Sedation for dogs and cats with anaesthesia

• Premedication in dogs with respiratory disease

  1. Opioid alone OR
  2. Dexmedetomidine OR Acepromazine OR benzodiazepine AND methadone.

  administer oxygen (mask/flow), IV access.

  Other drug interventions may be administered at this time;

  1. Omeprazole, metoclopramide, maropitant for nausea, regurgitation.
  2. Xylometazoline to reduce decongested nares, terbutaline
  3. NSAIDs or paracetamol.
• Premedication in cats with respiratory disease

  1. Opioid alone OR
  2. Dexmedetomidine OR Acepromazine OR Benzodiazipine AND methadone (or Butorphanol)
  3. Alfaxalone AND midazolam AND opioid (methadone or Butorphanol) IM
  4. Ketamine AND midazolam IM or IV

  Administer oxygen (mask/ flow by oxygen cage), IV acess do ot delay induction if animal v compromised.

  Other drugs may be administered at the same time;

  1. NSAIDs or steroids
  2. Terbulatine or salbutamol.
• Induction of anaesthesia (cat and dog)

  1. Alfaxalone IV or
  2. Propofol IV
  3. Ketamine IV (less common)

  Intubate as quickly as possible (have several sizes of ET tubes ready) inflate cuff. Don’t forget to spray the cats larynx with lidocaine. Assess the airway too at this point, BOAS, laryngeal paralysis, collapse, masses, polyps, etc… Suction may be necessary (or swab out mucous before placing tube). Use a laryngoscope.

  Ketamine induction is often recommended as it is associated with bronchodilator via central release of catecholamines.
• Maintenance of anaesthesia for respiratory patients

  1. Use appropriate FGF for selected breathing system (try and use a circle wherever possible as it warms the air the patient is breathing in)

  2. Minimise dead space (ET tubes cut to suitable length)

  3. Use Isoflurane or sevoflurane in oxygen - adjust vaporiser setting to maintain suitable plane of anaesthesia

  4. You may need to assist ventilation (use the capnograph to judge) 8-15 breaths usually OK

  5. Depending on the procedure you may need to maintain anaesthesia with injectable (TIVA) e.g. bronchoscope alfaxalone and Propofol are suitable for topping up or CRI
• Monitoring the respiratory patient

  Respiratory rate and effort, mucous membrane colour, CRT and reflexes.

  SPO2% and pulse rate (does it match the manual reading).

  ECG (or oesophageal stethoscope if no other equipment).

  ET CO2 - why is this so valuable? Blood pressure - Doppler, Oscillometric, HDO, direct, temperature.
• Recovery of the respiratory problems

  Critical period, often associated with most risk as support is withdrawn. Recover animals in prep area and carefully monitor. Supplement with oxygen as hypoxaemia is common if they return to FiO2 21%. Be prepared to reintubate if the animal decompensates. Low dose sedation may be required.