Nausea and Vomiting in palliative care

Nausea and Vomiting in palliative care



audiojungle hello my name is penny – I'm advanced practice pharmacist and today we're going to be talking about managing nausea and vomiting in people with palliative care needs there's lots of different causes for nausea and vomiting across people in the general population but also in people with palliative care needs commonly we see people who are constipated or have slowing of their gastro intestinal transit they may have liver disease may have infections or medication that can cause slowing of the gut people with biochemical abnormalities particularly as they're in their advanced stage so the disease are quite common movement can cause nausea and vomiting as can therapies like chemotherapy and radiotherapy and some people may have raised intracranial pressure particularly if they have brain metastases or what brain cancer I find this diagram quite useful it's quite old was produced by twycross in the 1980s but it gives a little bit of an indication of what the common modalities of nausea and vomiting are in people with palliative care needs so if you look at the top half of that pie graph all of those those two causes are by intestinal slowing of the gut so therefore about half the nausea and vomiting within people with part of care needs is induced because their gut is working much slower than a normal person's might be it's about a sixth of nausea and vomiting that's caused by biochemical abnormality another six by medication and then about 5% generally because of raised intracranial pressure and then the other little slice there is a whole lot of mixed etiology so when we're looking at treating nausea and vomiting in palliative care we need to do a really clear assessment and there's lots of things that are going to be useful in us trying to determine the cause and determine what medications and what modalities of treatment are going to be most useful so we want to know when it started how long it's been going for how but it is whether it is nausea whether it is just vomiting whether it is nausea and vomiting because we will treat those differently we want to have some idea of the frequency and the timing for instance is that just after meals we want to have a bit of an idea about what they think makes it worse so is that when they get up and move around that they feel worse and we want to know also if there's particular medications or other things they have tried that have actually made their nausea or vomiting better we will always do a medication review because medications are a common cause of nausea and vomiting in people and we want to look at the character whether it's projectile which will mean that it's probably got a central cause as opposed to a not normal nausea picture that we might see in somebody else we want to look at whether there's any precipitating factors so that will be maybe we do we check their biochemistry to look for things like renal dysfunction or look to high levels of calcium for instance in their blood so the general principles of managing nausea and vomiting are that we try and determine what we think of the underlying causes we want to treat any underlying cause that we're able to so for instance it's an infection we might want to treat that if we have biochemical abnormality we might want to treat that if it's due to constipation we definitely want to treat that we would give general advice and support and I'll talk a bit more about that later on and we also then want to prescribe the appropriate medication and we'll choose the medication based on what we think is the cause and therefore what mechanism the nausea and vomiting is being precipitated by and therefore what neurotransmitters are involved and what medication will modify how those neurotransmitters are being released so the general advice some non pharmacological methods that we will use include these we need to have people with good oral hygiene um so making sure that their teeth are clean they haven't got thrush their mouth is moist will all help with May can someone feel less nauseated we generally recommend frequent small meals not just a great big plate full of meat and veggies for dinner the patient may actually prefer just to graze during the day rather than being presented with one big meal but generally avoid smells and sight that are disturbing for the person and that may be the smell of the food cooking for some people they just find that really difficult to tolerate and feel really nauseated by that so it might mean that you know they move to a different part they move to a different part of the house or they go outside when meals are being cooked fresh air in a calm environment is always very useful in terms of just keeping the person in a good frame of mind and not making them feel like there's things that are stimulating their nausea and vomiting and there's a general recommendation we should try and have people sitting upright after their meal so that the food can actually process through down to their gut appropriately the mechanism of nausea and vomiting is quite complex and I'm going to run through quite a simplified version of what happens to give us some idea of how we might choose which medications might be the most appropriate for different types of nausea and vomiting so as you can see here there's various different imports into your vomiting center and then your once the messengers reach your vomiting center you then release a whole cascade of effect through your body which will then stimulate you to vomit so prior to you actually vomiting you may feel nauseated or not and the stimulation will come from various different places so it may be your higher cortex Center so your cerebellum it may be through your balance center or your vestibular Center it may be through your chemoreceptor trigger zone which is very responsive to changes in chemicals in your body or it may be from your stomach or small intestine so when food is actually getting into that area and your body doesn't have the normal processes to process the food all of those stimulate back to your vomiting and there's other neurotransmitters in your vomiting Center that can be affected as well and we'll go through each of these in turn so when we're talking about the higher cortical centers being involved we're talking about generally sensory important that might be from the smell as I've already mentioned the smell of food for instance looking at things pain can cause you to feel nauseated fear and anxiety also can stimulate the feeling of nausea if we're looking at the chemoreceptor trigger zone it's normally toxins that are affecting that and so it'll be drugs are generally considered by your body to be a toxin as is when your body becomes out of balance in your biochemical your general biochemical balance is affected in some way and that will then influence through your chemoreceptor trigger zone to make you feel nauseated or to vomit your small intestine is about movement of food through your small intestine and that may be for a whole range of reasons you may have had surgery may have disease in your small intestine and so you can't transit food properly and that will give stimulation back to your vomiting center and then we have our balance or vestibular Center and that may be affected generally by movement so the most common people can think about is seasickness or travel sickness it's a very that is mediated through your vestibular Center but for people who have lost lots of weight their vestibular system might not be in quite the same balance as it would have been previously and so they can feel quite nauseated when they're being moved and then your vomiting Center and this controls your actual vomiting reflux process there can be various interactions that will happen that happened before you vomit so you get pale sweaty you get extra saliva and these are all moderated 3 or vomiting Center for each of these centers is their neurotransmitters that are involved and these affecting different ways the amount of neurotransmitter that's released it's different balances within each Center and these are mentioned here on this slide so for your higher cortical centers we're talking about things like gaba and serotonin your chemoreceptor trigger zone is mainly moderated by dopamine and serotonin your stomach and small intestine have a stock Hellenic mass screening and colonic receptors serotonin and dopamine receptors whereas your vestibular Center is mainly moderated by histamine and has some estoy Cola muscarinic input as well and you can see if your vomiting center also has input so when we're trying to decide by our assessment which of the Centers may be involved we're really trying to look at what neurotransmitters as listed here might be involved in nausea and vomiting and that's what we might be able to moderate with medication there's lots of different antiemetic drugs we can use and we will talk about these individually to try and relate them back to the types of nausea vomiting they'll be most effective in I'm also going to talk a little bit about the doses and the side-effects which you might see for each of these sorts of nausea and vomiting metoclopramide is the most commonly prescribed and here machine it has dopamine antagonism and a high dose serotonin antagonism as well but generally the doses that we're looking at for treating most nausea and vomiting we're looking mainly at an effect on dopamine it also has good prokinetic effect so for patients who have palliative care needs who may have nausea and vomiting either because they got is slowed or they have biochemical or drugged mediated nausea and vomiting metoclopramide is going to be our first choice and that is why generally in part of care we see a lot of metoclopramide prescribed because it generally is a good first choice and a good antiemetic for most types of nausea and vomiting so metoclopramide the general dose will be ten milligrams three times a day roughly eight hourly generally it's recommended it's given before food but that is really only important if we know that it's a prokinetic if it's the slowing of the gut then we want to get the drug into the person before they have their food so it's already working if it's caused more by about biochemical abnormalities or medication it doesn't particularly matter in relation to food when we take the metoclopramide the side effects that we see most commonly in sedation and extrapyramidal effects and we need to monitor for these there's a whole range of other side effects too that we may see with metoclopramide ranging from diarrhea and depression rashes itchiness so we need to always be monitoring for side effects metoclopramide ease contraindicated if we have a complete bowel obstruction so we don't want a drug that's going to be pushing and causing more peristalsis if we actually have actual blockage of the gut and they're also contraindicated in Parkinson's disease because of the dopamine effect so just to give a little refresher on what we mean by extrapyramidal effects because it's very important a lot of the medications we're using have dopamine effects we can have acute dystonic reactions where we get within a couple of hours generally patients will start to have facial spasm they may have ocular go crisis and that is where they may get a stiffening and straightening back of the neck and also their eyes might start rolling back so it's a very obvious effect but we need to always look for it they may get an echo seizure which happens over a longer period of time so just because a person hasn't had a reaction to a dopamine antagonists in the first couple of hours of therapy doesn't mean that they're going to be safe from any extrapyramidal effects so that's where they might get a restlessness and they just can't sit still it may be possible for patients to actually get parkinsonian type symptoms and that will happen after several weeks of therapy and also tardive dyskinesia which is less common in palliative care people because it generally occurs over several months of therapy but we need to be very mindful of what these adverse effects are and for them so let's move on to the next medication and that's protocol paracin prochlorperazine is a dopamine antagonists it also is a partial histamine antagonist and therefore it's going to be useful for any nausea vomitting mediated through the chemoreceptor trigger zone so any medication or biochemical abnormalities but by having the antihistamine effect it can also be useful for people who get vertical or movement induced nausea and vomiting as well it comes in various different formulations so it's available as oral rectal or injectable forms it's generally recommended that prochlorperazine isn't given subcutaneously because it can be quite irritant to the tissue and it also has the same precaution with Parkinson's disease because of the extrapyramidal side effects the doses are generally orally five milligrams TDS to four times a day we give higher doses if we're giving it intramuscular or intravenously we should though however try not to give it intramuscular intravenous is going to be far more effective but also not painful like an intramuscular injection the most common side effect with prochlorperazine is drowsiness but we can also see it's terminal effects we can get hypertension we can get confusion and we can get anticholinergic effects as well haloperidol is another very common antiemetic used in palliative care it is a stronger dopamine antagonists than any of our other agents that we use and therefore it'll often be our second line if we found that metoclopramide or prochlorperazine haven't worked then we may use haloperidol for nausea and vomiting mediated by chemoreceptor trigger zone type causes doses are generally low um we'll start with 0.5 for milligram once or twice a day and move up to 1 milligram the side effects are similar to the last two drugs I mentioned so drowsiness extrapyramidal effects hypotension haloperidol also can cause some confusion or agitation and we need to be looking out for that in terms of its drowsiness although it does have and generally at these low doses it is far less sedating than metoclopramide or prochlorperazine it comes in oral and injectable forms and can be used subcutaneously domperidone is very very similar to metoclopramide except that it only becomes available in an oral formulation and the most important note is that it doesn't cross the blood-brain barrier so therefore it doesn't have extrapyramidal effects making it one of the only ante medics we have for controlling nausea and vomiting in people who have Parkinson's disease the dose is similar to metoclopramide we would generally start with 10 milligrams TDS but we may move up as high as 20 milligrams qid the side effects are very limited and that makes it a very useful drug however because it's only available in oral formulation that means that if someone's actively vomiting it's not going to be useful because they're not going to be able to absorb the medication so generally it will be reserved for people who have nausea only then we have to antihistamine antiemetics promethazine and cyclers in promethazine is generally more sedating than cycling but both medications being antihistamines can cause sedation the doses promethazine is generally 2010 to 25 milligrams BD whereas cycling is 50 to d/s there different types of medication and so the dosing is quite different and we need to remember that they're both available in oral or injectable forms but promethazine is can be quite nourishing when given subcutaneously so we need to be mindful of that cycling however is tolerated quite well subcutaneously and it can be used in infusions as well if it is used in a subcutaneous infusion we need to dilute it with water rather than saline because it will precipitate out when mixed with water ondansetron is an antiemetic that she's commonly particularly in nausea and vomiting associated with chemotherapy and radiotherapy and also postoperatively and that's because it works on serotonin and so it's very useful in sort of situations where Northam vomiting is because of the release of serotonin generally because the body's under stress however it's not going to be useful generally for biochemical abnormalities or other medication induced nausea and vomiting because these don't have an effect on serotonin levels therefore it generally won't be useful for opioid induced nausea and vomiting for instance it does have a range of side effects um headache and constipation are particularly troublesome and are obviously not side effects that we want to see in patients with palliative care needs who are prone particularly to constipation because of other things as well the doses generally four to eight milligrams twice a day so to put all that into a summary we can see that various different medications are going to be useful for various different causes of nausea and vomiting and these are listed on this slide so in summary the medications that we're going to use are going to be dependent upon what we think is the cause of the nausea and vomiting where we think it's being mediated and therefore what neurotransmitters are involved so if we're talking about sensations having input into the higher cortical centers we're not going to specifically use antiemetics we're going to use medications like dexamethasone and benzodiazepines to reduce the sensational input into those areas when we're talking about nausea and vomiting induced through the chemo is set to trigger zone will be using medications that affect dopamine in particular so we'll be talking about metoclopramide prochlorperazine domperidone and haloperidol if we're talking about increasing motility through the gut we will be looking at metoclopramide and Don para donar to prokinetic antiemetics when we're talking about movement induced nausea and vomiting we'll be talking about the medications that affect histamine so particularly promethazine and cycling and prochlorperazine to a lesser extent but it is still quite useful in that setting if our first-line antiemetics haven't worked there we can look at using medications that affect the vomiting center and generally that will be antihistamines so promethazine and cycling so our basic principles for treating nausea and vomiting in public people with palliative care needs that if we've got nausea and vomiting present we're generally going to want to use an antiemetic on a regular basis so we would prescribe medical open mind ten milligrams TDS so that we can have medication in their system all the time rather than prescribing on an apparent basis where we're not having that constant effect on the neurotransmitter we will have a breakthrough antiemetic available as well encase in our assessment we haven't actually worked out what the major problem is for that person so for instance if we've chosen metoclopramide as our first line agent thinking that is mediated through the chemoreceptor trigger zone we might choose haloperidol is our PRN medication and back up because it's a stronger agent we need to reassess frequently because nausea and vomiting is a difficult symptom to assess and to work out the cause of and so therefore we need to have ongoing assessment and being prepared to change our antiemetic or even use to antiemetics if we think there's importing from two different causes thank you for watching video today audiojungle audiojungle audio channel

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