MDM Templates

Community-Acquired Pneumonia — Discharge

Patient presents with *** days of cough, fever, and mild dyspnea. Well appearing, hemodynamically stable. Vital signs: BP ***, HR ***, RR ***, O2 saturation *** on room air. Lung exam shows focal crackles or consolidation in the *** lobe consistent with pneumonia. CXR confirms focal consolidation. Labs: WBC ***, Cr ***, lactate ***.

Assessment: Community-acquired pneumonia, non-severe. Adequate oxygenation and perfusion. Able to tolerate oral intake. Social support available. Patient appropriate for discharge with outpatient follow-up.

Plan:

1. Antibiotics: Start [amoxicillin-clavulanate 875/125 PO BID x 7 days OR azithromycin 500 mg PO daily x 3 days then 250 mg daily x 4 days OR fluoroquinolone per regimen below]
2. Supportive care: Cough/cold measures. Acetaminophen or ibuprofen for pain/fever.
3. Follow-up: Return to PCP in 3-5 days to assess response to antibiotics and repeat CXR in 4-6 weeks to confirm resolution (especially if patient >50 years or immunocompromised).
4. Return precautions: Worsening dyspnea, persistent fever >72 hours despite antibiotics, hemoptysis, or signs of sepsis.

Community-Acquired Pneumonia — Admit

Patient presents with *** days of cough, fever, and dyspnea. Moderate distress. Vital signs: BP ***, HR ***, RR ***, O2 saturation *** on room air or *** on *** L O2. Lung exam shows *** consolidation. CXR shows *** infiltrate. Labs: WBC ***, Cr ***, lactate ***, [ABG if altered or hypoxic].

Assessment: Community-acquired pneumonia with [specify severity indicators: hypoxia, tachypnea, hypotension, altered mental status, multilobar involvement, evidence of sepsis, acute kidney injury, or comorbidities].

Plan:

1. Admission: Medicine floor or ICU depending on severity and respiratory status. Continuous pulse oximetry.
2. Antibiotics: [See regimen below. Initiate within 1 hour.]
3. Respiratory support: Supplemental O2 to target SpO2 >90% (>88% if COPD). Reassess need for escalation to noninvasive ventilation.
4. Supportive care: IV fluids for hypotension or dehydration. Blood cultures before antibiotics. Consider ICU consultation if signs of severe sepsis/ARDS.
5. Source control: Diagnostic bronchoscopy if immunocompromised, atypical presentation, or no improvement on standard therapy. Consider repeat CXR at 48-72 hours if not improving.
6. Monitoring: Daily assessment of clinical response. Consider repeat lactate if initially elevated. Reassess antibiotic regimen at 48-72 hours if stable or improving; consider broader coverage if deteriorating.
7. Discharge planning: Once stable and able to tolerate oral meds, transition to oral antibiotics and discharge to home or facility depending on ability to follow up.

Hospital-Acquired and Aspiration Pneumonia

Patient on the floor/ICU with *** days of new fever, productive cough, and/or declining respiratory status. CXR shows new or progressive infiltrate. Consider risk factors: mechanical ventilation, reintubation, aspiration event, ICU stay >48 hours, prior antibiotics.

Assessment: Hospital-acquired pneumonia (HAP) [or ventilator-associated pneumonia (VAP) if intubated, or aspiration pneumonia if witnessed/suspected aspiration]. Consider severity and prior antibiotic exposure.

Plan:

1. Cultures: Blood cultures, sputum culture (via endotracheal tube if intubated), and consider bronchoalveolar lavage (BAL) if diagnosis uncertain or high risk for resistant organisms.
2. Antibiotics: [Cover gram-negative rods and Staphylococcus aureus. Empiric regimen depends on risk factors for MDR (see regimens below). Initiate within 1 hour.]
3. Source control: Assess airway. If on ventilator, optimize sedation, minimize reintubations, perform daily spontaneous breathing trials, and elevate head of bed 30-45 degrees. If aspiration suspected, NPO status, verify tube placement if present, consider post-pyloric feeding or parenteral nutrition.
4. Monitoring: Daily assessment of clinical response and adjust antibiotics based on culture results and clinical trajectory at 48-72 hours.
5. Duration: 7-8 days for HAP/VAP; 3-4 days for uncomplicated aspiration (if anaerobic coverage adequate).

CAP with Influenza

Patient presents with fever, cough, malaise, and CXR findings consistent with pneumonia. Rapid influenza testing is positive (PCR preferred).

Assessment: Community-acquired pneumonia with concurrent influenza infection.

Plan:

1. Antivirals: Oseltamivir (Tamiflu) 75 mg PO BID x 5 days (or IV peramivir if unable to take oral). Start within 48 hours of symptom onset if possible, though benefit exists even if started later in severe disease or in immunocompromised hosts.
2. Antibiotics: Initiate empiric antibiotics as per CAP regimens (above) to cover both typical and atypical organisms, as bacterial superinfection is common.
3. Supportive care: Supplemental oxygen, IV fluids if needed. Contact precautions in hospitalized patients.
4. Influenza prophylaxis: Offer to close contacts if no contraindications (oseltamivir 75 mg daily x 10 days).

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Clinical Education

CAP Antibiotic Regimens (IDSA 2019)

Outpatient CAP (non-severe):

1. Previously healthy, no antibiotics in past 3 months:
   • Amoxicillin 1 g PO TID x 7 days, OR
   • Doxycycline 100 mg PO BID x 7 days
2. Comorbidity (COPD, diabetes, heart disease, immunocompromise) or antibiotics in past 3 months:
   • Fluoroquinolone (levofloxacin 750 mg daily x 5 days OR moxifloxacin 400 mg daily x 7 days), OR
   • Amoxicillin-clavulanate 875/125 mg PO BID x 7 days PLUS macrolide (azithromycin 500 mg day 1 then 250 mg daily x 4 days)

Inpatient CAP (non-ICU, non-severe):

1. No pseudomonas risk:
   • Ceftriaxone 1 g IV daily (or cefotaxime 1 g IV Q6-8H) PLUS azithromycin 500 mg IV/PO daily, OR
   • Fluoroquinolone (levofloxacin 750 mg IV/PO daily), OR
   • Ampicillin/sulbactam 3 g IV Q6H

Inpatient CAP (ICU):

1. No pseudomonas or MRSA risk:
   • Ceftriaxone 1-2 g IV Q12H OR cefotaxime 1-2 g IV Q6H PLUS azithromycin 500 mg IV/PO daily (or respiratory fluoroquinolone)
2. Pseudomonas risk:
   • Piperacillin-tazobactam 4.5 g IV Q6H OR cefepime 1-2 g IV Q8-12H OR meropenem 1 g IV Q8H PLUS ciprofloxacin 400 mg IV Q8H OR azithromycin 500 mg IV daily
3. MRSA risk:
   • Add vancomycin (15-20 mg/kg IV Q8-12H) OR linezolid (600 mg IV/PO BID)

HAP/VAP (non-MDR risk):

1. Ceftriaxone 1-2 g IV Q12H OR cefotaxime 1-2 g IV Q6H OR ampicillin-sulbactam 3 g IV Q6H, OR
2. Fluoroquinolone (levofloxacin 750 mg IV daily OR moxifloxacin 400 mg IV daily)

HAP/VAP (MDR risk: prior antibiotics, ICU stay >5 days, high prevalence unit, immunocompromise):

1. Antipseudomonal beta-lactam: Piperacillin-tazobactam 4.5 g IV Q6H OR cefepime 1-2 g IV Q8-12H OR meropenem 1 g IV Q8H
2. PLUS antipseudomonal fluoroquinolone: Ciprofloxacin 400 mg IV Q8H OR levofloxacin 750 mg IV daily
3. If MRSA risk or not responding: Add vancomycin 15-20 mg/kg IV Q8-12H OR linezolid 600 mg IV/PO BID

Aspiration pneumonia (anaerobes):

1. Ampicillin-sulbactam 3 g IV Q6H, OR
2. Piperacillin-tazobactam 4.5 g IV Q6H, OR
3. Clindamycin 600 mg IV/PO Q6H (if penicillin allergy)

Disposition Tools: CURB-65 and PSI/PORT

CURB-65 Score (for risk stratification in CAP):

1 point each for:

• Confusion (acute mental status change)
• Urea >7 mmol/L (BUN >20 mg/dL)
• Respiratory rate ≥30
• Blood pressure: SBP <90 or DBP ≤60 mmHg
• Age ≥65 years

Interpretation:

• 0-1 point: Low risk (~1% mortality). Treat outpatient.
• 2 points: Intermediate risk (~8% mortality). Consider admission or close outpatient follow-up.
• ≥3 points: High risk (≥15% mortality). Admit to hospital.

PSI/PORT Score (Pneumonia Severity Index):

Assigns points based on demographic (age, sex) and clinical factors. Produces risk class I-V.

• Class I-II: Low risk (<1% mortality). Outpatient treatment.
• Class III: Moderate risk (~1-5% mortality). Consider admission vs. discharge with intense follow-up.
• Class IV-V: High risk (>5% mortality). Admission, likely ICU.

Clinical Pearl: CURB-65 is simpler and easier to use at the bedside; PSI is more comprehensive and predictive. Both help guide admission decisions and antibiotic intensity.

HAP, VAP, and Aspiration Pneumonia

Hospital-Acquired Pneumonia (HAP): Pneumonia occurring >48 hours after hospital admission, not incubating at admission. Risk increases with prolonged ICU stay, mechanical ventilation, and prior antibiotics.

Ventilator-Associated Pneumonia (VAP): Pneumonia occurring >48 hours after endotracheal intubation. Often polymicrobial. Consider Pseudomonas, Acinetobacter, and MRSA, depending on unit flora and prior antibiotic exposure.

Aspiration Pneumonia: Results from inhalation of oropharyngeal contents. Risk factors include altered mental status, dysphagia, GERD, recent anesthesia. Can be anaerobic (if aspiration of oral flora) or aerobic (aspiration of gastric contents with H. pylori, gram-negative rods). Presentations range from indolent (anaerobic, low virulence) to fulminant (gram-negative in acutely ill patient).

Diagnosis: Clinical suspicion + CXR/CT findings + sputum culture or BAL culture if available. Blood cultures often negative in HAP/VAP but helpful if positive. Consider endoscopic or bronchoscopic sampling if diagnosis uncertain or no improvement on empiric therapy.

Key differences:

• HAP/VAP require broader coverage (typically antipseudomonal agents) due to resistant gram-negatives.
• Aspiration pneumonia coverage depends on suspected organism (anaerobes vs. aerobic gram-negatives).
• HAP/VAP often require longer duration of antibiotics (7-8 days), while uncomplicated aspiration may respond to 3-4 days of therapy.

HIV-Associated Pneumonia by CD4 Count

CD4 >200 cells/μL: Typical CAP organisms (S. pneumoniae, H. influenzae) predominate. Treat per standard CAP regimens. PCP prophylaxis not needed at this CD4 count.

CD4 50-200 cells/μL: Increased risk of both typical CAP organisms and opportunistic infections (PCP, MAC, cryptococcal pneumonia). PCP prophylaxis indicated (TMP-SMX first line). If fever and respiratory symptoms, consider PCP, atypical mycobacterium, or CMV. Obtain CD4 count urgently and consider specialist referral.

CD4 <50 cells/μL: High risk for severe opportunistic infections including PCP, MAC, CMV, cryptococcal disease, and atypical mycobacterium. Requires aggressive evaluation and prophylaxis. Consider ICU admission and specialist (ID) involvement.

Diagnostic approach: CXR (may be normal in early PCP), labs, blood cultures, and consider BAL or induced sputum (for PCP, TB, fungal organisms) in hospitalized or severely ill patients. ABG helpful to assess oxygenation and alveolar-arterial gradient.

PCP Pneumonia: Recognition and Treatment

Clinical presentation: Subacute dyspnea, fever, and nonproductive cough, often with progressive hypoxia. CXR may be normal early or show diffuse interstitial infiltrates; lower lobes and apices often spared. High A-a gradient out of proportion to CXR findings is typical.

Diagnosis: Induced sputum or BAL showing trophozoites or cysts (silver stain, immunofluorescence). Blood cultures negative. PCR assays increasingly available.

Risk factors: CD4 count <200, not on PCP prophylaxis, advanced AIDS, other opportunistic infections.

Treatment:

• High-dose TMP-SMX (15 mg/kg/day TMP component IV or PO divided Q6H) x 21 days, OR
• Pentamidine 4 mg/kg IV daily x 21 days, OR
• Dapsone 100 mg daily PLUS trimethoprim 15-20 mg/kg/day divided Q6-8H x 21 days, OR
• Clindamycin 600 mg IV/PO Q6H PLUS primaquine 30 mg daily x 21 days (use if TMP-SMX intolerance; caution in G6PD deficiency)

Adjunctive corticosteroids: Consider prednisone 40 mg BID x 5 days, then 40 mg daily x 5 days, then 20 mg daily to completion of PCP therapy if PaO2 <70 or A-a gradient ≥35 mmHg on room air. Reduces mortality in moderate-to-severe disease.

Prophylaxis: TMP-SMX 1 double-strength tablet daily (or three times weekly) for CD4 200 x 3 months on ART.

CAP and Influenza Coinfection

Epidemiology: Influenza increases risk of secondary bacterial pneumonia, particularly in the elderly and those with underlying chronic diseases. Staphylococcus aureus superinfection (including MRSA) is not uncommon and associated with worse outcomes.

Clinical clues: Biphasic illness (initial influenza symptoms followed by worsening), rapid deterioration, or hemoptysis may suggest superinfection. Isolation of bacteria from blood cultures or respiratory secretions supports bacterial coinfection.

Management:

• Antivirals: Oseltamivir (Tamiflu) 75 mg PO BID x 5 days (or IV formulation). Start as soon as possible, ideally within 48 hours, though benefit exists in severe cases even beyond 48 hours.
• Antibiotics: Initiate empiric CAP therapy with coverage of typical organisms (S. pneumoniae, H. influenzae) and consider coverage of MRSA if signs of severe disease, hemoptysis, or ICU admission. Respiratory fluoroquinolone or beta-lactam plus macrolide are reasonable outpatient choices; ICU patients warrant broader coverage including antipseudomonal agents if risk factors present.
• Supportive care: Aggressive respiratory support, careful fluid management, vasopressor support if septic shock.
• Influenza vaccination: Recommend to unvaccinated contacts and for next season in recovered patient if current season vaccine available.

ARDS and Severe Pneumonia: Ventilator Management

ARDS definition (Berlin, 2012): Acute hypoxemic respiratory failure with bilateral opacities on imaging, not fully explained by effusions/atelectasis/nodules, and PaO2/FiO2 ≤300 mmHg (on PEEP ≥5 cm H2O). Timing: <1 week from onset of known insult.

Severity:

• Mild: PaO2/FiO2 201-300 mmHg
• Moderate: PaO2/FiO2 101-200 mmHg
• Severe: PaO2/FiO2 ≤100 mmHg

Management principles:

• Lung-protective ventilation: Low tidal volumes (6 mL/kg ideal body weight, target Pplat <30 cm H2O), higher PEEP (≥5 cm H2O, titrate based on oxygenation), avoid high FiO2 (wean as tolerated).
• Prone positioning: Consider in severe ARDS (PaO2/FiO2 ≤100) for 12-16 hours daily if available. Reduces mortality.
• Neuromuscular blockade: Consider early paralysis in first 48 hours of severe ARDS. May improve oxygenation and reduce mortality.
• Sedation/analgesia: Adequate sedation to facilitate lung-protective ventilation. Use analgesics first if patient is in pain/discomfort.
• Conservative fluid strategy: Target euvolemia; avoid fluid overload which worsens oxygenation and prolongs ventilator dependence.
• ECMO: Consider for refractory hypoxemia or severe air-trapping despite optimal conventional ventilation and lung-protective measures. Requires specialized centers.

Antibiotic management in ARDS: Ensure prompt empiric antibiotics for underlying infection (pneumonia, aspiration, etc.). Reassess and de-escalate at 48-72 hours based on cultures and clinical response.

Procalcitonin and Antibiotic Stewardship

What is procalcitonin? A 116-amino acid peptide released during systemic inflammation, particularly in response to bacterial endotoxin. Levels typically <0.05 ng/mL in healthy individuals and without infection.

Clinical utility in CAP: Elevated procalcitonin (>0.1 ng/mL) suggests bacterial infection and supports initiation of antibiotics. Low or declining levels support stopping antibiotics even if patient feels better. Serial measurement (at baseline, 24-48 hours, and end of treatment) may guide therapy duration.

Advantages:

• More specific than WBC or CRP for bacterial infection.
• Helps reduce unnecessary antibiotic use in viral infections.
• May guide earlier discontinuation of antibiotics (stewardship).

Limitations:

• Can be elevated in non-infectious inflammatory states (trauma, surgery, some autoimmune conditions).
• Not universally available or reimbursed.
• Clinical judgment still essential; do not use in isolation.

Antibiotic stewardship approach: In hospitalized patients with CAP, obtain procalcitonin at baseline and consider discontinuation or de-escalation if procalcitonin is <0.25 ng/mL at 72 hours and patient is clinically improving. This can reduce duration of therapy and antibiotic-associated complications (e.g., C. difficile, drug toxicity) while maintaining excellent outcomes.

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References

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