Thoracic and ocular surgery

Question 1

Define a tracheostomy

Answer 1

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

Question 2

Define an tracheotomy

Answer 2

Incision into trachea but to remove foreign body/biopsy

Question 3

Describe management of a tracheostomy tube

Answer 3

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

Question 4

Describe care of a permanent tracheostomy

Answer 4

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

Question 5

What are animals with a permanent tracheostomy prone to?

Answer 5

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?

Question 6

How can you access the airways in an emergency?

Answer 6

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

Question 7

Describe laryngeal paralysis

Answer 7

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

Question 8

What is the aim of surgery for laryngeal paralysis?

Answer 8

AIM: TO PERMANENTLY ENLARGE THE GLOTTIS LUMEN

LARYNGEAL TIE BACK COMMONLY PERFORMED

Question 9

Describe post-operative care for laryngeal paralysis surgery

Answer 9

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

Question 10

What is a collapsing trachea?

Answer 10

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

Question 11

What can cause a collapsing trachea?

Answer 11

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

Question 12

What signs may there be of a collapsing trachea?

Answer 12

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)

Question 13

How can you manage a collapsed trachea?

Answer 13

Long term medical treatment is possible. All options should be explored before considering surgery

Question 14

How can you surgically manage a collapsed trachea?

Answer 14

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

Question 15

Describe post-operative management of a collapsed trachea

Answer 15

Weight loss

Treatment of left sided heart failure

Removal of inhaled irritants/allergens

Treatment resp tract infections

Replace collar with harness

Question 16

In what ways can the thorax be approached during a thoractomy?

Answer 16

Lateral or Intercostal Thoracotomy

Sternal Thoracotomy or Sternotomy

Question 17

In what ways can the thorax be approached during a thoractomy?

Answer 17

Lateral or Intercostal Thoracotomy

Sternal Thoracotomy or Sternotomy

Question 18

Describe the intercoastal thoracotomy

Answer 18

Intercostal Thoracotomy is the most common approach. Access to the lungs, heart, oesophagus and one side of the pleural cavity

Question 19

What is an advantage of a sternotomy?

Answer 19

Advantage of a Sternotomy is that both sides of the chest can be explored

Question 20

What are complications of a thoracotomy?

Answer 20

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

Question 21

What is a ruptured diaphragm?

Answer 21

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

Question 22

How can a ruptured diaphragm affect the body?

Answer 22

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

Question 23

When should a ruptured diaphragm be repaired?

Answer 23

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

Question 24

What are the clinical signs of a ruptured diaphragm?

Answer 24

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

Question 25

When should a ruptured diaphragm be treated as an emergency?

Answer 25

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

Question 26

What anaesthetic considerations should you make with a ruptured diaphragm?

Answer 26

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

Question 27

Describe surgery for a ruptured diaphragm

Answer 27

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

Question 28

Describe post-op care for a ruptured diaphragm

Answer 28

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