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) www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 2 Case 1 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. www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 3 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 5 (1) 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 7 Pathophysiology 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 8 Pathophysiology 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 10 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 11 Investigations 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 12 (5) 13 (6) 14 15 (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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 20 (7) www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 21 Management: tension • 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 23 Chest drain insertion www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 24 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 26 Top decile question www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 27 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 30 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 31 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 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine 37 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: