Respiratory Flashcards
What are the causes of Respiratory acidosis?
- Hypoventilation e.g. neuromuscular diseases
- “Alveolar hypoventilation” e.g. COPD
What should the A-a values be ?
- Young healthy people: <2 kPa
- Older people: <4 kPa
- >4 kPa- lung pathology
What happens in anaphylaxis?
Immunological response: – IgE → antigen → mast cell & basophils ‡ → histamine ↑ → body response
Symptoms of Anaphylaxis and Angioedema?
- Pruritus, urticaria & angioedema
- Hoarseness, progressing to stridor & bronchial obstruction
- Wheeze & chest tightness from bronchospasm
How is Anaphylaxis treated?
- Remove trigger, maintain airway, 100% O2
- Intramuscular adrenaline 0.5 mg (Repeat every 5 mins as needed to support CVS)
Management following stabilisation:
- non-sedating oral antihistamines, in preference to chlorphenamine
- Serum tryptase levels are sometimes taken in such patients (remain elevated for up to 12 hours)
- Referral to a specialist allergy clinic
How is mild to moderate asthma defined?
- Mild: No features of severe asthma; PEFR >75% Moderate:
- No features of severe asthma; PEFR 50-75%
How is severe asthma defined?
- PEFR 33-50%
- Cannot complete sentences in 1 breath
- RR > 25/min
- HR >110 BPM
How is life threatening asthma defined?
- Life threatening (if any one of the following):
- PEFR < 33% of best or predicted
- Sats <92% or ABG pO2 < 8kPa
- Cyanosis, poor respiratory effort, near or fully silent chest
- Exhaustion, confusion, hypotension or arrhythmias
- Normal pCO2
How is acute asthma managed?
- ABCDE
- Aim for SpO2 94-98% with oxygen as needed, ABG if sats <92%
- 5mg nebulised Salbutamol (can repeat after 15 mins)
- 40mg oral Prednisolone STAT (IV Hydrocortisone if PO not possible)
If severe:
- Nebulised Ipratropium Bromide 500ug
- Consider back to back Salbutamol If life threatening or near fatal:
- Urgent ITU or anaesthetist assessment
- Urgent portable CXR
- IV Aminophylline
- Consider IV Salbutamol if nebulised route ineffective
- Magnesium sulphate
What are some of the signs and sx of COPD?
Symptoms
- Cough + sputum
- Dyspnoea
- Wheeze
- Wt. loss
Signs
- Tachypnoea
- Prolonged expiratory phase
- Hyperinflation
- ↓Cricosternal distance (normal = 3 fingers)
- Loss of cardiac dullness
- Displaced liver edge
- Wheeze
- May have early-inspiratory crackles
- Cyanosis
- Cor pulmonale: ↑JVP, oedema, loud P2
- Signs of steroid use
How are COPD Exacerbations treated?
- ABCDE
- Oxygen: - via a fixed performance face mask due to risk of CO2 retention - aim for SaO2 88-92% (use ABGs)
- NEBs – Salbutamol and Ipratropium
- Steroids – Prednisolone 30mg STAT and OD for 7 days
- Abx if raised CRP / WCC or purulent sputum
- CXR
- Consider IV aminophylline
- Consider NIV if Type 2 respiratory failure and pH 7.25-7.35
- If pH <7.25 consider ITU referral
How is pneumonia investigated?
- Bedside: urine CAP (pneumococcal and legionella ), ECG?, sputum sample MC+S
- Bloods: FBC, UE, CRP, LFT
- Imaging: CXR
What are the signs + sx of pneumonia?
- Sx: Fever, rigors, Malaise, anorexia, Dyspnoea, Cough, purulent sputum, haemoptysis, Pleuritic pain
- Signs: ↑RR, ↑ HR, Cyanosis, Confusion,
- Consolidation: ↓ expansion, Dull percussion, Bronchial breathing, ↓ air entry, Crackles, Pleural rub , ↑VR
What aids in the diagnosis of pneumonia?
What antibiotics are used for the treatment of pneumonia?
- ABCDE - appropriate management
-
Antibiotics
-
CURB65 score 0 or 1 (low severity): amoxicillin 500mg TD 5 days
- Atypical: Doxycycline (e.g. legionella)
-
CURB65 score 2: Amoxicillin 500mg TD 5 days + Clarithromycin 500 mg BD 5 days
- Atypical: Doxycycline
- CURB65 score 3 to 5: Co-amoxiclav (500/125 mg 3 times a day orally or 1.2 g 3 times a day IV) and Clarithromycin (500 mg twice a day orally or IV for 5 days)
-
CURB65 score 0 or 1 (low severity): amoxicillin 500mg TD 5 days
What is considered a massive haemoptysis?
- >240mls in 24 hours OR
- >100mls / day over consecutive days
Define the Management of Massive Haemoptysis?
- ABCDE
- Lie patient on side of suspected lesion (if known)
- Oral Tranexamic Acid for 5 days or IV
- Stop NSAID’s / aspirin / anticoagulants •
- Antibiotics if any evidence of respiratory tract infection
- Consider Vitamin K
- CT aortogram – interventional radiologist may be able to undertake bronchial artery embolisation
How is a tension pneumothorax detected?
- Hypotension
- Tachycardia
- Deviation of the trachea away from the side of the pneumothorax
- Mediastinal shift away from pneumothorax
How is a tension pneumothorax managed?
- Large bore intravenous cannula into 2nd ICS MCL
- Chest drain into the affected side: 4th ICS MAL
- Give high flow 02 and admit
What are some of the sx of a PE?
- Chest pain (pleuritic)
- SOB
- Haemoptysis
- Low cardiac output followed by collapse (if Massive PE)
What are some of the Major Risk Factors of a PE?
- Surgery – Abdominal/pelvic; Knee/ hip replacement; Post-op spell on ITU
- Obstetric – Late pregnancy; C- section
- Lower Limb – Fracture; Varicose veins
- Malignancy – Abdominal/ Pelvic/ Advanced/ Metastatic
- Reduced Mobility
- Previous proven VTE
How is a PE managed?
- ABCDE
- Oxygen if hypoxic
- Fluid resuscitation (if hypotensive)
- Thrombolysis: if haemodynamically unstable (large PE) - 100mg alteplase IV; (2nd: streptokinase)
- Anticoagulation
- LMWH - Dalteparin on admission
- After admission:
- 1st line: DOAC - provoked 3 months, unprovoked life long
- 2nd: LMWH (bridging) + warfarin (check INR 2-3 - warfarin needs 5 days to be effective and is prothombotic)
How do sx and management change for a massive PE?
- Hypotension/ imminent cardiac arrest
- Signs of right heart strain on CT / Echo
- Consider thrombolysis with IV alteplase
- Consider Thrombolysis Contraindications
What are some of the absolute contraindications of thrombolysis?
What are some of the relative contraindications of thrombolysis?
What are the characteristics of asthma?
- Asthma is a chronic inflammatory disease of the airways
- Airway obstruction that is reversible, either spontaneously or with treatment
- Increased airway responsiveness (airway narrowing) to a variety of stimuli
Asthma Pathophysiology
- Airway epithelial damage – shedding and subepithelial fibrosis, basement membrane thickening
- An inflammatory reaction characterised by eosinophils, T-lymphocytes (Th2) + mast cells. Inflammatory mediators released include histamine, leukotrienes, and prostaglandins
- Cytokines amplify inflammatory response
- Increased numbers of mucus secreting goblet cells and smooth muscle hyperplasia and hypertrophy
- Mucus plugging in fatal and severe asthma
How is Acute Asthma Managed?
- ABCDE
- Aim for SpO2 94-98% with 02 as needed, ABG if sats <92%
- 5mg nebulised Salbutamol (can repeat after 15 mins)
- 40mg oral Prednisolone STAT (IV Hydrocortisone if PO not possible)
- Severe: ipratroprium bromide 500mg + back to back salbutamol
- Life threatening fatal: IV aminophylline. IV salbutamol
What are the histological features of asthma?
- Thickening of basement membrane
- Mucosal thickening
- Mucus plugging
- Bronchial wall smooth muscle hypertrophy
How do you treat severe or life threatening asthma?
- If severe: Nebulised Ipratropium Bromide 500 micrograms
- Consider back to back Salbutamol If life threatening or near fatal
- Urgent ITU or anaesthetist assessment
- Urgent portable CXR
- IV Aminophylline
- Consider IV Salbutamol if nebulised route ineffective
- Magnesium sulphate
Criteria for safe asthma discharge after exacerbation
- PEFR >75%
- Stop regular nebulisers for 24 hours prior to discharge
- Inpatient asthma nurse review to reassess inhaler technique and adherence
- Provide PEFR meter and written asthma action plan
- At least 5 days oral prednisolone
- GP follow up within 2 working days
- Respiratory Clinic follow up within 4 weeks
- For severe or worse, consider psychosocial factors
What are the NICE guidelines for chronic asthma management?
- SABA
- +ICS
- +LTRA
- +LABA
- +SABA=/- LTRA
What is Eosinophilia
- Some patients with asthma have eosinophilic inflammation which typically responds to steroids. However, there are several differentials of eosinophilia:
- Airways inflammation (asthma or COPD)
- Hayfever / allergies
- Allergic Bronchopulmonary Aspergillosis
- Drugs
- Churg-Strauss / vasculitis
- Eosinophilic Pneumonia
- Parasites
- Lymphoma
- SLE
- Hypereosinophilic syndrome
What is the COPD definition?
- COPD is characterised by airflow obstruction.
- The airflow obstruction is usually progressive, not fully reversible and does not change markedly over several months.
- The disease is predominantly caused by smoking
What is the pathophysiology of COPD?
- COPD is an umbrella term which encompasses emphysema and chronic bronchitis
- Mucous gland hyperplasia
- Loss of cilial function
- Emphysema – alveolar wall destruction causing irreversible enlargement of air spaces distal to the terminal bronchiole
- Chronic inflammation (macrophages and neutrophils) and fibrosis of small airways
What are the common causes of COPD?
- Smoking
- Inherited α-1-antitrypsin deficiency
- Industrial exposure, e.g. soot
What outpatient COPD management?
- COPD care bundle
- Smoking cessation
- Pulmonary Rehabilitation
- Bronchodilators
- Antimuscarinics
- Steroids
- Mucolytics
- Diet
- LTOT if appropriate
- Lung volume reduction if appropriate
General Measures
- Stop smoking
- Specialist nurse
- Nicotine replacement therapy
- Bupropion, varenicline (partial nicotinic agonist)
- Support programme
- Pulmonary rehabilitation / exercise
- Influenza and pneumococcal vaccine
Medications:
- Mucolytics -Consider if chronic productive cough
- E.g. Carbocisteine (CI in PUD)
- Breathlessness and/or exercise limitation
- SABA and/or SAMA (ipratropium) PRN
- SABA PRN may continue at all stages
Exacerbations or persistent breathlessness
- FEV1 ≥50%: LABA or LAMA (tiotropium) (stop SAMA)
- FEV1 <50%: LABA+ICS combo or LAMA
- Persistent exacerbations or breathlessness: LABA+LAMA+ICS
- Roflumilast / theophylline (PDIs) may be considered
- Consider home nebs
LTOT: Aim: PaO2 ≥8 for ≥15h / day (↑ survival by 50%)
Surgery
- Recurrent pneumothoraces
- Isolated bullous disease
- Lung volume reduction
What are the three types of pneumonia?
- Community Acquired
- Hospital Acquired
- Others, e.g. aspiration
How is CAP diagnosed?
- CURB-65 score
- ABX according to CURB-65 score and patient allergies
- ABCDE approach - Even if CURB-65 score is low do not ignore signs of sepsis
- NO DELAY in initiating Abx (or IV fluids if indicated) + / - Paracetamol
- ITU referral if high CURB-65 score
What other tests are used for CAP diagnosis?
- CXR
- Bloods: FBC, U&E, CRP and sputum cultures
- Blood cultures if febrile
- If high CURB-65 score -
- Urinary CAP screen - Atypical pneumonia screen – legionella
- ABG if low sats