29. Respiratory Emergencies Flashcards
What is a pneumothorax?
Differentiate between primary and secondary spontaneous pneumothorax.
What are some risk factors?
What can you see in this pictures - what has been caused?
Air in the pleural space.
1o: normal lungs. 2o: underlying lung disease.
Tall, thin men, male, cigarettes, cannabis. Rarely familial. Age = bimodal (15-34, then >55).
Air leak from apical bulla (it burst) in visceral pleura leading to a R spontaneous pneumothorax.
What pathophysiologies may be responsible for a 2o pneumothorax?
An 18yo F with known asthma presents with SoB. What symptoms would make you suspect a pneumothorax?
What signs would you look for if she did have a pneumothorax?
COPD (60%), asthma, connective tissue disease (Marfan’s), interstitial lung disease: fibrosis, lung infection - TB (abscesses in lung -> pneumothorax), CF (cysts in lung -> pneumothorax).
Less common: pulmonary endometriosis, anorexia nervosa, intersititial lung diseases: histocytosis x (rare disease involving clonal proliferation of Langerhans cells, abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes), lymphangioleiomyomatosis (rare, progressive and systemic disease that typically results in cystic lung destruction).
Acute pleuritic chest pain (“stabbing”, worse on inspiration) +/- SoB. Sudden onset.
Reduced expansion (on affected side), hyper-resonnant percussion, quiet/absent breath sounds, tachycardia.
What are some differential dx for pneumothorax?
What tests would you do to help make your dx?
What should you look for in a lung XR when looking for pneumothorax? What classifies a pneumothorax as small/large?
Infection, muscle, pericarditis, PE.
CXR. Bloods (inflamm markers etc.) ECG (exclude pericarditis). +/- USS. CT chest (helps differentiate cysts/bullae from pneumothorax).
Lung edge. No peripheral lung markings. Small: <2cm. Large: ≥2cm (over 50% of lung collapsed). Measure from hilar point. (pic - L spontaneous pnuemothorax)
How is pneumothorax managed:
a) conservative
b) medical
c) surgical
How is primary pneumothorax managed?
How is secondary pneumothorax managed?
a) Observation, high flow O2 (be careful if COPD - some pts have tendency to retain CO2 under high flow O2)
b) Pleural aspiration, chest drain, suction
c) Open surgery, VATS (video assisted thoracic surgery)
(pic) NB. aspirate <2.5l; if take out too much too fast, lung goes into shock
(pic)
Lucy’s CXR reveals a right sided pneumothorax which is 3 cm wide as measured from the lung edge at the hilar point to the chest wall. She is breathless. What will you do next?
Where would you do this (body location)?
How would you manage a chest drain?
Aspirate with 16-18G cannula.
Safe triangle - avoids diaphragm (L pic)
(R pic) Underwater seal drainage. Don’t lift bottle above waist -> retrograde entry of fluid/air into pleural space. Never clamp a bubbling chest drain -> tension pneumothorax. Bubbles while pneumothorax still present. If no “swing” tube’s come out/in wrong place/blocked.
As you are collecting the equipment for inserting a chest drain, you get fast bleeped back to the resuscitation room. Lucy has become acutely distressed with a respiratory rate of 28/min, her blood pressure and oxygen levels have fallen (88/35mmHg; 89% on 40% oxygen). Her trachea is deviated to the left. Her JVP is raised. What is going on and what will you do next?
Tension pneumothorax. Needle decompression, 2nd intercostal space, mid clavicular line.
Describe a tension pneumothorax.
What are the signs and symptoms of a tension pneumothorax?
What action would you take with a TP?
Causes one way valve in lung, shift in mediastinum, reduced venous return, hypotension and cardiac arrest (pic). Breathe in = -ve intrapleural pressure. Breathe out = +ve pleural pressure -> flap shuts against lung, air builds up in pleural space and squashes lung then whole mediastinum and vena cava.
Severe breathlessness, tachycardia, pulsus paradoxus (abnormally large decrease in systolic blood pressure and pulse wave amplitude during inspiration: >20 mmHg), distended jugular veins, tracheal deviation, ipsilateral reduced/absent breath sounds on TP side.
DON’T WAIT FOR CXR. NEEDLE DECOMPRESSION. Large bore cannula (14G). Mid clavicular line, 2nd ICS. His of air as you release tension. Then CXR and chest drain.
What does this CXR show?
What advice would you give someone following a pneumothorax?
What is Boyle’s law?
Severe tension pneumothorax.
No diving. No plane travel for 2-6w after pneumothorax has resolved. Stop smoking. Pregnancy can increase risk of recrrence - monitor closely. Return immediately if any SoB/pain recurs.
If volume of gas increases, pressure exerted by it decreases.
What is a pulmonary embolus?
What is the pathophysioloy?
What factors predispose you to a PE?
Obstruction of pulmonary vascular tree (L pic). Commonest cause of maternal death.
75% thrombi formed in deep venous system of lower limbs and pelvis (R pic). Initiated by platelet aggregation around venus valve sinuses -> clotting cascade activated.
Immobility incl. air travel. Trauma. Surgery. Pregnancy. Oestrogen (pill). Malignancy. Hereditary/acquired thrombophilia. Acute illness.
A 60 year old male, Steven, who has had a recent hip replacement, presents with shortness of breath. What symptoms would make you suspect a pulmonary embolus?
What signs would you look for?
How is is diagnosed?
Explain the Well’s score.
SoB, chest pain/pleuritic pain, haemoptysis, low grade fever, collapse. Sudden onset.
May be none. Sinus tachycardia/new AF. Reduced chest movement (pain). Pleural rub (inflammation of pleura). Pleural effusion (due to inflammation of pleura). DVT.
Hx and exam. Pre-test probability score (Well’s). CXR. ECG. D-dimer and other bloods. CTPA (CR pulmonary angiogram, gold std)/VQ scan (better for chronic PE, less radiation). Tropnin (if have PE and tropanin increases = large PE impacting on heart = mortality higher).
(pic) Score >4 - PE likely, consider diagnostic imaging - CTPA. Score ≤4 - PE unlikely, consider D-dimer to rule out PE. If +ve = scan them. If -ve = probability of PE even less.
What changes might you see on an ECG of a patient with a pulmonary embolism?
What are A and B in this CTPA?
How is PE managed:
a) medically
b) interventional radiology
c) surgical (rare)
Non-specific. Sinus tachycardia. New AF. RBBB. R ventricular strain - ant T wave inversion. S1Q3T3 (S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III, but doesn’t always indicate PE).
A: infarct of lung b/c of clot. B: clot in vessel.
a) Anticoagulation: LMWH/oral anticoag like warfarin for 3-6m. Thrombolysis (if pt collapsed and v. tachycardic)
b) Inferior vena cava filter (only if can’t give anticoag e.g. recent stroke)
c) Embolectomy (for life-threatening massive PE). Pulmonary thrombo-endarterectomy (chronic PEs unresolved after 3m).
A 30 year old gentleman who flies frequently has been brought in by ambulance. You are asked to see him as the FY1 on call. He had collapsed at home in the shower, after sudden onset shortness of breath. He denied chest pain. He is hypotensive (75/35mmHg) and hypoxic (90% on high flow oxygen via non-rebreathe mask.
What is the differential diagnosis?
What is the correct management?
Massive PE, pneumothorax, infection, haemorrhage.
Need to thrombolise him with fibrinolytics e.g. streptokinase, urokinase, rtPa.
What are signs of a massive PE?
How is it managed?
What is an inferior vena cava filter used for?
What is PE recurrence rate?
Hypotension, collapse, MI. Acute R heart strain (loud P2, splitting of 2nd heart sounds, gallop rhythm). R heart failure (low CO, raised JVP, low BP).
ABCDE. Call for help. Thrombolysis if collapsed/hypotensive.
Contraindication to anticoagulation. For recurrent VTE despite anticoag. Only a temp. solution. (pic)
30% after 10 yrs (need to tell pt).
