Pneumothorax and Diaphragmatic Hernias Flashcards
What is a pneumothorax characterized by? (2)
Pneumothorax is characterised by a rapid, shallow breathing pattern (tachypnoea but hypoventilation) with reduced/absent lung sounds
How is a pneumothorax most commonly diagnosed in a stable patient?
Radiographs
What is initially performed in a pneumothorax?
Thoracocentesis
When is a thoracostomy tube required for a pneumothorax? (2)
- when repeated thoracentesis required
- negative pressure cannot be achieved
When is surgery indicated for a pneumothorax? (3)
- Significant wounds
- Failure of the pneumothorax to resolve after 5 days of intermittent/continuous suction,
- Abnormality seen on radiography/CT
What are the pathogenesis of a pneumothorax? (6)
- Penetration of thoracic wall
- Penetration of oesophagus
- Penetration of airways
- Iatrogenic
- Primary spontaneous
- Secondary spontaneous
What is the causes of secondary spontaneous pneumothorax?
The lung is the cause of the leak, with clinical evidence of pulmonary disease e.g., bacterial pneumonia, chronic obstructive lung diseases, asthma, tuberculosis, fungal granuloma, neoplasia, ruptured pulmonary abscesses, heartworm thromboembolism (causing bronchopleural communications) etc.
What is the causes of primary spontaneous pneumothorax?
The lung is the cause of the leak, but there is no clinical evidence of pulmonary disease. In this case, pneumothorax is secondary to rupture of pulmonary blebs (local accumulations of air within the visceral pleura) or bullae (confluent alveoli). This condition has been reported most commonly in large, deep chested breeds of dogs. The aetiology of the pulmonary blebs and bullae are unknown in dogs.
How does a tension pneumothorax develop?
From a closed pneumothorax where soft tissue acting as a one-way valve allows air to enter the pleural space during inspiration, but not to exit during expiration.
How does a tension pneumothorax cause death within minutes?
supra-atmospheric pressure, which severely compromises ventilation and venous return, and leads to death
What is seen on x-ray with a tension pneumothorax? (4)
- Large volume of pleural air visible.
- Marked lobar collapse
- Mediastinal shift to the right
- A flattened left hemidiaphragm.
What radiographic signs are consistent with pneumothorax? (4)
- Increased radiolucency and absence of pulmonary vasculature in the periphery of the thoracic cavity
- Dorsal elevation of the cardiac silhouette
- Increased parenchymal radiopacity
- Pneumomediastinum
What is a CT scan better at detecting with a spontaneous pneumothorax?
Blebs
Bullae
How often should a thoracostomy tube be evacuated?
Every 2-4 hours
When can a thoracostomy tube be removed following a pneumothorax?
When production is nil
When should continuous suction be used in a thoracostomy tube for pneumothorax? (2)
- Air reaccumulates rapidly following thoracic percutaneous drainage (e.g., PleuralPort) for pneumothorax,
- Negative pressure cannot be reached
Other than surgery/thoracostomy tubes. What other techniques have been described? (2)
- Autologous blood patch pleurodesis
- PleuralPort
Name post-operative complications of a pneumothorax (7)
- Recurrent pneumothorax
- Haemorrhage
- Pyothorax
- Pneumonia
- Sepsis
- Reflux oesophagitis
- Wound complications.
In cats, what is a spontaneous pneumothorax almost exclusively associated with? Give examples (5
Lung disease
- Inflammatory airway disease
- Neoplasia
- Heartworm
- Lungworm
-Abscessation
When should surgery be performed urgently in traumatic diaphragmatic hernia?(3)
- Gastric entrapment and tympany;
- Ongoing haemorrhage or hypovolaemia;
- Severe/relentless abdominal pain.
What must happen before surgical repair of a diapragmatic hernia?
cardiovascular stabilisation
What surgical closure is performed on a traumatic diaphragmatic hernia?
Primary apposition
How often are complications in a traumatic diaphragmatic hernia repair?
50%
Survival to discharge in traumatic diaphragmatic hernia?
89%
What diaphragmatic hernia is congenital
Peritoneo-pericardial diaphragmatic hernia (PPDH)
How can we manage non symptomatic patietns with a PPDH?
Conservative tx with monitoring.
How do we manage PPDH patients who are symptomatic?
Surgery
PPDH surgery survival rate - dogs?
82-100%
PPDH surgery survival rate - cats?
86%
What is the complication rate of PPDH surgery?
78%
What “type” of structure is the diaphragm?
Musculotendinous
What are the physical roles of the diaphragm? (2)
- Ventillation
- Assist in lymphatic drainage
What are the 3 types of diaphragmatic hernia and where are these located?
- Along the fibre orientation of the costal musculature (radial tear, seen in 45% of cases),
- The muscular attachment to the ribs (circumferential tear, seen in 23% of cases),
- A combination of both
What is the most common organ to herniate through the diaphragm?
Liver
Are traumatic diaphragmatic hernia acute or chronic at presentation?
Either
Clinical signs of a diaphragmatic hernia (15)
Dyspnoea (41.1%)
Muffled heart sounds (29.4%)
Vomiting (11.7%)
Anorexia
Diarrhoea
Open mouth breathing
Cyanosis
Cachexia
Icterus
Increased or decreased lung sounds
Exercise intolerance
Shock
Cardiac arrhythmia
Pale mucous membranes
Hypothermia.
What type of injuries do patients have concurrently with a diaphragmatic hernia:
A) 27%
B) 33.3%
A) Soft tissue
B) Orthopedic
What causes respiratory compromise in a diaphragmatic hernia? (5)
- Loss of the mechanical function of the diaphragm
- Pleural space-occupying effect of abdominal organs (plus associated air or fluid accumulation),
- Compression of lung lobes
- Atelectasis of lung lobes
- Ventilatory impairment
What is the end results of significant hypoventilation and alveolar ventilation-perfusion mismatch in a diaphragmatic hernia?
Life threatening hypoxia
How many dogs with a diaphragmatic hernia have a cardiac arrythmia?
12%