Veterinary Anesthesia and Seizure Management

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Questions and Answers

Which two drugs are contraindicated in animals with a history of seizures?

Xylazine, ketamine (correct)

Ketamine, diazepam

Xylazine, thiopental

Morphine, phenobarbital

Which anesthetic breathing system allows for the greatest environmental freshness of gas during maintenance?

Nonrebreathing (correct)

Semi-closed system

Partial rebreathing

Closed system

Which drug should not be used in cases with high intracranial pressure?

Acepromazine

Diazepam

Xylazine

Morphine (correct)

What effect did acepromazine previously have on seizure activity that has been proven incorrect?

It decreased seizure thresholds Signup and view all the answers

What is the typical cause of prolonged recoveries following anesthesia with thiopental in Greyhounds?

Liver enzyme deficiency Signup and view all the answers

Which of the following inhalation anesthetic systems has the least efficient use of fresh gas flow?

Closed system Signup and view all the answers

What is a common misconception regarding phenobarbital in the context of seizures?

It is used to treat seizures Signup and view all the answers

Which of the following anesthetics is contraindicated for animals with a history of asthma?

Thiopental Signup and view all the answers

Which regional nerve block prevents blinking in horses to facilitate complete ophthalmic examination?

Auriculopalpebral Signup and view all the answers

How can laryngospasms in cats be effectively prevented during anesthetic induction?

Pretreat with topical lidocaine Signup and view all the answers

Which inhalant anesthetic has the lowest minimum alveolar concentration (MAC)?

Halothane Signup and view all the answers

What is the purpose of the auriculopalpebral nerve during ocular examinations in horses?

Prevents blink reflex during examinations Signup and view all the answers

What is the minimum alveolar concentration (MAC) used to measure?

Anesthetic potency in preventing physical responses Signup and view all the answers

What is the role of topically applied lidocaine prior to intubation in cats?

It prevents laryngospasm Signup and view all the answers

Which inhalant anesthetic is noted for having the highest minimum alveolar concentration (MAC)?

Desflurane Signup and view all the answers

Which of the following is considered a challenge associated with feline anesthesia?

Laryngospasm during intubation Signup and view all the answers

What is the primary reason that commercial topical preparations of benzocaine should be avoided?

They can cause methemoglobinemia. Signup and view all the answers

Which statement best defines neuropathic pain?

A painful response caused by damage to neural tissue. Signup and view all the answers

What are two common phenomena associated with neuropathic pain?

Hyperalgesia and allodynia. Signup and view all the answers

Which medication is commonly used to treat neuropathic pain in veterinary patients?

Gabapentin. Signup and view all the answers

What is a typical description of neuropathic pain experienced by patients?

Shooting or stabbing with a burning sensation. Signup and view all the answers

In treating a dog with a lick granuloma using gabapentin, which side effect is most frequently reported by clients?

Sedation or drowsiness. Signup and view all the answers

What condition can be exacerbated by the use of benzocaine preparations in animals?

Methemoglobinemia. Signup and view all the answers

Which factor does NOT typically contribute to the development of neuropathic pain?

Exposure to environmental allergens. Signup and view all the answers

What is the fresh gas flow rate for a closed anesthetic rebreathing system?

5-10 ml/kg/min Signup and view all the answers

Which flow rate characterizes the semi-closed anesthetic systems?

10-30 ml/kg/min Signup and view all the answers

Which condition contraindicates the use of ketamine in dogs?

Increased intraocular pressure Signup and view all the answers

What is the primary concern if an endotracheal tube is placed too long?

Only one lung is ventilated Signup and view all the answers

What is a potential adverse effect of ketamine use in dogs?

Hypersensitivity reactions Signup and view all the answers

For which of the following conditions is ketamine NOT recommended?

Head trauma Signup and view all the answers

What can result from increased length of an endotracheal tube?

Increased mechanical dead space Signup and view all the answers

What is the primary effect of delivering high fresh gas flow rates in anesthetic systems?

Enhanced metabolic support Signup and view all the answers

What is the most commonly seen side effect of gabapentin?

Sleepiness Signup and view all the answers

Which substance found in human gabapentin elixir should not be used in veterinary patients due to its harmful effects?

Xylitol Signup and view all the answers

How does hyperalgesia differ from hypoalgesia?

Hyperalgesia involves increased pain response, while hypoalgesia involves decreased pain response. Signup and view all the answers

What mediators are involved in the inflammatory response amplifying pain during hyperalgesia?

Histamine, serotonin, bradykinin, and cytokines Signup and view all the answers

What is allodynia?

Pain response triggered by stimuli that are not normally painful Signup and view all the answers

What role do nociceptors play in the phenomenon of hyperalgesia?

They transform in response to inflammation and exhibit hypersensitivity. Signup and view all the answers

Which of the following is an incorrect statement about pain?

Pain responses can only occur at high pain stimulus levels. Signup and view all the answers

Which condition is characterized by an exaggerated response to normally painful stimuli?

Hyperalgesia Signup and view all the answers

Study Notes

Contraindicated Drugs in Cases of Seizures

Ketamine and xylazine are contraindicated in animals with a history of seizures.
Acepromazine was previously thought to decrease seizure thresholds, but this is now known to be incorrect.
Thiopental is contraindicated in animals with a history of asthma because it can cause apnea and in Greyhounds because they have prolonged recoveries with this drug.
Thiopental is currently unavailable in the U.S. and Canada.
Morphine should not be used in cases of high intracranial pressure.
Diazepam and phenobarbital are used to treat seizures.

Anesthetic Breathing System Flow Rates

Nonrebreathing systems have no remixing of inhaled and exhaled gasses.
Nonrebreathing systems operate at high fresh gas flows of 100-300 ml/kg/min.
Closed rebreathing systems only deliver enough fresh gas to meet an animal's metabolic needs.
Closed rebreathing system flow rates are approximately 5-10 ml/kg/min, depending on animal size.
Semi-closed and partial rebreathing systems are the same and run at intermediate flow rates of approximately 10 ml/kg/min (large animals) and 30 ml/kg/min (small animals).

Ketamine Contraindictions

Ketamine can cause seizures in some dogs and should not be used in dogs with epilepsy.
Ketamine is contraindicated in dogs with increased intraocular pressure (like glaucoma).
Ketamine can cause respiratory depression.
Other contraindications for ketamine use include prior hypersensitivity reactions, animals to be used for human consumption, ketamine used alone for general anesthesia, and increased CSF pressure or head trauma.
When using ketamine in cats, protect their eyes with ophthalmic ointment because they remain open.

Endotracheal Tube Placement

If an endotracheal tube is inserted too far into the airway, it can direct ventilation to only one lung, cutting the gas administration in half and making it difficult to keep the patient sedated.
An endotracheal tube that is too long can increase mechanical dead space.

Auriculopalpebral Nerve Block

The auriculopalpebral nerve, located along the dorsal zygomatic arch, provides motor innervation to the upper orbicularis oculi muscle.
Anesthesia of this nerve prevents the horse from blinking and allows for a complete ophthalmic examination.
The frontal nerve provides sensory innervation to the upper eyelid.

Preventing Laryngospasms in Cats

Laryngospasms can be prevented by applying lidocaine gel or spray to the larynx before attempting intubation.
Topical lidocaine requires 15-20 seconds to take effect.
Laryngeal spasm can occur in cats, small ruminants, and swine.

Minimum Alveolar Concentration (MAC)

MAC is the minimum concentration of inhalant anesthetic in the alveolar gas necessary to prevent a physical response to surgical stimulation in 50% of animals.
MAC is a measure of anesthetic potency.
Desflurane has the highest MAC.

Neuropathic Pain

Neuropathic pain (NP) is a painful response caused by damage to neural tissue.
NP can result from direct injury to nerve tissue or indirectly from the inflammatory and neurochemical response to injury of non-neural tissue.
Symptoms of NP include burning, shooting, or stabbing pain.
NP is often associated with chronic pain, but is now believed to also develop as an acute pain.
Many medications are used to treat NP, including gabapentin.

Gabapentin Side Effects

Sleepiness is the most common side effect of gabapentin, generally at higher doses.

Hyperalgesia

Hyperalgesia is an increased response to a stimulus that normally produces pain.
Damaged areas develop an exaggerated response or hypersensitivity to painful stimuli.
Inflammatory mediators, like bradykinins, cytokines, serotonin, and histamine from activated inflammatory cells, amplify the inflammatory response and resulting pain.
Allodynia is the triggering of a painful response by stimuli that are not normally painful.
Hypoalgesia is a decreased response to normally painful stimuli.

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Description

This quiz covers important guidelines regarding contraindicated drugs in cases of seizures and the effective use of anesthetic breathing systems. Test your knowledge on veterinary pharmacology and anesthesia principles essential for safe clinical practices. It's a must for veterinary professionals and students aspiring to understand essential anesthetic protocols.