Resp Session 6 Flashcards
What two conditions is COPD a combination of?
Emphysema and chronic bronchitis
What is the pathogenesis of chronic bronchitis?
Inflammation in large always causes:
Remodelling and narrowing of airways
Hyper secretion of mucus and proliferation of goblet cells
Chronic productive cough and frequent infections
What is the pathogenesis of emphysema?
Terminal bronchioles and distal airspaces destroyed causing:
Loss of elastic tissue –> hyperinflation
Small airways collapsing on expiration
Bullae due to large redundant air spaces
What causes COPD?
Smoking
Alpha-1 antitrypsin deficiency (esp
What are the S/S if COPD?
Cough with sputum Purse lip breathing SoB Use of accessory muscles in breathing Tachypnoea Wheeze --> quiet breath sounds --> silent chest
What are the S/S of more advanced cases of COPD?
Silent chest Peripheral +/- central cyanosis CO2 retention flap Cor pulmonale Oedema
What are the 5 stages of the MRC dyspnoea score used to assess COPD?
- SoB on strenuous exercise only
- SoB on hurrying/walking up slight hill
- Walks slower due to SoB
- Stops for breath after walking ~100m on level ground
- Too SoB to leave house/SoB on dressing
What investigations can be used in COPD?
Spirometry CXR HRCT ABG Alpha-1-antitrypsin blood test
Why is HRCT used in investigation of COPD?
Gives detailed assessment of macroscopic alveolar destruction in emphysema, useful if considering surgery
Why is CXR mandatory in COPD investigation?
To exclude other diagnoses
What do NICE guidelines state are mild, moderate and severe levels of airflow obstruction detectable by spirometry?
Mild: FEV1 = 50-80%
Moderate: FEV1 = 30-49%
Severe: FEV1
How is COPD diagnosed?
Hx: smoker, >40 y.o. with onset of symptoms later in life, chronic productive cough, persistent and progressive SoB
AND
obstructive pattern on spirometry
How is stable COPD managed?
Smoking cessation Pulmonary rehabilitation Bronchodilators Antimuscarinics Steroids Mucolytics Dietary review Supportive Tx Long term O2 and surgery if appropriate
What is the cycle of reconditioning seen in stable COPD pts?
Feel SoB –> avoid activities that worsen SoB –> do less –> muscles weaken –> worsened SoB –> feel depressed –> avoid activities etc.
What are some of the S/E associated with treatment of stable COPD?
Beta-2 agonist: tachycardia, anxiety, hypokalaemia, tremor
Antimuscarinics: urinary difficulty, dry mouth, URT, glaucoma
Steroidal S/E
How is an acute COPD exacerbation managed?
Aim for sats of 88-92% with titrated O2 therapy
Nebulised bronchodilators
Oral steroids
Abx if blood tests indicate infection
Consider IV bronchodilator
Repeat ABG to assess need for ventilation
How can COPD generally be distinguished from asthma by using clinical features?
Pts tend to be smokers
S/S >65 y.o.
Chronic productive cough
Persistent and progressive SoB
Night time waking with cough/wheeze uncommon
Diurnal pattern/day-to-day variability uncommon
What characterises COPD?
Airflow obstruction which is usually progressive, not fully reversible and does not change markedly over several months
What are common microbial flora of the URT?
Viridans streptococci
Neisseria sp.
Candida sp.
What are URTIs most commonly caused by?
Self limiting viruses
Why can viral URTI lead to secondary bacterial infection?
Due to viral action on cilia
Give some examples of common URTIs.
Rhinitis Tracheitis Pharyngitis Sinusitis Laryngitis Otitis media
What deferences does the respiratory tract have against infection?
Nasal hairs Ciliated columnar epithelium Cough+sneeze reflexes Respiratory mucosa Lymphoid follicles of pharynx and tonsils Alveolar macrophages Secretory IgA and IgG
Give some examples of LRTIs.
Bronchitis Pneumonia Bronchiolitis Empyema Bronchiectasis Lung abscess
How does a poor swallow lead to aspiratory pneumonia?
Allows secretory pool in pharynx which can enter LRT
What is acute bronchitis?
Inflammation of medium sized airways often seen in smokers
What are the S/Sof acute bronchitis?
Cough Fever Increased sputum production Sob due to exudation Pulmonary oedema and cellular infiltration
How does a CXR appear in acute bronchitis?
Normal as terminal bronchioles and air sacs are not affected
What can cause acute bronchitis?
Viruses
S.pneumoniae
H.influenzae
M.catarrhalis
What is the treatment for acute bronchitis?
Bronchodilation
Physiotherapy
Abx if absolutely necessary
What is penumonitis?
Non-infective inflammatory disease
What is chronic bronchitis?
Recurrent bouts of SoB associated with but not caused by infection (not primarily infective)
What is pneumonia?
Inflammation of the lung alveoli, terminal bronchioles and lung parenchyma
What are the S/S if pneumonia?
Fever Cough Pleuritic chest pain SoB Opacities on CXR
How is pneumonia classified?
Clinical setting
Presentation (acute->bacterial/viral, chronic->TB)
Causative organism
Lung pathology - lobar, broncho (patchy), interstitial
What is the pathogenesis of pneumonia?
Acute inflammatory response –> exudation of fibrin rich fluid, neutrophil and macrophage infiltration –> fluid filled air sacs –> heavy, stiff lung –> red hepatisation –> grey hepatisation
What factors may help identify the causative agent in pneumonia?
Pre-existing lung disease Immunocompromise Geography Seasons Epidemics Travel Animal exposure Recent ventilation
How long does grey hepatisation take to develop following red hepatisation in pneumonia?
2-3 days
What are the typical causative agents of CAP?
S.pneumoniae
H.influenzae
What are atypical causes of CAP?
Legionella
Mycoplasma
Coxiella bunetti (livestock)
Chlamydia psittaci (birds)
What are the S/S of CAP?
SoB Cough +/- sputum (yellow, rusty, recurrent jelly) Fever Rigors Pleuritic chest pain Malaise Nausea
What causative agent does recurrent jelly sputum suggest?
Klebsiella
What is detected O/E in CAP?
Pyrexia Tachycardia Bronchial breathing Tachypnoea Cyanosis Crackles Dullness to percussion Tactile vocal fremitus
What investigations are used to support diagnosis and assess severity of CAP?
FBC U&Es CRP ABG CXR
What methods can be used to collect samples for sputum and blood culture to identify the causative agent in CAP?
Broncho alveolar lovage fluid
Nose and throat swabs
Urine antigen tests
Serum antibody test
When are urine antigen tests or serum antibody tests used to investigate CAP?
Atypical causes due to difficulty in culture
What are the criteria included in the CURB-65 score used to assess severity of CAP?
Confusion
Urea > 7 mmol per litre
RR > 30
Blood pressure
What does a CURB-65 indicate?
Severe pneumonia, consider admittance to hospital
What is the empiric Tx for CAP?
Mild-moderate: amoxicillin (doxycycline or erythromycin for penicillin allergic pts)
Moderate-severe: co-amoxiclav (clarithromycin/doxycycline for penicillin allergic pts and to cover atypical penicillin resistant causes)
How can CAP lead to chronic lung disease?
Resolution of infection with fibrous scarring
What complications can arise following CAP?
Lung abscess –> empyema
Bronchiectasis –> recurrent infections
What is atypical pneumonia?
Pneumonia caused by organisms without a cell wall
What additional features are seen in atypical pneumonia?
Extra-pulmonary features e.g. hepatitis, hyponatraemia
What is the Tx for atypical pneumonia?
Agents that work on protein synthesis: macrolides and tetracyclines
What is the pathogenesis of viral pneumonia?
Immune cells and virus cause damage to epithelial cells –> necrosis/haemorrhage into lung parenchyma –> acute hypoxia –> ARDS
How is viral pneumonia identified on CXR?
Patchy/diffuse ground glass opacity on CXR
What causes viral pneumonia?
Influenza
Parainfluenza
Respiratory syncytial virus
Adenovirus
What is the definition of hospital acquired pneumonia?
Onset within 48hrs of being in hospital
What causative agents are associated with hospital acquired pneumonia?
G-ve: Staph aureus Enterobacteriaciae Pseudomonas sp. H.influenza Acinetobacter baumannii Candida sp.
What is the Tx for HAP?
1st line: co-amoxiclav
2nd line: pipperacillin/Tazobactam/meropenem
What method is used to distinguish causative agent of HAP form UR flora?
Bronchial lava he
What is aspiration pneumonia?
Exogenous material/endogenous secretions –> resp tract seen in dysphagia, epilepsy, alcoholics, drowning
What is the causative agent for aspiration pneumonia?
Mixed infection as you can’t selectively aspirate certain organisms, commonly viridans streptococci and anaerobes
What is the treatment for aspiration pneumonia?
Co-amoxiclab
What causative agents are seen in immunosuppression associated LRTI?
HIV: PCP, TB, atypical mycobacteria
Neutropenia: fungi
BM transplant: CMV
Splenectomy: encapsulated organisms e.g. S.pneumoniae, H.influenzae, malaria
How is LRTI associated with immunosuppression prevented?
Flu vaccine every year
Pneumococcal vaccine every 5 years
Lifelong amoxicillin in asplenic
Smoking advice
