hi everybody I am Dr arushi Chri I'm doing my PG in Internal Medicine from Kims baneshwar I am back here to ask another question a lot of my juniors interns colleagues have been asking me and even my me myself do not have much idea about this there is a peculiar question they've been asking me what should be the initial ventilator settings while ventilating a patient so sir could you throw some light on it so than thank you IU for this question and this question has been very much asked on our Channel also so so whenever you ventilate a patient so what should be the initial setting we should keep so obviously whenever you go in the textbooks or um you manuals of critical care there is a whenever you study a venation chapter there is a table in which they give you different different settings for the initial ventilator settings and these are good tables and they give you an idea what should you start but what we are going to do in some 10 to 15 minutes uh of today's video that we'll try to understand the concept so that you will not forget whenever you are ventilating patient you will have better idea what those tables and what those settings are all about so I would start in a way that we'll divide the patients uh in certain categories so that in which category of the patient we should ventilate like that so I see like we need to V at and oxinate the lungs so oxin when we are talking about oxin is about providing the oxin oxygen and when we are talking about the ventilation we are talking about carbon dioxide so we need to ventilate the lung so we can divide the patient in certain categories like one first condition is you have a normal lung your patient is having a normal lung you are just ventilating or oxidating for some different uh reason like in uh gulan Berry syndrome or mathenia or patient became suddenly unconscious for XY reason arthia or some thought of so there is no problem in the lung parena or lung Airway there is no problem in the lung broncas or like that and no problem in the hill life so we are ventilating in normal then you have have patients with COPD and Asthma where the problem is mainly of the airway the parena is sort of normal so this is second category thirdly you have patient with a normal Airway but there is a problem in the parena it could be pneumonia it could be basil elect eles it could be congestive card failure like that there's a problem in the lung Eli lung parenta the sever form of this category is ards which is a different sort of scenario where there is a very stiff lung and you El has very much collaps and you need to ventilate such patients now now this is just about the lung like that you also have a combination of certain things when you are ventilating patient so you can have a patient with normal lung and patient is in trauma so that is a patient is in shock or for some reason so patient is in shock and you need to ventilate the patient can be in sever metabolic acidosis patient is hyperventilating and then you need to ventilate then one more important category is patient as having some neurological insult whether it's uh intal bleed or head injury or gtcs something like that so we'll try to find out the answers in dividing the patient in this category so uh you I hope you got this point yes sir so first we'll start with a normal normal individual so there is no problem with the lung parena there is no problem in the lung Airway only thing you need to you are ventilating because you just need to support the uh uh um oxidation and ventilation like in Gan Berry syndrome or mythia or motor neuron disease there is a problem with the pump so you need to understand and keep an eye on six parameters you just need to keep an eye on six parameters while ventilating so first will be your mode which mode second is your F2 third is your uh I would say tidal volume or pressure fourth is your respirator fifth is your Peak deep and the sixth is your I ratio I ratio so these are the six parameter which will play a part in adjusting the ventilatory settings so because we are discussing the initial ventilator settings so I assume that all the patients in whom we are ventilating we are giving sedation and neuromuscular blockers while ventilating the patients and we have give sedation to the patients and we are starting the ventilation so we'll keep we we'll assume that all patient which we have just incubated they are in in knockdown state with either some NE sedation or neuromuscular blockage so the first category so in first cat category where there is a normal air normal lung you just need to support the system so how will you do that first obviously the mode will be a control mode it can be volume control mode or it can be press pressure control mode secondly F2 so F2 because uh when you uh incubate a patient there there is a uh we don't know what is the safe apnea time you are just you have o ventilated the patient so for few minutes there is a depletion of the oxygen Reserve how much you have ooded the patient how much you have preate the patient so for few minutes uh some 5 to 10 minutes you keep the F2 on 100% yes so that whatever the Luna has there or whatever time Gap is been there during ventilation ventilating the patient it can get covered up then after that you need to Target the f52 according to your P2 level and SP2 level so initially we have to be safe we have to give the patient 100% And then we'll tiate accordingly by seeing the P22 and SP2 you need to careful this in Pediatrics but we are not talking about Pediatrics we are talking about adult patient so this is safe to give 100% fi2 for few 5 to 10 minutes then you will Target the F2 so that your P2 in the ABG is about 80 and SP2 is about 94% so this should be your tar Target so you can adjust accordingly then the second you have have you have selected your mode you have selected your F2 then comes your tital volume so how much tidal volume so because this is a normal lung usually the book say that every patient now should be ventilated with lung productive ventilation so 6 ml per kg but 6 to 8 ml per kg body weight in a normal lung is fair enough so for 60 70 kg patient somewhere around 420 to 450 is a good tidal volume you can multiply and then check so tidal volume is somewhere like this then minute ventilation is also there sir so H so once you have decided the tidle volume suppose 450 is the tidle now you need to because we are just replicating our normal respiratory p uh pattern in this with a normal lung so respiratory will be 12 to 14 so that your minute ventilation is somewhere around 6 to 7 L per minute so 45 into 12 45 to 14 somewhere like so minute ventilation should be there so this goes your respiratory so mode tidal volume mode F2 tidal volume respirator now two things left is one is your peep and other is your I so peep you should keep a physiological peep it's somewhere around 0 to 5 so we can we usually keep somewhere around 3 to 5 there is no brain no rocket signs you keep 3 to5 whatever is feasible because what happens so uh those who are listening they should understand that what is normal physiological peep what peep means is positive and expiratory pressure so at the end of expiration there is certain pressure which keeps the L open up it doesn't let the L collapse if there is no peep L will collapse so there is a peep which doesn't allow the pressure to go beyond certain limit so can you tell what is the what system keeps a physiological p in our normal patient sir in normal patient glotis GL GL is there so suppose now I'm not speaking so this is the airway this is the peep is maintained yes so whenever you talk the peep is lost when when you when you not talking so this physiological peep escaping and when you ventilate the patient incubate the patient you go between the vocal cords and then that physiological peep is lost so for that matter 3 to 5 uh is the peep value which you should keep on the machine on the on the machine on the machine and then you have an i ratio so I ratio because the lung is normal so in a normal patient average breaths are 12 to 14 per minute so if we keep 12 so 1 second for uh inspiration and 3 second for expiration so it covers now your 60 seconds so inspiration 1 second expiration 3 seconds so I ratio becomes 1 is to 3 m some says 1 is to 2 some says 1 is to3 so we keep 1 is to three so in a normal patient with a normal lung these are the settings a control mode fi2 100% then adjusting about according to the SP2 and your P2 then you have a minute ventilation so tidal volume and then into respirat why minute ventilation is important because if minute ventilation is too high like this pco2 will get wash out if minute ventilation is too low 4 lit 5 lit so ventilation is not taking place so pco2 be build up minute ventilation should be around 6 to7 lit so if you decrease the tidal volume increase the respirat if you increase the tidal volume then decrease the respirat so that minute ventilation should remain then you have physiological Peep and then you have normal I ratio okay yes sir now comes with second category of patient where there's a problem of the airway asthma and cop sort of sort of patients now what is the challenge in these patients two three challenges one is very obvious hyper ination of the lung is there sir so there will be air trapping air trapping is one but more than important that is the airway resistance what is happening one is air trapping so lot of amount of air is there which is not getting exit because the lung is not pushing them out secondly if at all the lung is getting out there is a resistance from the uh Airways it is not allowing the air to get exited properly so what is the problem is there is no problem in the oxygenation the problem is in the ventilation part so we need more time for the P to get exit so what setting adjustment you can do control mode is the same fi2 is the same tidal volume uh you have respirator Peep and I ratio which you can adjust obviously we need to maintain minute ventilation so we'll keep the tidle volume and respirate accordingly but important is here is I ratio which is very very important and the respirat rate so in that in this particular cop patient you need more time for the expiration so you can increase the I ratio 1 is to 3 to 1 is to 4 to 1 is to 5 to 1 is to 6 means if 1 second we are giving the time to Exhale you have four five 6 second for the ex second exhalation so we can increase the I ratio I have seen many COPD you have done everything right but I ratio remains 1 is to one somehow in the default setting or some like ventilator setting during vtil shifting and you feel that how this patient is retaining pco2 so keep an eye on I ratio it can can be 1 is to 4 1 is to 5 or in very severe patient 1 is to 6 secondly what will happen in this ke the air will go fast and it will slowly get exit secondly if if this is if this is not helping you out you can take care of you can help take help of the respirator rate if you decrease the respirator rate there will be more time for the year to come out if you hyperventilate such patient in a in an effort to incre is the pco2 exhalation but you are not allowing the uh through the I ratio the air to get exhale it will cause increase in the pco2 so you can decrease the respiratory rate you can increase the I ratio and if if that is not helping all you can play with the tidal volumes so this is something but in cop patients and asmatic patient two things also you need to understand that whenever give positive pressure ventilation to the patient so there is a increase in inic pressure because of increase in the thoracic pressure the preload which is coming from the um IVC and from the whole body and S SPC it gets decreased so there is an hypotension so make such patient prefill uh adequately make them U give some fluid bolus also you have given certain drugs which can cause hypotension so you can give some certain amount of flu buus during ventilation secondly if your eye ratio settings or if your respir settings if this is not correct it is very high what will happen the lii air trapping is already there they like get if their life get hyperextended they will get crushed so what will happen it will cause Dynamic hyperinflation and this will again crush the capillaries in L capillaries and there is a drastic fall and hyp potential how how can you check that simple rule disconnect the ventilator for few seconds and you will see BP start coming up very fast so this way you can check it now a a simp a word of question on peep what should be the peep so this is tricky in a in sorry airware disease patients usually we don't want the peep to be high in such patient because we don't want the at the end of expiration we don't want a pressure high we want the pr air to get released but there is a condition in Airway where there's Airway becomes fragile what happens during uh expiration if the patient is hyperactive it's not properly sedated it also tries to get active expiration so intrathoracic pressure causes the airway to collapse already there is a narrowed Airway during expiration there is resistance and if the patient hyper ventilate this is when patient is hyperactive on the ventilator then the this intrathoracic pressure build up causes the airway to collapse so for those collapsed Airway to remain open we need to increase the Peep Peep so that they don't go collapse so whenever a patient such patient who is hyper alert on this COPD patients and you are feeling that he's not able to you are not able to oxygenate the patient it's not about ventilation you are not able to oxidate the patient and this this is creating a problem so so in later stages of c h later stages it's an advanced stage of COPD you can increase a little bit of feep and check whether it is helping you outnight so this is just the concept you need to remember now I think we have covered normal lung then air L air and now the problem uh there is a third category of the ventilation in which there is a problem in the parena parena so it could be mild modate sort of like CCF is there bascus is there there is pneumonias are there so here we are not worried about CO2 problem we are worried about we need to oxinate the patient we need to keep the the P2 high so how will you do that obviously mode will remain the same then you have F2 obviously is a temporary measure we can increase minute ventilation has to be in the range of which is or require 6 to 7 l so tidal volume will remain same now what you have with you I ratio Peep and respirat rate now in this peep we can increase slightly like in CCF or like that there is a fluid in is there there is a consolidation is there we need to give a little bit you need to expand the L so we can increase peep up to 5 6 7 not more than that why not more than that because these are patchy diseases now in normal lii will get compromised they can get rupture so somewhere we need to increase the peep up to eight we can increase some can go safely up to 10 but 8 is a safe limit now if that doesn't help uh we can increase the rest a little bit high from 14 to 16 to 18 to 20 we can keep keep it little bit High then you can play with I ratio so here what is the problem we need to make the oxidation better so we'll increase the inspirat time so you are ventilating a patient on 1 is to 3 now you can go to 1 is 1 is one is very extreme we'll discuss in the ideas but up to go to 1 is to two but that's the principle now you are allowing more time for for inspiration and less time for expiration now the same continuation of this parent disease is Extreme is ards where there is very much po2 we are not able to oxinate the patient so now we need to go to take extreme steps so first thing is obviously mode uh mode we prefer pressure control mode in this because we have a safety limit in it so we know how much pressure we are giving otherwise it will again lead lead to volum trauma pressure trauma like that barot trauma baruma so pressure control mode which I personally prefer in ards and many some books also say that intensivist are more comfortable with pressure control because you know at what pressure you are giving the breast to the patient F2 obviously 100 according to F2 then comes your tidal volume so every study every guideline has set told that in lung protective ventilation 4 to 6 ml per kg body weight you need to give the tidle so tidal volume we need to keep low and then because you need to maintain vit ventilation what you will do respirator respirat will be high up to 35 you can go that's the limit so up to 35 you can go to uh respirat in secondly when if these are not helping you out see on low tidal volume on high respirator if you are not able to oxinate then on I ratio what you need to do you need to give more time to the patient to for inspiration so what you will do is you will come to 1 is to one ratio from 1 is to 3 to 1 is to 2 1 is to one and when you go beyond that you have increase the inspirat time to 1.2 second and8 is the uh expiratory time so you have reverse the ratio means in normal patient inspir time is less and expir time is high but now you're giving inspirated time more than the X time that's why it is called inverse ratio ventilation so I ratio will be revered or it get to 1 is to one or 1 is to two like that then uh PE so once you have oxidated the patient once you have opened up the Ali you want don't want the Ali to get collapsed so you increase the peep you give more positive pressure up to 8 10 12 up to 24 people have given so in ards it's just lot whole different lecture but you understand the concept low tidal pressure control mode low tidal volume High respirat rate high ratio 1 is to one or can we reverse and then high PE so these are the initial setting ultimately our goal is to maintain the oxygenation and ventilation now what will happen because we are giving low tidal volume and respiratory there is limit of 35 and you have an i ratio in which you are not allowing the pco2 to get out means M exhalation you are not allowing so what will happen the pco2 will rise in such patient yes sir pco2 will rise so but the problem is your body tolerates hypercarbia better as compared to hypoxia so hypoxia is not well tolerated but pco2 will get tolerated so you allow pco2 to rise Beyond a certain level or up to a certain level which is called as permissive hyper carvia which is written in ad to how much permissive till your pH because of the puu drops to 7.15 and beyond that you can use soda bicarbonate which is written in the guideline so this is the concept of permissive so this this uh completes the patient who has only lung pathology normal lung with airway disease with parental disease in moderate categories mild moderate and then you have sever category which you have Ardis now we were discussing before this video very crucial points uh that no the patient usually in intensive care whenever they get mined they come up with a combination things like so suppose a patient is in shock whether it's a normal lung Airway or whatever patient is in shock patient is not able to maintain the blood pressure so and now you are providing a positive pressure ventilation to the patient so you need to make sure that the BP doesn't get scratched after ventilating so you need to First make sure the patient is prefill patient is U volic and give bull assist to the patient what if possible if that's not the case you need to take a little amount of V presses like n support so if the pressure is on 6070s blood pressure systolic you give the fluid if that is not making the pp take the patient norling because whatever you do 10 to 20 mm of EDG blood pressure will be drop so even if it is 100 you take a norling support of 2 to 3 ml per kg so that 2 to 3 ml per hour so that your blood pressure is in the safe range so take precaution in that you give flute Bolis make the patient UIC and then take if the support of VES now there is one more scenario like if the patient has severe metabolic acidosis and the patient is hyperventilate like that and you know you are going to ventilate now what happens that patient is having severe metabolic acidosis whether high or normal that's a different thing but because to compens body is trying so if the patient is having severe metabolic acidosis so pH will drop in that compensation the pco2 patient hyperventilate and exhale pco2 so your pH bring backs to 7.3 or 7.2.5 like that body tries to do that so pco2 gets low and it compensate the pH but when you ventilate the patient so metabolic acidosis is is there itself there's no change in it but what what you will do for that patient if you keep the respiratory setting as if a normal patient like 12 14 16 pco2 will come somewhere around uh 35 to 40 so because pco2 compensation is left uh is now abolished your pH will drop drastically so this patient can crash because of the very low PH like 6.9 or 7 so in a severe metabolic acidosis whenever you are ventilating the patient for few uh hours at least for 6 30 minutes 60 Minutes of hour keep the respiratory a little high see how much the patient was if the patient was ventilating having a respirat rate of somewhere around 30 35 like 40 at least keep somewhere around 24 26 like that so that your pco2 compensation is maintained and you will get time to correct the metabolic acidosis and then after that you can adjust but don't keep the respiratory normal when you are ventilating a patient with sever metabolic acidosis anything left uh H one more important category neurological patients so you are ventilating a patient who has got a neurological problem like uh there's intracanal blade or stroke or there's a head injury where there is chances of raised intracanal pressure so in these patients we don't want the ICP to increase so what are the things we need to maintain firstly whenever you ventilate this patient make sure the patient doesn't get cough knock down completely and then rate as soon as the patient coughs there is a rise in the ICP so many must of you experience that whenever you having headache and you cough or talk too much you get the headache worse you need to calm down so make the patient properly seded and knocked down secondly your pco2 targets should be somewhere around so that your pco2 is maintained somewhere around 32 to 35 32 to 34 because pco2 is a veso dilator uh if the pco2 gets very high it will vesod dilate and increase the Eda if if suppose a normal pco2 40 45 will cause raise the ICP because it gets VOD dilated now if the pco2 is very low why not we decrease to 24 35 it will V constr and it will increase the infa schia it can cause chemia so we need to keep a target of somewhere around 32 34 in a neurop patient you need to adjust Med ventilation like that thirdly you don't have the Liberty to increase the peak Beyond a certain level try to keep peep minimum below five because the more the peep the more chances of R diing so suppose a COPD patient has a trauma has a chest injury contusion and had a head injury so a combination of all so you cannot give a straightforward guideline so that these are the ventilatory setting you need to maintain such a patient no you need to decide the priority COPD is there paral contusion is there and there IP obviously so priorities of the pain so you may need to maintain the mini ventilation so that your pco2 is 32 somewhere around 32 you need to maintain the oxidation so that your P2 SP2 is above 94% and pco2 sorry P2 is around 80 80 above 80 then you maintain the volume status then you try to keep the peep uh whatever minimal is there like that like that so one more category is there but like neorx this is also one condition in which there is certain Nemo thorx and you are not able to getting time to decompress it and you the patient C you need to ventilate so this is a tricky situation so what is happening there is a leak and this leak has is causing the air to get trapped in the plura and it has no time to uh get um exhale out me you to move out from the body till you put an ICD or needle torone so understand the principle what we want we just want the oxygen and ventilation to sustain the life of the patient we don't want to hyperventilate we just want to give give some time so that we ventilate and then by the time we put an ICD or something like that so what are the scenario already the intrathoracic pressure is high so already preload is low so give lot of fluts to this patient take the patient on V pressor support then when you are ventilating keep the respiratory little low we don't want the air to get pushed too much at the even like that then keep the peep zero we don't want the L to get extended like that like that so I ratio 1 is to 3 1 is to 4 like that we don't want too much pressure to for the inspiration and we don't want anything with pressure so in Nemo thorax certain in inert scenario we want just to give oxy the patient just to ventilate the patient so that the it passes that acute phase of somewhere 15 20 minutes by the time we put in something so we need to keep give minimum support we need to give minimum tidal volume whatever we can we need to give minimal respiratory what can we will keep the peep zero like that we uh will PR we give fluts to the patient we'll take the patient of VPR support so like that so these are the principles which you should understand and now you if you go back to your that tables in your Critical Care book or medicine book or ICU manuals you will find that these are the principles which are applied in those charts and now we'll pick up very easily why this is going so why this is going so I'm very thankful for I whenever she comes here she have a very interesting question and and which helps so many people uh it was asked so many times on the channel but I didn't get a time to make a video on this luckily she came and she's always behind me that we need to make this we need to make this very much thank you this was very helpful sir I feel so uh blessed to be part of this video because it helps a lot um a lot of my friends and juniors have told me that it has helped them a lot very basic yet very uh to the point and uh whatever we are encountering in day-to-day life uh day-to-day practice we are learning that only so if you have still have doubt you can just uh Post in the comment section of this video or you can go to esbm and then go to the forums and then post thank you once again and again do read more about it thank you