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Ok. Uh So welcome everyone uh to our prescribing and Surgery series. Um This is our second session on um fluids and electrolyte imbalance. My name is uh I, I'm one of the F one doctors um co uh for the prescribing and Surgery series with doctor My Gemme. Um So this is um uh a mind the bleep um medical research conference um that we'll be doing. Uh So if you guys could please in your spare time, um fill out the QR code on the sites. So this is the team. Um So doctor Sirna Patroon is the lead for prescribing at mind the Bleep and Doctor Hermione Gemma as well as myself, our co-lead for the prescribing in surgery series. So just a disclaimer that prescribing the surgery. It um it has been created by junior doctors. Uh It's entirely on an involuntary basis. We've of course, tried our best to make sure that the slides are accurate to the best of our knowledge. Uh But neither the teachers nor mindedly take responsibility for any unintentional inaccuracies. And this is um the provisional date for our prescribing in surgery series. So today's session will be on fluids and electrolyte imbalances and ne next week's session with uh doctor Hermina Gemme will be on antibiotics and blood transfusions. So this is our first case. So case one, a 70 year old woman presents to A&E with a four day history of vomiting positive history. She's got dementia, not currently on any medications on examination. Her respirate is 22. Her oxygen saturation is 97% on room air temperature. 36.5 BP, 100 and 5/60 heart rate. 100 and 20 heart sounds one and two present with no added heart sounds, chest is clear. Cap refill is three seconds. She's got reduced skin turgor and dry mucous membranes. In terms of investigations, her sodium is 100 and 39 potassium is 4.1. Urea is 16 and creatinine is 100 and 30. Uh So could you please uh in the chart write a prescription for one IV fluid that is most appropriate for the patient currently? Uh and I'll give you one minute for this question. OK. I'm just gonna check the chart for responses. OK. So for OK. Yeah. One, any any other suggestions? OK. Um OK. So, so for this question, what we're assessing is fluid resuscitation in adults. Um So the correct answer is sodium chloride, 0.9% solution IV 500 mL over 10 minutes alternative infusions that you could also give is ringer solution, plasma light and Hartman solution. Um and we would give it over. Uh so 500 Millers under 15 minutes. So, if you refer to the nice guidelines of 2017, it says for IV fluid resuscitation, we need to give crystalloids that contain sodium in the range of 130 to 100 and 54 minimal uh as a bonus of 500 mL over less than 15 minutes. So what tells us from the scenario that this patient requires fluid resuscitation is that the patient has signs of dehydration uh and hypovolemia. So the patient is tachycardic, hypertensive tachy and had uh dry mucous membranes as well as reduced skin turgor. Uh and the patient's urea and creatinine levels were also raised. Um So for the purpose of PSA in this kind of question, uh I would say to stick to 500 mL. But in clinical practice, if a patient is elderly, we tend to give 250 mL. Um And just to let you know that a volume less than 215 mL is not enough for a fluid challenge. Um And the correct answers would be anything under 15 minutes. So 15 minutes, 10 minutes, uh five minutes, even two minutes. Ok. I hope that helps. Um So the next case, so case two, a six year old boy presents to pediatric A&E department with a three day history of diarrhea and vomiting, um doesn't have uh any medical conditions or any, doesn't take any medications on examination. His respirate is 36 oxygen sats 98% on room air temperature, 36.5 and uh BP, 90/60 heart rate. 140 heart sounds one and two present. Uh no added heart sounds. His chest is clear. Cap refill is three seconds has reduced skin turgor and dry mucous membranes. Uh His weight is 15 kg in terms of investigations, sodium is 100 and 39. Potassium is 4.1. Urea is 12 and creatinine is 85. Uh So please, for this question, could you write a prescription of one IV fluid that is most appropriate for the patient currently? And can you please write it in the chart and I'll give you one minute for this doctor? Ok. Um Please be right in the chart. Um OK. And when we say now like I 15 minutes of EKG OK. OK. Um So for this question, uh so the correct answer uh would be sodium chloride 0.9% solution IV. Uh So it's 10 mL per kg. Uh And this patient's weight is 15 kg. So you'd give 100 and 50 mL and you'd give it. Um So for five minutes. So alternative infusion foods you could give is ringer solution, plasma, light heart solution. And uh the nice guidelines uh 2020 say to give 10 mL per kg under 10 minutes. So under 10 minutes would be 10 minutes, five minutes and even two minutes. Um And so again, in the case, the patient, you know, was hypertensive, had tachypnea, hypertension, tachycardia reduced skin tag. So we're looking at fluid resuscitation in Children for this question. OK. OK. So now we move on to case three. so case three is a 22 year old man who's admitted on the medical ward for aspiration pneumonia. Past medication, he's got cerebral palsy. Uh he takes baclofen uh and on examination, his respirate is 12 uh oxygen sats 98% on room air temperature. 36.5 BP, 100 and 40/80 heart rate, 70 heart sounds one and two present, no added heart sounds, uh crackles heard on auscultation and he's judged to have an unsafe swallow. His weight is 80 kg. Um So investigation sodium is 100 and 41 potassium is 4.3. Urea is 6.8 and creatinine is 60. He's already had sodium chloride, 0.9%. Uh potassium chloride, 0.3% bag. So 1000 Millers over 12 hours. Um So can you please write a prescription for one IV fluid most appropriate for the patient currently, whilst he's near by mouth and again, if you could write in the chart and I'll give you a minute for this question. OK. No, see that. Um any other suggestions? 180. OK. Any worse? Ok. Ok. So for this question, what we're assessing is uh so we're assessing fluid maintenance in adults. So if you look at the nice guidelines from 2017, it says in terms of daily requirements for uh patients that uh need IV fluids for routine maintenance alone. Um For example, if a patient is near by mouth, they're awaiting operation or if they have an unsafe swallow like our patient, um they require 25 to 30 mL per kg per day of water as well as one minimal per kg per day of potassium sodium and chloride and 50 to 100 g per day of glucose. So now if we look at the fluid infusion bags that are available, uh when we prescribe maintenance fluid, we give 8 to 12 hourly bags. So that means we give bags over 12 hours, 10 hours or eight hours. Um The fluid bag infusion bags available are um so you can give sodium chloride 0.9% with potassium chloride of 0.15% or you can give sodium chloride 0.9% with potassium chloride, 0.3% or you can give glucose 5% with potassium chloride, 0.15% or glucose 5% with potassium chloride, 0.3%. Uh and in terms of the composition of the above bags. So sodium chloride, 0.9% 1 L contains 100 and 54 minimal of sodium and chloride. Potassium chloride, 0.50% 1 L contains 20 millimoles of potassium uh potassium chloride, 0.3%. Uh 1 L contains 40 millimoles of potassium and glucose. 5% over 1 L contains 50 g of glucose. Um I would say uh in terms of maintenance, fluid questions stick to using the above bags because if you use Hartman's or ringers, uh 1 L of both bags contain five millimoles of potassium. So that could kind of complicate things when you're trying to calculate uh daily requirements. Um And as you can see on the right, the combination of food bags uh uh um available can be found on the BNF. Uh And this table just gives you a composition of the commonly used crystalloids in more depth. So for this question, the way that I would calculate it is um as this patient's weight is 80 kg, uh we know that his water requirements would be 25 mL per kg times 80 which is 2000 mL. Uh and then 30 mL per kg times 80 kg, which is 2400 mL. So his daily requirement for water is 2000 to 2400 mL. Um And in terms of his sodium uh or chloride um requirement, it would be one minimal per kg times 80 kg, which is 80 minimal of sodium uh such chloride. Um And his daily requirement of potassium is one minimal per kg times 80 kg, which is 80 millimoles of potassium. Uh and adults uh daily requirement of glucose is 50 to 100 g. So the question stated that the first bag given was sodium chloride, 0.9% potassium chloride, 0.3% 1000 mL over 12 hours. So that means this patient has already been given 1000 mL of water. 100 and 54 minimal of sodium and chloride uh as well as 40 millimoles of potassium. So that means in our second bag, uh we need to give 1000 to 100 and uh 1000 to 1000 400 mL of water. We don't need to give this patient any more sodium or chloride. We need to give them uh 40 millimoles of potassium and 50 to 100 g of glucose. So that means the second bag we give for this patient is glucose 5% slash potassium chloride, 0.3% solution. 1000 mL over 8 to 12 hours. Uh That's because this bag will contain 1000 mL of water, 40 minimal of potassium and 50 g of glucose. Um I hope that makes sense. OK. So now if you move on to our next case. So in case four, we have a 56 year old woman who presents to A&E with a two day history of diarrhea, which she said started after eating takeaway. Uh in terms of her past medical history, she's diagnosed with hypertension for which she takes uh amLODIPine 5 mg 5 mg daily on examination, her respirate is 12. Her oxygen sats are 99% on room air and her temperature is 36.2. Um, her BP is 100 and 40/80 her heart rate is 80. Uh heart sounds one and two are present with no added heart sounds and her chest is clear. Um, her weight is 80 kg. Um in terms of investigations, her sodium is 100 and 31 potassium 3.2 urea 5.4 and creatinine 60. Um So the question is uh could you please write a prescription for one IV fluid that is most appropriate for the patient currently? No, and I'll give you guys a minute this question. Uh Any suggestions for this question? OK. Is 500 minutes to seven hour. OK. Um Any other suggestions? Ok. OK. That's fine. Um OK, fine. So for this question, um what we're assessing is fluid maintenance and replacement in adults. OK. So nice. Uh guidelines 2017 says that we should adjust the IV prescription uh to account for any existing fluid and or electrolyte deficits or loss. Ok. Um So this patient has diarrhea. So if we look at the diagram on the right, um it says that when you have diarrhea, you know, you're using your sodium, your potassium and your bicarb. Uh In the question, the sodium and the potassium were just below the normal range. But if the patient continues to have diarrhea it will worsen. And therefore, we need to prescribe fluids that will replace the sodium and the potassium that's being lost. Therefore, the correct answer would be to give sodium chloride 0.9% potassium chloride, 0.3% infusion fluid. Uh We would give this IV and we would give uh 1000 mL over 46 hours. Um So it's better to prescribe uh infusion fluids containing potassium chloride, 0.3% solution instead of potassium chloride, 0.15 solution. The reason being is that the patient's weight in this question is 80 kg. So their daily requirement of potassium is 80 minimal. Um And the patient is also using around 30 to 70 millimoles of potassium because of the diarrhea. Um So it's better to prescribe potassium required 0.3% solution which contains 40 millimoles of potassium rather than 0.15% which contains 20 millimoles of potassium. Um And when prescribing fluids for maintenance and replacement, instead of giving a 8 to 12 hourly bag, we prescribe 4 to 6 hourly. So we prescribe it a lot quicker and that's to replace the loss or deficits. So um 4 to 6 hourly bag means you can prescribe over six hours, five hours or four hours. Ok. Yeah, I'm starting to see suggestions, let's say uh 6/6 hours, four hours. Ok. Um But y uh so the suggestions are in the chart, people are saying heart mint sodium chloride, normal saline. Yeah. So, so you'd give sodium chloride with potassium replacement. Ok? Because they're losing the potassium because of the diarrhea. I hope that makes sense. Ok. So our next case case five. so there's an 11 year old gal who's admitted to the pediatric ward and treated for tonsillitis with Clarithromycin past. She's, she's got rheumatic fever. Um and she doesn't currently take any medications. Uh she's allergic to penicillin on examination. Her respirate is 12. Her oxygen saturate sats are 99% on room air. Her temperature is 36.5. BP is 100 and 30/80 heart rate is 80. Um, heart sounds one and two present. No added heart sounds. Her chest is clear and her weight is 35 kg. Um In terms of investigations, her sodium is 100 and 39. Her potassium is 4.2. Urea is 5.4. Creatinine is 40. So for this patient, can you please calculate the 24 hour maintenance food requirement? Um And can you put it in the chart and I'll give you guys a minute for this question. Yeah. Um Any suggestions for this question? Ok. Um Anyone managed to calculate the 24 hour maintenance food requirement? Yeah. Uh If not, that's fine, we can calculate together. Um ok, so I'll go through the explanation. Um So if you look at the nice guidance from 2020 it says to calculate the routine maintenance IV fluid rates for Children and young people. We need to use the holiday Sear formula. Um And what that says is that you would give 100 mL per kg per day for the 1st 10 kg of weight, you then give 50 mL per kg per day for the next 10 kg. Um And then 1020 mL per kg per day for weight over 20 kg on the right. You can also see a table that is found on B NFC if you go on the fluids and electrolytes page. Uh So you don't need to memorize the Holiday Saga formula for your PSA exams. So if we use the holidays formula for this patient, so the patient weighs 35 kg. Uh So her weight's over 20 kg. Um This means for the 1st 10 kg, we would give uh 10 kg times 100 mL. So that's 1000 mL for the next 10 kg. We would give 10 kg times 50 mL, which is 500 mL and for her remaining weight which is 15 kg, we would uh give 15 kg times 20 mL, which is 300 mL. So her total fluid maintenance is 1000 and 800 mL over 24 hours. Does anyone have any questions? Ok. Um If not, I'll move on to the next question. Ok. Um So now we move on to case six. So case six, an 80 year old woman is admitted to the trauma and orthopedics ward. After surgery for her neck of feur fracture ward. Doctors have been asked to see the patient as she becomes unconscious. After the ward round past medical history, she's got type two diabetes um for which she takes Metformin 500 mg three times a day with meals on examination. Her respirate is 12. Her SATS are 95% on room air. Her temperature is 36.5. BP is 100 and 40/70 heart rate is 90. Heart sounds one and two present. Uh no added heart sounds, her chest is clear and her blood glucose test is uh 1.3. Uh She's unresponsive to Glucagon after 10 minutes. Um Could you please uh in the chart, write a prescription for one IV fluid that is most appropriate for the patient currently? Ok. So we've got uh someone said 10% glucose status. Ok. Um Any other suggestions? Ok. Ok. 5050 mL, I think. Ok. So the key thing for this uh question is to note that the this patient has severe hypoglycemia. Uh The fingerprint finger prick glucose test is 1.3. The patient is unconscious and is unresponsive to Gluco can after 10 minutes. Ok. So if you look at the B NF nice guidelines, it says if the hypoglycemia is prolonged or if the patient is unresponsive to glucagone after 10 minutes, we would give um a glucose 10% and we would give 100 and 50 to 200 mL over 15 minutes or we would give glucose 20% IV 75 to 100 mL over 15 minutes. Um So an advice I'd give you guys is to kind of try and stick to learning uh one volume. So, for example, for me, I learned glucose 10% 200 mL uh or glucose 20% 100 mL rather than learning the range and maybe getting get confused. Um So I hope that helps. So if we then check uh the BNF guidelines, um it includes uh kind of more in depth on how to treat hypoglycemia. So if you go on the BNF medical emergencies in the community section, it's got detailed guidelines on how to treat hypoglycemia. So, of course, first line is by mouth, we would give a glucose liquid or if the patient is conscious but uncooperative, we would give bal administration. Um if the oral route cannot be given is when we give the Glucon injection and if the hypoglycemia is prolonged or if the GlucaGen is not working after 10 minutes is when we give the um is when we give the glucose 10% or glucose 20%. I hope that makes sense. OK. So our next case is case seven, a 45 year old man is being treated in A&E for burn secondary to a house fire. During admission, he suddenly develops palpitations and chest pain. Uh So his past history has got eczema on examination, uh, respirate 12 oxygen sats 97% on room air temperature. 36.5 BP, 100 and 40/70 heart rate, 100 heart sounds one and two present, um, chest clip. So in terms of investigations, sodium is 100 and 40. Potassium is 6.6 urea 7.6 creatine, 85 ECG shows two tented T waves and flattened P waves. So please in the chat, if we could uh write a prescription for one IV fluid that is most appropriate for the patient currently. Uh And I'll give you guys a minute for this question. OK. Any, any suggestions for this question? Ok. So OK, take care. Thank you. Um OK. So in this case, what we were assessing is that the patient has um severe hyperkalemia. So the patient's potassium uh was above 6.5. Um um So if we check the nice guidelines, what it says is that you would give calcium chloride 10% or calcium gluconate 10%. And that would be to temporarily protect against myocardial excitability. And then we would prescribe insulin glucose and salbutamol um to reduce the plasma potassium concentration. Um we would only give salbutamol if there was no tachy arrhythmia present. So if we look at um guidelines from the renal association 2020. Um So in this uh case, it's severe hyperkalemia because the potassium was 6.5 there were ecg changes present, there was peaked, uh T waves as well as flattened P waves. Um Therefore, what we need to prescribe initially is calcium chloride or calcium gluconate IV. So the correct answers would be calcium chloride. 10% IV, 10 mL over five minutes or calcium gluconate. 10% IV, 30 mL over 10 minutes. So if you look at the Renal Association guidelines, it does say that we can give calcium gluconate 10% over five minutes. But if you referred to the nice guidelines, um 2024 it says that 30 mL of calcium gluconate needs to be given over 10 minutes. Uh So for full um kind of uh exam purposes, um I would say to give it to follow the BNF guidelines and give it over 10 minutes. Um So, so yeah, I've seen someone see say normal saline and ringers lactate. So um to treat hyperkalemia as an initial infusion of fluid, we would give calcium chloride 10% or calcium gluconate 10%. Um And that's to protect the heart against the effects of the hyperkalemia. Um I hope that makes sense. So now we go through case eight. Um So case eight, a 30 year old woman presents to A&E with myalgia and generalized weakness. Uh Past medical history shows that she has acne vulgaris for which she takes Benzyl peroxide on examination. Her respirate is 12, her oxygen sat is 96% on room air temperature, 36.5 BP, 100 and 40/70 heart rate, 90 heart sounds one and two present, no added heart sounds. Uh chest is clear in terms of investigations, her sodium is 100 and 40 potassium is 2.2. Urea is 5.4 creatinine is 60 her ecg um shows ST depression and a prominent U wave. Um So please kindly in the chat. Could you write a prescription for one IV fluid that is most appropriate for the patient? Currently? Uh any suggestions for this question? Ok. Um We can go through it together. So in, in this scenario, the patient has severe hypokalemia. Um and her potassium is 2.2 she has myalgia and generalized weakness which are signs of hypokalemia. And she's also got ECG changes with ST depression and a prominent eu wave. So if we check um the BNF guidelines from 2024 it says that the initial treatment for correction of severe hypokalemia is potassium chloride with sodium chloride. Um They said that initial potassium replacement therapy should not involve glucose infusions because glucose can further decrease the potassium concentration. Um And the max rate that we can give uh potassium without ECG monitoring is to give 10 millimoles per hour. We already know that potassium 0.3% contains 40 minimal of potassium. So the shortest duration without ECG monitoring is four hours. Therefore, the correct answer is sodium chloride 0.9% potassium chloride, 0.3% solution IV. And to give 1000 mL over four hours. Uh for the purpose of the PSA I would stick with a max rate of 10 minimal per hour. In practice with ECG monitoring, we can give a max rate of 20 millimoles per hour. Also, in practice, we need to check the magnesium level and correct it as low potassium can be caused by low magnesium. And if you don't treat low magnesium, it can make it difficult to treat low potassium. I hope that makes sense. So case nine, a 60 year old man presents to A&E with nausea, constipation and painful bones. Uh He's not diagnosed with any medical conditions and he takes calcium supplements on examination. Uh His respirate is 12 oxygen sats 98% on room air temperature. 37 BP, 100 and 40/80 heart rate. 80 heart sounds one and two present with no added heart sounds, chest clear investigations. So his calcium's 3.5 his sodium's 100 and 42. His potassium is 4.4. Urea is 5.7. Creatinine is 60. So please in the chart, could you write a prescription for one IV fluid that is most appropriate for the patient currently? Um, and I'll give you a minute for this question. Ok. Ok. Someone said 10 min more potassium over 12 hours and normal saline every eight hours. Ok. Um, any other suggestions. Ok. Yes. So this uh case uh shows severe hypercalcemia. Um So if you think about the causes of hypercalcemia, it could be caused by dehydration or excessive calcium supplements. Um, and the symptoms are uh kind of painful bones, nausea, vomiting, constipation, and it can also present with psychiatric symptoms like uh anxiety or depression. Um, and we can see from the investigations that this patient's calcium is 3.5. Um, The normal range is between 2.14 and 2.51. So in terms of the nice guidelines for severe hypercalcemia, um they said that the first thing we should uh correct is dehydration and we should correct this with the IV infusion of sodium chloride. We should also stop uh drugs like thiazides and Vitamin D compounds and bisphosphonates are useful and pamidronate is uh most effective. Um So when we already know when prescribing fluids for maintenance and replacement, instead of giving the 8 to 12 hourly bag, we need to give uh 4 to 6 hourly bag because we're replacing uh a deficit. So the correct answer would be sodium chloride, 0.9% I va 1000 mL over 46 hours in severe hypercalcemia. Um because we're correcting dehydration, we tend to give around 2 to 3 L over 24 hour period. But of course, uh we need to be more careful and uh consider reducing the total daily volume if the patient is elderly or has heart failure. Um If you do give IV pamidronate, we need, you need to make sure to monitor calcium and phosphate because it lowers the levels and can cause seizures if the levels become very low. I hope that makes sense. So this is our last case for today. Um So this is case 10, uh a 30 year old woman presents to ae with perioral paresthesia and muscle cramps past medical histories. And uh she's diagnosed with anxiety for which she takes sertraline on examination. Her respirate is 12. Her oxygen sets on 98% on room air. Her temperature is 36.5 BP, 100 and 40/70 heart rate. 90 heart sounds well and two present with no added heart sounds, chest is clear, uh S signs positive and sign is positive. Her calcium is 1.5 sodium, 100 and 41 potassium, 4.3 urea 6.3 creatinine 60 her ECG shows a prolonged QT in the chart. Uh Can you please write a prescription for one IV fluid that is most appropriate for this patient initially? Yeah. Any any suggestions for this question? OK. We can go through this together. Um Oh OK. Someone said calcium gluconate and normal saline? Ok. OK. Thank you. So, so this case uh shows severe hypocalcemia. Um So symptoms that if you, I just go back to the case quickly. So the patient has perioral paresthesia, hasso signs positive uh which is the carbo pedal spasm. Um When the bronch uh brachial artery is occluded when you use a pressure cuff. And the SPS sign is facial muscle twitching. When you tap the protid, uh there's also prolonged QT shown in the ECG. So nice guide. Uh So the B NF 2024 show says that um you'd give initial slow IV injection of calcium gluconate 10% uh followed by continuous IV infusion to prevent reoccurrence. So initially, you'd give 10 to 20 mL, calcium gluconate injection, 10% followed by a continuous IV infusion initially fif 50 mL per hour and adjust according to the response. Um And you administer it using 100 mL of calcium gluconate, 10% diluted in 1 L of glucose, 5% or sodium chloride. 0.9% in clinical practice. Make sure to give the infusion after to ensure the patient doesn't become hypocalcemic after the initial IV injection. This question um was asking for the initial IVF uh fluid. So the initial IV fluid is calcium gluconate 10%. Um So you can give 10 to 20 mL uh over 5 to 10 minutes. So if you decide to give 10 mL, you, you give that over five minutes. But if you decide to give 20 mL, you give that over 10 minutes. Um And then in clinical practice, you'd have ECG monitoring and you would give repeats as required. Uh So this is just uh illustrating what we mentioned earlier, which is that if you give 10 mL of calcium gluconate, 10% you'd give it over five minutes. Uh And you'd also do ECG monitoring and calcium monitoring. Um and also to prevent reoccurrence, you'd give a continuous infusion after. So these are the references um and this is a feedback form. Um If you could kindly uh please uh fill out the feedback form, it helps guide us for our future sessions. It lets us know what went well and how we can improve. And it also allows you to get a certificate of attendance. Um And the next session is on the sixth of March on antibiotics and blood transfusions, which will be delivered by Doctor Hermione Janet. Um Thank you for attending today, sir.