Respiratory
Lecture 7
Dr Azeem Alam, MBBS BSc (Hons) Surgical AFP Guy’s and St. Thomas’ Hospital
[email protected] www.bitemedicine.com www.facebook.com/biteemedicine @bitemedicine Content reviewed on 21/04/2020. 1 Learning objectives
• 2 respiratory topics: Pneumothorax and Pulmonary Embolism
• 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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History
A 23-year-old male presents with sudden onset left-sided chest pain and shortness of breath after meeting his friends.
He is usually fit and well.
On examination, there is left-sided hyper-resonance on percussion and diminished breath sounds.
Observations
HR 114, BP 120/82, RR 26, SpO2 92%, Temp 37.2°C.
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Pathophysiology
Definition: accumulation of air within the pleural space
Spontaneous occurs without trauma • Primary pneumothorax: without underlying pulmonary disease • Secondary pneumothorax: complication secondary to underlying pulmonary disease
Traumatic pneumothorax • Penetrating or blunt injury to the chest, including iatrogenic causes
Tension pneumothorax (EMERGENCY) • Intrapleural pressure exceeds atmospheric
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www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 6 Pathophysiology
Primary spontaneous Pathogenesis Spontaneous rupture of a subpleural bleb Typical presentation Young, tall, healthy, male presenting with sudden onset breathlessness and chest pain Underlying lung No disease? Risk factors • Tall, slender, young (20-30) • Smoking • Marfan syndrome • Family history (2) • Diving or flying
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Secondary spontaneous
Pathogenesis Rupture of damaged pulmonary tissue Typical presentation Middle-aged patient with COPD presenting with sudden onset breathlessness and chest pain Underlying lung disease? Yes: occurs due to ruptured bleb or bullae secondary to lung disease Risk factors • Underlying lung disease: COPD, asthma, lung cancer • Tuberculosis (3) • Pneumocystis jirovecii
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Tension (emergency)
Pathogenesis • Air is forced to enter the thoracic cavity without any means of escape • Results in a ‘one- way-valve’ Typical presentation Ventilated patient suddenly becomes breathless and acutely unwell Underlying lung disease? Yes/no: usually occurs in ventilated or trauma patients Risk factors • Mechanical ventilation • Trauma (4) • Iatrogenic: central line insertion, biopsy
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 9 Clinical features
Symptoms Signs Sudden onset pleuritic chest pain Tachycardia and tachypnoea Sudden onset dyspnoea Cyanosis Hyper-resonance ipsilaterally Reduced breath sounds ipsilaterally Hyperexpanded chest ipsilaterally: associated with tension pneumothorax Contralateral tracheal deviation and circulatory shock in tension pneumothorax
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Pneumothorax Pulmonary embolism Pneumonia • SOB • SOB • SOB • Pleuritic chest pain • Pleuritic chest pain • Pleuritic chest pain • Haemoptysis • Productive cough • Pain / swelling in one leg • Fever
• Any age • Risk factors for • Usually middle-aged or • Primary spontaneous thromboembolism elderly • Secondary spontaneous • Obesity • More common with • Tension • Prolonged bed rest underlying lung disease • Pregnancy • Malignancy
Confirmed on CXR ECG usually non-specific, but Usually confirmed on CXR sinus tachycardia and S1Q3T3
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Imaging • Chest x-ray: visible visceral pleural edge with no lung margins peripheral to this • CT chest: gold-standard imaging method but not routinely performed
Bedside • ECG: exclude a cardiac cause
Bloods • Arterial blood gas: may demonstrate respiratory failure
Additional points • Other investigations will depend on the aetiology • ALL patients require a repeat CXR after intervention
• Tension pneumothorax: decompress prior to imaging if high clinical suspicion
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(5) (5)
Management: spontaneous
• Needle aspiration: 2nd intercostal space midclavicular line
• Chest drain: 5th intercostal space mid-axillary line; triangle of safety
• Remember to always insert above the upper border of the rib
• High-flow oxygen
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• EMERGENCY: high-flow oxygen and urgent needle decompression
• Aspirate: 14G cannula at the 2nd-3rd intercostal space midclavicular line
• After decompression: chest drain insertion
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 22 Chest drain insertion
Base of axilla
Lateral edge of pectoris major
Nipple or 5th intercostal space
Lateral edge of latissimus dorsi
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Management: recurrent pneumothoraces
Options • Open thoracotomy and pleurectomy: lowest recurrence rate (1%) • VATS pleurectomy: lower morbidity than open • Surgical chemical pleurodesis: less popular now
Indications for referral to a thoracic surgeon First contralateral pneumothorax Second ipsilateral pneumothorax Bilateral spontaneous pneumothorax Persistent air-leak despite chest drain High risk professions: e.g. pilots Pregnancy
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Management: follow-up
Flying • Patients can fly 1 week post check CXR as long as the pneumothorax has resolved
Diving • Avoid indefinitely until the patient has had a definitive bilateral surgical pleurectomy, post-operative CT chest and normal lung function tests
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 29 Recap
• Pneumothorax is classified as primary or secondary spontaneous, or tension
• Patients present with dyspnoea and pleuritic chest pain
• The most important initial investigation is a CXR
• Tension pneumothorax is an emergency, requiring immediate aspiration
• Management is either conservative, or with oxygen, aspiration or drainage
• There are numerous surgical options for recurrent pneumothoraces
• Patients must be offered discharge advice regarding flying and diving
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History A 65-year-old female presents with sudden onset shortness of breath and pleuritic chest pain.
She has a history of a right-sided mastectomy for breast cancer, 1 year ago.
She has a BMI of 27.
Observations
HR 125, BP 85/60, RR 28, SpO2 89%, Temp 37.7°C
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Pathophysiology
Definition: obstruction of the pulmonary vasculature secondary to an embolus
• Virchow’s triad • Often secondary to deep vein thrombosis • Embolus dislodges and migrate to the lung circulation • Obstructed pulmonary vasculature ⟶ increased pulmonary vascular resistance
• Can result in arrhythmias, pulmonary infarction, cor pulmonale and cardiac arrest Pathophysiology Clinical features
Symptoms Signs Pleuritic chest pain Tachypnoea and tachycardia Dyspnoea Hypoxia Cough or haemoptysis Deep vein thrombosis: swollen, tender calf Fever Pyrexia Syncope: a red flag symptom Hypotension: SBP < 90mmHg suggests massive PE Elevated JVP: suggests cor pulmonale Right parasternal heave: suggests right ventricular strain
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 35 Differentials
Pneumothorax Pulmonary embolism Pneumonia • SOB • SOB • SOB • Pleuritic chest pain • Pleuritic chest pain • Pleuritic chest pain • Haemoptysis • Productive cough • Pain / swelling in one leg • Fever
• Any age • Risk factors for • Usually middle-aged or • Primary spontaneous thromboembolism elderly • Secondary spontaneous • Obesity • More common with • Tension • Prolonged bed rest underlying lung disease • Pregnancy • Malignancy
Confirmed on CXR ECG usually non-specific, but Usually confirmed on CXR sinus tachycardia and S1Q3T3
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 36 Case 2
History A 65-year-old female presents with sudden onset shortness of breath and pleuritic chest pain.
She has a history of a right-sided mastectomy for breast cancer, 1 year ago.
She has a BMI of 27.
Observations
HR 125, BP 85/60, RR 28, SpO2 89%, Temp 37.7°C
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Wells score
Wells Two-Level PE Score Clinical feature Points Clinical signs and symptoms of a DVT 3.0 PE is number 1 diagnosis or equally likely 3.0 Tachycardia (>100 BPM) 1.5 Immobilisation for more than three days or surgery in the 1.5 previous four weeks Previous, objectively diagnosed PE or DVT 1.5 Malignancy with treatment within the last 6 months, or palliative 1.0
Haemoptysis 1.0
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 39 Investigations
Bedside • ECG: sinus tachycardia (most common); RBBB and right axis deviation; S1Q3T3
Bloods • ABG: may demonstrate respiratory failure
Imaging • CXR: typically normal, although a wedge-shaped opacification can be seen • ECHO: assess for right ventricular strain in massive PE
Specialist tests: depends on Wells score • CTPA is performed if high probability (Wells score > 4) or • D-dimer performed if low probability (Wells score ≤ 4)
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Further investigations: unprovoked PE
Investigations for cancer • All patients: full set of blood tests, CXR, and urinalysis • Patients > 40 years old: CT abdomen and pelvis should be considered
Investigations for thrombophilia • Antiphospholipid antibodies: considered in people who have an unprovoked PE • Hereditary thrombophilia: considered in people who have an unprovoked PE and a first-degree relative who has had a DVT
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 45 Management
Massive PE • Thrombolysis: e.g. alteplase
Non-massive PE • Anticoagulation: • Oral anticoagulation: warfarin or DOAC for 3 months if provoked, or 6 months if unprovoked • LMWH used for 6 months in cases of active cancer
Alternative treatments • Inferior vena cava filter: consider in patients with recurrent PEs, despite anticoagulation • Surgical embolectomy: when thrombolysis has failed or is contraindicated
www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 46 Recap
• A pulmonary embolism presents with dyspnoea and pleuritic chest pain
• Risk factors can be remembered using Virchow’s triad
• A massive PE can cause cor pulmonale and rapid deterioration
• Initial investigations include ABG, ECG, CXR, D-dimer, CTPA and ECHO for a massive PE
• Patients with an unprovoked PE require further investigations
• Management options include thrombolysis, DOAC, LMWH or specialist interventions
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References
1. OpenStax College / CC BY (https://creativecommons.org/licenses/by/3.0). https://upload.wikimedia.org/wikipedia/commons/0/0d/2313_The_Lung_Pleurea.jpg 2. Mileny ES Colovati, Luciana RJ da Silva, Sylvia S Takeno, Tatiane I Mancini, Ana R N Dutra, Roberta S Guilherme, Cláudia B de Mello, Maria I Melaragno and Ana B A Perez / CC BY (https://creativecommons.org/licenses/by/2.0) 3. National Heart Lung and Blood Institute / Public domain 4. Royalty—free stock illustration from Shutterstock. 5. James Heilman, MD / CC BY (https://creativecommons.org/licenses/by/3.0) 6. Photographed by User Clinical Cases 00:42, 7 November 2006 [CC BY-SA 7. Egmason / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0). https://upload.wikimedia.org/wikipedia/commons/e/e2/Endothoracic_fascia.svg 8. James Heilman, MD / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://upload.wikimedia.org/wikipedia/commons/b/bd/Sinustachy.JPG 9. James Heilman, MD / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://upload.wikimedia.org/wikipedia/commons/4/4e/Cardiogram_indicating_right_bundle_branch_block_ with_tachycardia.jpg
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