Aula 13 - MPA - princípios da MPA e fenotiazinas (Curso básico de anestesiologia veterinária)

Summary

This veterinary lecture focuses on the importance of pre-anesthetic medications, specifically phenothiazines like acepromazine, in ensuring safe sedation and analgesia during procedures. It highlights the need for personalized treatment plans based on animal species, condition, and the procedure's invasiveness. The session covers drug mechanisms, their potential effects on the cardiovascular system, and the ethical responsibility to minimize animal suffering. Emphasizing the careful selection of dosage and environmental management, it provides essential guidelines for veterinary professionals to optimize patient care before anesthesia.

Takeaways

• 😀 Pre-anesthetic medication serves various purposes, such as reducing stress during patient handling, minimizing the use of general anesthetics, and promoting smoother recovery.
• 😀 Analgesia is crucial in pre-anesthesia to prevent pain before surgery, with an emphasis on preemptive analgesia to manage pain before it even starts.
• 😀 Protocols for pre-anesthetic medication should be tailored to individual patients and procedures, as there is no one-size-fits-all approach.
• 😀 The role of pre-anesthetic medication also includes stabilizing patients with underlying health issues or conditions that may complicate surgery.
• 😀 Medications like phenothiazines (e.g., acepromazine) can be used for sedation and tranquilization, depending on the required effect and dosage.
• 😀 The patient's breed, temperament, and medical conditions should influence the choice of pre-anesthetic medications and protocols.
• 😀 Environmental factors, such as reducing noise and light, play a significant role in managing stress and ensuring a more effective pre-anesthetic process.
• 😀 The myth that acepromazine cannot be used in animals with epilepsy has been debunked. It can be used to sedate animals with epilepsy, though not to control seizures.
• 😀 It is essential to adjust the pre-anesthetic medication protocol according to the patient’s condition, breed, and the specifics of the surgical procedure.
• 😀 The use of pre-anesthetic medication should always prioritize the well-being of the animal, minimizing pain, stress, and potential complications during and after surgery.

Q & A

What is the primary function of pre-anesthetic medication in veterinary practice?

Pre-anesthetic medication primarily aims to reduce stress during animal handling, enhance sedation, provide analgesia, and ease the recovery process post-surgery. It also helps in stabilizing the patient before the procedure, contributing to better overall management and minimizing the need for general anesthesia.

What are the key pharmacological classes discussed in pre-anesthetic medication?

The main pharmacological classes discussed include phenothiazines, alpha-2 adrenergic agonists, opioids, and other drugs that may be used in pre-anesthetic medication protocols.

How does the choice of pre-anesthetic medication vary based on the patient?

The choice of pre-anesthetic medication depends on factors such as the species of the animal, breed, temperament, and any underlying health conditions. Additionally, the specific nature of the procedure, its duration, and the animal's response to previous medications are all considered in determining the best approach.

What role does preemptive analgesia play in pre-anesthetic medication?

Preemptive analgesia involves administering pain relief before the stimulus of pain occurs. It helps in preventing pain from becoming more severe during and after the procedure. This approach often leads to better pain management and recovery for the animal.

What is the myth about using acepromazine in cardiopathic animals, and what is the reality?

A common myth is that acepromazine should not be used in cardiopathic animals, but this is not true for all cases. While acepromazine may cause vasodilation, it can actually help manage hypertension in certain cardiopathic animals by reducing systemic vascular resistance. However, care must be taken in specific cases where bradycardia or respiratory issues may arise, especially in brachycephalic breeds.

What environmental considerations should be taken into account when administering pre-anesthetic medication?

It is important to manage the environment by reducing noise, dimming lights, and minimizing disturbances in the clinical or hospital setting. This helps in calming the animal before medication is administered, reducing stress and improving the efficacy of the pre-anesthetic medication.

How do sedatives like phenothiazines affect an animal's response to environmental stimuli?

Phenothiazines, like acepromazine, primarily have a tranquilizing effect. At lower doses, they make animals more cooperative and less reactive to environmental stimuli, while higher doses can induce a sedative effect, lowering consciousness and making the animal less aware of its surroundings.

What are the key side effects of phenothiazines like acepromazine?

Phenothiazines can cause side effects such as vasodilation, hypotension, bradycardia, splenomegaly, and reduced blood volume. Additionally, they can induce respiratory depression, although their effect on respiratory rate is generally not significant. They may also cause alterations in libido and even galactorrhea in some cases.

What should be kept in mind when using acepromazine intravenously?

When using acepromazine intravenously, it is important to administer it slowly with low doses to avoid a rapid drop in blood pressure. Care must be taken when combining acepromazine with other vasodilators, as it can exacerbate hypotension. Continuous monitoring is essential during its use.

Why is it essential to tailor pre-anesthetic protocols to individual patients rather than using a one-size-fits-all approach?

Pre-anesthetic protocols should be customized to each patient to account for differences in species, breed, health conditions, and the specifics of the procedure. Using a universal protocol is problematic because it may not adequately address the unique needs of each animal, leading to inadequate sedation, analgesia, or increased risks during the procedure.