Respiratory Lecture 6 Dr Azeem Alam, MBBS BSc (Hons) Surgical AFP - - PowerPoint PPT Presentation

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Respiratory Lecture 6 Dr Azeem Alam, MBBS BSc (Hons) Surgical AFP - - PowerPoint PPT Presentation

Sep 10, 2022 243 likes •711 views

Respiratory Lecture 6 Dr Azeem Alam, MBBS BSc (Hons) Surgical AFP Guys and St. Thomas Hospital Email: admin@bitemedicine.com Website: www.bitemedicine.com Facebook: https://www.facebook.com/biteemedicine Content reviewed on 11/04/2020.

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Respiratory

Lecture 6

Dr Azeem Alam, MBBS BSc (Hons) Surgical AFP Guy’s and St. Thomas’ Hospital

Email: admin@bitemedicine.com Website: www.bitemedicine.com Facebook: https://www.facebook.com/biteemedicine Instagram: @bitemedicine Content reviewed on 11/04/2020.

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Learning objectives

  • 2 respiratory topics: COPD and Pneumonia
  • Case-based discussion(s) to identify the top differentials and why
  • Theory to cover pathophysiology, diagnostic criteria, investigations and

management

  • Quiz (Mentimeter and multi-step SBAs)

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Our commitment to you

We have listened to your feedback and we have…

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Added differentials for every topic More diagrams More Multistep-SBA questions

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Case 1

History A 57-year-old male presents with a 4-month history of a productive cough and shortness of breath at rest. He has a 20-pack-year smoking history. The diameter of the chest is increased on examination, with some wheezing on auscultation. Observations HR 94, BP 128/84, RR 20, SpO2 93%, Temp 37.6°C.

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Pathophysiology

Definition: progressive airflow limitation that is irreversible. Characterised by emphysema and chronic bronchitis. Inflammation

  • Inhaled stimuli causes the activation of macrophages and neutrophils

Risk factors

  • Smoking
  • Alpha-1 antitrypsin deficiency
  • Air pollution
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Pathophysiology

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Pathophysiology

Physiological outcome

  • Remodelling and narrowing of airways
  • Increased airway resistance
  • Enlargement of mucus-secreting glands
  • Hypoxia and vascular bed changes result in pulmonary hypertension (cor pulmonale)

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Clinical features

Symptoms Signs Shortness of breath: initially exercise- induced, eventually at rest Tar staining Productive cough Tachypnoea Fatigue Barrel chest Hyperresonance on percussion Wheeze and quiet breath sounds Exacerbation

  • Coarse crepitations
  • Pyrexia
  • Asterixis
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Differentials

COPD Asthma Bronchiectasis

  • Smoking
  • Alpha-1 antitrypsin

deficiency

  • Allergen
  • Pollution
  • Exercise
  • Associated with cystic

fibrosis

  • Recurrent infections
  • Later in life
  • Irreversible
  • Early in life
  • Atopy
  • Family history
  • Diurnal variation
  • Reversible
  • Bronchial dilation
  • Significant purulent

sputum

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Suspected cases

NICE recommend investigating for suspected COPD in people over 35 years old, with a risk factor (currently smoking or ex-smoker) and 1 or more of the following:

  • Exertional breathlessness
  • Chronic cough
  • Regular sputum production
  • Winter ‘bronchitis’
  • Wheeze
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Investigations

Bedside

  • ECG: right sided heart failure (e.g. right axis deviation and RBBB)
  • Sputum: culture if evidence of exacerbation

Bloods

  • Inflammatory markers: if evidence of exacerbation
  • Arterial blood gas: possible type 2 respiratory failure

Imaging

  • CXR: flattened diaphragm and hyperinflation

Special tests

  • Spirometry: FEV1/FVC <0.70 and lack of reversibility post-bronchodilator
  • TLCO: perform if symptoms are disproportionate to spirometry results
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Investigations

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Management

The GOLD classification is widely used, more so than NICE, in guiding the management of COPD [2]. GOLD classify airway obstruction as follows: Severity of airflow obstruction Post-bronchodilator FEV1/FVC FEV1% predicted Stage 1: Mild <0.70 ≥80% Stage 2: Moderate <0.70 50-79% Stage 3: Severe <0.70 30-49% Stage 4: Very severe <0.70 <30%

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Management

  • Smoking cessation advice should be offered to all
  • Vaccinations: one-off pneumococcal and annual influenza
  • Inhaler therapy: all patients will be started on a short-acting bronchodilator PRN and

may have additional long-acting agents

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Management: initial therapy

Exacerbations Symptoms between exacerbations Inhaler GOLD A ≤ 1 per year not requiring admission Mild Any bronchodilator (short or long acting) GOLD B Severe LABA or LAMA GOLD C ≥ 2 per year or 1 requiring admission Mild LAMA GOLD D Severe

  • LAMA or
  • LAMA + LABA or
  • ICS + LABA

Mild symptoms (MRC ≤ 1 OR CAT <10) Severe symptoms (MRC ≥ 2 OR CAT ≥ 10)

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Long-term oxygen therapy

  • Long term oxygen therapy (LTOT): supplemental O2 for at least 15 hours per day. ABG

measured on 2 separate occasions

  • Indicated if a non-smoker and:
  • PaO2 <7.3 kPa
  • r
  • PaO2 ≥7.3 and <8 kPa and 1 of the following:
  • Secondary polycythaemia
  • Peripheral oedema
  • Pulmonary hypertension
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Management: exacerbation

Management is guided by observations, ABG, inflammatory markers, and CXR.

  • Controlled oxygen: aim SpO2 88-92% if hypercapnic on ABG, otherwise aim for 94-98%
  • Nebulised bronchodilators: salbutamol and ipratropium bromide
  • Corticosteroids: usually a 5-day course
  • Antibiotics: empirical antibiotics such as amoxicillin and doxycycline
  • Theophylline: consider if there is an inadequate response to nebulisers
  • Ventilation: if evidence of worsening respiratory acidosis
  • Non-invasive ventilation: BiPAP
  • Mechanical ventilation if BiPAP fails
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Summary: COPD

  • COPD is a progressive, irreversible airflow obstruction due to chronic bronchitis and

emphysema

  • Risk factors include smoking, occupational exposure (dust, chemicals, gases, coal), and

genetic causes (alpha-1-antitrypsin deficiency)

  • COPD can be distinguished from asthma with a lack of reversibility post bronchodilator
  • GOLD criteria for management is dependent on frequency and severity of the

exacerbations

  • One-off pneumococcal vaccine and an annual influenza vaccine
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Distinction question

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A1AT genotypes

Disease Genotype Normal PiMM Moderate deficiency PiSS Severe deficiency PiZZ

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Case 2

History A 64-year-old female presents to the emergency department with shortness of breath and a productive cough. She has a history of hypertension, for which she takes amlodipine. Observations HR 100, BP 120/80, RR 20, SpO2 94%, Temp 38.2 °C.

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Pathophysiology

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Aetiology

Categorised into:

  • Community-acquired pneumonia (CAP)
  • Hospital-acquired pneumonia (HAP)
  • Atypical pneumonia
  • Aspiration pneumonia
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Aetiology

Category Organism Clinical feature Community-acquired pneumonia Streptococcus pneumoniae

  • The most common cause
  • f pneumonia

Haemophilus influenzae

  • Associated with COPD

Staphylococcus aureus

  • Post viral URTI

(commonly)

  • Abscess and empyema

Hospital-acquired pneumonia

  • Occurs ≥ 48 hours after

admission to hospital Gram-negative bacteria and staphylococcus aureus

  • May require broad-

spectrum antibiotics

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Aetiology

Category Organism Clinical feature Atypical pneumonia

  • Difficult to gram stain and

culture

  • Interstitial inflammation
  • Atypical presentation
  • CXR: no consolidation

Mycoplasma pneumoniae

  • Young adults
  • Autoimmune haemolytic

anaemia and erythema multiforme Legionella pneumophila

  • Water source exposure
  • Hyponatraemia
  • Deranged LFTs

Chlamydia psittaci

  • Exposure to birds

Aspiration pneumonia

  • Inhalation of oropharyngeal

contents

  • Commonly right lower lobe

Klebsiella pneumoniae, anaerobes, streptococcus pneumoniae, staphylococcus aureus, haemophilus influenzae

  • Redcurrant jelly sputum
  • Upper lobe abscess
  • Alcoholics and diabetics
  • Poor swallow
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Clinical features

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Investigations

Bedside

  • Sputum culture: allows assessment of organism and antibiotic sensitivities

Bloods

  • FBC: leukocytosis
  • U&Es: deranged renal function and elevated urea in severe disease
  • CRP: raised
  • Arterial blood gas: perform if hypoxic to assess for respiratory failure

Imaging

  • CXR: consolidation is the classic finding, but may be absent with atypical pneumonia

Investigations to consider:

  • Urinary antigen testing: useful to determine if the cause is pneumococcal

pneumonia or legionella

  • Serology: can identify mycoplasma infection
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Investigations

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CURB-65

Estimate mortality with CAP to determine inpatient vs. outpatient treatment

  • Low-risk (0-1): community-based care
  • Intermediate-risk (2): hospital-based care
  • High-risk (≥ 3): consider ITU assessment

CURB-65 Criteria Marker (1 point for each marker) Confusion Abbreviated Mental Test Score ≤ 8, or new disorientation in person, place or time Urea > 7mmol/L Respiratory rate ≥ 30/min Blood pressure SBP < 90mmHg or DBP < 60mmHg 65 ≥ 65 years of age

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Management: CAP

Category Antibiotic(s) Low severity (CURB ≤ 1) Amoxicillin Penicillin-allergic or atypical: offer doxycycline or clarithromycin Moderate severity (CURB 2) Oral amoxicillin and add clarithromycin if atypical High severity (CURB ≥ 3) IV co-amoxiclav and clarithromycin

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Management: HAP

Category Antibiotic(s) Low severity Oral co-amoxiclav Penicillin-allergic: doxycycline or levofloxacin High severity Broad-spectrum: such as IV tazocin or ceftriaxone Suspected or confirmed MRSA Add IV vancomycin

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Summary: Pneumonia

  • Pneumonia presents with a brief history of shortness of breath, pleuritic chest pain,

productive cough, and fever

  • Atypical pneumonia can cause ‘atypical’ symptoms with a normal CXR
  • Categorised into CAP, HAP, atypical and aspiration pneumonia
  • Streptococcus pneumoniae is the most common bacterial cause
  • CURB-65 is used to risk-stratify patients with CAP, with a score of ≥ 2 warranting

admission

  • Management is with antibiotics as per local guidelines and tailored to sensitivities
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Distinction question

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Further information

  • We need your feedback!
  • Lecture series / schedule
  • New, interactive website coming soon
  • Stay up-to-date!
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  • Want to get involved? Contact us at
  • pportunities@bitemedicine.com to get your information pack

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References

1) National Heart Lung and Blood Institute / Public domain. https://upload.wikimedia.org/wikipedia/commons/3/37/Copd_2010Side.JPG 2) James Heilman, MD / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://upload.wikimedia.org/wikipedia/commons/0/0b/COPD.JPG 3) See page for author / Public domain. https://upload.wikimedia.org/wikipedia/commons/f/fb/New_Pneumonia_cartoon.jpg 4) Häggström, Mikael (2014). Medical gallery of Mikael Häggström 2014. https://upload.wikimedia.org/wikipedia/commons/2/20/Symptoms_of_pneumonia.svg 5) Mikael Häggström, M.D. - Author info - Reusing imagesWritten informed consent was obtained from the individual, including online publication. / CC0. https://upload.wikimedia.org/wikipedia/commons/5/51/X-ray_of_lobar_pneumonia.jpg

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