Respiratory Flashcards
What is the normal physiological anatomical relationship between visceral and parietal pleura?
- Parietal and visceral pleura are closely opposed to each other- no ligament or connective tissue joining them
- Small amount of serous fluid- keeps them opposed to each other- surface tension forming a seal
- Potential space
why is the close relationship (pleural seal) essential for lung function
- Ensures that lung expansion can occur by connecting lungs to chest wall, therefore when the chest wall expands the lungs can also expand
- Frictionless movement
-
Keeps alveoli open during expiration by maintaining a negative intrapleural pressure even during expiration
- Always a negative intrapleural pressure
State 2 disease conditions that arise because of a problem with the pleura
- Pleurisy
- Tension pneumothorax
- Pleural effusion
- Mesothelioma- malignant tumour
A 73 y/o woman with long standing COPD is admitted to hospital with pneumonia. Her admission vital signs are: temperature 38 C, blood pressure 140/80, RR= 30, heart rate 95 bpm and oxygen saturation 85%. She is placed on IV antibiotics and nasal cannula oxygen (4 L/min). Her temperature decreases to normal, her respiratory rate is 28, and her oxygen saturation increases to 94%; follow up arterial blood gas is shown below.
pH: 7.20
PaO2: 9.5 kPa (10.6-13.3)
PaCO2: 10.5 kPa (4.6 – 6.0)
HCO3: 30 mmol/L (22-26)
What is/are the major reason(s) for this patient’s increased PaCO2 ?
a) The increased partial pressure of oxygen in arterial blood has led to reduced firing of the peripheral chemoreceptors therefore causing loss of the patient’s respiratory drive and markedly reduced respiratory rate.
b) The patient has developed a metabolic acidosis secondary to sepsis and CO2 has increased in compensation
c) There is increased V/Q mismatch and decreased ability of oxygenated haemoglobin to carry CO2 (Haldane effect)
d) Hyperventilation secondary to hypoxaemia has pushed the equation to the right
There is increased V/Q mismatch and decreased ability of oxygenated haemoglobin to carry CO2 (Haldane effect)
- Due to reduced surface area (emphysema), increased perfusion, but reduced ventilation- therefore V/Q mismatch <1
- Cant get rid of CO2 because of reduced surface area
The pulmonary embolism has led to V/Q mismatch that has caused hypoxaemia, in response his central chemoreceptors have increased firing causing him to hyperventilate, his CO2 to fall, leading to respiratory alkalosis
A 56 y/o man with a BMI of 45 kg/m2 collapses at home after returning from a 14 hour work-related car journey. He is successfully resuscitated and diagnosed with a pulmonary embolism. His arterial blood gas is shown. What is the best explanation for his arterial blood gas results?
pH: 7.48
PaO2: 8.3 kPa (10.6-13.3) PaCO2: 3.6 kPa (4.6 – 6.0) HCO3: 25 mmol/L (22-26)
b) The pulmonary embolism has led to V/Q mismatch that has caused hypoxaemia, in response his peripheral chemoreceptors have increased firing causing him to hyperventilate, his CO2 to fall, leading to respiratory alkalosis
c) The pulmonary embolism has led to shunting in his lung, that has caused hypoxaemia, in response his central chemoreceptors have increased firing causing him to hyperventilate, his CO2 to fall, leading to respiratory alkalosis
d) The pulmonary embolism has led to impaired diffusion across the alveolar-capillary membrane, that has caused hypoxaemia, in response his central chemoreceptors have increased firing causing him to hyperventilate, his CO2 to fall, leading to respiratory alkalosis
e) The pulmonary embolism has led to impaired diffusion across the alveolar-capillary membrane, that has caused hypoxaemia, in response his peripheral chemoreceptors have increased firing causing him to hyperventilate, his CO2 to fall, leading to respiratory alkalosis
The correct t answer is b- The pulmonary embolism has led to V/Q mismatch that has caused hypoxaemia, in response his peripheral chemoreceptors have increased firing causing him to hyperventilate, his CO2 to fall, leading to respiratory alkalosis.
An28y/omanisoutforhisdailyrunwhenhesuddenly develops severe right sided chest pain and shortness of breath. He sits on the curb and calls 999 and is taken to A&E. On arrival his RR is 30 breathes/minute, blood pressure 110/70 and heart rate 98 bpm. His chest x-ray is shown.
The most likely event leading to his presentation is which of the following?
a) Myocardial infarction precipitated by exercise
b) Primary spontaneous pneumothorax secondary to bleb rupture of visceral pleura
c) Exercise induced traumatic pneumothorax secondary to rupture of parietal pleura
d) Pulmonary embolism precipitated by exercise
e) Secondary spontaneous pneumothorax secondary to COPD
b - Primary spontaneous pneumothorax secondary to bleb rupture of visceral pleura - CXR shows a pneumothorax and most common cause in this age group is primary spontaneous pneumothorax
Signs on a chest x-ray of emphysematous COPD
- Flattening of diaphragm- look the costophrenic angle
- Increased lung lucency just air darker
- More ribs visible
- Air trapping
A 29-year-old man arrives at the emergency department reporting a 3-week history of cough, fatigue, night sweats, and intermittent fevers. He reports no prior medical problems. He is from Mexico, has no health insurance, and lives in a boarding house with several other men. He reports no sick contacts.
His temperature is 38.3°C, and his lungs are clear on auscultation. He has a leukocyte count of 8000 per mm3 (reference range, 4500– 11,000), a serum creatinine level of 1.6 mg/dL (0.8–1.3), and a random glucose level of 180 mg/dL (<140). An initial chest radiograph reveals a small nodular infiltrate in the apical portion of the right upper lobe and a calcified hilar lymph node. Which one of the following diagnostic approaches is most appropriate for this patient?
a) Order an interferon-gamma release assay
b) Obtain a urine sample for acid-fast bacilli culture
c) Place a tuberculin skin test
d) Obtain a bronchoalveolar lavage for acid-fast bacilli smear microscopy and culture and fungal testing
e) Obtain three sputum samples for acid-fast bacilli smear microscopy and culture
e - obtain three sputum cultures for acid-fast bacilli smear and culture - diagnosing active pulmonary tuberculosis should include evaluation of at least three sputum samples for acid-fast bacilli smear microscopy and culture.
A 27 y/o man presents to his GP with several months of coughing and dyspnea associated with cold air exposure. On further discussion he has noted that sometimes he awakens in the middle of the night with a dry cough and feeling short of breath. He notes that between these episodes he has no respiratory symptoms.
His Pulmonary Function Test results are shown. What type of lung disease does this patient most likely have?
Normal FVC
FEV1 <80% predicted
FEV1:FVC (3.52/5.23) ratio = 0.67 (or 67%) - so <0.7
And improvement of FEV1 >12% with bronchodilator
Obstructive lung disease with a reversible (responsive to bronchodilator) component - consistent with asthma which also fits clinical picture
A 47 y/o man presents to his GP with
a cough for the past two years that has been worsening, and dyspnea on exertion. On further discussion he describes the cough as productive of white sputum. His Pulmonary Function Test results are shown. What type of lung disease does this patient most likely have
The correct answer is obstructive lung disease, with an FEV1:FVC ratio of .69 only minimally reversible therefore not asthma but COPD.
Abnormal DLCO also consistent with COPD as is patient’s history and age
- emphysema- reduced SA
A 59 y/o woman presents to her GP with several months of increasing dyspnea on exertion and a dry cough; on further discussion she has noted dyspnea and cough when she exercised for several years but dismissed this as being secondary to her smoking (1 pack/day for 20 years stopped 20 years ago ). Her PFT results are shown. What type of lung disease does this patient most likely have?
Reduced FVC
Reduced FEV1 but less reduced c/w FVC NORMAL FEV1:FVC ratio - >0.7 FEV1/FVC = 2.35/2.70= .87 (87%) Reduced TLC - total lung capacity
Normal FEV1:FVC with decreased lung volumes is consistent with restrictive lung disease
DLCO is also low -suggests intrinsic lung disease
This suggests restrictive lung disease secondary to lung parenchymal disease (INTRINSIC) such as diffuse pulmonary fibrosis
A 27 y/o woman, Ms Seidler, carrying the diagnosis of asthma is referred to to a respiratory consultant because of recurrent sinus and chest infections for the past decade with Ms Seidler’s most recent sputum culture growing pseudomonas aeruginosa. The consultant suspects that rather than asthma Ms Seidler has an atypical form of adult onset Cystic Fibrosis (CF). Why is it important in this patient to differentiate whether she has asthma or CF?
a) People with asthma need to avoid/eliminate triggers whereas people with CF need to ensure daily mucous clearance.
b) People with asthma need to have up to date pneumococcal and influenza vaccinations whereas routine immunization is ineffective in CF
c) People with asthma need to maintain good nutritional status whereas nutrition plays no role in CF
d) People with asthma need to isolate from other asthmatics to prevent exchange of resistant bacterial strains whereas people with CF have infections with sensitive bacteria
e) Lung function in people with asthma can be monitored with spirometry whereas spirometry in people with CF is normal
a - People with asthma need to avoid triggers whereas people with CF need to ensure daily mucous clearance. mucous clearance one of the key parts of management of CF and bronchiectasis, but NOT part of asthma treatement
A 47 y/o woman presents to her GP with several months of increasing dyspnea on
exertion; on further discussion she had noted dyspnea and dry cough when she exercised for
several years but dismissed this as being secondary to her smoking (1 pack/day for 20 years). She is healthy other than having rheumatoid arthritis for which she has been on methotrexate for the last 5 years. The Respiratory Consultant diagnoses her with restrictive lung disease secondary to methotrexate induced pulmonary fibrosis. Which spirometry tracing (A, B or C?) would be consistent with this diagnosis?
The correct answer is Tracing A - low FEV1 c/w normal but more low FVC and never reaches volume of normal lung
B- suggests Obstructive lung disease - low FEV1, FVC almost normal but takes almost the full 6 seconds for all the air to be expired
C- normal tracing
A 53 y/o man, Mr Treacher, with a long history of cigarette smoking develops high blood pressure, a moon face and central obesity. Serum ACTH is increased, but MRI studies of the pituitary and hypothalamus fail to demonstrate any tumours. A chest x-ray reveals a small tumour in the right upper lobe, and a biopsy is performed. The biopsy results are shown. Which of the following is the most likely diagnosis?
Metastatic melanoma
Metastatic breast cancer
Adenocarcinoma of the lung
Small cell lung cancer
Squamous cell carcinoma of the lung
The correct answer is d - the slide shows the characteristic appearance of small cell cancer cells with high nuclear:cytoplasma ratio and dense sheets of cells. There are no glands ruling out adenocarcinoma of the lung, and there are no islands of keratin ruling out squamous cell lung lung. In addition, small cell ca of the lung is the lung cancer most strongly associated with smoking.
A 30 y/o woman, Ms Smythe, with no significant past medical history, presents to her GP with 4 days of a high temperature, cough productive purulent sputum, rigors and chills. In the last 24 hours she has also started to feel short of breath with exertion. She is on no medications and does not smoke. Her oxygen saturation is 93%. Her GP diagnoses her with community acquired pneumonia. Which of the following microbes does the GP not need to cover when treating this patient?
a) Haemophilus influenzae
b) Legionella species
c) Pseudomonas aeruginosa
d) Mycoplasma pneumonia
e) Streptococcus pneumonia
c- pseudomonas aeruginosa
This patient has community acquired pneumonia. There is nothing in the history or exam to suggest an underlying other medical condition that would predispose this patient to infection with organisms that affect patients with underlying lung disease or immunosuppression. All the other listed pathogens - Haemophilus influenzae, Legionella species, Mycoplasma pneumonia, Streptococcus pneumonia may cause community acquired pneumonia.
A 25-year-old man is brought to the emergency department because of a 1-week history of fever and cough productive of purulent sputum. His temperature is 38.9°C (102°F), pulse is 110/min, respirations are 24/min, and blood pressure is 110/70 mm Hg. Crackles, decreased breath sounds, and stony dullness to percussion are present in the right lower lobe. A chest x-ray shows a pleural effusion over the lower third of the thorax on the right in the midscapular line. A thoracocentesis is scheduled. Exactly where in the intercostal space should the needle be inserted?
a) Just above the rib to avoid damaging the neurovascular bundle.
b) Just below the rib to avoid damaging the neurovascular bundle.
Just above the rib to avoid damaging the neurovascular bundle.
An 26 y/o person presents to their GP with 48 hours history of cough productQiveupuerusletntiospuntumO, fnevers, chills and myalgias. The GP percusses the lung and finds dullness to percussion only in the area of the right middle lobe. Auscultation of the same area reveals crackles and breath sounds. The GP suspects pneumonia and sends the patient for a chest x-ray that reveals a right middle lobe pneumonia. Which of the following chest x-rays most likely represents this patient’s CXR?
a) A b) B c) C d) D e) E
the correct answer is A= RML consolidation consistent with pneumonia. The CXR shows
consolidation in the right mid/lower zone with effacement of the right heart border.
The right hemidiaphragm silhouette is
clearly outlined - it would be hazy or
obscured in a RLL pneumonia
