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==Pre-anaesthetic evaluation and preparation==

==Pre-anaesthetic evaluation and preparation==

==Sedation for standing procedures==

==Sedation for standing procedures==

Many minor surgical procedures may be accomplished with a combination of sedation/analgesia and a local anaesthetic. A variety of drugs at differing dosages have been used to accomplish this (Matthews et al, 1997). Generally the best combination for sedation and analgesia seems to be an [[Donkey - Sedatives and Opioids#α2 agonists|'''alpha-two agonist''']] (such as''' xylazine, detomidine''' or '''romifidine''') with an [[Donkey - Sedatives and Opioids#Opioids|'''opioid''']]. '''Butorphanol''' (El-Maghraby and Atta, 1997) and '''buprenorphine'''

Many minor surgical procedures may be accomplished with a combination of sedation/analgesia and a local anaesthetic. A variety of drugs at differing dosages have been used to accomplish this (Matthews et al, 1997). Generally the best combination for sedation and analgesia seems to be an [[Sedatives - Donkey#α2 agonists|'''alpha-two agonist''']] (such as''' xylazine, detomidine''' or '''romifidine''') with an [[Opioids - Donkey#Opioids|'''opioid''']]. '''Butorphanol''' (El-Maghraby and Atta, 1997) and '''buprenorphine'''

are the most commonly used, but other opioids can be used depending on availability.  

are the most commonly used, but other opioids can be used depending on availability.  

All of the above mentioned drugs can also be administered i.m. if the animal is fractious, and generally it is necessary to give twice the dose to achieve the desired effect. Another option is to administer i.m. xylazine or detomidine, wait 20 to 30 minutes for sedation to occur, then add additional drugs i.v. as indicated by the patient.

All of the above mentioned drugs can also be administered i.m. if the animal is fractious, and generally it is necessary to give twice the dose to achieve the desired effect. Another option is to administer i.m. xylazine or detomidine, wait 20 to 30 minutes for sedation to occur, then add additional drugs i.v. as indicated by the patient.

In addition to the analgesic effects of the above-mentioned drugs, use of a [[Donkey - Anaesthetics#Local anaesthetic agents|'''local anaesthetic''']] ( '''lidocaine''', or the longer-acting '''bupivicaine''') is always recommended. This may be <u>locally infiltrated, or a line-block or anatomic nerve block</u> may also be used.  

In addition to the analgesic effects of the above-mentioned drugs, use of a [[Anaesthetics - Donkey#Local anaesthetic agents|'''local anaesthetic''']] ( '''lidocaine''', or the longer-acting '''bupivicaine''') is always recommended. This may be <u>locally infiltrated, or a line-block or anatomic nerve block</u> may also be used.  

[[Donkey - Sedatives and Opioids#Acepromazine|'''Acepromazine''']] may be used for tranquillization, but one must remember that it has no analgesic effects, so appropriate analgesia must be provided with other drugs.

[[Sedatives - Donkey#Acepromazine|'''Acepromazine''']] may be used for tranquillization, but one must remember that it has no analgesic effects, so appropriate analgesia must be provided with other drugs.

==Injectable (field) anaesthesia==

==Injectable (field) anaesthesia==

Many drug combinations and techniques have been successfully used for injectable anaesthesia in donkeys. General guidelines which may be helpful are:

Many drug combinations and techniques have been successfully used for injectable anaesthesia in donkeys. General guidelines which may be helpful are:

* different sizes of donkeys appear to metabolize drugs at differing rates. <u>Miniature donkeys seem to require more drug/kg body weight than larger donkeys</u> (Matthews et al, 2001; Matthews et al, 2002)

* different sizes of donkeys appear to metabolize drugs at differing rates. <u>Miniature donkeys seem to require more drug/kg body weight than larger donkeys</u> (Matthews ''et al'', 2001; Matthews ''et al'', 2002)

* donkeys metabolize [[Donkey - Anaesthetics#Ketamine and tiletamine|'''ketamine''']] faster than horses, but are more sensitive to [[Donkey - Anaesthetics#Guaifenesin|'''guaifenesin''']]. Doses of these drugs must be adjusted appropriately (Matthews et al, 1997).

* donkeys metabolize [[Anaesthetics - Donkey#Ketamine and tiletamine|'''ketamine''']] faster than horses, but are more sensitive to [[Anaesthetics - Donkey#Guaifenesin|'''guaifenesin''']]. Doses of these drugs must be adjusted appropriately (Matthews ''et al,'' 1997).

Since donkeys are more stoical than horses, the anaesthetist must be vigilant about monitoring the depth of anaesthesia to make sure that they are maintained at a suitable plane. Routine use of [[Donkey - Anaesthetics#Local anaesthetic agents|'''local anaesthetics''']] in conjunction with injectable anaesthesia is encouraged, since it facilitates intra-operative analgesia as well as post-operative analgesia.

Since donkeys are more stoical than horses, the anaesthetist must be vigilant about monitoring the depth of anaesthesia to make sure that they are maintained at a suitable plane. Routine use of [[Anaesthetics - Donkey#Local anaesthetic agents|'''local anaesthetics''']] in conjunction with injectable anaesthesia is encouraged, since it facilitates intra-operative analgesia as well as post-operative analgesia.

'''For short procedures''', pre-medication with [[Donkey - Sedatives and Opioids#α2 agonists|'''xylazine or detomidine''']] followed in 3 to 5 minutes by induction with '''ketamine''' is generally effective. Addition of '''butorphanol to the xylazine''' will increase the degree of sedation achieved. In some instances the donkey will lie down with these premeds and anaesthesia can be induced with the ketamine with the donkey already sternally recumbent.  

'''For short procedures''', pre-medication with [[Sedatives - Donkey#α2 agonists|'''xylazine or detomidine''']] followed in 3 to 5 minutes by induction with '''ketamine''' is generally effective. Addition of '''butorphanol to the xylazine''' will increase the degree of sedation achieved. In some instances the donkey will lie down with these premeds and anaesthesia can be induced with the ketamine with the donkey already sternally recumbent.  

[[Donkey - Sedatives and Opioids#Diazepam|'''Diazepam''']] (can be mixed with the ketamine) can also be used to ‘smooth’ the effects of the ketamine . Since diazepam produces muscle relaxation but little cardiovascular depression, it is a useful addition for sick or debilitated animals, where it is important to minimize the dose of xylazine or detomidine used. These combinations should provide approximately 15 to 30 minutes of anaesthesia in standard and Mammoth donkeys.

[[Sedatives - Donkey#Diazepam|'''Diazepam''']] (can be mixed with the ketamine) can also be used to ‘smooth’ the effects of the ketamine . Since diazepam produces muscle relaxation but little cardiovascular depression, it is a useful addition for sick or debilitated animals, where it is important to minimize the dose of xylazine or detomidine used. These combinations should provide approximately 15 to 30 minutes of anaesthesia in standard and Mammoth donkeys.

<u>Miniature donkeys appear to be much more ‘resistant’ to xylazine and ketamine anaesthesia</u> (Matthews et al, 2002).  

<u>Miniature donkeys appear to be much more ‘resistant’ to xylazine and ketamine anaesthesia</u> (Matthews et al, 2002).  

Acceptable injectable anaesthesia can be accomplished if xylazine and butorphanol are used to pre-med, with diazepam and ketamine used for induction and a local block is added. Alternatively, good anaesthesia is provided by pre-medicating with xylazine (or detomidine) and butorphanol, then the combination of tiletamine-zolazepam.

Acceptable injectable anaesthesia can be accomplished if xylazine and butorphanol are used to pre-med, with diazepam and ketamine used for induction and a local block is added. Alternatively, good anaesthesia is provided by pre-medicating with xylazine (or detomidine) and butorphanol, then the combination of tiletamine-zolazepam.

For '''longer periods of anaesthesia''' (40 minutes to 2 hours), we have found that the combination of '''guaifenesin-xylazine-ketamine'''  works well (Taylor et al, 2002). Following premedication with xylazine, anaesthesia is induced by rapid administration of the combination. Once the donkey becomes recumbent the infusion rate is slowed. This rate should be adjusted as is appropriate for the individual based on [[Donkey - Anaesthesia and Sedation#Monitoring the depth of anaesthesia|monitoring]].

For '''longer periods of anaesthesia''' (40 minutes to 2 hours), we have found that the combination of '''guaifenesin-xylazine-ketamine'''  works well (Taylor et al, 2002). Following premedication with xylazine, anaesthesia is induced by rapid administration of the combination. Once the donkey becomes recumbent the infusion rate is slowed. This rate should be adjusted as is appropriate for the individual based on [[Anaesthesia and Sedation - Donkey#Monitoring the depth of anaesthesia|monitoring]].

[[Donkey - Anaesthetics#Thiopentone (thiopental)|'''Thiopental''']] has been used for induction and maintenance of anaesthesia in donkeys. It is usually used following sedation and can be combined with guaifenesin for administration as a slow drip. Lower doses of thiopental can be used as an adjunct to xylazine/ketamine anaesthesia, to increase muscle relaxation and the length of anaesthesia (Crane, 1997). Recoveries are likely to be longer when thiopental is used, especially if multiple doses are given. Use of an intravenous catheter is strongly advised, since perivascular administration of thiopental causes tissue sloughing.

[[Anaesthetics - Donkey#Thiopentone (thiopental)|'''Thiopental''']] has been used for induction and maintenance of anaesthesia in donkeys. It is usually used following sedation and can be combined with guaifenesin for administration as a slow drip. Lower doses of thiopental can be used as an adjunct to xylazine/ketamine anaesthesia, to increase muscle relaxation and the length of anaesthesia (Crane, 1997). Recoveries are likely to be longer when thiopental is used, especially if multiple doses are given. Use of an intravenous catheter is strongly advised, since perivascular administration of thiopental causes tissue sloughing.

==Inhalant anaesthesia and monitoring==

==Inhalant anaesthesia and monitoring==

Maintenance of anaesthesia with '''halothane, isoflurane''' or '''sevoflurane''' in donkeys is similar to maintenance of horses with these agents. '''Minimal alveolar concentrations (MAC-value)''' of halothane and isoflurane in donkeys are similar to values reported in ponies (Matthews et al, 1997). Although the MAC-value for sevoflurane in donkeys has not been measured, our clinical

Maintenance of anaesthesia with '''halothane, isoflurane''' or '''sevoflurane''' in donkeys is similar to maintenance of horses with these agents. '''Minimal alveolar concentrations (MAC-value)''' of halothane and isoflurane in donkeys are similar to values reported in ponies (Matthews et al, 1997). Although the MAC-value for sevoflurane in donkeys has not been measured, our clinical

experience with this agent in donkeys indicates that vaporizer settings are very similar to those used in horses. Intermittent small boluses of an [[Donkey - Sedatives and Opioids#Opioids|opioid]] (''e.g.'' butorphanol) may be used to provide additional

experience with this agent in donkeys indicates that vaporizer settings are very similar to those used in horses. Intermittent small boluses of an [[Opioids - Donkey#Opioids|opioid]] (''e.g.'' butorphanol) may be used to provide additional

analgesia, and for some surgical procedures, the use of a [[Donkey - Anaesthetics#Local anaesthetic agents|long-acting local anaesthetic]] (''e.g.'' bupivicaine; not to exceed 2 mg/kg) will provide intra- and post-operative analgesia (''i.e.'' distal limb procedures where the peripheral nerves can be blocked). Since less inhalant is required when additional analgesics are used, cardiovascular stability is improved. MAC-values for all inhalants are generally reduced in older or debilitated animals so vaporizer settings must be adjusted, based on monitoring.

analgesia, and for some surgical procedures, the use of a [[Anaesthetics - Donkey#Local anaesthetic agents|long-acting local anaesthetic]] (''e.g.'' bupivicaine; not to exceed 2 mg/kg) will provide intra- and post-operative analgesia (''i.e.'' distal limb procedures where the peripheral nerves can be blocked). Since less inhalant is required when additional analgesics are used, cardiovascular stability is improved. MAC-values for all inhalants are generally reduced in older or debilitated animals so vaporizer settings must be adjusted, based on monitoring.

'''Intra-operative fluid administration''' is important when the inhalants are used, since they produce a dose-dependent vasodilation. A balanced electrolyte solution given at a rate of 10 ml/kg/hr (or greater if pre-operative dehydration has not been corrected) will help maintain blood pressure. Aggressive fluid therapy (up to 40 mls/kg/hr) or use of hypertonic saline (4

'''Intra-operative fluid administration''' is important when the inhalants are used, since they produce a dose-dependent vasodilation. A balanced electrolyte solution given at a rate of 10 ml/kg/hr (or greater if pre-operative dehydration has not been corrected) will help maintain blood pressure. Aggressive fluid therapy (up to 40 mls/kg/hr) or use of hypertonic saline (4

* decreasing the anaesthetic plane

* decreasing the anaesthetic plane

* giving intravenous fluids

* giving intravenous fluids

* using an inotrope such as [[Dobutamine|'''dobutamine''']]

* using an inotrope such as [[Interventional_Agents#Dobutamine|'''dobutamine''']]

==Complications of anaesthesia==

==Complications of anaesthesia==

Recovery from anaesthesia is '''usually calm and smooth in donkeys''', although it is wise to insufflate oxygen nasally when possible, provide good padding for recovery and a quiet environment when possible. Causes of rough recovery are pain and difficulty in breathing.

Recovery from anaesthesia is '''usually calm and smooth in donkeys''', although it is wise to insufflate oxygen nasally when possible, provide good padding for recovery and a quiet environment when possible. Causes of rough recovery are pain and difficulty in breathing.

Analgesia may be provided in a number of ways including [[Donkey - Anaesthetics#Local anaesthetic agents|local aesthetics]], [[Donkey - Sedatives and Opioids#Opioids|opioids]], which can be given i.v., i.m. or administered epidurally (Naeni et al, 1999), and [[Donkey - NSAIDs|non-steroidal anti-inflammatories]] ([[NSAIDs]]).

Analgesia may be provided in a number of ways including [[Anaesthetics - Donkey#Local anaesthetic agents|local aesthetics]], [[Opioids - Donkey|opioids]], which can be given i.v., i.m. or administered epidurally (Naeni et al, 1999), and [[NSAIDs - Donkey|non-steroidal anti-inflammatories]] ([[NSAIDs]]).

[[Donkey - Sedatives and Opioids#α2 agonists|Xylazine and detomidine]] are also good analgesics and can be administered

[[Sedatives - Donkey#α2 agonists|Xylazine and detomidine]] are also good analgesics and can be administered

i.v., i.m. or used epidurally.

i.v., i.m. or used epidurally.

[[Donkey - NSAIDs|'''Phenylbutazone''' and '''flunixin meglumine''']] are more rapidly metabolized in donkeys than in horses; doses should be larger or given more frequently than for a horse. [[Donkey - NSAIDs|'''Carprofen''']] lasts longer in donkeys than in horses, so administration once a day should be sufficient (Matthews et al, 2003).

[[NSAIDs - Donkey|'''Phenylbutazone''' and '''flunixin meglumine''']] are more rapidly metabolized in donkeys than in horses; doses should be larger or given more frequently than for a horse. [[NSAIDs - Donkey|'''Carprofen''']] lasts longer in donkeys than in horses, so administration once a day should be sufficient (Matthews et al, 2003).

'''Oedema of the nasal passage''' may occur during recumbency and cause difficult breathing following extubation. Intranasal '''neosynephrine spray''' usually quickly treats this problem. '''Laryngeal obstruction''' due to soft palate displacement can also cause difficulty breathing and have serious consequences (''e.g.'' pulmonary oedema) or require an emergency tracheotomy. It can usually be relieved by passing a small tube into the nasopharynx or nasotracheally, or by leaving the endotracheal tube in place until the donkey stands up.

'''Oedema of the nasal passage''' may occur during recumbency and cause difficult breathing following extubation. Intranasal '''neosynephrine spray''' usually quickly treats this problem. '''Laryngeal obstruction''' due to soft palate displacement can also cause difficulty breathing and have serious consequences (''e.g.'' pulmonary oedema) or require an emergency tracheotomy. It can usually be relieved by passing a small tube into the nasopharynx or nasotracheally, or by leaving the endotracheal tube in place until the donkey stands up.

Post-operative complications can include [[Hyperlipaemia - Donkey|hyperlipaemia]], [[Colic - Donkey|colic]] and [[Laminitis - Donkey|laminitis]].

Post-operative complications can include [[Hyperlipaemia - Donkey|hyperlipaemia]], [[Colic - Donkey|colic]] and [[Laminitis - Donkey|laminitis]].

==References==

==References==

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|sublink1 =Nursing Care - Donkey

|subtext1 =Nursing Care - Donkey

|subtext1 =Nursing Care - Donkey

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