Injectable Anaesthesia and Analgesia Quiz

WIKIQUIZ

Questions reviewed by:

Juliet Duncan BVM&S MSc DipECVAA MRCVS Richard Hammond BSc BVetMed DipECVA DVA PhD MRCVS

1

Naloxone is a reversal agent for which group of drugs? Butyrophenones Benzodiazepines Alpha-2 agonists Opioids Phenothiazines Please select an option Incorrect. Benzodiazepines can be antagonised by flumazenil and sarmazenil. Naloxone is an antagonist to exogenous and endogenous opioids. It is frequently used in human medicine to antagonise opioid narcotics in the incidence of overdose. Naloxone may be administered intravenously, intramuscularly, intrathecally or subcutaneously. It has a short duration of action (1-2 hours) and so repeated administrations may be necessary. Although diprenorphine (LA Revivon) is the licensed reversal agent for LA Immobilon in animals, naloxone should also be drawn up in case of accidental self-injection which can be rapidly fatal in man. Link to Wiki Vet: opioids.WikiVet Article: opioids. Incorrect. Alpha-2 agonists can be antagonised with atipamazole. Naloxone is an antagonist to exogenous and endogenous opioids. It is frequently used in human medicine to antagonise opioid narcotics in the incidence of overdose. Naloxone may be administered intravenously, intramuscularly, intrathecally or subcutaneously. It has a short duration of action (1-2 hours) and so repeated administrations may be necessary. Although diprenorphine (LA Revivon) is the licensed reversal agent for LA Immobilon in animals, naloxone should also be drawn up in case of accidental self-injection which can be rapidly fatal in man.WikiVet Article: opioids. Correct! Naloxone is an antagonist to exogenous and endogenous opioids. It is frequently used in human medicine to antagonise opioid narcotics in the incidence of overdose. Naloxone may be administered intravenously, intramuscularly, intrathecally or subcutaneously. It has a short duration of action (1-2 hours) and so repeated administrations may be necessary. Although diprenorphine (LA Revivon) is the licensed reversal agent for LA Immobilon in animals, naloxone should also be drawn up in case of accidental self-injection which can be rapidly fatal in man.WikiVet Article: opioids. Incorrect. Phenothiazines have no reversal agent. Naloxone is an antagonist to exogenous and endogenous opioids. It is frequently used in human medicine to antagonise opioid narcotics in the incidence of overdose. Naloxone may be administered intravenously, intramuscularly, intrathecally or subcutaneously. It has a short duration of action (1-2 hours) and so repeated administrations may be necessary. Although diprenorphine (LA Revivon) is the licensed reversal agent for LA Immobilon in animals, naloxone should also be drawn up in case of accidental self-injection which can be rapidly fatal in man.WikiVet Article: opioids.

2

In which dog breed can acepromazine cause fainting and syncope? Cavalier King Charles Spaniel Doberman St Bernards Boxer German shepherd dogs Please select an option Incorrect. Acepromazine has not been associated with fainting and syncope in Cavalier King Charles Spaniels. In Boxers given acepromazine, spontaneous fainting and syncope can occur due to sinoatrial block caused by excessive vagal tone. Acepromazine should be used at low doses or avoided in this breed. WikiVet Article: phenothiazines. Incorrect. Acepromazine has not been associated with fainting and syncope in Dobermans. In Boxers given acepromazine, spontaneous fainting and syncope can occur due to sinoatrial block caused by excessive vagal tone. Acepromazine should be used at low doses or avoided in this breed. WikiVet Article: phenothiazines. Incorrect. Acepromazine has not been associated with fainting and syncope in Cavalier King Charles Spaniels. In Boxers given acepromazine, spontaneous fainting and syncope can occur due to sinoatrial block caused by excessive vagal tone. Acepromazine should be used at low doses or avoided in this breed. WikiVet Article: phenothiazines. Correct! In Boxers given acepromazine, spontaneous fainting and syncope can occur due to sinoatrial block caused by excessive vagal tone. Acepromazine should be used at low doses or avoided in this breed. WikiVet Article: phenothiazines.

3

Which injectable anaesthetic should be avoided in sighthounds? Propofol Ketamine Alfaxalone Fentanyl-fluanisone Thiopentone Please select an option Incorrect. Propofol is an appropriate induction agent in sighthounds. Initial recovery from anaesthesia induced by thiopentone is dependent on redistribution of thiopentone from the plasma to the fat. Greyhounds and other sight hounds may exhibit longer recovery times than other breeds. This may be due to these breeds low body fat levels or differences in the metabolic han­dling of the thiobarbiturates. Both propofol and alfaxalone are preferable induction agents in sighthounds.WikiVet Article: thiopentone. Incorrect. Propofol is an appropriate induction agent in sighthounds. Initial recovery from anaesthesia induced by thiopentone is dependent on redistribution of thiopentone from the plasma to the fat. Greyhounds and other sight hounds may exhibit longer recovery times than other breeds. This may be due to these breeds low body fat levels or differences in the metabolic han­dling of the thiobarbiturates. Both propofol and alfaxalone are preferable induction agents in sighthounds.WikiVet Article: thiopentone. Incorrect. Fentanyl-fluanisone is not licensed in dogs, it is only licensed in rabbits, guinea pigs, rats and mice. Initial recovery from anaesthesia induced by thiopentone is dependent on redistribution of thiopentone from the plasma to the fat. Greyhounds and other sight hounds may exhibit longer recovery times than other breeds. This may be due to these breeds low body fat levels or differences in the metabolic han­dling of the thiobarbiturates. Propofol and alfaxaolne are preferred induction agents in sighthounds. WikiVet Article: thiopentone. Correct! Initial recovery from anaesthesia induced by thiopentone is dependent on redistribution of thiopentone from the plasma to the fat. Greyhounds and other sight hounds may exhibit longer recovery times than other breeds. This may be due to these breeds low body fat levels or differences in the metabolic han­dling of the thiobarbiturates. Propofol and alfaxalone are preferable induction agents in sighthounds. WikiVet Article: thiopentone.

4

Which drug is commonly used for total intravenous anaesthesia (TIVA) in dogs? Propofol Ketamine Thiopentone Alfaxalone Fentanyl-fluanisone Please select an option Correct! Propofol has a very high volume of distribution and so a rapid re-distribution. It also has a very fast clearance by the liver metabolism in dogs therefore it is non-cumulative and can be used for TIVA. This is not true in cats, they can not metabolise propofol as effectively and so repeated doses can cause Heinz body anaemia, anorexia, diarrhoea and prolonged aneasthetic recovery.WikiVet Article: propofol. Incorrect. Thiopentone is cumulative following repeated doses so is not suitable for TIVA in any animal. Propofol has a very high volume of distribution and so a rapid re-distribution. It also has a very fast clearance by the liver metabolism in dogs therefore it is non-cumulative and can be used for TIVA. This is not true in cats, they can not metabolise propofol as effectively and so repeated doses can cause Heinz body anaemia, anorexia, diarrhoea and prolonged aneasthetic recovery.WikiVet Article: propofol. Incorrect. Thiopentone is cumulative following repeated doses so is not suitable for TIVA in any animal. Propofol has a very high volume of distribution and so a rapid re-distribution. It also has a very fast clearance by the liver metabolism in dogs therefore it is non-cumulative and can be used for TIVA. This is not true in cats, they can not metabolise propofol as effectively and so repeated doses can cause Heinz body anaemia, anorexia, diarrhoea and prolonged aneasthetic recovery.WikiVet Article: propofol. Incorrect. Fentanyl-fluanisone is not licensed for use in dogs in the UK. Propofol has a very high volume of distribution and so a rapid re-distribution. It also has a very fast clearance by the liver metabolism in dogs therefore it is non-cumulative and can be used for TIVA. This is not true in cats, they can not metabolise propofol as effectively and so repeated doses can cause Heinz body anaemia, anorexia, diarrhoea and prolonged aneasthetic recovery.WikiVet Article: propofol.

5

Which injectable anaesthetic increases intracranial pressure and central nervous system (CNS) excitement? Fentanyl-fluanisone Propofol Thiopentone Alfaxalone Ketamine Please select an option Incorrect. Fentanyl-fluanisone does not increase intracranial pressure. Ketamine increases intracranial pressure and CNS excitement which is not usually a problem in healthy animals, but it should be avoided in cases where increasing intracranial pressure may be detrimental or those with a history of seizures. WikiVet Article: ketamine. Incorrect. Thiopentone actually reduces intracranial pressure and is excellent at treating and preventing seizures so it is often selected for anaesthetising animals with seizures or intracranial disease. Ketamine increases intracranial pressure and CNS excitement which is not usually a problem in healthy animals but it should be avoided in cases where increasing intracranial pressure may be detrimental or those with a history of seizures. WikiVet Article: ketamine. Incorrect. Thiopentone actually reduces intracranial pressure and is excellent at treating and preventing seizures so it is often selected for anaesthetising animals with seizures or intracranial disease. Ketamine increases intracranial pressure and CNS excitement which is not usually a problem in healthy animals but it should be avoided in cases where increasing intracranial pressure may be detrimental or those with a history of seizures. WikiVet Article: ketamine. Correct! Ketamine increases intracranial pressure and CNS excitement which is not usually a problem in healthy animals but it should be avoided in cases where increasing intracranial pressure may be detrimental or those with a history of seizures. WikiVet Article: ketamine.

6

Which local anaesthetic also has anti-arrhythmogenic properties? Mepivicaine Proxymetacaine Procaine Bupivicaine Lidocaine Please select an option Incorrect. Bupivicaine does not have anti-arrhythmogenic properties. Lidocaine is an amide-linked local anaesthetic, which also has anti-arrhythmic properties. Lidocaine has class 1b antiarrhythmic actions; decreasing the rate of ventricular firing, action potential duration and absolute refractory period, and increasing relative refractory period. However do not give lidocaine preparations containing adrenaline intravenously. WikiVet Article: lidocaine. Incorrect. Proxymetacaine does not have anti-arrhythmogenic properties. Lidocaine is an amide-linked local anaesthetic, which also has anti-arrhythmic properties. Lidocaine has class 1b antiarrhythmic actions; decreasing the rate of ventricular firing, action potential duration and absolute refractory period, and increasing relative refractory period. However do not give lidocaine preparations containing adrenaline intravenously. WikiVet Article: lidocaine. Incorrect. Bupivicaine does not have anti-arrhythmogenic properties. Lidocaine is an amide-linked local anaesthetic, which also has anti-arrhythmic properties. Lidocaine has class 1b antiarrhythmic actions; decreasing the rate of ventricular firing, action potential duration and absolute refractory period, and increasing relative refractory period. However do not give lidocaine preparations containing adrenaline intravenously. WikiVet Article: lidocaine. Correct! Lidocaine is an amide-linked local anaesthetic, which also has anti-arrhythmic properties. Lidocaine has class 1b antiarrhythmic actions; decreasing the rate of ventricular firing, action potential duration and absolute refractory period, and increasing relative refractory period. However do not give lidocaine preparations containing adrenaline intravenously. WikiVet Article: lidocaine.

7

Which local anaesthetic has the longest duration of action? Bupivicaine Lidocaine Procaine Proxymetacaine Mepivicaine Please select an option Correct! Bupivicaine has a time to onset of 20-30 minutes and it has a duration of action of around 8 hours. WikiVet Article: bupivicaine. Incorrect. Lidocaine has a time to onset of action of 3-10 minutes and a duration of action of 60-90 minutes. Bupivicaine has a time to onset of 20-30 minutes and it has a duration of action of around 8 hours. WikiVet Article: bupivicaine. Incorrect. Proxymetacaine has an onset of action of 10 seconds and a duration of action of 10-20 minutes. Bupivicaine has a time to onset of 20-30 minutes and it has a duration of action of around 8 hours. WikiVet Article: bupivicaine. Incorrect. Lidocaine has a time to onset of action of 3-10 minutes and a duration of action of 60-90 minutes. Bupivicaine has a time to onset of 20-30 minutes and it has a duration of action of around 8 hours. WikiVet Article: bupivicaine.

8

Atipamazole is the reversal agent for which group of drugs? Opioids Butyrophenones Alpha-2 agonists Benzodiazepines Phenothiazines Please select an option Incorrect. Benzodiazepines can be antagonised by flumazenil and sarmazenil, not atipamazole. Atipamazole is licensed for the reversal of the sedative effects of dexmedetomidine and medetomidine, however it will also reverse other alpha-2 agonists to provide a quick recovery from anaesthesia and sedation. WikiVet Article: alpha-2 agonists. Correct! Atipamazole is licensed for the reversal of the sedative effects of dexmedetomidine and medetomidine, however it will also reverse other alpha-2 agonists to provide a quick recovery from anaesthesia and sedation. WikiVet Article: alpha-2 agonists. Incorrect. Benzodiazepines can be antagonised by flumazenil and sarmazenil, not atipamazole. Atipamazole is licensed for the reversal of the sedative effects of dexmedetomidine and medetomidine, however it will also reverse other alpha-2 agonists to provide a quick recovery from anaesthesia and sedation. WikiVet Article: alpha-2 agonists. Incorrect. Phenothiazines have no reversal agent. Atipamazole is licensed for the reversal of the sedative effects of dexmedetomidine and medetomidine, however it will also reverse other alpha-2 agonists to provide a quick recovery from anaesthesia and sedation. WikiVet Article: alpha-2 agonists.

Injectable anaesthesia & analgesia quiz/8

Which non-steroidal anti-inflammatory (NSAID) drug is banned in food producing animals because it has caused death by aplastic anaemia in man? Phenylbutazone Meloxicam Flunixin Ketoprofen Carprofen Please select an option Correct! Phenylbutazone has caused death by aplastic anaemia in man, and since safe milk and meat residue levels cannot be established, it is banned in food producing animals. Horses treated with phenylbutazone may never be slaughtered for human consumption. phenylbutazone. Incorrect Animals treated with meloxicam must not be slaughtered for human consumption during treatment but they can be slaughtered after an appropriate withdrawal period. Phenylbutazone has caused death by aplastic anaemia in man, and since safe milk and meat residue levels cannot be established, it is banned in food producing animals. Horses treated with phenylbutazone may never be slaughtered for human consumption. phenylbutazone. Incorrect Animals treated with flunixin must not be slaughtered for human consumption during treatment but they can be slaughtered after an appropriate withdrawal period. Phenylbutazone has caused death by aplastic anaemia in man, and since safe milk and meat residue levels cannot be established, it is banned in food producing animals. Horses treated with phenylbutazone may never be slaughtered for human consumption. phenylbutazone. Incorrect Animals treated with ketoprofen must not be slaughtered for human consumption during treatment but they can be slaughtered after an appropriate withdrawal period. Phenylbutazone has caused death by aplastic anaemia in man, and since safe milk and meat residue levels cannot be established, it is banned in food producing animals. Horses treated with phenylbutazone may never be slaughtered for human consumption. phenylbutazone. Incorrect Cattle treated with carprofen must not be slaughtered for human consumption during treatment but they can be slaughtered after an appropriate withdrawal period. Carprofen should not be used in horses intended for human consumption. Phenylbutazone has caused death by aplastic anaemia in man, and since safe milk and meat residue levels cannot be established, it is banned in food producing animals. Horses treated with phenylbutazone may never be slaughtered for human consumption. phenylbutazone.

Injectable anaesthesia & analgesia quiz/7

Which opioid should never be given intravenously as it will cause massive histamine release? Morphine Pethidine Buprenorphine Methadone Fentanyl Please select an option Incorrect Morphine can be given i.v. however it should be given slowly to avoid histamine release. If pethidine is given i.v. it results in histamine release which causes hypotension, tachycardia and bronchoconstriction. opioids. Correct! If pethidine is given i.v. it results in histamine release which causes hypotension, tachycardia and bronchoconstriction. opioids. Incorrect Buprenorphine can be given i.v. If pethidine is given i.v. it results in histamine release which causes hypotension, tachycardia and bronchoconstriction. opioids. Incorrect Methadone can be given i.v. without causing histamine release. If pethidine is given i.v. it results in histamine release which causes hypotension, tachycardia and bronchoconstriction. opioids. Incorrect Fentanyl can be given i.v. If pethidine is given i.v. it results in histamine release which causes hypotension, tachycardia and bronchoconstriction. opioids.

Injectable anaesthesia & analgesia quiz/6

Which opioid is a partial OP3 (μ) receptor agonist? Fentanyl Pethidine Buprenorphine Butorphanol Methadone Please select an option Incorrect Fentanyl is a full OP3 (μ) receptor agonist.Buprenorphine is a partial agonist at the OP3 receptor. This gives it a bell-shaped dose response curve, with large experimental doses actually causing opioid receptor antagonism. Buprenophine may therefore cause partial reversal of administration of full OP3 agonists such as morphine, methadone, pethidine or fentanyl. opioids. Incorrect Pethidine is a full OP3 (μ) receptor agonist. Buprenorphine is a partial agonist at the OP3 receptor. This gives it a bell-shaped dose response curve, with large experimental doses actually causing opioid receptor antagonism. Buprenophine may therefore cause partial reversal of administration of full OP3 agonists such as morphine, methadone, pethidine or fentanyl. opioids. Correct! Buprenorphine is a partial agonist at the OP3 (μ) receptor. This gives it a bell-shaped dose response curve, with large experimental doses actually causing opioid receptor antagonism. Buprenophine may therefore cause partial reversal of administration of full OP3 agonists such as morphine, methadone, pethidine or fentanyl. opioids. IncorrectButorphanol is an antagonist at the OP3 (μ) receptor and an agonist at the OP2 (κ) receptor. Buprenorphine is a partial agonist at the OP3 receptor. This gives it a bell-shaped dose response curve, with large experimental doses actually causing opioid receptor antagonism. Buprenophine may therefore cause partial reversal of administration of full OP3 agonists such as morphine, methadone, pethidine or fentanyl. opioids. Incorrect Methadone is a full OP3 (μ) receptor agonist.Buprenorphine is a partial agonist at the OP3 receptor. This gives it a bell-shaped dose response curve, with large experimental doses actually causing opioid receptor antagonism. Buprenophine may therefore cause partial reversal of administration of full OP3 agonists such as morphine, methadone, pethidine or fentanyl. opioids.

Injectable anaesthesia & analgesia quiz/5

Which opioid is an agonist-antagonist? Pethidine Fentanyl Buprenorphine Butorphanol Methadone Please select an option Incorrect Pethidine is a full OP3 (μ) receptor agonist. Butorphanol is an antagonist at the OP3 receptor and an agonist at the OP2 (κ) receptor. This means they provide poorer analgesia (due to OP3 antagonism) but it does provide good sedation. If full OP3 agonists are to be used following butorphanol use, they will not be as effective so higher doses may be needed. opioids. Incorrect Fentanyl is a full OP3 (μ) receptor agonist.Butorphanol is an antagonist at the OP3 receptor and an agonist at the OP2 (κ) receptor. This means they provide poorer analgesia (due to OP3 antagonism) but it does provide good sedation. If full OP3 agonists are to be used following butorphanol use, they will not be as effective so higher doses may be needed. opioids. Incorrect Buprenorphine is a partial OP3 (μ) receptor agonist.Butorphanol is an antagonist at the OP3 receptor and an agonist at the OP2 (κ) receptor. This means they provide poorer analgesia (due to OP3 antagonism) but it does provide good sedation. If full OP3 agonists are to be used following butorphanol use, they will not be as effective so higher doses may be needed. opioids. Correct! Butorphanol is an antagonist at the OP3 (μ) receptor and an agonist at the OP2 (κ) receptor. This means they provide poorer analgesia (due to OP3 antagonism) but it does provide good sedation. If full OP3 agonists are to be used following butorphanol use, they will not be as effective so higher doses may be needed. opioids. Incorrect Methadone is a full OP3 (μ) receptor agonist.Butorphanol is an antagonist at the OP3 receptor and an agonist at the OP2 (κ) receptor. This means they provide poorer analgesia (due to OP3 antagonism) but it does provide good sedation. If full OP3 agonists are to be used following butorphanol use, they will not be as effective so higher doses may be needed. opioids.

Injectable anaesthesia & analgesia quiz/4

Azaparone is used as a premedicant in which species? Sheep Horse Pig Goats Cattle Please select an option Incorrect Azaperone is not licensed in sheep in the UK, it is only licensed for use in pigs. It is used against aggresssion and transport stress, to aid obstetrical intervention and as a premedicant. butyrophenones. Incorrect Azaperone is not licensed in horses in the UK, it is only licensed for use in pigs. It is used against aggresssion and transport stress, to aid obstetrical intervention and as a premedicant. butyrophenones. Correct! Azaperone is a butyrophenone which is only licensed for use in pigs. It is used against aggresssion and transport stress, to aid obstetrical intervention and as a premedicant. butyrophenones. Incorrect Azaperone is not licensed in goats in the UK, it is only licensed for use in pigs. It is used against aggresssion and transport stress, to aid obstetrical intervention and as a premedicant. butyrophenones. Incorrect Azaperone is not licensed in cattle in the UK, it is only licensed for use in pigs. It is used against aggresssion and transport stress, to aid obstetrical intervention and as a premedicant. butyrophenones.

Injectable anaesthesia & analgesia quiz/3

Which premedicant is contraindicated in breeding stallions? Azaperone Xylazine Detomidine Acepromazine Diazepam Please select an option Incorrect Azaperone is not licensed for use in horses in the UK. Acepromazine is contraindicated in breeding stallions because it may cause penis protrusion and priapism. phenothiazines. Incorrect Xylazine is not contraindicated in breeding stallions. Acepromazine is contraindicated in breeding stallions because it may cause penis protrusion and priapism. phenothiazines. Incorrect Detomidine is not contraindicated in breeding stallions. Acepromazine is contraindicated in breeding stallions because it may cause penis protrusion and priapism. phenothiazines. Correct! Acepromazine is contraindicated in breeding stallions because it may cause penis protrusion and priapism. phenothiazines. Incorrect Diazepam is not contraindicated in breeding stallions. Acepromazine is contraindicated in breeding stallions because it may cause penis protrusion and priapism. phenothiazines.

Injectable anaesthesia & analgesia quiz/2

Which opioid has the longest duration of action at standard therapeutic doses? Buprenorphine Pethidine Methadone Morphine Butorphanol Please select an option Correct! Buprenorphine has an onset of action of 45 minutes and its actions last 6-8 hours. opioids. Incorrect Pethidine has a 5-10 minute onset of action and a duration of action of 30-60 minutes. Buprenorphine has an onset of action of 45 minutes and its actions last 6-8 hours. opioids. Incorrect Methadone has a 15-30 minute onset of action and a duration of action of around 4 hours. Buprenorphine has an onset of action of 45 minutes and its actions last 6-8 hours. opioids. Incorrect Morphine has a 10-15 minute onset of action and a duration of action of 2-4 hours. Buprenorphine has an onset of action of 45 minutes and its actions last 6-8 hours. opioids. Incorrect Butorphanol has a 15 minute onset of action and a duration of action of 2-4 hours. Buprenorphine has an onset of action of 45 minutes and its actions last 6-8 hours. opioids.

Injectable anaesthesia & analgesia quiz/1

Which drug, when used as a premedicant, significantly reduces the risk of death during anaesthesia in horses? Azaperone Xylazine Diazepam Acepromazine Detomidine Please select an option Incorrect Azaperone has not been shown to reduce anaesthetic risk in horses, in fact it is not licensed in horses in the UK. The risk of anaesthetic fatalities is much higher in horses than in other species, in fact 1 in 100 horses die within 7 days of anaesthesia and surgery. A study by Johnston et al. showed that there was a marked decrease in risk when acepromazine was used as a premedicant. phenothiazines. Link to relevant webpage: The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2. Incorrect Xylazine has not been shown to reduce anaesthetic risk in horses on its own. The risk of anaesthetic fatalities is much higher in horses than in other species, in fact 1 in 100 horses die within 7 days of anaesthesia and surgery. A study by Johnston et al. showed that there was a marked decrease in risk when acepromazine was used as a premedicant. phenothiazines. Link to relevant webpage: The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2. Incorrect Diazepam has not been shown to reduce anaesthetic risk in horses. The risk of anaesthetic fatalities is much higher in horses than in other species, in fact 1 in 100 horses die within 7 days of anaesthesia and surgery. A study by Johnston et al. showed that there was a marked decrease in risk when acepromazine was used as a premedicant. phenothiazines. Link to relevant webpage: The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2. Correct! The risk of anaesthetic fatalities is much higher in horses than in other species, in fact 1 in 100 horses die within 7 days of anaesthesia and surgery. A study by Johnston et al. showed that there was a marked decrease in risk when acepromazine was used as a premedicant. phenothiazines. Link to relevant webpage: The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2. Incorrect Detomidine has not been shown to reduce anaesthetic risk in horses on its own. The risk of anaesthetic fatalities is much higher in horses than in other species, in fact 1 in 100 horses die within 7 days of anaesthesia and surgery. A study by Johnston et al. showed that there was a marked decrease in risk when acepromazine was used as a premedicant. phenothiazines. Link to relevant webpage: The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2.