Acute respiratory Flashcards
PE, pneumothorax, pneumonia
What is the definition of a pulmonary embolus?
An emboli lodged within the pulmonary circulation.
The lung parenchyma is ventilated but not perfused.
What are the risk factors for a pulmonary embolus?
Risk factors for venous thromboembolism-
CT Sil Vous Plais:
C:
- cancer
- chemo
- CF
- COPD
- factor C deficiency
T:
- trauma
- time (age)
- thrombocytosis
S
- stasis
- surgery
- Factor S deficiency
V
- Varicose veins
- Virchow’s triad
- Factor V Leiden
P
- Pill OCP
- Pregnancy
- Previous VTE
- Polycythaemia
What is the presentation of an acute submassive/small PE?
Sudden onset Pleuritic chest pain SOB \+/- haemoptysis \+/- haemodynamic compromise
What will you find on examination of a Pt with a PE?
Tachypnoea Tachycardia Lower limb swelling/redness/hotness Cyanosis May have signs of shock
What is the scoring system used to dictate PE investigations?
Well’s score, points for:
- Previous DVT/PE
- Evidence of DVT
- Stasis
- Cancer
- Opinion is PE
- Rate Raised (>100)
- Exsanguination (Haemoptysis)
What should you do if the Well’s score is >=4?
Admit to hospital
Perform a CTPA
What should you do if the Well’s score is <4?
Measure the D-dimer (fibrin degradation product)
If D-dimer is positive, admit and do CTPA
If D-dimer is negative, consider alt diagnosis
What other investigations other than CTPA/D-dimer can you do for a PE?
ECG
CXR
What would an ECG show on a Pt with a PE?
Sinus tachycardia
Right axis deviation
RBBB
S1Q3T3
What would an CXR show on a Pt with a PE?
Pleural effusion
Elevation of hemidiaphragm
Westermark’s sign
What would your first line manage be for a Pt with a PE?
Analgesia
Oxygen >94%
Fluids
How would you manage a haemodynamically unstable Pt with a PE?
Respiratory support
1st line: Thrombolysis
2nd line: Embolectomy
IV Thrombolytics (fibrinolytics):
- Alteplase
- Streptokinase
RISK OF HAEMORRHAGE
How would you manage a haemodynamically stable Pt with a PE?
Respiratory support
ANTICOAGULATION:
- Immediately start apixaban/rivaroxaban (DOAC) if suspect PE
- LMWH for 5 days = bridging warfarin
- Warfarin or DOAC for 3 months if obvious reversable cause- 6 if cancer or irreversable/unclear cause
What is the definition of a pneumothorax?
Accumulation of air in the pleural space
What are the types of pneumothoraces?
PRIMARY-
no underlying respiratory illness (typically young and otherwise healthy patient)
SECONDARY-
associated with pre-existing lung pathology OR 50+ old smoking
What is the presentation of a pneumothorax?
Sudden onset
SOB
Chest pain
What are the risk factors for a pneumothorax?
Underlying lung disease
Smoking
CTD
Trauma
What will you find on examination of a Pt with a pneumothorax?
Reduced/absent breath sounds
Hyper-resonance
Reduced chest expansion
What investigations would you do on a Pt with a pneumothorax?
CXR
CT
Why is a CXR important for a pneumothorax?
Can differentiate between a bullae and pneumothorax
Can locate the pneumothorax
Why is a CT important for a pneumothorax?
Can differentiate between a bullae and pneumothorax
Can locate the pneumothorax
Is more sensitive than a CXR
What is the management plan for a primary pneumothorax either:
- <2cm
- asymptomatic (no SOB)
O2
Consider discharge + OPD review
What is the management plan for a primary pneumothorax either:
- > 2cm
- Symptomatic (SOB)
Needle aspiration
If unsuccessful –> chest drain
Then, observation and O2
What is the management plan for a secondary pneumothorax either:
- <2cm
- asymptomatic (no SOB)
If <1cm, high flow O2 + observe
If 1-2cm –> needle aspiration –> if unsuccessful –> chest drain
What is the management plan for a secondary pneumothorax either:
- > 2cm
- Symptomatic (no SOB)
Chest drain
Lanky Schmidt is a tall, 29 year old male. He has presented to A+E feeling short of breath. He has right sided pleuritic chest pain. He is a non-smoker and otherwise healthy.
A chest radiograph shows a right sided pneumothorax 11mm in diameter.
How should the medical team proceed?
Needle Aspiration and give O2
What would you find on examination of a tension pneumothorax that you wouldn’t find in a normal pneumothorax?
Tracheal deviation
Distended neck veins
Displaced apex beat
What is the definition of a pneumonia?
Inflammation of the alveoli which can be caused by bacteria, viruses or fungi.
Inflammation results in air sacs filling with fluid or pus
What are the types of pneumonia?
Community-acquired pneumonia
Hospital-acquired pneumonia
Aspiration pneumonia
What are the common causes of CAPs?
Streptococcus pneumoniae
Haemophilus influenzae
What is the presentation of pneumonias?
Fever Malaise Rigors Productive cough Pleuritic chest pain
What will you find on examination of a Pt with pneumonia?
Pyrexia Cyanosis Tachypnoea Confusion Decreased expansion Dull percussion Increased vocal resonance Bronchial breathing
What investigations would you do on a Pt with pneumonia?
Bloods (FBC, CRP)
Sputum sample- MC&S
Blood cultures if severe
CXR
What is the scoring system to assess the severity of a pneumonia?
CURB 65 Confusion Urea >7mmol/L RR >=30 BP: SBP<90mmHg, DBP<=60mmHg Age >=65
What would you do for a Pt with a CURB-65 score of 0-1?
Treat at home if possible
What would you do for a Pt with a CURB-65 score of 2?
Consider hospital treatment
What would you do for a Pt with a CURB-65 score of 3+?
Severe, treat in ITU
What is the management for a Pt with pneumonia?
Antibiotics
Oxygen
Analgesics
Fluids
What antibiotics would you give a low severity pneumonia?
Oral amoxicillin
What antibiotics would you give a moderate severity pneumonia?
Oral/IV amoxicillin + macrolide (eg. clarithromycin)
What antibiotics would you give a high severity pneumonia?
IV co-amoxiclav + macrolide (eg. clarithromycin)
Where is Legionella pneumophila commonly found?
Aqueous environments
- air conditioning
- whirlpool spas
- contaminated water supplies
- airplanes
What is the difference between Legionnaire’s disease and Pontiac fever?
Legionnaire’s disease- Legionella pneumonia
Pontiac fever- non-pneumatic Legionella
What is the presentation of a Legionella pneumonia?
Prodromal flu-like symptoms Dry cough (can become productive) GI symptoms (nausea, D+V)
What investigations would you do for a Legionalla pneumonia?
Sputum culture
Urinary antigen detection
U+E for hyponatraemia
CXR- bi-basal consolidation
What is the treatment for Legionella pneumophila?
IV macrolide or fluoroquinolone
Clarithromycin or ciprofloxacin
What is Pneumocystis jirovecii?
Opportunistic fungal infection
AIDS defining illness
Causes pneumocystis pneumonia (PCP)
What are the risk factors for a Pneumocystis jirovecii infection (PCP)?
Recurrent bacterial pneumonias
Significant weight loss
HIV
What is the treatment for a Pneumocystis jirovecii infection (PCP)?
High dose IV co-trimoxazole
Which patients are at risk of a Pseudomonas aeruginosa infection?
Bronchiectasis
Cystic fibrosis
What is the treatment for a Pseudomonas aeruginosa pneumonia?
Piptazobactam
Piperacillin + tazobactam
What is the presentation of a Mycoplasma pneumoniae infection?
Insidious onset
Persistent cough
Low grade fever
Seen in close community settings (boarding school, uni, army bases)
What investigations would you do for a Mycoplasma pneumoniae infection?
CXR
PCR
What is the treatment for a Mycoplasma pneumoniae pneumonia?
Erythromycin/clarithromycin
What kind of patients commonly present with Staphylococcus aureus infections?
IVDU
What are the risks of Staphylococcus aureus infections?
Can arise from blood-borne spread of organisms form an area of infection
Can develop into septicaemia
What investigation would you do for a Staphylococcus aureus infection?
CXR
What is seen on a CXR for a Staphylococcus aureus pneumonia?
Patchy consolidation
Breaks for form abscesses which appear as cysts
What is the treatment for MSSA?
Flucloxacillin
What is the treatment for MRSA?
Vancomycin
A gentleman presents with acute breathlessness and chest pain. O/E his respiratory rate is 25bpm with good air entry in all fields. His ECG shows right axis deviation. What is the most likely diagnosis?
A. Pneumothorax
B. Pneumonia
C. COPD
D. Pulmonary embolism
D. Pulmonary embolism
A 35 year old lady presents with acute onset SOB, chest pain and one episode of haemoptysis. She has recently noticed a swelling in the left leg. O/E her RR is 28 and HR is 105. You suspect a pulmonary embolism. What is the most appropriate investigation to perform?
A. Chest X-Ray
B. CTPA
C. D-Dimer
D. ECG
B. CTPA
A 23 year old student presents to A&E with SOB. He says it came on suddenly. O/E his trachea is undisplaced with reduced breath sounds on the left. A CXR confirms a 1cm pneumothorax. What is the most appropriate management?
A. Immediate chest decompression
B. Intercostal drain
C. Aspiration
D. High flow oxygen
D. High flow oxygen
What signs would you expect on physical examination of someone with pneumonia?
A. Deviated trachea, ↓ expansion, dull to percussion
B. Bronchial breathing, ↓ expansion, ↓ vocal resonance
C. Pyrexia, ↓ expansion, ↑ vocal resonance
D. Dull to percussion, ↑ expansion, pyrexia
C. Pyrexia, ↓ expansion, ↑ vocal resonance
A 55 year old man has a 3 day history of shivering, general malaise & productive cough and is vomiting. The x-ray shows right lower lobe consolidation. He is diagnosed with a moderate pneumonia, what is the first line therapy?
A. Oral Amoxicillin
B. IV Co-Amoxiclav + Clarithromycin
C. Doxycycline
D. IV Amoxicillin + Clarithromycin
D. IV Amoxicillin + Clarithromycin
A 71 year old gentleman is brought in by his carer with a 4 day history of a fever and a cough. As you go to examine him he shouts and asks that you leave his bedroom. His RR is 30, BP 103/68. The lab phones you a hour later and lets you know his urea is 7.8mmol/L. Where would you manage this patient?
A. Admit and treat
B. Treat at home
C. Consider ITU
D. Refer for palliative care
C. Consider ITU
CURB-65 score: 4
25M presents to A&E with a fever and a cough. He says he has been generally unwell over the last year. O/E he is acutely SOB with a RR of 28. You also note an incidental finding of purple patches on his nose. What is the most likely causative organism?
A. Pseudomonas aeruginosa
B. Streptococcus pneumoniae
C. Pneumocystis jirovecii
D. Mycoplasma pneumoniae
C. Pneumocystis jirovecii
Purple patch- Kaposi’s sarcoma (HHV 8)
Indicative of a HIV Pt
55M presents with a cough and fever. He recently travelled to New York to speak at a conference. After bloods revealed Na+ of 130, you decide to test the urine. What is the most likely causative organism?
A. Haemophilus influenzae
B. Pseudomonas aeruginosa
C. Legionella pneumophilia
D. Pneumocystis jirovecii
C. Legionella pneumophilia
Flu-like symptoms
Recent travel- airplane
Hyponatraemia
Urine sample for antigens
10F presents to A&E with a fever and a cough and O2 sats: 92%. Her parents don’t seem worried as they are used to bringing her into hospital for treatment for her respiratory illness.
A. Pseudomonas aeruginosa
B. Haemophilus influenzae
C. Staphylococcus aureus
D. Coronavirus
A. Pseudomonas aeruginosa
Commonly seen in bronchiectasis or cystic fibrosis, which is what this Pt has.
A known IVDU is brought into A&E, he was found unconscious by two friends who were worried he might have overdosed. You notice an abscess in his groin. Temp 39, HR 120, BP 90/50. You immediately admit him.
A. Haemophilus influenzae
B. Staphylococcus aureus
C. Coronavirus
D. Legionella pneumophila
B. Staphylococcus aureus
IVDU
Infected abscess
Likely in septic shock
What are the 2 types of respiratory failure?
TYPE 1:
- hypoxia
- due to focal, lobal issue (V/Q mismatch)
TYPE 2:
- hypoxia
- hypercapnia
- due to global problem with entire lung- issue with gas exchange
Causes of low perfusion
Pulmonary embolism
Areas of the pulmonary circulation are obstructed, limiting blood flow to alveoli.
As a result, blood has to be redirected to other areas of the lung.
Define ventilation
Volume of gas inhaled and exhaled from the lungs in a given time period- ie reaching the alveoli
Define perfusion
Total volume of blood reaching the pulmonary capillaries in a given time period.
The initial effect of reduced lung ventilation is what? Why is this the case?
Reduced ventilation affects O2 levels, as CO2 is more soluble and continues to diffuse despite the impairment.
Thus, the initial effect of reduced ventilation is TYPE 1 RESPIRATORY FAILURE
(so reduced pO2 and a normal/low pCO2).
Causes of low ventilation
Acute asthma Atalectasis Pulmonary Oedema Pneumonia Pneumothorax PE ARDS (affect gas exchange and delivery to alveoli)
Explain how a V/Q mismatch causes type 1 respiratory failure
- causes hypoxia
- hypoxic vasoconstriction causes blood to be diverted to better ventilated/perfused parts of the lung
- Hb in well-ventilated parts of the lung are already saturated so PO2 remains low
- acts as a stimulus for hyperventilation leading to low/normal pCO2
What are the causes of type 2 respiratory failure?
Most commonly COPD
Acute severe asthma
Upper airway obstruction
Neuropathies (GBS, MND)
Drugs (opiates)
What is the ventilation support for type 1 respiratory failure?
CPAP
pumping air in on inspiration, increases airway recruitment to increase ventilation
What is the ventilation support for type 2 respiratory failure?
BIPAP
CPAP plus sucking CO2 out
What is normal intrapleural pressure?
-5 to -8 cm H2O
Pressure is subatmospheric. This keeps the lungs inflated
What may cause primary pneumothoraces? Who is at greater risk of this?
Pleural blebs or pleural adhesions forming.
More common in:
- Males
- Marfanoid habitus (not strictly just those with marfan’s)
- Smoking
What are the signs of tension pneumothorax?
DUE TO LUNG COMPRESSION
- Severe Dyspnoea
- Tracheal Deviation (away from lesion)
- Silent chest, Hyperresonance, Reduced expansion (on lesioned side)
DUE TO MEDIASTINAL SHIFT
- Hypotension
- Tachycardia
How do you acutely manage a tension pneumothorax?
orange or grey needle just above the third rib (inferior region of 2nd ICS) in MCL
3 invasive management options for pneumothorax
- aspirate with orange/gray gauge cannula
- needle aspiration (uses sterile technique)
- chest drain (triangle of safety)
What are the 3 severities/types of PE?
ACUTE MASSIVE
- sudden complete occlusion of pulmonary artery –> collapse/death
ACUTE SUB-MASSIVE/SMALL PE
- incomplete/distal occlusion of pulmonary artery
CHRONIC PE
- occlusion of pulmonary microvasculature
What are the classic signs of PE on ECG?
Indicative of RV strain (increased vascular resistance):
S1Q3T3 pattern - prominent S wave in lead I - Q wave and inverted T wave in lead III RAD RBBB Sinus tachycardia
What sign may be present on CXR in PE?
Westermark’s sign
highly specific, only 10% cases however
What prophylaxis is given to inpatients?
TED stockings
LMWH (Enoxaparin, Tinzaparin)
How does LMWH work?
- Promotes the action of antithrombin III
Antithrombin inhibits clotting factor Xa and Thrombin. - Blocks secondary haemostasis (fibrin deposition by the clotting cascade)
LMWH cannot dissolve a clot like thrombolysis can –but prevents future emboli occurring.
What investigations do you do for PE?
- CTPA (Well’s =>4)
- D-dimer
Investigate the underlying cause (if no obvious RF):
- if 40+, CTAP + mammogram (check for cancer)
- hereditary thrombophilia testing if FHx
What is ARDS?
NON-CARDIOGENIC pulmonary oedema and diffuse lung inflammation syndrome that often complicates critical illness.
State some causes/RF for ARDS
- drugs
- nearly drowning
- ventilation
- severe burns
- sepsis
- pneumonia
- transfusion reactions
The diagnosis of ARDS is based on fulfilling which three criteria?
- Acute onset (within 1 week)
- Bilateral opacities on chest x-ray
- PaO₂/FiO₂ (arterial to inspired oxygen) ratio of ≤300 on PEEP
Briefly explain the pathophysiology of ARDS
Complicated, profound inflammatory response –> diffuse alveolar damage
- recruitment of inflammatory cells–> increase the vascular permeability
- this promotes further recruitment
- leads to fluid entering the alveolar
- leads to alveolar collapse + damage
- fluid leaks out of alveoli -> increased diffusion distance –> no perfusion
What type of respiratory failure is ARDS?
T1RF
Despite being a bilateral problem – only causes shunting in 50% of alveoli.
leads to severe V/Q mismatch
ARDS can be defined by which criteria?
‘Berlin’ Criteria:
- No alternative cause (cardiogenic pulmonary -oedema)
- Rapid onset i.e <1 week
- Dyspnoea
- Bilateral opacities on chest x-ray
Investigation for ARDS
ABG
CXR/CT
Echocardiogram
COVID Swab
On chest radiograph in ARDS, findings are similar to cardiogenic pulmonary oedema (heart failure). What are these findings?
A - alveolaroedema(bat wing opacities) B - Kerley B lines. C - cardiomegaly. D - dilated upper lobe vessels. E - pleural effusion.
