Oral anaerobes, S. aureus, S. pneumoniae serotype III, aerobic gram-negative bacilli, M. tuberculosis , and fungi as well as certain noninfectious conditions can produce tissue necrosis and pulmonary cavities.
H. influenzae , M. pneumoniae , viruses, and most other serotypes of S. pneumoniae almost never cause cavities.
Apical disease, with or without cavities, suggests reactivation tuberculosis.
Anaerobic abscesses are located in dependent, poorly ventilated, and poorly draining bronchopulmonary segments and characteristically have air-fluid levels, unlike the well-ventilated, well-drained upper-lobe cavities caused by M. tuberculosis , an obligate aerobe.
Air-fluid levels may also be present in cavities due to pulmonary necrosis of other infectious etiologies, such as S. aureus and aerobic gram-negative bacilli.
Mucor and Aspergillus invade blood vessels and cause pleural-based, wedge-shaped areas of pulmonary infarction.
In the patient with an uncomplicated course, chest radiographs need not be repeated before discharge, since the resolution of infiltrates may take up to 6 weeks after initial presentation.
In patients who do not respond clinically, who have a pleural effusion on admission, who may have postobstructive pneumonia , or who are infected with certain pathogens (e.g., S. aureus , aerobic gram-negative bacilli, or oral anaerobes) need more intensive surveillance.
d The new macrolides azithromycin and clarithromycin are more active against H. influenzae than erythromycin and are equally or more active against other respiratory pathogens. c In the United States, about 42% of strains are currently resistant to penicillin (15% with high-level penicillin resistance), 20% to amoxicillin and cefuroxime, 20-30% to trimethoprim-sulfamethoxazole, 7-10% to doxycycline (tetracycline), 14% to erythromycin, and <4% to the newer fluoroquinolones. b Levofloxacin, gatifloxacin, moxifloxacin, and sparfloxacin. a +, effective; -, ineffective; ±, sometimes effective. + + + ± ± - - - Legionella pneumophila + + + + - - - - Chlamydia pneumoniae + + + + - - - - Mycoplasma pneumoniae ± - - - - ± + ± Anaerobes + + + + + + + - Moraxella catarrhalis + + - d + + + + - Haemophilus influenzae + c ± ± c + c ± c ± c ± c ± c Streptococcus pneumoniae Newer Fluoroquinolones b Ciprofloxacin Erythromycin Doxycycline Trimethoprim- Sulfamethoxazole Cefuroxime Amoxicillin/ Clavulanate Penicillin G Pathogen Value of Indicated Antimicrobial a Table 255-5. Empirical Oral Antimicrobial Therapy for Outpatient Management of Community-Acquired Pneumonia
EMPIRIC Rx FOR CAP: Clarithromycin 500mg BIDx10 days; Azithromycin 500mg PO 1 dose then 250 mg/d x 4 days; Doxycyline 100mg BID x 10 days. OPD, no CP disease, no risk factors Regimen Rx Settings
Quinolone with enhanced activity against S. pneumonia- Levox, Moxifloxacin; B-Lactam (cefpodoxime, amox, co-amox.); Telithromycin OPD, CP disease and/or risk factors; high prevalence in the comunity Regimen Rx Settings
d In the United States, about 42% of strains are currently resistant to penicillin (15% with high-level penicillin resistance; ampicillin slightly less active than penicillin), 20% are resistant to cefuroxime (similar activity displayed by the first-generation cephalosporin cephalothin), 4-5% are highly resistant to third- or fourth-generation cephalosporins, 20-30% are resistant to trimethoprim-sulfamethoxazole, 7-10% are resistant to doxycycline (tetracycline), 14% are resistant to erythromycin, and <4% are resistant to the newer fluoroquinolones. c Levofloxacin, gatifloxacin, moxifloxacin, and sparfloxacin. b Ceftriaxone, cefotaxime, and cefepime. a +, effective; -, ineffective; ±, sometimes effective. + - + - - - - - Mycoplasma pneumoniae + - + ± - - - - Legionella pneumophila + - + - - - - - Chlamydia pneumoniae ± + - - + - - - Anaerobic gram-negative bacilli ± + ± - ± + + + Anaerobic gram-positive cocci + + + + - + + - Moraxella catarrhalis + + - + - + + - Haemophilus influenzae + + + + - + + - Staphylococcus aureus + d ± d ± d ± d - + d ± d ± d Streptococcus pneumoniae Newer Fluoro- quinolones c Ampicillin/ Sulbactam Erythromycin Trimethoprim- Sulfamethoxazole Metronidazole Third- and Fourth- Generation Cephalosporins b Second- Generation Cephalosporins Penicillin G Pathogen Value of Indicated Antimicrobial a Table 255-6. Empirical Antimicrobial Therapy for the Management of Hospitalized Patients with Community-Acquired Pneumonia
a Dosage must be modified for patients with renal failure. Guidelines on the duration of therapy for each pathogen are given in the text of this chapter and of chapters on specific infecting agents. 1 g (15 mg/kg) IV q12h Vancomycin 3.1 g IV q4h Ticarcillin/clavulanate 4.5 g IV q6h Piperacillin/tazobactam 3 million units IV q4-6h Penicillin G 2 g IV q4h Nafcillin 500 mg IV or PO q6h Metronidazole 500 mg IV or PO q24h Levofloxacin 500 mg IV q6h Imipenem 5 mg/kg/d in 3 equally divided doses IV q8h Gentamicin (or tobramycin) 0.5-1.0 g IV q6h Erythromycin 600-900 mg IV q8h Clindamycin 400 mg IV or 750 mg PO q12h Ciprofloxacin 750 mg IV q8h Cefuroxime 1-2 g IV q12h Ceftriaxone 2 g IV q8h Ceftazidime 1-2 g IV q8-12h Cefotaxime, ceftizoxime 2 g IV q8h Cefepime 1-2 g IV q8h Cefazolin 2 g IV q8h Aztreonam 3 g IV q6h Ampicillin/sulbactam Dosage Drug Table 255-7. Dosage of Antimicrobial Agents for the Treatment of Pneumonia in Hospitalized Patients a
e Add vancomycin if methicillin-resistant S. aureus is present in the institution. d Metronidazole must be combined with vancomycin or another antimicrobial that covers microaerophilic and anaerobic gram-positive cocci. c Use when chromosomally encoded, inducible b-lactamase producers are endemic in the institution. b Use when extended-spectrum b-lactamase producers are endemic in the institution. a If methicillin-resistant S. aureus is known to exist in the institution, use vancomycin; otherwise, use an antistaphylococcal b-lactam such as nafcillin or cefazolin. 1. Ceftazidime or cefepime + clindamycin (or metronidazole) ± aminoglycoside e 2. Ticarcillin/clavulanate or piperacillin/tazobactam ± aminoglycoside e 3. Aztreonam + clindamycin (or metronidazole d ) ± aminoglycoside e 4. Imipenem b ± aminoglycoside e 5. Fluoroquinolone c + clindamycin (or metronidazole d ) ± aminoglycoside or b-lactam Mixed flora 1. Ceftazidime or cefepime ± aminoglycoside 2. Ticarcillin/clavulanate or piperacillin/tazobactam ± aminoglycoside 3. Aztreonam ± aminoglycoside 4. Imipenem b ± aminoglycoside 5. Fluoroquinolone c ± aminoglycoside or b-lactam Presumptive enteric aerobic gram-negative bacilli or Pseudomonas aeruginosa Nafcillin or vancomycin a Presumptive Staphylococcus aureus Regimen Etiology Table 255-8. Empirical Antimicrobial Therapy, Based on Gram's Staining of Sputum, for Institutionally Acquired Pneumonia
Imipenem/meropenem 500mg q6h or Piperacillin/tazobactam 3.375g q6h + ciproflox ICU; risk factors Azithromycin 1G iv then 500mg OD + ceftriaxone or cefotaxime or quinolone ICU; no risk factors for P.aeruginosa infxn Regimen Rx Settings
Wait 24H; if symptoms persist, give antibiotic Aspiration pneumonitis Metronidazole or Piperacillin/tazobactam 3.375 g q6h or Imipenem 500mg q6h or Levofloxacin, ceftri,or cefotaxime aspiration pneumonia Regimen Rx Settings