choosing appropriate sedation.pdf

Choosing appropriate premedication and sedation CP3.14 Supporting the animal Pamela Murison 1 year 3 2 Year Intended Learning Outcomes (ILOs) Therapeutics and management CP3024 a Formulate an analgesic, sedative or anaesthetic plan for a veterinary patient, demonstrating an understanding of t...

Choosing appropriate premedication and sedation CP3.14 Supporting the animal Pamela Murison 1 year 3 2 Year Intended Learning Outcomes (ILOs) Therapeutics and management CP3024 a Formulate an analgesic, sedative or anaesthetic plan for a veterinary patient, demonstrating an understanding of the underpinning principles, including pharmacology & the safe use of anaesthetic equipment. For more information: Chapter 13 of the BSAVA manual of canine and feline anaesthesia (pages 170-189) is a good resource 3 Lecture ILOs After this lecture, you should be able to:  Explain the purposes of pre-anaesthetic medication  Identify clinical situations where one drug, or drug combination, may be chosen over another  Select appropriate agents for premedication/sedation in a range of clinical situations 4 Aims of premedication      To produce a calming effect, or sedation To provide analgesia To reduce doses of other agents required To ‘smooth’ induction and recovery To counteract unwanted effects of other anaesthetic drugs 5 Drug groups     Phenothiazines – Acepromazine Alpha-2 agonists – Medetomidine, dexmedetomidine, xylazine, detomidine, romifidine Opioids Benzodiazepines 6 Other drug groups     Anti-cholinergics Induction agents – Ketamine – Alfaxalone Antihistamines? Steroids/NSAIDs? 7 Know the pharmacology of these drugs! 8 Anticholinergics     BLOCK effect of acetyl choline at receptors BLOCKS parasympathetic effects Atropine Glycopyrrolate 9 Anticholinergics  Reduce salivation & respiratory secretions  Pupillary dilation  Increase HR  Increase oxygen consumption  Decrease gut motility Not used routinely nowadays 10 Drug combinations   Different effects – e.g. analgesia, sedation Synergy 11 Drug combinations   Different effects – e.g. analgesia, sedation Synergy 12 Drug combinations  Acepromazine combinations – –  ACP + buprenorphine ACP + methadone Alpha-2 agonists combinations – Medetomidine + butorphanol – Dexmedetomidine + methadone 13 Drug combinations  Alfaxalone (IM in cats) – – –  Alfaxalone Alfaxalone + butorphanol Alfaxalone + midazolam Can be useful – – Sick but not easy to handle (!) Not so useful healthy 14 Drug combinations  Ketamine – – Midazolam + ketamine IM (Cats) Alpha-2 agonist + opioid + ketamine Increase sedation  Could induce anaesthesia  15 Sedatives to modify recovery   Residual sedative effects from premedication will influence recovery – Remember acepromazine- long effect Horses – Alpha-2 agonist often used at recovery – Slow down – Allow elimination of other drugs 16 What sedation is needed?   Temperament of animal Procedure – – – Duration? Immobility required? What degree of responsiveness acceptable? 17 Think about ‘side effects’    What effects will drug have on the organ system? What effects will any abnormal organ system have on the drugs? e.g. think about cardiovascular system 18 Care with sedation     May be rousable Allow time for effect Think about analgesia required Can combine with local anaesthesia /regional anaesthesia 19 Conclusions    Sedation is not essential for pre-anaesthetic medication – If animal calm/handleable – If effects of sedatives undesirable BUT premedication may reduce stress of procedures/IV cannulation Opioids, benzodiazepines may be useful as premedication or co-induction