Pneumonia

ACUTE BRONCHITIS:

Definition: 

• Infection of trachea and bronchi due to spread of URI or exposure to irritants

MCC:

• Non-smokers: Mycoplasma pneumoniae (Dx: high agglutinin titer)
• Smokers: S. pneumoniae + H. influenza

Clinical features: 

• Productive cough, sore throat, fever, wheeze

CXR:

• Mild congestion

Treatment: 

• Most cases are viral -> self-limited, if suspecting bacteria -> give abx

 

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PNEUMONIA:

Definition: 

Infection of the bronchoalveolar tree

Types:

a. Community acquired pneumonia (CAP):

• From the community or w\ in the first 72 hrs of hospitalization
• MCC pathogen: Pneumococcus

b. Nosocomial pneumonia:

• After the first 72 hrs of hospitalization
• MCC pathogen: Gram neg (E. coli, pseudomonas) and Staph aureus

Diagnosis:

CXR:

• PA + lateral. Sensitive (if neg  -> don’t treat)
• Once URI is excluded, CXR is done to differentiate between acute bronchitis and pneumonia, which are both LRI
• False negative -> neutropenia, dehydration, PCP infection, early ds
• Changes after treatment take up to 6 weeks

Sputum:

• Gram stain: in all pts
• Culture: in pts requiring hospitalization
• Acid-fast stain -> for mycobacterium
• Silver stain -> for fungi (PCP) in HIV\immunocompromised pts
• Legionella -> urinary Ag assay. Very sensitive, remains for wks even after treatment
• PCP -> Broncho-alveolar lavage
• Mycoplasma -> cold agglutins
• “Consider” two Pretreatment blood cultures from diff sites

Thoracentesis:

• PH < 7.2: empyema -> chest tube drainage
• LDH > 0.6 or protein > 0.5: exudate; infection or cancer

 

Treatment:

Outpatients:

• Continue treatment for 5 days. Don’t stop until pt is afebrile for 48 hrs
• < 60 yo -> 1^st Macrolides (azithromycin or clarithromycin) or doxycycline. 2^nd fluoroquinolone
• > 60 yo OR those treated w\ antibiotic in the last 3 mo -> 1^st fluoroquinolone (levofloxacin, moxifloxacin). 2^nd third-gen cephalosporin

Hospitalized:

1. Fluoroquinolone
2. Third-gen cephalosporin + macrolides (ceftriaxone + azithromycin)

HAP: tailored towards gram-neg rods

• Cefrazidime or cefepime (cephalosporin w\ pseudomonal coverage)
• Carbapenems: imipenem
• Piperacillin\tazobactam

 

When to admit?

Based on pneumonia severity (index, CURB65)

• Hypotension (sys <90)
• RR > 30, or pO₂ <60 mmHg, PH <7.35
• BUN > 30 mg\dL, Na < 130 mmol\L, glucose > 250 mg\dL
• Pulse > 125
• Confusion
• Temprature > 40 c
• > 65 yo, or w\ comorbid: ca, COPD, CHF, renal failure, liver ds

 

Pneumococcal vaccinations given to?

• Pts > 65 yo
• Younger pt w\ risk: CSF leak, cochlear implant, sickle cell, DM, alcoholic cirrhosis, asplenic, pulmn\cardiac ds
• NOT healthcare workers

 

Complications:

• Pleural effusion (50%). If significant (>1cm on lateral) -> thoracocentesis
• Pleural empyema (2% of CAP, 7% hospitalized CAP)
• Acute respiratory failure

 

 

 Random notes:

• Nursing home residents -> nosocomial pathogens + prefer upper lobes (Pseudomonas)
• Legionella –> transplant recipients, renal failure pts, chronic lung ds, smokers: present w\ GI sx + hyponatremia

 

 

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Download the PDF version: here

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References:

• Step up to medicine
• Master the boards
• Kaplan step 2 videos