Respiratory Lecture 7 Dr Azeem Alam, MBBS BSc (Hons) Surgical AFP Guy’s and St. Thomas’ Hospital admin@bitemedicine.com 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) 2 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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, SpO 2 92%, Temp 37.2°C. 3 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 • 5 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
(1) 6 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 • 7 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 8 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 (4) • Trauma Iatrogenic: central • line insertion, biopsy 9 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 10 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 11 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 12 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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Management: spontaneous Needle aspiration : 2 nd intercostal space midclavicular line • Chest drain : 5 th intercostal space mid-axillary line ; triangle of safety • • Remember to always insert above the upper border of the rib • High-flow oxygen 20 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
(7) 21 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
Management: tension • EMERGENCY : high-flow oxygen and urgent needle decompression Aspirate : 14G cannula at the 2 nd -3 rd intercostal space midclavicular line • • After decompression: chest drain insertion 22 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
Chest drain insertion Base of axilla Lateral edge of pectoris major Nipple or 5 th intercostal space Lateral edge of latissimus dorsi 23 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
Chest drain insertion 24 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 26 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
Top decile question 27 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 29 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 30 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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, SpO 2 89%, Temp 37.7°C 31 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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 35 www.bitemedicine.com Instagram: @bitemedicine Facebook: /biteemedicine
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