Thoracic and ocular surgery Flashcards
Define a tracheostomy
Creation of an opening into the trachea with insertion of an indwelling tube to facilitate passage of air
An opening is made halfway down the neck to bypass an obstruction to breathing within the upper airway
Define an tracheotomy
Incision into trachea but to remove foreign body/biopsy
Describe management of a tracheostomy tube
Post operative management is of paramount importance
Obstruction of the tube can lead to death of the patient. The animal must be very closely or continually monitored
Use of a humidifier to reduce viscosity of secretions
Remove and clean cannula tube initially every -
Single lumen tubes -
Periodically -
Trachea should then be suctioned
Tubes should only be left in place for a few days
A permanent tracheostomy should be performed if needed for longer periods of time
Describe care of a permanent tracheostomy
Skin is sutured to the tracheal mucosa to leave a permanent opening
Gently bath in warm water/saline to remove secretions, care not to disrupt suture line
2 weeks post surgery minimal care is required
What are animals with a permanent tracheostomy prone to?
Animals are prone to aspiration of foreign bodies and water – do not allow animals to swim and be careful when bathing
Can be prone to chronic respiratory infections and chronic mucus discharge. Why?
How can you access the airways in an emergency?
Use of a wide gauge hypodermic needle or catheter can be pushed quickly through the ventral midline of the neck, between the tracheal rings
Oxygen can then be administered
Describe laryngeal paralysis
Common cause of upper respiratory obstruction
Most cases - Idiopathic condition, but can develop due to nerve damage, tumour etc.
Common in older, large breed dogs
Arytenoid cartilage fails to abduct during inspiration
Results in narrowing of glottis lumen
What is the aim of surgery for laryngeal paralysis?
AIM: TO PERMANENTLY ENLARGE THE GLOTTIS LUMEN
LARYNGEAL TIE BACK COMMONLY PERFORMED
Describe post-operative care for laryngeal paralysis surgery
Sternal recumbency
Delay extubation for as long as possible
Cool, stress free environment
Supplement oxygen available
Sedate agitated animals
Tinned food for 12-24 hours
Avoid strenuous exercise for 6 weeks
Discourage barking
What is a collapsing trachea?
Syndrome characterised by a flattening of the tracheal rings
Commonly seen in toy or miniature breeds i.e. Yorkshire terriers, Toy poodles, Pomeranians and Chihuahuas.
Occurs in middle aged or older animals
What can cause a collapsing trachea?
Development of this condition requires the presence of an underlying factor that causes a defect in the tracheal cartilage resulting in a weakening of the cartilage rings and the presence of a secondary factor –
Obesity recent intubation resp tract infection cardiomegaly Inhalation of irritants or allergens
What signs may there be of a collapsing trachea?
Animals with this condition will have a harsh, honking cough when they become excited or during exercise
Severely effects animals may become cynotic during episodes or even syncopal (faint)
How can you manage a collapsed trachea?
Long term medical treatment is possible. All options should be explored before considering surgery
How can you surgically manage a collapsed trachea?
Extra Luminal Prostheses
Introduction of a structure on the outside of the trachea
Collapsing trachea is sutured to plastic rings placed around it, reopening the trachea and offering support
Intra-Luminal Prostheses
Expandable wire cylinder is inserted into the trachea to provide an internal stent
Describe post-operative management of a collapsed trachea
Weight loss
Treatment of left sided heart failure
Removal of inhaled irritants/allergens
Treatment resp tract infections
Replace collar with harness
In what ways can the thorax be approached during a thoractomy?
Lateral or Intercostal Thoracotomy
Sternal Thoracotomy or Sternotomy
In what ways can the thorax be approached during a thoractomy?
Lateral or Intercostal Thoracotomy
Sternal Thoracotomy or Sternotomy
Describe the intercoastal thoracotomy
Intercostal Thoracotomy is the most common approach. Access to the lungs, heart, oesophagus and one side of the pleural cavity
What is an advantage of a sternotomy?
Advantage of a Sternotomy is that both sides of the chest can be explored
What are complications of a thoracotomy?
Rib fractures or luxations can occur with excessive retraction. Use of supporting bandages and analgesia indicated
Wound complications; oedema, seromas, haematomas, discharge, dehiscence. Also non union of the sternotomy incision.
Subcutaneous emphysema can occur due to free air in the pleural space escaping into subcutaneous tissues
Pneumothorax – corrected by intermittent or continuous aspiration by a chest drain
Haemothorax – can occur intra-operatively or post operatively via vessel haemorrhage
Post op care – care of the chest drain
Covered in medical nursing
What is a ruptured diaphragm?
Relatively common condition following trauma e.g. RTA
Violent compression of the abdomen results in rupture of the diaphragm and protrusion of abdominal organs into the thoracic cavity
How can a ruptured diaphragm affect the body?
Loss of diaphragm contraction result in impaired ventilation
Collapsed lungs and reduced resting lung volume causes impaired gaseous exchange
Pressure of the abdominal organs on major veins reduces venous return and cardiac output
Dilation of a herniated stomach may cause profound cardiopulmonary compromise
Ischaemia of herniated organs may occur
When should a ruptured diaphragm be repaired?
Higher mortality rate in animals that undergo surgery with 24 hours of trauma or in animals when surgery is performed more than one year later.
It is important to stabilise the animal prior to surgery
What are the clinical signs of a ruptured diaphragm?
Dyspnoea
Tachypnoea
Paradoxical Respiration (inward movement of the abdominal wall while the thoracic wall moves outward during inspiration)
Palpation of the abdomen may reveal a relatively ‘empty’ abdomen
When should a ruptured diaphragm be treated as an emergency?
Supportive care cannot stabilize respiratory function
Massive organ displacement has occurred
Continual haemorrhaging
An enlarging gas filled viscus i.e. the stomach is in the thoracic cavity
Bowel rupture has occurred
What anaesthetic considerations should you make with a ruptured diaphragm?
avoid ACP, this can cause hypotension and also splenic enlargement.
Use of an opioid, with an anticholinergic, Atropine Sulphate. Dependant on veterinary surgeons preference
Throughout induction and 5min prior to the animal should receive 100% oxygen to increase inspired oxygen to a level greater than 95%
No Nitrous Oxide. It rapidly diffuses into air filled pleural spaces or into gas filled loops of bowel
IPPV required throughout the procedure
Use a high respiratory rate with a low peak airway pressure.
Rapid expansion of a collapsed lung can lead to pulmonary oedema. Provide adequate ventilation but not re-expand the lung
The lung will re-expand gradually following repair
Constant monitoring of arterial oxygenation is essential to ensure that oxygen saturation is maintained
Describe surgery for a ruptured diaphragm
Be fully prepared before induction of the anaesthetic, including the vet fully scrubbed.
Normally preformed through a cranial midline incision, possibly expanding laterally to allow for better access
As soon as the abdomen is open IPPV must begin
Organs are repositioned
The diaphragm can either have –
A radial tear, from the centre to the outside
Circumferential tear, around the circumference
Repaired using simple interrupted sutures
As the final suture is tied the lungs should be gently expanded
Describe post-op care for a ruptured diaphragm
Sternal recumbancy to allow for equal lung expansion
Use of oxygen cage initially
Regular/constant monitoring of the respiration rate and effort and mm colour
