Transcript Appearance Of Seasonal Allergens
#1005 Hospital & Community Acquired Pneumonias
October 19 to October 22
Stephen Hoffmann, MD
Clinical Instructor of Internal Medicine Division of Pulmonary & Critical Care Medicine The Ohio State University Medical Center
William Maher, MD
Associate Professor of Clinical Internal Medicine Division of Infectious Diseases The Ohio State University Medical Center
William Maher, MD
Associate Professor of Clinical Internal Medicine Division of Infectious Diseases The Ohio State University Medical Center
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Profile
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Chuck Healthy 46 year old physician Well until he developed a flu-like illness prior to a business trip Felt better with non-specific treatments Returned home, then developed a productive cough and high fevers, coughed up phlegm and parts of lungs Ultimately hospitalized Diagnosis: Bacterial Pneumonia due to Staphylococcus Aureus 2
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Pathogens Typical Pneumonia
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Streptococcus pneumoniae
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Haemophilus influenzae Moraxella catarrhalis Legionellae
Staph. aureus Aerobic gram-negative bacilli 5
Pathogens Atypical Pneumonia
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Mycoplasma pneumoniae Chlamydia pneumoniae
Influenza, adenovirus, RSV Q-fever Chlamydia psittaci TB, Endemic Fungi
Pneumocystis carinii
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Pneumonia Therapeutic Categories
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Age < 60 years; no comorbidity
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Age > 60 years; or with comorbidity Requires hospitalization
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Severe pneumonia 7
Age < 60 Years; No Comorbidity
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Streptococcus pneumoniae
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Mycoplasma pneumoniae
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Chlamydia pneumoniae
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Respiratory viruses 8
Age > 60 Years; Or With Comorbidity
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Streptococcus pneumoniae
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Respiratory viruses
b
-lactamase produces (H. flu etc.)
S. aureus
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Community Acquired Requiring Admission
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Streptococcus pneumoniae Haemophilus influenzae
Aspiration / polymicrobic Legionellae
S. aureus (post influenza)
Gram-negative bacilli ECF: as per comorbidity, except influenza, TB, MRSA 10
Severe Pneumonia
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Streptococcus pneumoniae
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Legionella
• Viruses • Aerobic gram-negative bacilli
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More Specific CXR Patterns
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Cavities - Aspiration, GNB, Staph. Aureus, TVE - TB, Histoplasma, aspergillus Segmental - Post-obstructive, aspergillus - Pulmonary embolism Hilar / mediastinal adenopathy - Primary TB, fungal infection - Malignancy, sarcoid 12
More Specific CXR Patterns
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Diffuse Interstitial - Viral, Pneumocystis carinii - CHF, allergic, etc.
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Nodules - Fungal, TB, septic emboli - May cavitate - Metastatic Ca 13
Prescribing Practices
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1968 antibiotics prescribed for: - 51% patients with Dx: “common cold”
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1997 antibiotics prescribed for: 51% with Dx: “cold” 52% with Dx: “URI” 66% with Dx: “Acute Bronchitis” (no COPD) 14
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Summary
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Chuck Had a flu-like illness Diagnosed with Bacterial Pneumonia due to Staphylococcus Aureus
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Treatment Prolonged course of IV and oral antibiotics Was very ill but recovered completely Annual flu shots expected 19
Stephen Hoffmann, MD
Clinical Instructor of Internal Medicine Division of Pulmonary & Critical Care Medicine The Ohio State University Medical Center
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Case
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37 year old male
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1st Day Underwent a CT scan Fiberoptic bronchoscopy with BAL Transbronchial biopsy Results were negative That evening, had an aspiration event Developed fevers to 103 degrees Started on pipercillin / tazobactum but condition worsened 24
Case
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3rd Day Ciprofloxcin added to antibiotic regimen A CXR showed worsening infiltrate and pleurl effusion Thoracentesis was performed but no evidence of empyema
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4th Day Developing significant hypoxemia and respiratory insufficiency Required intubation and ventilation 24 A
Case
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Repeat fiberoptic bronchoscopy was performed Gram stain of the BAL revealed gram positive cocci Due to high incidence of MRSA, started on vancomyocin He developed ARDS with severe respiratory failure requiring 100% oxygen and significant amounts of PEEP Enrolled in Liquid Ventilation Study 24 B
Case
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Over 5 days, he improved Peflubron was discontinued Patient was extubated One day later, patient was transferred to floor 24 C
Hospital Acquired Pneumonia
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Pneumonia occurring greater than 48 hours after hospital admission Accounts for 13-18% of all nosocomial infections 5-10m cases per 1000 hospital admissions Incidence increases 6-20 fold in mechanically ventilated patients Up to 25% of ICU patients develop pneumonia Associated mortality 20-50% Attributable mortality more difficult to define but may be in excess of 10% 25
Pathogenesis Respiratory Infections
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Impaired host defenses
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Sufficient innoculum to overwhelm the host defense
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Virulent organisms 26
Routes Of Bacterial Entry
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Microaspiration of oropharyngeal secretions colonized with pathogenic organisms
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Aspiration of esophageal / gastric contents Inhalation of infected aerosols Hematogenous spread Contiguous spread from infected site
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Direct inoculation into airways of intubated patients Translocation from GI tract 27
Etiology
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Type of infection largely determined by the bacteria colonizing the oropharynx - Hospitalized patients may become colonized with aerobic gram negative bacteria within several days - 75% of severely ill patients become colonized within 48 hours Overgrowth of the near sterile environment of the stomach and UGI tract may occur due to alterations in gastric pH - Illness, drugs, enteral feedings 28
Common Bacteria
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Pseudomonas aeruginosa - 17% Enterobacteriaceae - 11% Klebsiella species - 7%
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Escheichia coli - 6% Haemophilus influenzae - 6%
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Serratia marcens - 5%
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Staphylococcus aureus - 16% 29
Other Pathogens
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Less common pathogens include: - Streptococcus pneumoniae, anaerobes, influenza A and other viruses, Legionella species, Candida sp., Aspergillus sp.
Acinetobacter species have emerged as significant pathogens in some centers The incidence of anaerobic bacteria as the cause of HAP may be overestimated: - Marik et al evaluated 185 patients with anaerobic cultures of PSB and BAL specimens - Only 1, nonpathogenic anaerobic species was isolated Frequently polymicrobial 30
Etiology Based On Epidemiology 1995 ATS Criteria
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Severity of pneumonia
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Presence of coexisting illness
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Prior therapy
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Length of hospitalization prior to pneumonia 31
Core Organisms
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E. coli Klebsiella Proteus
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Serratia Hemophilus influenza
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Methicillin - sensitive S. aureus
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Streptococcus pneumoniae
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Late Onset Severe Hospital Acquired Pneumonia: Greater Than 5 Days After Admission
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Core organisms plus
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P. auriginosa
Acinetobacter species Methicillin resistant staph aureus
Candida
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Risk Factors For Specific Pathogens
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Anaerobes (witnessed aspiration, recent abdominal surgery) S. Aureus (coma, head trauma, IVDA, renal failure, DM) Legionella (high dose steroids)
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Pseudomonas aeruginosa (steroids, structural lung disease, prolonged ICU stay, mechanical ventilation) 34
Diagnosis
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Clinical definition - A new or progressive infiltrate in a patient with fever, leukocytosis and tracheobronchial secretion Mimics - CHF - Atelectasis - Pulmonary embolism - Drug reaction - Pulmonary hemorrhage - ARDS 35
Microbiologic Evaluation
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Blood cultures
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Sputum
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Endotracheal aspirates
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Fiberoptic bronchoscopy - Protected brush specimen - Bronchoalveolar lavage 36
Diagnosis
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Purulent sputum A significant respiratory pathogen predominating on gram stain
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Peripheral leukocytosis Fever New or persistent infiltrate on chest x-ray, with a concurrent deterioration in gas exchange 37
Treatment
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Adequacy of initial treatment crucial Patients suspected of having HAP and particularly VAP should be treated with broad spectrum antibiotics aimed at covering all likely bacterial pathogens
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Knowledge of local bacterial spectra and antimicrobial resistance patterns are essential in formulating initial coverage Treatment then should be narrowed based on the results of microbiologic data Usual duration of treatment is 10-14 days 38
Antibiotic Regimens: Core Coverage
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Extended spectrum penicillins - Pipercillin / tazobactam - Ticarcillin / clavulanate
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Third / fourth generation cephalosporins - Cefepime - Not ceftazidime Fluroquinolones - Levafloxcin 39
Antibiotic Regimens: Late Onset Coverage
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Common regimens include two of the following classes plus / minus Vancomyocin - Extended spectrum penicillins - Pipercillin / tazobactam - Ticarcillin / clavulanate - Third / Fourth generation cephalosporins - Cefepime - Not ceftazidime - Fluroquinolones Levafloxcin Ciprofloxcin - Aminiglycosides - Imipenem-cilastin - Aztreonam 40
Antibiotic Regimens: Coverage For Patients With Risk Factors
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Prolonged ICU stay, mechanical ventilation, structural lung disease - double coverage for pseudomonas plus / minus vancomyocin Steroids therapy - macrolide Witnessed aspiration, recent abdominal surgery - anerobic coverage - Clindamyocin - Metronidazole - Extended spectrum penicillins - Imipenem-cilastin 41
NEXT WEEK
#1006 New Approaches to Cardio Re-vascularization October 26 to October 29
Robert E. Michler, MD
Professor of Surgery Chief, Division of Thoracic and Cardiovascular Surgery The Ohio State University Medical Center
Gregory M. Eaton, MD
Assistant Professor of Clinical Internal Medicine Division of Cardiology The Ohio State University Medical Center