with altered mental status without fever have a delay in receiving antibiotics and this delay affects mortality. - The treatment for pneumonia should be pathogen-directed, but pathogens are rarely identified initially. Therefore, the setting in which the patient resides (e.g., community, hospital, nursing home), the severity of the disease, the age of the patient, the presence of comorbidities and immunosuppression, previous antimicrobial therapy, and specific clinical and radiologic manifestations of the illness must be considered. - If the etiologic agent has been reliably identified, the antimicrobial regimen should be adjusted based on the results of in vitro susceptibility testing. The ideal drug for a known pathogen has the narrowest spectrum of activity and is the most efficacious, least toxic, and least costly.


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