Lower Respiratory Tract Flashcards
Which lung lobes can be FULLY removed?
Left
Do the intercostal muscles relax or contract on inspiration?
Contract
How many costal arches are on each side?
4
How many pairs of ribs are in a dog?
13
Into what does the thoracic duct drain?
The caudal vena cava
What are 5 examples of obstructive disorders?
- Stenotic nares
- Nasal tumors
- Foreign body
- Rhinitis
- Sinusitis
What are 2 examples of restrictive disorders?
- Decreased lung compliance
2. Conditions affecting the pleural cavity (pyothorax, chylothorax, fibrosis, hemothorax, pneumothorax)
What are 3-4 examples of vascular conditions?
- PDA
- PTE
- Heartworm
- Interstitial edema
What is the pressure within the thoracic space?
-5 cm H2O
What do you call a loss of the negative pressure within the thoracic space?
Pneumothorax
Where would you aim to collect fluid off the chest?
Ventral 1/3 of the chest cavity between the 6th and 9th ribs
Where would you aim to collect air off the chest?
Dorsal 1/3 of the chest cavity between the 6th and 9th ribs
What is a thoracostomy?
Construction of an opening through the chest wall
Which of the following is NOT a proper consideration for a thoracotomy: (1) all animals with respiratory distress require oxygen supplementation, (2) all animals with open chest cavities require intermittent positive pressure ventilation, except diaphragmatic hernias, (3) high ventilator pressures should be avoided in chronic lung collapse, (4) use of post-operative analgesia.
(2) ALL animals with open chest cavities require intermittent positive pressure ventilation, INCLUDING diaphragmatic hernias.
Which hurts more, a lateral thoracotomy or a median sternotomy?
Lateral thoracotomy - use heavy pain medication
What are the 2 advantages of a lateral thoracotomy?
- Good access to dorsal structures
2. Good access to structures directly under intercostal space
What are the 2 disadvantages of a lateral thoracotomy?
- Poor access to contralateral hemithorax
2. Poor access to ipsilateral structures not directly under the incision
When you cut through an intercostal space, where should you make your cut?
Cranial to mid intercostal space
Explain how you would close an intercostal incision…
- Pre-place sutures around the adjacent ribs
2. Apposition of intercostal muscles WITHOUT over-tightening
Into which intercostal space(s) would you incise to reach the heart/pericardium?
Right or left side, 4th or 5th
Into which intercostal space(s) would you incise to reach the cranial lung field?
Right or left side, 4th or 5th
Into which intercostal space would you incise to reach the caudal lung field?
Right or left side, 5th or 6th
Into which intercostal space would you incise to reach the cranial esophagus?
Right 3th/4th
Into which intercostal space would you incise to reach the caudal esophagus?
Right or left side, 7th-9th
Into which intercostal space would you incise to reach the thoracic duct in a dog? Cat?
Dog - right 8-10
Cat - left 8-10
What are the 2 advantages to a median sternotomy?
- Access to entire thoracic cavity
2. Able to combine with an abdominal approach
What is the disadvantage to a median sternotomy?
Difficult to access dorsal structures
When performing a median sternotomy, which 2 things should be left intact?
- Manubrium
2. Xyphoid
When would you use wires around the sternebra to close a median sternotomy?
Patient > 10 kg
When would you use heavy gauge suture around the sternebra to close a median sternotomy?
Patient
What are the 4 advantages to a thoracoscopy?
- Less pain
- Quick recovery
- Magnification, illumination
- Visualization of difficult to reach places
When performing a complete lobectomy, would you ligate the artery or vein at the hilus first?
Artery
Explain the triglyceride and cholesterol levels for chylothorax…
Triglycerides in thoracic fluid > triglycerides in peripheral blood
Cholesterol of thoracic fluid
How would you medically manage a chylothorax?
- Low fat diet
- Supplement with rutin (increases protein removal, decreases lymphatic leakage)
- Intermittent thoracocenteses
Explain the purulent exudate associated with a pyothorax…
- Cytology: neutrophils + intracellular bacteria
- TP > 3 g/dL
- Cell count > 3000 cells/uL
