Women obste transcript — SMP305 lecture transcript

I. Right, good, sorry about that everyone. So hopefully I'm uh gonna show you and I'm also gonna record this, OK. So my name's Rose Buckley. I'm one of the consultant anaesthetists here and I'm giving you a talk today on obstetric anaesthesia. Um, I think from memory you guys haven't done your general anaesthetic block yet, is that correct? Right, so, uh, bear with me, please ask me anything as we go if if there's. Thing that I'm not making clear. OK, so today we're going to cover an overview of what we do here as obstetric anaesthetists and how that ties in with women's health and obstetrics generally. Going to specifically be covering pain relief for labour and then anaesthesia if people need to come to theatre. That's for caesarean sections, but also for things like forceps delivery or manual removal of the centres. And then I'm going to touch on the other things that we get involved with in. The descent wing. Um, so our main roles are provision of pain relief for labour and we're gonna cover that in quite a lot of detail. Um, and then anaesthesia, and we're gonna talk about regional anaesthesia or neuraxial anaesthesia versus general anaesthesia and the specifics to the pregnant women. And we're gonna cover some of our emergencies that we, um, uh, deal with in obstetrics, um, what we do on our high dependency unit or. We call it ARCU, the Advanced Obstetric Care Unit here at the Jessup Wing, um, and also, uh, we, we also run an antenatal clinic where we see high risk patients. Go to talk about that as well. Um, so here at the Jessup Wing we're a pretty big unit, um, nationally, um, we deliver around just under 6000 deliveries a year, so that's total number of babies born at Jessop Ring, um, and. About 45% of that comes for a caesarean, so both planned section and emergency section, and that rate fits with what's going on nationally and it's an increasing rate, so more and more people are having caesareans, and I guess that's not entirely surprising because once you've had one caesarean, you're more likely to choose to have another caesarean or the reason that you had a caesarean in the first place is more likely to be there for the 2nd, 3rd, etc. times around. Um, we're gonna see that that rate increase and increase. Um, we're involved with over 3500 anaesthetic interventions, um, and over 2000, uh, labour analgesic episodes. So, uh, whether that's epidurals or we're gonna talk about remifentanyl as a labour analgesic as well. Um, so we'll talk about labour pain first. So labour pain's quite unique, um, it, uh, it changes from the beginning of labour. Of the delivery of the baby, so it starts with these intermittent periods of intense pain that increase in frequency during the labour. It can go on for many, many hours, and people are very different in their ability to be able to cope with that pain. There's cultural, social, personal reasons for that. So the same pain or on paper the same pain is perceived very differently by different people and the amount of pain relief and help they'll need with their pain. Varies immensely. um, and even the same person within the same labour can change how they how they're coping with pain and stuff as you get tired and more fatigued, your ability to cope with pain obviously um decreases.

Um, so, uh, we talk about it in different stages. So the first stage of labour, um, starts with the uterus contracting, um, and there's um cervical changes and the cervix slowly dilates. Um, this sort of initial pain is, um, sort of the nerve supply is, um, lower thoracic to, um, L1, lumbar 1, via the uterine sympathetic nerves, um, uh, and then there's an element towards the end of that of getting some, um, sacral innovation as well. The second stage of labour, which is the delivery of the baby, is the stretching of the vagina and the perineum, um, and that's much more sacral with a little bit of lumbar input as well. Um, I mention this because because when we do an epidural, and we're going to talk in detail about an epidural, um, we are targeting a sort of band of nerves. So, so it may be that we've got the sort of lower thoracic nerves really well anaesthetized with that epidural, so so people aren't feeling contractions and that's all great, but as the delivery continues and as they go on to deliver baby, if we've not then covered the sacral nerves, then suddenly they may get pain during their delivery,

so um. Uh, that's why it's relevant to us. OK. So we've got different ways we can approach, um, providing labour analgesia, and this is a good approach generally to exam questions and things is thinking about or classifying it into to different, um, uh, categories. So here we've got non-pharmacological categories and then we're gonna talk pharmacological. I'm in fact I'm only gonna brush over this bit because because this isn't where we're really involved as anaesthetists. But it's important to know that um patients will come in with with their own ideas about what they want to try uh and the these things are effective um for many people, so we've got um just having support so um emotional um support during uh labour um can help a lot um acupuncture, hypnotherapy, so there's a lot of birth hypnotherapy courses that go on and books and things before people come into labour. Um, massage, TES machines, so this is those trans. A cutaneous electric nerve stimulation machines, they're quite popular and they work on the gate theory of pain. So if you stimulate a touch um type nerve, um, it overrides the pain nerve, so that's your gate theory of pain um and they're supposed to be very effective and hydrotherapy, so we've got water, um, people can have a water birth here if they're midwifery led care and there's no complications, um, and again that's supposed to help.

Ansically, um, homoeopathy and aromatherapy as well. So, uh, labour analgesia, so pharmacological sort sort of things are, um, we've got Entonox, the gas and air, um, simple mild painkillers, paracetamol, codeine, and you've got your stronger intramuscular opiates, uh, patient controlled analgesia, PCA opiates, and so that's something that we're involved with quite a lot as anaesthetists. That's your Remifentanyl and I will talk about that in more detail. And then your region regional techniques which is uh essentially epidurals. So I'm gonna go through each of those in a little bit more detail. So your Entonox Gasina is a very commonly used. um it is a mild pain relief, so you're never gonna get full analgesia from this, but it, it may take the edge off your contractions enough to make you be able to cope with them. Um, it's uh very available so you can have it as soon as you come. Into the dessert wing when you rock up, um, midwives can start it, so you don't need to wait for doctors to come and assess you, so it's very accessible. Um, it's got a very quick onset and offset, so, so the idea is obviously as soon as you feel some contraction pain, you breathe your Entonox in, you get the pain relief as you stop using it, as the contraction wears off, it'll disappear and any side effects or any influence of the Entonox will disappear and you'll be back to your normal self in between. So it's, it's a simple way, but um. Uh, it is very effective. It's got some side effects. It does make some people feel sick, it does make people feel a little bit spaced out. Some people don't like how it makes them feel. You've got to get your timing right, so if you start using it too late in your contraction, you're not gonna get the benefit before, um, before the contraction's already gone. Um, it's self limiting, so that means that if you're making yourself too drowsy or anything on it, then you stop using it and you wake up again, so, so it's got that sort of inbuilt built safety mechanism. And there are some longer term concerns with it, so there is a theoretical risk of bone marrow suppression, so if you were using it for some reason for a long time or if you're a member of staff and you're exposed to it, um, i.e. if you're a midwife and you're in a room day after day after day breathing in ox and then there's this. Risk, uh, and we're, we're much more, uh, vigilant about that now. We've got sort of, um, uh, ways of capturing that, uh, Enox and, um, what's the word? scavenging the air to, to try and to improve the air quality for the, for the staff that work in this environment. Um, there's also, uh, a big environmental concern about Entonox, um, and some countries don't even use it anymore during labour pain because of the environmental impact of Entonox. Um, culturally we are very, uh, used to using it in this country. It would be very difficult to remove this from common use, um, but whether in years to come we stop using it, um, I don't know. It, we haven't got a very suitable, easy alternative to something like Entonox. Um, but I know in sort of general anaesthesia we used to use this all the time alongside. Are are volatiles and, and we very rarely use it now. So, uh, so that's um an ongoing and probably gonna influence our decisions in the future about um pain relief. So, um, I'm, I'm not gonna touch on codeine as such, but yes, another easy thing people can have is a co-codamol or paracetamol and codeine separately, um, as a mild analgesic. The next strongest thing, um, someone can have, and again the midwives can give this so. Relatively easily accessible to a, to a labouring woman is an intramuscular injection of opiates, so it's strong pain relief, it's decent pain relief. Um, it, at the moment we use here at Jessop's morphine or diamorphine depending on availability. Um, historically people used to get given pethidine and that's gone a bit out of fashion these days. Um, it's a strong opiate, so you're gonna get all your side effects, so your drowsiness, potentially respiratory depression. Um, it will go to the baby, um, but we don't see. Sort of, uh, problems with babies being um respiratorily depressed as they as they're delivered can cause some sickness, um, and itching.

Um, once it's in, it's, it's in obviously and you can't take it away so any side effects you have to live with for, for 4 hours or so. Um, so Remmifentanyl, um, is a relatively new thing within label analgesia. It's been a, it's been around for a good few years, but in terms of acceptability, um. From the obstetric and midwife staff and uh patient's knowledge about it, it's it's increasing and increasing. um, so it's patient controlled analgesia um and it's a bit like when you have a big laparotomy operation and you're given a morphine button to press afterwards for pain relief. It's the same sort of idea. So a woman is given a button to press, it's connected to a, uh, a, a PCA machine, uh, connected to a dedicated cannula, um. And then it's got Remifenty in it, so it is a strong opioid, so it's a synthetic opiate, um, it is very quick acting and very quick offset, so just like Entonox, um, it comes on very quickly, its effects and it disappears very quickly once you've stopped using it. So in that way it's quite similar to Entonox, you feel your. Contractions start, you press your button, you get this delivery of Remyfentanyl. You get the benefits of that ideally during the peak of your um contraction pain and then it all disappears again and so in between contractions you're supposed to feel back to normal again. Um, but this time instead of mild pain relief you're getting very good strong pain relief. Um, currently, uh, we as anaesthetists come and set this up. It's not set up for midwives to set this up, but I'm sure that will change. It needs a dedicated cannula because we don't want to accidentally flush a, a dose of Remifentanyl with something else, so you have to have a, uh, a separate cannula, just a pink one or a small one. it's. It is strong, so um you get your potential respiratory depression as well, so people have to have a SATs monitor on just to check they are uh not desaturating on it. Um, no one else is allowed to press the button for safety reasons and again it's got that self limiting aspect that a woman will not press it if she's too drowsy and then she'll wake up again. Um, it's a very sort of Marmite, uh, analgesic, so people love it or they hate it. Um, the ones that hate it just don't like how spaced out it makes them feel or they can't get the timing right and they're just not getting the sort of pain relief from it, but they're getting all the sort of spaced out drowsiness aspects of it. It does go to the baby, but again we don't let them press it as the baby's been delivered, so it's already out of the baby's system by the time they're born in theory, and we haven't seen, um, problems with babies being too, too opiateized as they're born. Uh, the context in sensitive Half-Life refers to Remifentanyl as a drug, so it's not metabolised by the kidneys or liver, it's metabolised by esterases in the blood, and it doesn't matter how many hours you've been exposed to Remifentanyl, it'll all disappear in your bloodstream in the same amount of time, which is about 2 minutes or so. So, um, uh, unlike most of our infusions where the longer you've been given it, the longer it takes to then be excreted. Remy fentanyl's got this unique property that it doesn't matter how long you've had it for, it'll go very quickly. Um, and this paper at the bottom, uh, respite that I think that's from 2018 now, that was a big paper in The Lancet, um, and it's showing that you, it showed that you were, if you Remiphentyl was superior to intramuscular pethidine, which was what was commonly used at the time in terms of stopping you then going on to ask for a uh an epidural. OK, so we're gonna talk now about regional techniques, um, so hopefully I'm gonna clear up a few things for you, um, because there's a lot of confusion about what's the difference between an epidural and a spinal and, and when would you use each one. So we're gonna go over that in a little bit of detail. So we're gonna talk about spinals, epidurals, and then CSEs which are a combined spinal and epidural. Um, so a bit of anatomy for you. So, um, we've got, um, from left to right going in from the skin, so you've got your yellow layer of skin there going all the way, um, into your, uh, vertical column. And you've got three different needles there to show you where they end up. Um, so just to go through the anatomy, you've got your yellow skin, uh, you've then got a, uh, variable amount of subcutaneous fat in that sort of hatch light grey, uh, and then you reach your, um, spinous processes. Um, so this is lumbar spine, so they're quite relatively horizontal at this point. As you go higher up the spine they become more acutely vertical and it's more difficult to get a needle in between them. Um, the sort of solid yellow represents, uh, the ligaments in between those spinous processes, and then you've got a big ligament called the ligament flavum right at the back of all that, so that's represented in green. Beyond that, you've got your meninges, um, and. In terms of um neurorexia techniques, we don't think about them as three different layers. I know you learn uh dura, arachnoid and Pia, but we just think of them as one layer because they're essentially all stuck together for our our purposes and then you get into CSF. So because this is lumbar spine, your spinal cord in an adult terminates um around L1, L2. So below that you've got, um, uh, just essentially CSF with all your nerve roots hanging. Down into it. So we, for safety reasons, we don't, when we're deliberately going into the um CSF we we stick below where we think the spinal cord's uh ended. That is quite variable though, so when you do MRI's of people, um, sometimes it's a bit lower than that, but we've got no way of really telling. So for safety, yeah, we go below L1, L2. and then you can see we've got our epidural needles going into different, sorry, our different, our needles going to different places. So you first. One is the epidural needle which has got a little blue catheter, plastic catheter that we thread in. So that the idea of that is you're going into an epidural space which is beyond the ligament and plasm but not through the meninges um and not into the CSS. Your spinal needle is like a lumbar puncture and we are deliberately piercing through the meninges to get into the cerebrospinal fluid, uh, and then your CSE, um, which, sorry is the middle needle is a combination of both, so we're. We, we are, uh, getting an epidural needle into that epidural space, we're then putting a little tiny spinal needle through it to get into the CSF and deliver some drug there, taking it out and then threading a little plastic catheter into the epidural space so they get a spinal and they get left with an epidural catheter as well. um, and we'll mention when you might use one of those. Any questions about that anatomy? Um, so we'll talk about this epidural space then. So it's a theoretical space, um, and it extends from the foramen for foramen magnum to the, um, right down to the, uh, sacrococcygeal membrane, um, so right, the, the length of your spinal cord essentially. Um, it's theoretical as in it's, it's quite when, when there's nothing in it, it's all closed up, um, it's. Uh, got some blood vessels in, it's got some, uh, fat fatty tissue and lymphatics in, um, but it will expand when you, when you put, um, medicine or saline or air into it, um, and you therefore can thread a little catheter into it.

OK, so we've mentioned all that. So for labour analgesia, we, we aim for a L3, L4. Um, insertion. So as I said, for an epidural, we're not so worried about where the spinal cord ends. It's more about where it's going to provide the band of numbness that you, that you want. So we think that little plastic tube is going to go into an epidural space and we're going to put local anaesthetic down to numb those nerve roots as they come out into the epidural space. Um, the, the local anaesthetic that you put in will spread equally up and down, so it will give you a band of numbness. Um, and for labour pain, if we go in at L3, L4, we'll go up a bit to the. The lower thoracic segments and we'll go down a bit to the sacral segment. So that's why we're, we're ending, we're aiming for an L3 L4 type level. Um, if we, if someone was having a big laparotomy with a sort of incision that went above the umbilicus, we would put a thoracic epidural in because we'd want a band that was a little bit higher. Um, but for labour analgesia it's lumbar, um, so I'm gonna show you a series of photos to try and describe the technique. It is doing an epidural is one of, I think medicine. Weirdest things that we do because it's so um cos it's such a theoretical space and what we do is so we can't see anything, we're just feeling. um it's it's a difficult procedure to teach someone but um when you get a feel for it, it's um it's much more easier than it looks. So the idea with an epidural is you've got to think of that diagram, all the different layers we're going through. Um, we take a big needle, so the epidural need needles need to be big. um, the bigger the needle, the more sort of feel you get as you crunch. Through different um tissues and also remember we've got to thread a little plastic tube through it afterwards so we can't put a small needle in because you wouldn't be able to get a plastic tube down it. So we put a big 16 gauge needle in um and we, so you feel for someone's spine, you, you feel the dimples in their back in their backbones, um, and you find the space. You put local anaesthetic in it first, um, and then you aim to get between those spinous processes. You go in, uh, once you're into that sort of big band of ligament, you feel. Other needle sort of be grass um and it's, it feels much more solid as you go through that ligament, um, you then take, so the needle comes with a little stilette in it again because it's such a chunky needle, you don't want to be hollowing sort of subcutaneous tissue, um, you wanna keep that out so you have a stilet in it, you get into the um ligament, you take the stilet out and on top of it, onto the needle, you put a syringe of saline, um, so the whole. The technique is called loss of resistance, um, and this, this is the sort of slightly mediaeval sounding bit of it. So this is a special syringe, it's not like a normal syringe, it's got less resistance than a normal 10 mil syringe. Um, it's very easy to push that fluid out if, if you were to push on the plunger. Um, but you stick it onto that needle and because you're right in the middle of that ligament, you press on the end and you can't get that fluid in. It's, it's got resistance against it, so you, you slowly advance that needle while pressing on the end of your. Plunger of saline and you keep going through that ligament and you'll feel that crunch, crunch, crunch of ligaments, um, and as you pop through that ligament flavour, you are suddenly into that theoretical epidural space and all your saline suddenly pushes in and you know you're in the epidural space, so you get this loss of resistance. If saline goes into that space and you know you're in the right space. From there, you take your syringe off and you thread the little plastic tube um into that. Catheter, you don't really know which way it's going, but if you keep the bevel of the needle up as you've done your epidural, it, it should in theory go up. Uh, you thread it in, take the needle out, you make sure, so they've got markings on this little catheter, um, and it allows you to measure how far you've gone in, and we try and keep like 4 centimetres in the epidural space, um, just to, you, you don't want too little, otherwise there's a risk it'll pop out again. Um, and then you tape it all down.

Uh, and you can inject your local anaesthetic, so we tend to put a local anaesthetic and a, uh, temil or, uh, any opiate to act for pain relief. Uh, and that can stay there for as long as you need it to. It can stay there for days potentially, and people who have epidurals for post-op pain relief from laparotomies, it, it stays there for 72 hours maybe. Um, but for labour labour analgesia, we keep it there till the baby's born and then we, then we take it out. If you've got an epidural in and it's working well and you need to come to the theatre for a caesarean. We can then um um I've talked about this band of numbness, we can put a lot more local anaesthetic and really sort of extend that band of numbness and and then and um do a caesarean under uh an epidural top up if we need to. Um, so the reasons why people have epidurals, and most commonly it's because people want it for pain relief, so it's a maternal request. Um, but there's sometimes where we tell patients, so we can never make a patient have an epidural, but there's a few. An army is where we tell people it would be a really good idea. So if you've got preeclampsia or you're hypertensive, an epidural can bring your blood pressure down by providing that pain relief and stopping any pain contributing to your hypertension. If you've got a cardiac condition and the stress of labouring is going to be too much for your heart to deal with, then we'd encourage you to have an epidural again to take that cardiac stress out of it. If you're having an induction, so induction. It's quite a, um, there's different stages to it and hopefully someone else has covered this for you, but in terms of it's, if the obstetricians decide to induce you, there's, there's the first bit where you have a pessary or bloom, there's a second bit where they rupture your membranes, and the third bit is having a scentocin on drip, so an oxytocin drip to get your contractions going again. That can be quite, uh, hard work to do without an epidural, uh, the, the oxytocin drip bit because the contractions come on a lot more thick and fast and if they've built up over time and, um.

Uh, sometimes they, they, they, they're a lot quicker, so, um, uh, often people have an epidural then, um, and that, that's sort of, those are the main reasons. Few few reasons people cannot have epidurals, so again I've said if people refuse, don't want an epidural, we can't make them. If you've got a very local patch of infection over your skin where we would put an epidural in, we wouldn't put an epidural needle through it for the risk of introducing infection further into the spine. And if you're known to have an allergy to local anaesthetic, um, then we couldn't do one. Relative refers to the sort of risks of having an epidural. So, um, where our epidural needle ends up, there is quite a vascular place. If you don't have the right clotting factors or you have a um a clotting disorder or you've been on something like low molecular weight heparin, um and you haven't left it long enough for that to come out of your system, then, um, because it's so deep down you can't press on it to stop bleeding like you could on on the surface, there's a real risk of you bleeding around your nerve roots as they come out and, um, tamperarding on them, uh, and causing permanent nerve damage. So if your clotting's at all out the spout we don't, uh, do an epidural. Uh, we, we, we like the right number of platelets, so in our mind it's sort of 50 to 70, which is pretty low, uh, that's a pretty low platelet count, um, and, and again it's a relative contraindication if the benefits of the epidural outweigh the risk, then, then, uh, we, we may still do one. If you're systemically unwell with infection, again, the risk of introducing infection further down and causing an epidural abscess and subsequent nerve damage, um, we might not do an epidural. Um, if you're very hyper. bulimic, um, or you've got a sort of a a detrimental cardiac output state then epidurals um can make your blood pressure drop a little bit, so again we might consider not doing one of those and if anatomically your lumbar spine is, is very different, so severe scoliosis or if you've got lots of metalwork in your lumbar spine, then, um, we might struggle to get an epidural in. We we might still try, but, but there's a much higher risk that we wouldn't be able to find that epidural space. Um, so, um, obviously the effects of the epidural, we're looking for the analgesic effects, the other effects that they can have, so, um, depending on how high your epidural spreads, um, it can affect some of the, um, sympathetic nerves that control, uh, your vasculature, so you can get some vasodilation peripherally, and that's why your blood pressure drops. Um, you, you can in theory, again if you put enough down of a strong, um, concentration, local anaesthetic, you'll get some motor blockade as well. We try and run quite dilute epidurals so that people don't get the er the motor blockade because we want them to be able to move a little bit. um for reasons I don't think we fully understand, er you get a sometimes get a fever with an epidural which can be a little bit confounding because then the er midwives and obstetricians don't know whether this is sepsis in labour or whether it's just from the epidural. uh and they can make you a little bit itchy. Uh, the complications, so I've mentioned a few of them, so the ones that we consent. Patients for are the common things are that it's not gonna work, so as I said we really don't know where that little tube ends up. Sometimes it goes one sided and you get a one sided block. Sometimes it isn't in the epidural space and you don't know where it's gone, but you don't, you put your local anaesthetic down and you don't get any effect. Um, I mentioned low blood pressure, so we have to keep an eye on the blood pressure, um, for, uh, after each sort of top up dose that we do. um. The significant risks, so, so reasonably common is the risk of a postdural puncture headache, uh, and I know we mentioned that in your last lecture. So, um, I've talked about the epidural needle going into the epidural space and not beyond that, uh, because it's such a tactile thing and, and, uh, people move and sometimes we don't know where we are. Sometimes we accidentally pierce the meninges and end up in the CSF instead of the epidural space and because it's such a large needle that creates quite a big hole in your meninges. And so a postdural puncture headache. is when um you get a leakage of CSF through the hole that we've accidentally created with our epidural needle um and that can cause a very postural headache and it's a bad headache and it's a horrible thing to happen to a woman, especially when she's just had a baby and she's trying to look after her newborn baby. You it tends to appear in the 1st 48 hours after it's happened. Um, as I said, it's very postural, so it's much worse when you sit up and it's much better when you lie down. You tend to get a bit of neck stiffness and a bit of photophobia with it. Um, uh, yeah, and it, it, it, so if we accidentally go into that CSF because it's such a large needle, you normally know about it because there's a, a rush of CSF coming back out your needle, so you tend to know it's happened, so you can, you can debrief a woman and tell her what to look out for and we'll go and uh follow up these patients on the ward and, and look out for it. There is something we can do called an epidural blood patch if it happens. Uh, this is another sort of archaic type procedure. Um, this is where. So, so those holes, some of them will, if you don't do anything, some of those holes will, will close up, uh, on their own, um, and people just have conservative management with fluids and, and painkillers. Most of them don't close up very quickly on their own and because it's so debilitating this headache, they, uh, we, we tend to offer this procedure to women. So this is where we, uh, bring them back down to theatre, we, uh, repeat the epidural, um, and when we. Get into the epidural space, we then take, and we do it all sterilely, we then take 20 to 40 mL of their blood. So we need two people to do this procedure. Someone's doing the epidural, someone's at the front of the woman taking blood and we then inject blood, their own blood into their epidural space, um, and we think the blood clots over the hole, closes the hole, and, and all the pressure differences, uh, go back to normal. Um. So that's epidural blood patch. Um, in terms of other epidural complications, so people worry about nerve damage, um, it's a significant risk. The, the risk is rare, so we say 1 in 1000 patients who have an epidural will get patches of numbness on their legs that are temporary and will get better in 6 weeks. In 1 in 13,000 cases those are permanent patches of numbness. And then paralysis or not being able to move your legs after you've had an epidural, we quote as 1 in a 25 million chance. Uh, and the reason for those type things, it's not because we've rogered the whole of the spinal cord or a nerve with an epidural needle. It'd be very difficult to pick out all those nerves. It's more from those either from the hematomas, from abnormal clotting or from an abscess that sort of press on everything and and constrict everything. Um, but it is, it is very rare.

Um, OK, I'm gonna move on. Um, what have I said here? So yeah, just, uh, to, there's also quite a lot of misconception out there that if you have an epidural, it will cause long term back pain. There's no evidence that it does. Uh, there is evidence that having a child, uh, so labour and having small children and picking up small children will give you long term back pain. So we do know that women of childbearing who have children go on to have low back pain. Um, but there's no evidence that it's from the epidural. There's a bit of evidence that if you have an epidural, that you might have a slightly prolonged labour. Um, there we are. So, so we talked about epidurals and labour analgesic. We're gonna move on to operative delivery. Um, so most of our caesarean sections we do under a spinal anaesthetic. So if you've got nothing on board, you'll come to theatre and you'll have a spinal rather than an e. Aural um or a general anaesthetic. um the reason being is a spinal's a bit quicker to do for than an epidural, so as, as I showed you in that diagram, you're going all the way into the CSF. It's a one shot injection, you're not threading any tubes or anything. It's a much finer needle, so patients generally find it slightly less uncomfortable than having an epidural. um and it gives you a much denser block because all that medicine's gone straight into the CSF the block that you get from it. Is much denser, so again it's um both of them block your pain and um sharp sensation um or that's the idea anyway. Both of them you'll still feel a bit of touch and pressure but in an epidural anaesthetic it's, it's much more uh the touch and pressure stimulations are much stronger which um can get a bit much for some people and sometimes we have to convert that to a general anaesthetic for the spinal. You, you, you, we have less issues with that, so, so yeah, if you, if you've not got anything on board you'll be offered a spinal. Um, we like to keep our patients awake rather than get them off to sleep for various reasons, um, well, I'll put those at the top there. So it's safer to not, um, so pregnant women um have uh more airway risk factors, um, and I'll go into those when you, when you give them a general anaesthetic. Um, it's safer in terms of, uh, there's a less risk of postpartum haemorrhage, so when you anaesthetize someone, the all the anaesthetic that we give will also relax the uterus, so it, when you've delivered the baby, you want that uterus to contract again, um, to reduce that risk of bleeding, and, and we see that's more of an issue with when they've had a general anaesthetic. Um, you're, um, more mobile because your pain relief's, um, more, um, superior. Um, so generally it's a safer anaesthetic, um, the big thing that patients. is that they're awake and their partners can be with them, so they're there when their baby's born, so that's obviously really important. They can do skin to skin in theatre. Um, so generally overall increased patient satisfaction. Um, and then because we get the opportunity to put a strong opiate painkiller in that spinal mixture that we give them, they tend to have um superior post-op analgesia as well. Um, it's got the having a spinal's got the same sort of risk factors as an epidural but probably slightly less. So this time we are deliberately piercing that meninges, so we know. Going into the CSF, so there is a risk of a postural puncture headache, but because it's such a fine needle compared to an epidural, we don't tend to see the problems with the hole and the CSF leaking out. For the headache, the postural puncture headache, we quote 1 in 200 for a, a spinal as opposed to 1 in 100 for a uh epidural. Um, your blood pressure is much more likely to drop with a spinal than it is with an epidural, and that's, um, mainly because we're trying to get a higher block. So if you're coming for a section, we need you anaesthetized from T4 downwards. Um, and that's because although your uterus is, um, innervated much lower down, um, because the surgeons have to go through your perineum and, uh, the way your bowel's innervated, we need a, a T4 block. So we have to get that block higher, um, and therefore we definitely affect the sympathetic chain and you definitely get peripheral vasodilatation. Um, so low blood pressure, um, if we, if we didn't do anything to try and counteract it, everyone's blood pressure would drop. To try and counteract it we give fluid bonuses and we use phenylephrine, which is a peripheral. Vasoconstrictor, so we run an infusion of that at the same time to help to try and prevent that vasodilation. um, despite that we still see a reasonable amount of sickness um initially after our, our spinal's gone in. Uh, risk of nerve damage and stuff we would quote as similar to the epidural. So why do people have general anaesthetics? um, so the, um, I guess just to do a bit of background to this, um. In obstetrics you need to be intubated so um when you do your, your anaesthetics, you'll see some people end up with eye gels, some people get intubated. um this is thinking about all sorts of surgery and that there's lots of reasons why you might intubate someone. Uh, in obstetrics we have to intubate because um so endotracheal tube will end up in the trachea with a cuff and it stops any sort of stomach material. or um liquid going down into the lungs. Um, pregnant women, uh their esophageal sphincter, their lower esophageal sphincter is um because of the bump is uh quite deficient so um they get a lot of reflux and acid, especially towards the end of pregnancy. Um, so we know that if we anaesthetize someone there's a real, a genuine risk of, um, stomach contents coming up. Uh, and soiling the lungs, so, so they have to be intubated, uh, so that means doing, uh, laryngoscopy with a, um, laryngoscope, um, and so that's, that's like our key anaesthetic skill when, when you do your anaesthetics, you'll hopefully have an opportunity to, to see that and maybe do it. Um, in obstetrics it's more difficult to perform that procedure. Um, so that's a procedure where you put a blade into someone's mouth, you lift their tongue out of the way to get a view of the vocal cords and you put that endotracheal tube down. Uh, in obstetrics, uh. Everyone gets a bit more swollen and edematous towards the end of pregnancy, so they've got a more difficult airway in the first place. There's lots of situational um factors, so the reason people come for general anaesthetics is often it's an emergency and they're rushed around. They might be bleeding, they'll be terrified, they're often poorly positioned on a bed. The staff in theatre are all all stressed cos it's got to be done quick, quick, quick, um, and so there's a lot of human factors involved with, um, uh, the procedure. Physiologically, women divert a lot of their blood.