Resp Formative Qs Flashcards
What is expiratory reserve volume?
Volume of air that can be forcefully exhaled after normal respiration.
What is Functional Residual capacity?
Volume left in lungs after normal expiration.
ERV + RV
What is residual volume?
The volume of air that cannot be voluntarily expired.
What is vital capacity?
The maximum volume of air that can be voluntarily exhaled following a maximum inspiration
Why does air flow into the lungs during inspiration?
The external intercostal and diaphragm muscles contract and thoracic volume increases.
What is tidal volume?
The volume of air breathed in and out of the lungs during each breath.
How do you calculate alveolar ventilation?
(Tidal Vol - Dead space) x Respiratory rate.
What is the partial pressure of oxygen in mixed venous blood?
40mmhg (5.3kPa)
Which condition will reduce the Arterial partial pressure of oxygen?
Emphysema - oxygen conc. in solution will be reduced
What sedative is not safe to use on individuals with chronic lung disease?
Nitrous oxide - it blunts the peripheral chemoreceptor response to falling oxygen and patients are on hypoxic drive so they have no means of controlling ventilation.
What happens to arterial PCO2 levels in individuals with chronic lung disease?
Arterial PCO2 levels are elevated due to poor alveolar ventilation.
Why are patients with chronic lung disease said to be on hypoxic drive?
Chronic elevation of PCO2 has blunted central response to CO2. Too they rely on peripheral receptors.
What is shunt?
When perfusion exceeds ventilation in L/min.
In what direction would an asthma attack shift the haemoglobin oxygen binging curve?
RIGHT
Broncho-constriction will decrease ventilation meaning PCO2 will rise, pH will fall.
In what direction will hypothermia shift the haemoglobin oxygen binding curve?
LEFT
Decrease in body temp makes it difficult to offload oxygen to peripheral tissues. Want to keep core ventilated/warm.
In what direction will the presence of foetal haemoglobin shift the haemoglobin oxygen binding curve?
LEFT
It has a higher affinity for oxygen than adult haemoglobin so wants to keep it more.
In what direction will respiratory alkalosis shift the haemoglobin oxygen binding curve?
LEFT
Decrease in H+ means a decrease in PCO2. Doesn’t need to release oxygen to balance it out.
In what direction does voluntary hyperventilation shift the haemoglobin oxygen binding curve?
LEFT
Decreases PCO2
Which vertebral bodies does the head of the 9th rib articulate with?
T8 and T9
The one ABOVE and its OWN.
Where does the cardiac notch appear?
Left lung anterior border.
What pleura do lung fissures contain?
Visceral
Which lung has an eparterial broncos in its hilum?
Right - as it has 3 lobes.
What would be the most appropriate investigation if a patient with known squamous carcinoma of lung is admitted with abdominal pain, constipation and confusion?
Serum calcium - squamous carcinoma is associated with hypercalcaemia due to parathyroid hormone related protein.
What would be the most appropriate investigation if a patient with peripheral spiculated opacity on chest x-ray and enlarged supraclavicular lymph node is admitted?
Fine Needle Aspiration lymph node - sample I needed for pathology to diagnose what type of cancer it is.
What is an obese man who has excessive daytime somnolence, snoring and napping as well as 10 desaturations per hour on overnight oximetry classification on the Obstructive Sleep Apnoea scale?
Mild - 5 - 15 desaturations per hour
What organism is most likely to cause lobar pneumonia?
Streptococcus pneumoniae
What are the blood gas values most likely to be if a patient with exacerbation of asthma is too tired to speak or do a peak flow?
pH will be decreased e.g 7.22 - acidosis
PaO2 will be decreased e.g 7.8 - hypoxia
PaCO2 will be increased e.g 8.6 - hypercapnia
What treatment should a newly diagnosed asthmatic who is waking up at night because of asthma receive?
Inhaled corticosteroids (night time waking) and inhaled beta-2-agonist.
What is the most likely diagnosis of a previously fit 19 yr old who has a sudden onset of severe right sided chest paining breathlessness whilst walking up stairs? The symptoms are still present an hour later.
Primary pneumothorax
What is the most likely diagnosis of a 32yr old man recovering from a bad attack of pneumonia, who develops riggers, persistently poor appetite and increasing SOB on exertion?
Empyema thoracis- is a collection of pus in pleural space and is a complication of pneumonia. Antibiotics haven’t helped so must be a deep seated infection.
What is acute interstitial pneumonitis?
Rare, rapidly progressive lung disease presenting with acute breathlessness and dry cough.
What is aspiration pneumonia?
Pneumonia caused by inhaling food/liquids into the lungs.
What is giant pulmonary bulla?
Seen in chronic emphysema.
Big air pocket within the lung tissue.
What is the most likely diagnosis for 62yr old male smoker who has coughed up blood 4 times in the last month, lost his appetite and lost 1 stone in weight?
Lung Cancer
What clinical signs would you look for if you suspect lung cancer?
Hands- finger clubbing
Abdomen - hepatomegaly
Neck- lymphadenopathy, tracheal deviation, SVC obstruction
What are the clinical signs in patient with left lower lobe pneumonia/consolidation?
Tachypnoea Tachycardia Fever Cyanosis Reduced expansion of affected side of chest Dullness to percussion at base Bronchial breathing at base Crackles Increased vocal resonance.
What organisms may cause pneumonia in a young previously healthy individual?
Chlamydia psittaci Streptococcus pneumoniae Mycoplasma pneumoniae Staph. aureus Haemophilus influenza
What investigations would aid the diagnosis of pneumonia?
CXR Sputum culture Mycoplasma IgM Full Blood Count Blood culture Atypical serology Legionella urinary antigen Pneumoccocal urinary antigen
