Interview with Professor Jan Wernerman of Intensive Care Medicine, Karolinska Institutet, Stockholm, Sweden by Meg Blogg Marquardt, Nestlé Health Science.
From ESICM Paris 23rd October 2018
MB: So, hello, Professor Jan Wernerman. We’re here at the ESICM in Paris. Professor Wernerman has worked in Karolinska Hospital in Intensive Care for many years. It is Meg Blogg here from Nestlé Health Science. So we heard a controversial debate this morning on earlier better nutrition in the critically ill population. And it seems that overall the conclusions are undecided: there’s not enough data?
JW: No, I disagree with you because I think that everybody in the panel, and I heard nobody in the crowd who was against early nutrition. The problem is how to select patients to be very early. And the problem is when patients are ready to receive full nutrition, I think everybody agrees that we should start nutrition, so there is no controversy along that. I wouldn’t call it a controversy, but I would rather call it a difficulty to realise how much you could give to the individual patient. We need to consider what are the signs, the clinical signs, so the biochemical markers or whatever to guide you how to advance nutrition.
MB: So lack of concrete guidance in the specifics about nutrition?
JW: I think it’s…another thing that was not controversial is that there is no cookbook. A lot of people would like it to be a cookbook. And you know on the second day you can do, on the third day you can do, there is no such thing because the time course for the individual patients in this extremely heterogeneous cohort, it doesn’t look the same. So you have to use your clinical skills and to integrate all the type of information that you have to decide how to do.
MB: And this will always be the case in intensive care, won’t it?
JW: Yes, it will. Yes, it will.
MB: So is it unrealistic trying to define guidelines somehow?
JW: I think guidelines have to be phrased accordingly. That means you should move away from saying full caloric support should be given on…in 48 hours or something like that because this may be correct in some cases but it actually may even create harm in other cases. And on the reverse, as also was stated, to not give full nutritional support in 48 hours may do harm in other cases. So when you randomise a huge group of patients into rather rigid schedules you will probably help some patients and you will probably harm some other patients and very often they equal out. So the conclusion of the study is indecision.
MB: So how do you manage this in a day-to-day world at the bedside in intensive care?
JW: It’s not that difficult but I would emphasise that everybody who does intensive care medicine, in particular nutrition in the critically ill, must be comfortable with their knowledge in metabolic basics. And if you are not then you, of course, are in trouble, then you are looking for the cookbook and then it’s very easy to come wrong. But I think anybody who gets the professional skills and everybody who remembers this type of basic physiology and how the physiology changes in response to the different trauma, sicknesses or whatever, this is important. The insulin resistance, the inability to suppress mobilisation of endogenous substrates, for example, all of this is very, very important otherwise you may go wrong, you may overfeed. And recently we also come up with this re-feeding-like syndrome which is usually come to attention by dropping phosphate in response to start of feeding. And it’s unfortunate that we presently are not very well aware of the mechanism behind this, but from observational studies it’s clear that full nutrition in these cases do harm, actually even on the mortality level, so it’s important. And what happens doesn’t happen immediately, it happens over time. So if you full feed patients in the early phase who show this drop in phosphate, you compensate for it through to a normalised level, still they have an unfavourable mortality outcome in the next few weeks. So in that case, as an example, when knowledge of the basic metabolism isn’t good enough because we…our global knowledge is not good enough, so many people think that we know the alterations in metabolism in response to trauma, sepsis and so on, but I disagree with that. I would like to emphasise that there is still a lot to do. And I mean this is a research phase, a research area for myself and my research group and very often have the comment that you’re investigating old things, these are well known, but I don’t agree to that because it’s not well known, in particular the temporal pattern of these changes is not well characterised.
MB: You’re an expert in this field, not only in critical care but also in metabolism and nutrition. Is it reasonable to expect other intensivists to have this passion and this knowledge when they have a lot of other priorities, managing the critically ill?
JW: Of course, as an intensivist you will have a profile; somebody’s more interested in infections, somebody’s more interested in central circulation in the acute phase, so you will have your profile of expertise, but I don’t think that you can call yourself an intensivist if you don’t take this into account. You have to have a minimal pass level on all important fields. I mean you can’t disregard the psychological parts of it, I mean you have to recognise how to handle families. There is a lot of things that you have to do as an intensivist and you can’t be an expert in all fields but there is a minimal pass level and if you are below that you should consider doing something else.
MB: So it’s really an art and adapted to the individual patient?
JW: Definitely. I mean just like somebody said this morning, I mean you don’t give noradrenaline on a certain infusion rate on day one or two, but you have parameters and there is controversy what parameter is good enough to dose noradrenaline, should it be blood pressure, should it be lactate and so on, so I mean nutrition or metabolism and nutrition doesn’t stand out, it’s just like the others. The difficulty is that markers like blood pressure or lactate as well as talking the circulation, these are not readily available actually. So how should we dose it? So we look upon, for example, gastric retention and it’s controversial how that should guide your enteral nutrition but it’s something that we do and that the nurses like to do and we take it into account. But also I mean even if past the stomach, is it readily absorbed, how is it utilised and also for parenteral nutrition, even if it’s given intravenously, you can’t be sure that it’s utilised by cells in the way that it’s utilised. And I think the insulin resistance, for example, to take an example, is a good marker for that. So it’s an art, like you say. And you look upon biochemistry, you look upon blood sugars, urea, whatever, and you adjust your nutrition accordingly. That’s the way I can say. And I think the guidelines should focus upon early enteral nutrition, as we all agree upon, you should start as early as you can but in my institution we usually don’t start enteral nutrition until you have secured airways, for example, so there may be an early period when we don’t know if we are going to secure an airway by intubation or how we will do and then perhaps the nutrition is just by a small amount of dextrose or something like that. But you’ve got to have a protocol and then you have to adjust it too, but I mean there is no shortcut, if you ask me.
MB: Thank you very much. It’s a complex story. It sounds like we’re just at the beginning?