Recovery

Question 1

How d you disconnect the animal with the maintenance gas?

Answer 1

• Surgery ends
• Vaporiser is switched off
• If using nitrous oxide, switch off and increase oxygen to deliver adequate FGF and minimise diffusion hypoxia (leave on 100% O2 if N2O was used for 10 mins)
• ‘Dump’ the reservoir bag on the circuit and fill with fresh gas- oxygen by increasing the flowmeter

Question 2

How do you remove the ET tube?

Answer 2

• Deflate cuff on ET tube (if a cuffed tube was used) & loosen any ties
• Cuff may not be fully deflated following dental/oral procedures so as to prevent blood/ debris (teeth) being inhaled
• Extubate on expiration

Question 3

When do you remove the ET tube?

Answer 3

• ET tube is removed when gag reflex returns in dogs & most other species e.g. horses, ruminants, pigs etc
• Gag reflex is indicated by attempts to swallow and tongue movement
• Cats – don’t delay extubation (can cause laryngospasm)

Question 4

What are the signs of airway obstruction?

Answer 4

» Increased respiratory noise & effort
» Abdominal effort, nares flaring
» ‘Air hunger’ posture – head and neck extended
» Cyanosis
» Restlessness & agitation
» Agonal breathing (terminal sign)

Question 5

How can we keep the animal normothermic during anaesthesia?

Answer 5

–	Ambient temp of OR
–	Breathing circuit (circle vs non re-breathing circuit) & HME
–	Prep solution/alcohol kept to min
–	Bubble wrap/socks/space blankets
–	Hot water beds
–	Hot ‘hands’, hot cherry stone bags
–	Warm IV fluids and flushing solution
–	Hot air blankets

Question 6

Most serious problems occur during maintenance in the horse but only then manifest as problems in recovery! For example….

Answer 6

– Hypotension (low blood pressure)
– Hypoxaemia (low oxygen tension in blood)
– Hypercapnia (high carbon dioxide in blood - changes blood pH)
– Poor positioning

Question 7

What is Post operative myopathy?

Answer 7

Occurs when horse wakes up
Is caused by intraoperative malposition and hypotension and pressure on the nerve
• Mild lameness to inability to stand - Hard, swollen and painful muscles
• Extreme distress
• Sweating
• Difficulty breathing
• Restlessness

Question 8

What is Spinal cord malacia?

Answer 8

• Occurs when horse wakes up
• Fatal
• Usually heavy breed horses & young
• Not related to duration of anaesthesia

Question 9

What can cause Eye problems post op?

Answer 9

• Usually when horse has been in lateral recumbency (on its side)
• Must protect lowermost eye with padding
• Lubrication for eye

Question 10

What causes upper airway obstruction and how can you identify it?

Answer 10

– Stridor or stertor following tracheal extubation
– Nostril flaring on inspiration
– Abdominal respiratory effort
– Exaggerated thoracic excursion
– Absence of airflow at the nostrils
Obstruction tends to occur within the nasal passages or at the level of the larynx

Question 11

How can we avoid nasal oedema?

Answer 11

– Common
– Usually resolves as horse stands
– Use nasopharyngeal tubes, or phenylephrine or both
– Can recover horse to standing with ET tube in place

Question 12

How do we avoid laryngeal obstruction?

Answer 12

– Select appropriate ET tube size and insert gently
– By dorsal displacement of soft palate or by Epiglottic retroversion
– Following laryngeal surgery may leave ET tube in place for recovery (secured appropriately)
– If obstruction occurs be prepared to reintubate (may need more drugs) or emergency tracheostomy

Question 13

What does pulmonary oedema look like? What should you do?

Answer 13

– Frothy, pinkish fluid at the nostrils after horse has been reintubated and airway patency returned
– Exaggerated respiratory efforts & cyanosis
– The pathogenesis of this condition is thought to be related to changes in venous return and an influx of fluid into the alveoli as a result of excessive negative pressures within the thorax
– Remove obstruction, provide oxygen, frusemide and dexamethasone