Respiratory Medicine
Seán Keenan
2022
,Pneumonia
Pneumonia in General
Presentation Investigations
- General: Dyspnoea; Cough; Pleuritic chest pain - CXR: Consolidation; Cavitation; Effusion
- Infection: Purulent sputum ± haemoptysis - ABG: Perform if SpO2 <92 %
- Observations: ↑To; ↑ HR; ↑ RR; ↓ BP; ↓ SpO2 - Bloods: FBC; U+E; CRP; LFTs
- Exam: ↓ Percussion; ↑ Fremitus; ↓ Expansion - Culture: Blood; Sputum
- Auscultation: Pleural rub; Bronchial breathing - Urine: Legionella/Pneumococcal antigens
Causes - Pleural fluid: MC&S + Microscopy
- Infectious (common) - BAL: Consider if immunocompromised / ITU
o NB: See lung infection notes - CURB-65: See below
- Non-infectious (uncommon) Management
o Common: Lung cancer; ARDS - Antibiotics: See lung infection notes
o Uncommon: Eosinophilic pneumonia; Sarcoidosis - Supportive: Fluids; O2 therapy
o Rare: Cryptogenic organising pneumonia - VTE Prophylaxis: LMWH
o AID: Vasculitis; RA - CXR: Repeat for progression + follow up at 6 wks
o Iatrogenic: amiodarone; Radiation pneumonitis
Aspiration Pneumonia
Description Causes
- Path: Oral or gastric contents get into lung lobes - Risks: Poor dental hygiene; Dysphagia; ↓ GCS
- NB: Acidic aspirates lead to chemical pneumonitis - G+Ve: S. pneumoniae; S. aureus
- Location: Right middle-lower lobes usually affected - G-Ve: H. influenzae; P. aeruginosa
Severity Assessment
CURB-65 Interpretation
- Confusion (abbreviated mental test ≤8) - 0-1: Home prescription is possible
- Urea >7 mmol/L - 2: Hospital admission + therapy
- Respiratory rate ≥30 breaths/min - ≥3: Severe pneumonia + consider ITU
- BP <90 mmHg systolic or <60 mmHg diastolic Prognosis
- Age ≥65 YO - Px: Score of 4 carriers 30 % mortality at 30 days
Pneumonia Complications
Respiratory Failure Empyema
- T1RF: Common complication - Features: Pneumonia; Recurrent fever
- Mx: High flow 60 % O2 - Ix: pH <7.2; ↓ Glucose; ↑ LDH
- Ix: ↓ O2; ↑ CO2 - Mx: Guided chest drain
- NB: Monitor ABG for CO2 retention Atrial Fibrillation (AF)
Pleural Effusion - Paroxysmal: Usually resolves with pneumonia mx
- Exudate Effusion: Protein >25 g/L; ↑ LDH - Mx: Short-term β-blockers or digoxin
- Transudate Effusion: Protein <25 g/L; ↓ LDH - NB: More common in elderly patients
- Pleurocentesis: If large or symptomatic drain effusion Septicaemia
- Mx: Guided aspiration (1-1.5 L max) - Spread: Pneumonia source may metastasise
- Cc: Re-expansion oedema; ↓ BP; Shock - NB: IE; Meningitis; Hepatitis; Pericarditis
,Lung Abscess (Liquefactive Necrosis)
Presentation Investigations
- System: Singing ↑To; ↓ Weight; Anaemia - Bloods: FBC (anaemia + neutrophilia); CRP
- Lung: Purulent sputum; Haemoptysis; Pleuritic pain - Cultures: Blood; Sputum
- Observations: Finger clubbing - Microscopy: Sputum; Aspirate
- Auscultation: Crepitation - Imaging: CXR (cavity >2 cm); CT (obstruction)
Causes Management
- Pneumonia: Occurs in 20-30 % of cases - Abx: According to MC&S for 4-6 wk course
- Aspiration: Alcoholism; Dysphagia; Bulbar palsy - Postural drainage: Guided chest drain
- Septic emboli: Right-sides IE; IVDU; Septicaemia - Surgical: May require resection
- Micro: S. aureus; Klebsiella; Pseudomonas common
, Infections of the Lung
Description
The lungs are one of the most exposed internal organ within the body to the outside environment and so are one of
the most common entry points and sites of infection. One of the most common lung infections in pneumonia which is
most commonly caused by contagious bacteria. Factors that increase the risk of lung infections include comorbidities
such as asthma, COPD and CF, immunocompromised and old age.
Infectious Pneumonia
Causes
- Community-Acquired Pneumonia (CAP) - Aspiration Pneumonia
o Common: S. pneumoniae o G+Ve: S. pneumoniae; S. aureus
o Mild: S. pneumoniae; H. influenzae o G-Ve: H. influenzae; P. aeruginosa
o Mod: S. pneumoniae; H. influenzae; M. pneumoniae - Neutropenic Pneumonia
o Severe: Panton-Valentine Leucocidin S. aureus o G+Ve: G+Ve cocci (e.g. Staphylococcus)
o Atypical: Legionella pneumophilia; PJP o G-Ve: G-Ve bacilli (e.g. Pseudomonas)
- Hospital-Acquired Pneumonia (HAP) o Fungi: Aspergillus; Candida; PJP
o Timing: Occurs ≥48 hrs post-admission - Viral pneumonia
o G-Ve: Usually G-Ve anaerobic Bacilli o Virus: Influenza; RSV; Parainfluenza; Rhinovirus
o Common: Pseudomonas aeruginosa o Cc: Increases chance of 2o bacterial infx
Bacterial Lung Infections
Pneumococcal Pneumonia Mycoplasmal (Walking) Pneumonia
- Sx: Rapid onset; ↑↑ Fever; Pleurisy; Herpes labialis - Sx: Dry cough (mild); Erythema multiforme; AIHA
- Cx: Streptococcus pneumoniae (encapsulated) - Cx: Mycoplasma pneumoniae
- Rx: ↑ Age; Lung condition; Hyposplenism - Ix: CXR (Reticulo-nodular shadows); PCR sputum
- Ix: CXR; Pneumococcal antigen test - Mx: Clarithromycin; Doxycycline
- Mx: Penicillin; Cephalosporin; Pneumococcal vax - NB: Epidemics tend to occur every 4 years
Staphylococcal Pneumonia Legionnaire’s Disease (Pontiac Fever milder form)
- Sx: Often bilateral bronchopneumonia - Sx: Hyponatraemia; Lymphopenia; Extrapulm. sx
- Cx: Staphylococcal aureus - Cx: Legionella pneumophilia
- Rx: Post-influenza infection - Rx: Hot-tubs; Air conditioning (Holidays)
- Mx: Flucloxacillin ± Rifampicin - Ix: CXR (bi-basal consolidation); Urinary antigen
Klebsiella Pneumonia - Mx: Fluoroquinolone; Clarithromycin
- Sx: Purple-jelly sputum - Cc: Coma; Hepatitis; RF
- Cx: Klebsiella pneumoniae Chlamydophila Pneumonia
- Rx: Alcoholism; Diabetes; Aspiration pneumonia - Sx: Pharyngitis; Otitis; Chronic wheezy child
- Ix: CXR (Cavitation in upper lobes) - Cx: Chlamydia pneumoniae
- Mx: Cefotaxime (resistance is common) - Ix: qPCR; Oropharyngeal swab/BAL culture (slow)
- Cc: Lung abscess; Empyema; Highly contagious - Mx: Doxycycline; Clarithromycin
- Px: Mortality is 30-50 %; Worse if alcoholic or septic - NB: Often presents as a biphasic disease
Pseudomonal Pneumonia Psittacosis (Parrot Fever)
- Sx: Green sputum - Sx: Arthralgia; Anorexia; Lethargy; NVD
- Cx: Pseudomonas spp. (aeruginosa) - Cx: Chlamydia psittaci
- Rx: >48 hrs hospital; Neutropenia; LT Abx use - Rx: Exposure to birds (esp. parrots)
- Ix: CXR - Ix: CXR (patchy consolidation); PCR
- Mx: Anti-Pseudomonal (Ticarcillin); Cipro. + Gent. - Mx: Doxycycline; Clarithromycin
- NB: Most common cause of HAP - Cc: Hepatitis; Nephritis
Seán Keenan
2022
,Pneumonia
Pneumonia in General
Presentation Investigations
- General: Dyspnoea; Cough; Pleuritic chest pain - CXR: Consolidation; Cavitation; Effusion
- Infection: Purulent sputum ± haemoptysis - ABG: Perform if SpO2 <92 %
- Observations: ↑To; ↑ HR; ↑ RR; ↓ BP; ↓ SpO2 - Bloods: FBC; U+E; CRP; LFTs
- Exam: ↓ Percussion; ↑ Fremitus; ↓ Expansion - Culture: Blood; Sputum
- Auscultation: Pleural rub; Bronchial breathing - Urine: Legionella/Pneumococcal antigens
Causes - Pleural fluid: MC&S + Microscopy
- Infectious (common) - BAL: Consider if immunocompromised / ITU
o NB: See lung infection notes - CURB-65: See below
- Non-infectious (uncommon) Management
o Common: Lung cancer; ARDS - Antibiotics: See lung infection notes
o Uncommon: Eosinophilic pneumonia; Sarcoidosis - Supportive: Fluids; O2 therapy
o Rare: Cryptogenic organising pneumonia - VTE Prophylaxis: LMWH
o AID: Vasculitis; RA - CXR: Repeat for progression + follow up at 6 wks
o Iatrogenic: amiodarone; Radiation pneumonitis
Aspiration Pneumonia
Description Causes
- Path: Oral or gastric contents get into lung lobes - Risks: Poor dental hygiene; Dysphagia; ↓ GCS
- NB: Acidic aspirates lead to chemical pneumonitis - G+Ve: S. pneumoniae; S. aureus
- Location: Right middle-lower lobes usually affected - G-Ve: H. influenzae; P. aeruginosa
Severity Assessment
CURB-65 Interpretation
- Confusion (abbreviated mental test ≤8) - 0-1: Home prescription is possible
- Urea >7 mmol/L - 2: Hospital admission + therapy
- Respiratory rate ≥30 breaths/min - ≥3: Severe pneumonia + consider ITU
- BP <90 mmHg systolic or <60 mmHg diastolic Prognosis
- Age ≥65 YO - Px: Score of 4 carriers 30 % mortality at 30 days
Pneumonia Complications
Respiratory Failure Empyema
- T1RF: Common complication - Features: Pneumonia; Recurrent fever
- Mx: High flow 60 % O2 - Ix: pH <7.2; ↓ Glucose; ↑ LDH
- Ix: ↓ O2; ↑ CO2 - Mx: Guided chest drain
- NB: Monitor ABG for CO2 retention Atrial Fibrillation (AF)
Pleural Effusion - Paroxysmal: Usually resolves with pneumonia mx
- Exudate Effusion: Protein >25 g/L; ↑ LDH - Mx: Short-term β-blockers or digoxin
- Transudate Effusion: Protein <25 g/L; ↓ LDH - NB: More common in elderly patients
- Pleurocentesis: If large or symptomatic drain effusion Septicaemia
- Mx: Guided aspiration (1-1.5 L max) - Spread: Pneumonia source may metastasise
- Cc: Re-expansion oedema; ↓ BP; Shock - NB: IE; Meningitis; Hepatitis; Pericarditis
,Lung Abscess (Liquefactive Necrosis)
Presentation Investigations
- System: Singing ↑To; ↓ Weight; Anaemia - Bloods: FBC (anaemia + neutrophilia); CRP
- Lung: Purulent sputum; Haemoptysis; Pleuritic pain - Cultures: Blood; Sputum
- Observations: Finger clubbing - Microscopy: Sputum; Aspirate
- Auscultation: Crepitation - Imaging: CXR (cavity >2 cm); CT (obstruction)
Causes Management
- Pneumonia: Occurs in 20-30 % of cases - Abx: According to MC&S for 4-6 wk course
- Aspiration: Alcoholism; Dysphagia; Bulbar palsy - Postural drainage: Guided chest drain
- Septic emboli: Right-sides IE; IVDU; Septicaemia - Surgical: May require resection
- Micro: S. aureus; Klebsiella; Pseudomonas common
, Infections of the Lung
Description
The lungs are one of the most exposed internal organ within the body to the outside environment and so are one of
the most common entry points and sites of infection. One of the most common lung infections in pneumonia which is
most commonly caused by contagious bacteria. Factors that increase the risk of lung infections include comorbidities
such as asthma, COPD and CF, immunocompromised and old age.
Infectious Pneumonia
Causes
- Community-Acquired Pneumonia (CAP) - Aspiration Pneumonia
o Common: S. pneumoniae o G+Ve: S. pneumoniae; S. aureus
o Mild: S. pneumoniae; H. influenzae o G-Ve: H. influenzae; P. aeruginosa
o Mod: S. pneumoniae; H. influenzae; M. pneumoniae - Neutropenic Pneumonia
o Severe: Panton-Valentine Leucocidin S. aureus o G+Ve: G+Ve cocci (e.g. Staphylococcus)
o Atypical: Legionella pneumophilia; PJP o G-Ve: G-Ve bacilli (e.g. Pseudomonas)
- Hospital-Acquired Pneumonia (HAP) o Fungi: Aspergillus; Candida; PJP
o Timing: Occurs ≥48 hrs post-admission - Viral pneumonia
o G-Ve: Usually G-Ve anaerobic Bacilli o Virus: Influenza; RSV; Parainfluenza; Rhinovirus
o Common: Pseudomonas aeruginosa o Cc: Increases chance of 2o bacterial infx
Bacterial Lung Infections
Pneumococcal Pneumonia Mycoplasmal (Walking) Pneumonia
- Sx: Rapid onset; ↑↑ Fever; Pleurisy; Herpes labialis - Sx: Dry cough (mild); Erythema multiforme; AIHA
- Cx: Streptococcus pneumoniae (encapsulated) - Cx: Mycoplasma pneumoniae
- Rx: ↑ Age; Lung condition; Hyposplenism - Ix: CXR (Reticulo-nodular shadows); PCR sputum
- Ix: CXR; Pneumococcal antigen test - Mx: Clarithromycin; Doxycycline
- Mx: Penicillin; Cephalosporin; Pneumococcal vax - NB: Epidemics tend to occur every 4 years
Staphylococcal Pneumonia Legionnaire’s Disease (Pontiac Fever milder form)
- Sx: Often bilateral bronchopneumonia - Sx: Hyponatraemia; Lymphopenia; Extrapulm. sx
- Cx: Staphylococcal aureus - Cx: Legionella pneumophilia
- Rx: Post-influenza infection - Rx: Hot-tubs; Air conditioning (Holidays)
- Mx: Flucloxacillin ± Rifampicin - Ix: CXR (bi-basal consolidation); Urinary antigen
Klebsiella Pneumonia - Mx: Fluoroquinolone; Clarithromycin
- Sx: Purple-jelly sputum - Cc: Coma; Hepatitis; RF
- Cx: Klebsiella pneumoniae Chlamydophila Pneumonia
- Rx: Alcoholism; Diabetes; Aspiration pneumonia - Sx: Pharyngitis; Otitis; Chronic wheezy child
- Ix: CXR (Cavitation in upper lobes) - Cx: Chlamydia pneumoniae
- Mx: Cefotaxime (resistance is common) - Ix: qPCR; Oropharyngeal swab/BAL culture (slow)
- Cc: Lung abscess; Empyema; Highly contagious - Mx: Doxycycline; Clarithromycin
- Px: Mortality is 30-50 %; Worse if alcoholic or septic - NB: Often presents as a biphasic disease
Pseudomonal Pneumonia Psittacosis (Parrot Fever)
- Sx: Green sputum - Sx: Arthralgia; Anorexia; Lethargy; NVD
- Cx: Pseudomonas spp. (aeruginosa) - Cx: Chlamydia psittaci
- Rx: >48 hrs hospital; Neutropenia; LT Abx use - Rx: Exposure to birds (esp. parrots)
- Ix: CXR - Ix: CXR (patchy consolidation); PCR
- Mx: Anti-Pseudomonal (Ticarcillin); Cipro. + Gent. - Mx: Doxycycline; Clarithromycin
- NB: Most common cause of HAP - Cc: Hepatitis; Nephritis
