Lungs Flashcards
How many sternebrae does a dog have?
9
List the muscle that cover the thoracic wall from internal to external
- Serratus dorsalis and ventralis
- Scalenus
- External abdominal oblique
- Latissimus dorsi
- pectoralis
- Cutaneous trunci
List the lung lobes
Left:
- Left cranial (subdivided into cranial and caudal)
- Left caudal
Right:
- Cranial
- Middle
- Caudal
- Accessory
Where are the pulmonary arteries and vein located in relation to the associated bronchus?
- Artery: craniodorsal
- Vein - Caudoventral
What muscles can be engaged to aid inspiration and expiration?
Inspiration:
- external intercostal
- sternocleidomastoid
- scalenus
- serratus ventralis
Expiration:
- Internal intercostals
- Abdominal rectus
What can alter lung complicance?
- Fibrosis
- Oedema
What cells produce surfactant?
What is its function?
- Alveolar type II cells
- Indirectly increases lung compliance by reducing surface tension
- Prevents collapse of small alveoli
What structures contribute to inspiratory resistance and expiratory resistance?
Inspiratory:
- Nares 79%
- Small airways 15%
- Larynx 6%
Expiratory:
- Nasal 74%
- Laryngeal 3%
- Small airways 23%
What controls ventilation?
- Chemoreceptors in respiratory centre in medulla
- Peripheral chemoreceptors in carotid and aortic bodies
- Stretch receptors in the airway and lung parenchyma stop inspiration
What is hypoxic ventilation drive?
An increase in ventilation is PaO2 is below 60mmHg
What is Ficks law?
The rate of transfer of a gas through a sheet of tissue is proportional to the surface area available for diffusion, diffusion coefficient of the gas, difference in gas partial pressures and inversely proportional to the tissue thickness
How does the diffusion coefficient compare between CO2 and O2
CO2 is 20x greater
What can cause the oxygen dissociated curve to shift to the right?
- Increased temp, PCO2, 2,3-DPG
- Decreased pH
What can cause a high V/Q and a low V/Q
- High V/Q - PTE
- Low V/Q - atelectasis, pneumonia, severe pulm oedema
What are common post-op problems to monitor for after a thoracotomy?
- Hypotension
- Hypothermia
- Hypoventilation
- Electrolyte imbalance
- Shock
What are the two thoracoscopic options?
- Intercostal (4th-9th ICS)
- Transdiaphragmatic (Manubrium, 9th-10th ICS)
Most commonly 5mm 0-30 degree telescope with 3-4 trocars
What is the sensitivity of CT scan in the diagnosis of cause of spontaneous pneumothorax?
42-58%
What imaging technique can be used for diagnosis of bronchoesophageal fistula?
What breeds are overrepresented?
- Contrast oesophogram with water soluble iodine
- Toy-breeds and small terriers
What bacteria are most commonly isolated from lung lobes abscesses?
- E.Coli
- Klebsiella pneumoniae
- Staph
- Strep
- Pseudomonas
- Fusobacterium
What is the maximum volume of lung which can be acutely removed?
50%
What is the surgical outcome after lung lobectomy for lung abscess?
- Mortality 20% (14% if 1 lobe removed, 60% if three removed)
- 54% of survivors has resolution of their pneumonia
- MST 96m with resolution of pneumonia vs 10m
What breeds are overrepresented for bronchiectasis?
- American Cocker Spaniels
- Min Poodles
Name these suture patterns for closure of a lung laceration
- A - Interrupted lembert mattress pattern
- B - Haemostatis mattress sutures (1) and simple continuous
What breeds are predisposed to lung lobe torsion?
- Large dogs with deep narrow chests (right middle and left cranial)
- Pugs (left cranial)
May be assoc with chronis resp disease, chylothorax, trauma, d-hernia, thoracic surgery, neoplasia
