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Pre-Operative Care

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Summary

This on-demand teaching session invites medical professionals to engage in an insightful discussion and learning session on preoperative care. The session, overseen by Florence, one of the chairs of SUA, will detail aspects of patient-centered multidisciplinary integrated medical care, aimed at safe and efficient preparation for surgery. Attendees will gain a thorough understanding of medical optimization, the importance of psychological support and holistic approaches, consent for anesthesia, and assessing physical and nutritional statuses. The teaching program offers the opportunity to fill a feedback form and receive a certificate of attendance along with discount codes for some of our sponsors. Furthermore, the session will also cover aspects of preoperative consent, guided by the UK's Montgomery ruling and the Mental Capacity Act 2005. Medical professionals will learn how to conduct specific risk counseling with patients using various standardized tools. Lastly, the session explains the necessity of doing a thorough medical history and physical examination pre-surgery, presenting suggestions for facing specific situations and complications through case studies for an applied practical understanding. This program offers crucial insights into preoperative care for any healthcare professional, promising new learning opportunities and knowledge enhancement.
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Learning objectives

1. Understand and implement preoperative care in a competent manner, understanding it's a patient-centered, multidisciplinary and integrated medical care. 2. Outline the basic steps and information required to perform an informed consent process for patients undergoing surgery, ensuring all legal and ethical requirements are adhered to. 3. Recognize the importance of a comprehensive preoperative assessment, focusing on patients’ medical history and physical examination, using tools such as the surgical outcome risk tool, the NSQIP surgical risk calculator, and the Rockwood Clinical Frailty Scale to assess individual patient risk. 4. Understand the specific respiratory and cardiovascular considerations during the preoperative assessment, specifically focusing on obstructive sleep apnea, asthma, and COPD in the context of surgical risk. 5. Evaluate the necessary changes to medication and nutritional adjustments needed for patients undergoing surgery and the implications for preoperative preparation.
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Computer generated transcript

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Um Hello everybody and welcome to the first up to talk of the year. Um We'll just give everyone five more minutes for people to join and then we will get started. So sit tight, grab a drink, grab a snack and yeah, we'll give it five minutes and then we'll get started. Perfect. So we can see the slides now. Sorry for the delay, everybody. Um Oh, we've gone back off. Um um OK, just well, so. Oh, perfect. Amazing. So, hello, my name is Florence. I am one of the chairs of SUA this year and a massive welcome to all of you, as I said before, this is the first um block of teaching out of our 14 week teaching program. So just so that you stay in the loop of when our teaching programs are. Make sure you follow us a medal and you will receive email notifications, reminding you of when to come and also give us a follow on Instagram as well. We're just supper on Instagram. Um Just before we start, I just wanna say a massive thank you to our partners for the 2024 teaching program. We have the MDU medal pass the MRC S Teach Me surgery and more than skin deep um supporting the US this year. At the end of Rita's talk, we will be sending out a feedback form. If you fill in the feedback form, you will not only get access to these slides and the recording, you will also get a certificate of attendance, which will also contain some discount codes um for some of our sponsors. So this time we have a discount code for teach me surgery and a discount code for past the MRC S. So make sure you stay to the very end to get the feedback form. So without further ado, I will hand over to a shooter for our first talk on preoperative care. Take it away. I think you might still be on mute. Yeah, not enough. Yeah, perfect. Wonderful. So hi everyone. My name is I'm one of the four fourth year medical students at the University of Birmingham. And today's lecture is gonna be on pre op care. So if you have any questions during the um lecture, please put them in the chat. I can't see them, but um Florence will have a look at them. And so yeah, just thank you to our partners. So these are our learning objectives for the lecture. So just an overview of preoperative care. Um a bit more detail on pre op consent assessment, drug management, nutrition, and also assessing preoperative op operative intraoperative blood loss and group and save and cross matching guidelines as well. So what is pre op care? So pre op care is patient centered, multidisciplinary, integrated medical care. And all of this is to prepare a patient to undergo surgery in a safe manner. And so the preoperative period it starts all the way from the decision to perform surgery to uh to the start of the surgical procedure. So within pre op care, we've got several things to think about. So you have a rehabilitation, which is um any intervention before the medical, medical surgical um procedure that you're undertaking to increa to with the aim of reducing side effects and complications and to also enhance recovery and then you have medical optimization. So this is things like making sure your patient's hypertension and diabetes are under control before they go or are optimized as best as they can be before they undergo surgery and the operative period and the perioperative period are quite stressful. So you, so this is also an opportunity to offer psychological support and more holistic support. And obviously, you have to get consent for the anesthesia and the surgery itself. You'd um assess their uh physical and nutritional status and you'd make any changes to medications that you need and also do the appropriate investigations. So, moving on to preoperative consent. So informed with, for consent to be informed consent, uh the GMC. So the Montgomery ruling is what governs uh informed consent in the UK So the information that is expected is material or significant risks or unavoidable risks of the proposed treatment. And this and you should mention them even if they are seemingly small and you also should discuss alternatives to the treatment that you've proposed and also the risks incurred by doing nothing. So the General Medical Council says that you should find out about a patient's individual needs and priorities when providing information about your treatment options and surgical options. So capacity for someone to give you a valid consent, you're meant to have you, you're supposed to have three things. So you, you, your patient is supposed to have capacity. The consent is supposed to be voluntary and not under any form of coercion. And your consent should be informed for a patient for, for to say that someone has capacity, your patient must be able to understand the information. They must be able to retain the information, weigh up the information, understand the risks and benefits and also communicate their decision. And the law governing this is the Mental Capacity Act of 2005, which says that everyone has the right to make their own decisions. Unless they, they are, they've been proven to not have capacity and you should go, you should do everything possible to make sure that somebody is to make sure that you're able to, that somebody is able to have capacity to make a decision before saying that they don't have capacity and um some people might, may make decisions that you do not think are wise. But that is a reason for lack of capacity and anything done on behalf of someone who lacks mental capacity must be done in their best interests. And these best interest decisions should not restrict the freedom of someone lacking mental capacity. So there are a couple of consent forms that you might see used around the NHS. So the consent form one is um it's, it's the, it's the form that you use for someone that has capacity and is consenting to um a treatment under general anesthetic. And form three is when their consciousness is not impaired. An example of that would be a biopsy and what if they aren't an adult or they don't have capacity. So for someone under the age of 18, you have consent form two, which is signed by someone with parental responsibility and for those who are not able to consent and the decisions the, the decision has been made in their best interest. It's formed for. So when you are consenting someone, you'd want to talk about the specific risks of anesthesia. So the Royal College of Anesthetics has uh come up with this scale of uh of uh showing how you can try and quantify the risk when counseling patients cos often that's quite difficult. So something that's very common, which uh you can tell which you can explain to the patient is um about as frequent as one, someone I within a family unit is thirst, sore throat, bruising, sickness, shivering or temporary memory loss, mainly in patients, elderly patients. And something that's a v, something that's as common as someone in the street would be pain at the injection site. This is for local anesthetics and you can have injuries to the lips, tongues or l lips to the lip and the tongue or any kind of um, oral tissue and something that's uncommon. So that's equivalent to someone in a village would be minor nerve injury and something that's a bit more common a bit. Um Something that's um even rarer than that is peripheral nerve damage again from a regional anesthesia and damage to the teeth and things like awareness during an anesthetic and loss of vision are incredibly rare. And so typically there aren't separate consent forms specifically for anesthetics. There's usually just a check box at the bottom of the consent form for the surgery. So these are some specific um uh tools that you can use to counsel someone on their individual risk. So you have the surgical outcome risk tool and then you have the N SQ IP um surgical risk calculator, which will give patients an individualized risk. And you also have les revised cardiac index which gives someone the, which, which can um help you counsel someone on their risk of a cardiovascular event it in during surgery. And you have the Rockwood Cli Clinical frailty scale, which will help you um engage the patient's frailty and obviously frailty uh correlates with the um surgical risk as well. So, moving on to preoperative assessment. So, um uh so within this, you have several components like the history examination of working out a patient's a SA grade and also that um are seeing what kind of investigations are necessary. So, within the medical history, you want to first uh find out what the presenting complaint is. So you want to know the reason for the surgery and like for the surgery and also before going into this. So this is usually done by um done in preoperative nurse run clinics. And if the nurse identifies someone that needs to be escalated, then they will see an anesthetist who specializes in preoperative medicine. So yeah, so once you confirm the presenting complaint, you want to take a de detailed past medical history, cos um it might reveal things like go which again has um implications for what kind of airway device you use during um anesthesia or things like ankylosing spondylitis. Um Again, that might um prevent you from using spinal anesthesia and through taking their past medical history, you'll be able to assess their risk of venous thromboembolism. So DVT and pe during the operative period and also their waterlow score for pressure ulcers. So you want to take a detailed cardiovascular and respiratory history and um I'll go through this in the following slides and also, if someone has diabetes, you want to clarify what type it is, how it's managed if they have any end organ damage to things like, uh, what is their renal function like? And do they have any diabetic eye disease? For example, you want to know if, um, for female patients, you want to ask about their, whether they're pregnant or how likely, or they, or, or if they think it, or how likely it is that they are pregnant. And um for patients of a certain ethnicity such as Afro Caribbean patients, you want to know their sickle cell status. And if anyone in their family has sickle cell disease, you also might want to ask them their M RSA status if they've ever tested positive for it. And you'd also typically do a swab for it during the preoperative clinic for elective surgeries and send that off. And last thing um I haven't seen it asked uh while I was placed during uh in the pre op clinic. But um you might also want to ask if they've been notified by uh public health that they might be at risk of um prion disease like CJD. So, within a respiratory history history, you want to ask specifically about obstructive sleep apnea and things like asthma and co PD. So within with, in patients with OSA, you want to estimate the BM I and you want to ask them if this is diagnosed or if this is under investigation and um ask about daytime sleepiness. Do they use a CPAP mask at night? And basically how well controlled this is. You also want to ask about their functional sta status. So their exercise tolerance and are they able to lie flat? So this is quite important because uh to undergo surgery, your patient probably will have to lie flat for prolonged periods of time. And they should be able to do this. And you want to know if they need airway support during this. And you also want to and for exercise tours. Can your patient make it from the day case unit all the way to the aesthetic room or do they need to be or do you need to have porters on hand for them and with asthma and CO PD. So cop DS can, they can be often treated with steroids and you, that's quite important to know, cos you'll have to make changes to their steroid medi medication, which I'll talk about soon. And you want to know um whether their asthma and CO PD are well controlled. And also I want to know about um recent hospital or ITU AIT U admissions and if they have any viral illnesses, cos this would make you want to postpone the surgery if that's possible. And again, um you want to take a detailed cardiovascular history and same things when it comes to heart failure. So, can they lie flat and what's their exercise tolerance like and if they have hypertension, uh, how is this managed? Is this managed by their GP or in secondary care? What is normal for them? And again, do they have any evidence of, um, endocrine damage, like reduced renal function, similar to diabetes? And again, if they've had an M I, that tells you that the perfusion to their heart is, uh, compromised and that's something the anesthetist would want to know. So if they've had a previous M I, what kind of treatment did they have for it? Uh What vessels were implicated? And have they had a recent echocardiogram? And again, for patients with af are they on anticoagulants? Do those need to be modified? Um If I'm going too fast or if uh something doesn't make sense? Oh, please do. Let me know. So then you want to take a specific anesthetic history. So you'd want to start off asking about past anesthetic problems and you'd want to ask about problems that they've had with previous surgeries or problems that were that their family members have had. So, uh you'd want to ask if they've had um an anaphylactic reaction or if they're allergic to um something in part uh any kind of drugs. And then you want to ask about malignant hyperthermia. So this is an autosomal dominant um a condition where patients they react, they react to uh some inhaled anesthetic agents and also Suxamethonium, which is a depolarizing muscle relaxant. So these patients can have a really high temperature and muscle rigidity. And this is quite similar to the thing of, to the one you see in neuroleptic malignant syndrome that happens in with the use of some antipsychotic medications. And the way you treat it with is with a drug called Dantrolene, which, um, prevents the release of calcium. And, um, also you want to ask if they've had a particular diff diff, if they took quite long to wake up from their previous surgery, cos that might give you an indication that they might um be predis, um, they might have, they might suffer, suffer with suxamethonium apnea. And this is when um the patients lack the, the enzyme that breaks down suxamethonium, which is the muscle relaxant. And so at the end of the surgery, they take really long to wake up and also don't, they don't breathe spontaneously. And then you want to ask about their um dentition. So, have they had any dental procedures recently? Do they have any loose teeth caps or crowns? Cos they might aspirate that tooth? And also you might uh damage it while securing their airway and have they had any postoperative nausea or vomiting previously? And you also want to ask about things that would increase their risk of aspiration aspirating during the uh during surgery. So, do you, do they have a high BM I, are they pregnant? Do they have a hiatus hernia and, or do they have go and you also want to review previous anesthetic notes to just to make uh just to see if there have been any difficulties in securing the airway in the past or any interpretative problems that have been documented, right? So, moving on to the physical assessment, so you'd want to assess your patients airways and the way you do that is um ask them to move their neck from side to side and up and down and see if their neck's flexible and if ask them if they have any problems with their jaw. And again, as um take a look at into their mouth, uh see if there, there are any loose teeth that loose teeth that might be knock knocked out. And then you want to calculate the Mallampati score. And this is quite subjective, but you just ask the patient to open their mouth and you see how many structures you can see at the back of their mouth. So if you can see the, the hard palate, the tonsils, the uvula, then you'd say that their score is one, you can hardly see anything, then you'd say their score is four. And this correlates with how easy it would be to um intubate them, right? So, moving on to the A sa grading. So this is something you see charted on the patient's surgical notes. And um people might use this to people and often the O DPS and anesthetics. Um talk about the patient using that. A SA grade. So there are six classes. So the first one is a pa is a patient in a normal health. And then the in the second one, you have a patient with mild systemic disease. So that's quite vague. But um lots of patients would be classed as a A SA two. So just being pregnant can make you drop you from a one to a two, any amount of smoking or alcohol use will put you in a two BMI of 30 to 40. And if you have diabetes or hypertension that is well controlled, that would still make you in a SA too. So you can see how quite a large proportion of patients would be in A SA two and then people with severe a severe systemic disease. So people with uncontrolled um, diabetes or hypertension co PD, um people who have had cardiovascular or cerebrovascular events in the last three months or those with alcohol abuse would be an A SA three. And again, it just goes, the severity just keeps increasing. So four is severe systemic disease with constant risk of death. And A SA five is um, if they're not expected to survive the surgery, if it's not survive, if the surgery is not performed. And A SA six is when your patient is brain dead. But uh they, and they're undergoing surgery for the purpose of all the donation, right? So, in the preoperative clinic, when deciding what kind of investigation, some someone has to have, you use the A SA grade that you determine from the previous slide and there's surgical severity. So, and that tells you what kind of investigations to do. So for minor surgeries, for things like things at the surface of the body or like draining breast abscesses, for example, you would, you wouldn't really do any kind of tests really. So even if your patient is in a, a SA three or four, you might consider a kidney function or, and an ECG. But to summarize, if it's a minor surgery, you're not really gonna be doing any kinds of tests. And the idea behind this is that um prior to this guideline coming out, people were uh uh ordering lots and lots of tests and um that was not quite cost effective. So that's the, that's the reason for this traffic light system to um yeah, that's the reason this guideline came out and then for uh intermediate surgeries. So things like tonsillectomies, uh varicose veins, uh arthroscopy of the knee. So again, if your patient is a SA one or two, you're not gonna be doing any kinds of tests. And but if your patient is a SA three or four, you'd be doing kidney function and an EG and you would consider things like a full blood count, hemostasis, lung function and ABG S and for major surgeries. So things where you're removing organs out of the body. So um um hysterectomies, uh uh radical prostatectomies, th uh thyroidectomies, things like that. So you do a full blood count for everyone regardless of their A SA grade. And um, you do a kidney function and E CG for A SA two and 3423 and four. And you'd what? And if indicated you want to do a clotting and an ABG for people on the higher end of the A SA scale. Yeah. So if you guys have any questions at any point, just drop it in the chat and we can go through them at the end of this. So, moving on to perioperative drug management. So this will cover things like what kinds of drugs to stop. And when. So there are a couple of medications that would increase your surgical uh surgical risk and give you poorer outcomes if you continue to take them during the perioperative period. So the first one would be hormonal replacement therapy and oral contraceptives. So you want to stop them about four weeks before surgery and, and especially surgery that involves prolonged immobilization because this increases your risk of a venous thromboembolism. And you'd want to restart this only after your patient starts mobilizing. And so when it comes to antidepressants of specifically monoamine oxidase inhibitors, you want to gradually withdraw them in a stepwise manner two weeks before surgery. And if your patient is on a tricyclic antidepressant, you want to put a note in for the anesthetist to review them because this increases your risk of cardiovascular complications during surgery and lithium, you want to stop it 24 hours but only before major surgery because you want to, because the surgery itself um puts a lot of stress on the kidneys and you want to avoid a li lithium just building up and uh leading to lithium toxicity. So, and when it comes to potassium, potassium sparing drugs, so you want to start ace inhibitors and A RBS and also potassium sparing diuretics again, because of the risk of renal under perfusion during surgery. And so, antiplatelets and anticoagulants. So we'll go into a bit more detail on them and also diabetic drugs, right. So just to summarize anticoagulant and antiplatelet um used during in the per in the preoperative period. So, if your patient's on aspirin or dipyridamole, you, there's, it's generally safe to continue. If your patient's on Warfarin, you want to stop, you want to stop the warfarin five days prior to surgery and measure their I nr and um make sure it's below 1.3. If your patient has had a VT in the last three months or has af and has had a stroke or a tia a in the last three months, and it has a mechanical heart valve, you want to bridge this with low molecular weight heparin during the perioperative period. And for Doac, so the time to stop before surgery um can either be 24 hours to 72 hours and the d this depends on lots of factors like which drug it is. So, dabigatran is slightly different from the other factor 10 A inhibitors like a Doan epoxim and Rivaroxaban. And you'll also take into account the bleeding risk from the surgery itself and your patient's renal function. So if their renal function is impaired, that means it will take longer for them to clear the drug. So that would increase the time before surgery that you need to stop it. Um When it comes to emergency surgery, you, if your patients on some kind of blood thinners, you want to have a risk benefit discussion and um weigh the balance of doing surgery now or delaying it. And um if you do want to perform surgery, then you might have to consider the use of reversal agents and some of them are on this slide. So for Warfarin, you're thinking Vitamin K because that's the antidote to Warfarin and also a prothrombin complex concentrate for Dora. You have specific reversal agents like um Dexone and um a monoclonal antibody that I can't pronounce. And for heparins, you have protamine sulfate. And yeah. So you want to see, y you might wanna check if you need to reverse the patient's anticoagulation. So, moving on to antidiabetic medications. So, Metformin, um you don't often you don't have to make any changes to it. The only change would be if your patient takes it three times a day you want to omit their lunchtime dose for DPP four inhibitors and uh G LP one analogs. So these ends in these end in Gliptin and Tide. Um, you're not gonna make any change during the preoperative period for SGL T two inhibitors and sulfonylureas because these ha in increase the risk of having a hypo. Um, you want to admit them on the day of the surgery rega whether it's a morning or a afternoon operation for SGL T two inhibitors and for sulfonylureas, you omit the morning dose and for, uh, but if it's an afternoon ser surgery, you omit, um, you omit both doses. If it's, uh, if it's taken twice a day or, or just the, or even if it's taken once a day, you omit that dose as well when it comes to insulin. So if it's a once daily insulin, you want to reduce the total dose by 20%. And if it's a twice daily insulin or an ultra long acting insulin like HumuLIN or nova, um, you only red, you have the dose of the usual morning dose and you leave the evening dose unchanged regardless of whether your surgery is in the morning or the afternoon. And one thing to remember for diabetic patients is always to try and put them, um, and, uh, f, uh, first in the, uh, in the theater list and try not to put them on evening or weekend list. So, steroids. So, the problem with long term steroid use, which is defer which is defined as more than 5 mg of prednisoLONE per day is that this can cause a suppression of the hypothalamic um pituitary adrenal axis. So, exogenous corticosteroids would uh uh negatively would provide ne negative feedback to the hypothalamus to stop producing C Rh and also negative feedback to the pituitary to stop producing ACTH. And this will all of this will mean that your adrenal cortex is not gonna be producing cortisol. And this is a problem because during surgery and other stress on oth other kinds of stress on the body, you actually need a dose that's higher than the normal physiological levels of cortisol. So you can see why this can be an issue. So there are specific guidelines as to how to manage this. But generally you'd want to put your patient on IV Hydrocort Cortisone and also double their steroid dose. But this guideline over here that I've signposted is quite useful and it tells you on what to do in specific scenarios of both primary and secondary adrenal insufficiency, right. So moving on to VT E risk assessment. So this is a common gene do job. And um so the way you do that is with this form over here to the left of the slide. So this this form must be filled out on admission and also reassessed if the clinical condition changes, some trusts assay, you must reassess it every 24 hours as well. And um so the problem with VT prophylaxis is um it causes issues with um spinal or spinal anesthesia or epidurals. So, you want to wait at least 12 to 24 hours. Uh depending on whether it's a treatment dose or a prophylactic dose of low molecular heparin before doing a spinal or an epidural. And also before recommencing it, you want to make sure it's four hours post either of these procedures. So this is the standard prescription for VT prophylaxis. So, low molecular weight heparin, which is enoxaparin sodium and skin subcutaneously. And for surgical patients, you want to give them 20 mg about two hours before surgery. Um if they're at moderate risk and then again, 20 mg every day and if it's a high risk surgery for. So things like orthopedic surgery, you want to give them 40 mg, 12 hours before the surgery and then 40 mg every day after that. And if your patient has renal impairment, unfractionated heparin is preferred over an Oxin. So, preoperative nutrition. So almost half of the patients that are admitted to hospital are malnourished or at risk of malnutrition. So, and um a your patient's nutritional status is a modifiable risk factor and taking control of that can uh reduce infection rates and also decrease your length of stay. So, surgery and hospitalization themselves, uh as you can see in this diagram on the left will, can impact your nutritional status. So the idea of identifying malnourished patients in the preoperative phase is to try and bring their baseline up to the top. So that um even with any kinds of any, any drop er, during the oper preop perioperative period, they should be OK at an OK level. So the must tool, which is the malnutrition universal screening tool is something that can be you, you can use to identify such patients. So it looks at their BM I, if they've had any unplanned weight loss and if they're acutely ill and it risk stratifies them and gives you uh gives you a, a general plan on what to do based on their risk group. So fasting before surgery. So pre op nutrition is clearly important, but you also want to um minimize the risk of things like aspiration. So your patient needs to be fasted before surgery. So the general is a six and two. So you want to stop all kinds of solid food and a any kind of nonhuman milk up to six hours before the intended surgery. And oh, so uh breast milk is ok, up to four hours before the surgery and clear fluids. So this is things like water, black coffee, um uh tea with no sugar and uh fruit, fruit juice with no pulp in it. Um up until two hours before the surgery. But um if you can see it's a picture of S Tilsen. So this is a new initiative um that's gaining more popularity in the region. And essentially, uh this can be some uh this uh can be summarized as um so the patients are allowed to have a small one, small cup of water and they can sit from it up until the point that they are sent for the anesthetic room. So there are a small number of contraindications to it. So things like bowel obstruction, but um generally, since it's been implemented, there's been no evidence to say that it's increased the risk of aspiration. So this might become more common um in the future. So um moving on to our last section. So, anticipating intraoperative blood loss. So before you transfuse someone, you want to do two tests and um they sound quite similar, but in reality, they are quite different and the output you get from them is quite different. So the first of the two tests is group and safe. So this when you request this test, um you use a pink blood bottle and it needs a handwritten label. So you can't use um preprinted stickers and this process takes about 40 minutes. And what this does is it just the lab takes your sample and it just works out what the blood group of the patient is and checks if there are any atypical antibodies in their blood. And if you request a group and save, you will not receive a bag of blood. So no blood is issued. So if you do want blood you'd have to ask for both a group and safe and a cross match. So a cross match is the final step uh to request blood from the laboratory. And in this process, they physically mix the patient's blood sample with the donor's blood and see if there's any clotting or a hallucination and basically see if there's any reaction to the blood. So after uh checking that the donor blood is compatible, um the blood is issued, issued and uh you can transfer it to the patient. So this takes an additional 40 minutes on top of the 40 minutes that the group and say um takes so the quickest you can get blood out to a patient would be 80 minutes if you want to, if you want their specific blood type. So how much blood for a surgery? So every twist, um they have their own M SBO S which is called the surgical blood ordering schedule. And um the aim of this is to try and relate the ordering of blood to the likelihood that a transfusion will be required. And this helps conserve blood bank resources. This is our guideline and it's obviously not set in stone and can and you can override it. And so it's confirmed during um the wh O surgical safety checklist, which I'll show in the next slide. And so, um in this sample M SBO S, it says for laparotomies, you want to group and save them and request uh, one unit only if their hemoglobin is less than 100 and for a, something like a total gastrectomy, which is quite a, um, which is surgery with an high, an anticipated blood loss. You want to both gri and save and cross match two units. So this is the surgical safety checklist and as you can see in these, um, red boxes. So before the induction of the anesthesia, somebody will ask the nests if there's a risk of more than half liter of blood loss or 7 mL per kg if it's Children. And um, also ask them what their backup plan is if this does happen. And also, um, once the patient's been anesthetized and before the first incision is made, um, the surgeon's also asked how much blood loss is anticipated. So, uh, so, um, the information that you get from this, you can use that to override the M SBO s. And yeah, that's the end of the lecture. And yeah, so do you guys have any questions? Thank you so much for such an informative talk. I definitely learned a lot from that as well and it was definitely needed for revision purposes. So, thank you. So, so much. Any questions, please pop them in the chat. Um And please follow us on Instagram and on Medal. So you get notified for the rest of our talks. We have a talk on postoperative care coming up on Thursday. So be sure to attend that I have also sent the feedback form in the chat. Please fill that in and you will get the certificate with the discount codes as well. I've just seen you've had a question. Um Can you explain the difference between group and straight save and cross match again, please? Yeah, yeah, I can do that. So a group and say so there are two blood tests. So in the group and say if you take a sample from the patient and you send that off to the lab and what the lab does is it figures out what your patient's blood type is and also sees if there are any kind of um antibodies in it that are and that aren't quite common in the general population. And what a cross match is is they take that sample of blood and then they mix it with a specific bag of donor blood. Well, a small sample of the bag and they see if it starts to clot or if any kind of immune reaction happens. If it doesn't happen, that means this blood is ok to transfuse to your patient and they will send you um a bag of blood. Thank you very much, really well explained. Um Any more questions at all? Well, in that case, thank you so much and hopefully see all of you on Thursday evening for postoperative care. Bye bye. Thank you so much for everyone for coming.