2⃣0⃣ ANESTÉSICOS LOCAIS EM ANIMAIS | Anestesia é o Básico #20

one of the ingredients to make this delicious of Pará cuisine is the Jambu is a plant that gives a certain numbness to the tongue. Tastes so good buddy This video lesson is not about cooking but it has a little to do with jambu Let's check it out after the vignette! Hello NAVE crew how are you in this video lesson from the anesthesia course Basics, we're going to talk a little about the pharmacology of the local anaesthetics which are the drugs used in one of the safest anaesthetics modality.

The locoregional anaesthesia. After the discover of inhalant anesthesia in 1846 the history of anesthesia had another big jump with the use of local anesthetics but actually local anesthesia originated hundreds of years ago with the Andean peoples who already felt a kind of numbness in the tongue when drinking coca tea and other pocitas but look crazy stuff good in 1855 the researchers Already managed to extract the cocaine from the coca leaves and already realized So what was it this substance that made the tongue numb thereafter several researchers were almost named as the father of local anesthesia until Freud was on this list who however This only happened in 1884 when the ophthalmologist the Austrian cal color used cocaine as a local anesthetic in glaucoma surgery thereafter the use of cocaine as a local anesthetic was widespread she was not alone used even for local anesthesia but also for beverage production non-alcoholic However, over the years, people realized that cocaine did not promote only local anesthesia but several undesirable effects mainly psychotropic and cardiovascular drugs And then their use was quickly discontinued after that came procaine and benzocaine which were very anesthetics safer than cocaine but the period of action was very short and they generated metabolite called paraaminobenzoic acid that had Allergen Characteristics An important change in local anesthesia has taken place. in 1948 with the synthesis of lidocaine the first anesthetic marketed starch derivative this is interesting because this drug did not generate opaba assume paraaminobenzoic then the possibility of promoting some effect allergen was much smaller than the others today we have an amount reasonable amount of local anesthetics in veterinary medicine we use basically lidocaine iva kahina and ropivacaine in this video In class we will address the pharmacology of local anesthetics worrying us with which it can influence the action latency period and the quality of the blockade no old man here we're just going to talk about anesthetic pharmacology local anesthetic techniques we have specific videos for this and also you can't say everything in a video class, just ok and local anesthetics are substances that block the nerve conduction of reversible form then that we have is the loss of motor sensitivity and sensory and a return after some time the local anesthetics block the sodium channels in the axons of afferent fibers with this the stimulus is blocked in that case the influx of sodium that after sure.

will promote the Cell depolarization an important piece of information is that local anesthetics are weak bases so we have the molecular form that is neutral and penetrates easily the phospholipid membrane and the protonated form that has difficulty in penetrate the membrane so what we have is that the neutral form passes the layer phospholipid and reaches the inner portion of the cell, but this relationship between the neutral and pronated form also tends to remain inside the cell and this is very important and who has the characteristic of blocking the ion channel is the protonated form preventing cell repolarization to Blocking Speed ​​is Fully Dependent on Front Fiber Anatomy so basically we have four types of fiber in the case the C EA Delta fibers are responsible for the propagation of the painful stimulus, as the alpha and A fibers the Beta are responsible for the armadillo depression stimuli and the exception that blockage happens as follows first we have fiber blockage thinner and myelinated and finally thicker and myelinated fibers then blockage Follows a logical sequence first we have the pain stone of armadillo of the pressure and after the exception itself, the return of the block follows the opposite way and the latency, effectiveness of the block and duration of this block It depends on several factors here we will see the main ones Ok the volume administered is fundamental for us to have a quick and effective effect, this is related to the diffusion of the anesthetic in that area being blocked not my old man Of course there is not a maximum dose of each anesthetic for each species so that we don't have toxicity, we'll see this later on ok the clear solubility is also an important factor that local anesthetics are highly fat soluble so when we administer the local anesthetic in a highly lipidic region this anesthetic tends to get stuck in that space making systemic absorption difficult, thus anesthesia tends to last longer time to the other side, this very liposolubility can hinder the diffusion of the anesthetic in that region the concentration also plays a role important in effectiveness o ok the higher the concentration the lower the latency period and longer action period but we can't do it either very high concentrations because we can be local toxicity the advantage that the anesthetics available today basically lack a concentration. high to the point of promoting local toxicity, use of vasoconstrictors is also good. important because it will reduce local irrigation, delaying absorption systemic with this we will increase the action period but never use local anesthetic ends like ear tip Black tail serenity of limbs and wound edges this can promote tissue necrosis And as we've talked about before, basically in veterinary medicine we we use lidocaine bupivacaine and clothes and go kahina let's talk a a little of them ok Despite being almost 100 years old, lidocaine is still a local anesthetic most used in veterinary medicine mainly due to its versatility it can be used simple or complex peripheral blocks or locoregional blocks to lidocaine one percent allows an anesthetic block for about an hour and that time can be increased if the concentration is two percent or if we we add the vasoconstrictor but lidocaine is also used with other purposes the first of them is the antiarrhythmic effect lidocaine a potent Class 1b antiarrhythmic it promotes delay in myocardial nerve conduction basically in purkinje fibers.