- Good evening. May I take your order? - Good evening.
A #1, please. Do you know what's in common between a McDonald's hamburger and our patient? I'll tell you right after the intro, bring it on!
"PATIENT ASSESSMENT" What's up NAVE crew! Today in this video of 'Anesthesia Unravelled', we will talk a little about patient assessment. However, before we start, I need to answer what's the connection between a Big Mac and our patient.
To answer this, I need to tell you I can't even remember how many times I've been asked: 'Professor, give me the protocol to operate a pyometra. ' My little dear, listen closely: you will not operate a pyometra, because pyometra is a disease. I want to know about our patient.
What animal are you going to operate on? Is it a bitch? Is it a cat?
Is it a rabbit? I don't know, is it an ET? Who even operates an ET?
A doctor or a vet? Anyway, the connection between a McDonald's hamburger and our patient is that, regardless of where in the world you order a burger at McDonald's, you will get the exact same thing inside that box. Or at least, you should.
Our patient, on the other hand, is unique. It isn't from an assembly line, it doesn't matter that we will de doing the same surgical procedure. It's very possible that, on the next animal, the anesthesia will turn out completely different and, for that reason, we need to understand our patient in order to provide the best possible anesthesia.
For this, we will be following five steps: Step #1: 'Patient's history' Well, we need to know our patient's species. That's because some drugs have a completely different effect depending on the species. For instance, the alpha-2 adrenergic agonists in ruminants, to which they are extremely sensitive.
The breed of the patient. Just imagine we anesthetize an English bulldog. In itself, it's already a slightly more complex anesthesia.
Brachycephalic, elongated soft palate, square and rigid rib cage, in other words, the anesthesia in an English bulldog tends to be quite different from, for example, one in a setter. The age of the patient. We need to know, naturally, that pediatric and geriatric patients have difficulty metabolizing some drugs.
Therefore, some of them must be avoided. The sex of the patient. Usually, an anesthetic procedure in males and females is the same, but if we consider a female in heat, she'll tend to bleed more in a laparotomy.
This is also important for the anesthesia. The weight of the patient. The weight is important, especially in order to calculate drug dosage, but we also have to know if that animal is obese or not.
Step #2: Anamnesis Anamnesis is extremely important, because we will be able to gather a good deal of information about our patient, and who will pass this on to us is the owner. A good piece of advice, as soon as you enter the room, introduce yourself to the person and explain what you are doing there, this will establish a link between you both, and he'll be more receptive to giving you, the necessary information. Something important in anamnesis is to have a logical sequence to the questions, because you are going to build you reasoning based on them.
I gonna give you a sequence that I believe makes more sense, based on experience, but this isn't strict, each one will have their own. Usually, I start with the central nervous system, then I go to the cardiovascular, then pulmonary, digestive and biotransformation system. Regarding the central nervous system, it's interesting to ask if the animal has any neurological disorder or has had any fainting or seizure episode, because it can define whether a drug is used or not.
Well, the key question which is going to connect the central nervous system to the cardiovascular system is 'fainting', because the animal that faints doesn't always have a neurological disorder, it can have a cardiovascular disease such as congestive heart failure. Regarding this system, we need to ask if the animal exercises, if it walks without effort or gets tired, if it gets breathless or if it coughs. Coughing is the connection to the pulmonary system.
Dr cough is frequently related to heart failure, productive cough, on the other hand, is related to the pulmonary system. Next, we examine the digestive system. We ask a few questions according to the species, obviously, as large animals have some peculiarities, but one key question, especially for small animals, is whether the animal has frequent vomiting.
Vomiting may be related to a gastric problem, to a bad diet, but it can also be related to kidney or liver problems. Then, we follow to the biotransformation system. Here, we'll be asking questions of interest, focusing on the kidneys and liver, such as frequency, color and odor of the feces, and what is the frequency and color of the urine, for example.
Finally, we ask if animal has been fasted, which seems like a ridiculous question, right? But it’s not. The owner has been instructed to fast his animal but, believe me, they love giving them food because they think the animal is hungry.
So, it's normal they'll offer a piece of bread, a piece of sausage, or something of the sort. If we press a little bit, the guy will say 'Doctor, I only gave it a piece of bread', 'Doctor, I only gave it a piece of cheese bread'. Regarding the fasting, we usually follow information from books.
For cats and dogs, a food fasting of 8 to 12 hours is sufficient, while water fasting is no longer deemed necessary. On fasting for horses, we generally recommend 12 hours, but this has been a somewhat questioned, especially during the last international meetings. It has been noticed that, as the horse has difficulty in regurgitating, the fasting doesn't make much difference to the anesthesia.
Obviously, provided this animal hasn't been given feed, but a roughage. This even helps, as the animal gets less agitated, less nervous, even for the preoperative handling. For ruminants, we recommend cutting off half of the solids 48 hours prior, removing all solids 24 hours prior and removing half of the water 12 hours prior.
Just remember that the fasting is not recommended in suckling animals. Step #3: Physical exam The physical exam is important, as this is perhaps the first time we will be having contact with the patient. Those who work in a hospital environment have an advantage, as the patient usually comes from the clinic with a physical examination already complete.
This is very good, but it doesn't excuse an anesthetist from the responsibility of retaking the exam. The first thing I do is checking if the animal is well hydrated by observing the skin turgor or eye hydration. At the same time we can observe the mucosal color and then go through capillary refill time, usually evaluated on the gums.
Next, we go to the cardiovascular system. The cardiovascular system is important. Cardiac auscultation should be done carefully, paying special attention to the heart rate and heart rhythm.
We also need to check the intensity of the peripheral pulse. After that, we go to the pulmonary system. Checking the lungs for any crackling noises.
Afterwards, we go to the digestive system, which in small animals is overlooked, but in large animals it's very important. In ruminants, we need to pay attention to the ruminal movements, and in horses, we need to try to listen to the animal's gut sounds, but especially to the opening of the ileocecal valve. Step #4: Complementary exams The complementary exams are important, but they shouldn't be the priority of our approach.
The priorities are anamnesis and physical exam. Complementary exams should aid us in understanding what's going on. When the patient reaches us, it usually already comes with the complementary exams.
This is great, and each place will have its own logic when asking for exams. This logic should be based on the animal's information and also on the physical examination previously performed. Below this video you can find a pdf file containing a table that we follow here in Pirassununga to request preoperative exams, but it's important to keep in mind that the anesthesiologist has the responsibility to ask for any other exams they find necessary, before starting the anesthesia.
A usual panel consists on a complete blood count, kidney function, liver function and an electrocardiogram. If necessary, we can ask for a blood gas analysis or other electrolytes and also an imaging exam, such as ultrasound or Doppler ultrasound. Now, I'm going to ask you a question: Do laboratory tests actually change the anesthetic protocol?
I know I might be asking for trouble here, but that's not my intention, okay? In an interesting study from 2008, it was assessed whether anesthesiologists would change the anesthetic protocol after receiving the complementary exams. Basically, blood count and biochemical tests.
The study found that, considering more than 1,500 dog anesthesia, only 0. 2% of the protocols were modified and 1. 5% of the anesthesia were postponed.
So that's it, we won't do exams anymore? No, my friend, that's not what I mean. But it's important we understand what the complementary exams are for.
Firstly, we're going to ask for complementary exams because we can't ignore the 0. 2% that were altered, and the 1. 5% that were postponed.
The complementary exams have three functions. The first is to learn how the patient is doing, because the anesthetic protocol can alter some parameters, and if there is no previous standard, we cannot compare them after anesthesia. The second important function is that we're going to have more information for, if necessary, treat the patient during anesthesia.
Well, my friend, the third concerns a legal issue. If you take an animal to anesthetize and fail to have all the necessary complementary exams for a given situation, if that animal dies during anesthesia, you will certainly be prosecuted. Step #5: Risk of anesthesia Now, to finish up, we have to classify this animal according to its physiology.
For that, we will classify the animals according to their physiology and surgical procedure to be performed, from 1 to 5. As we can see in this table, ASA I is used for healthy patients undergoing an elective surgical procedure, and worsens to the ASA V, in which we have a dying patient with low changes of survival, whether undergoing surgery or not. We also have the 'E' classification, used for emergency patients.
This scale is known as ASA, as it was developed by the American Association of Anesthesiologists. Well, to wrap it up, we’ll gather all this information and put it in the anesthetic record. This file will be better explained in the monitoring lesson, but you can notice here there are several spaces where you can register all the information obtained.
As a conclusion to this video lesson, we can agree that the patient must be meticulously examined, starting by learning the animal's history through anamnesis and physical examination. Also, we must request the complementary exams necessary to each case. Lastly, to determine the risk of anesthesia for our patient.
So guys, did you enjoy the video? Then give it a like, share it, subscribe, check the contents in the description below, it contains more information on the subject, and I hope you'll continue to attend the lessons from "Anesthesia Unravelled", okay? See you soon!
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