I am searching where was published for first time the notion of NOT offering the full amount of calories equivalent to the total energetic expenditure, measured in indirect calorimetry. I was looking for this concept in seminal works of Calvin Long but I could not find this notion. I looked after the classical papers of Prof. Hill and the same happened.
I am not asking about the interesting new trials about caloric offer on the first week in the ICU. What I want to know is about that notion seen in the "oral tradition" of some old-schoolers. In some services, here in Rio de Janeiro, Brazil, is current practice not to offer this full amount FOR HYPERMETABOLIC PATIENTS. For example: if indirect calorimetry finds an expenditure of 2400 kcal/24, some will prescribe about 80% of this value, ie, 1920 kcal.
Does anyone of you guys are aware about this concept?
Obviously it depends on the disease and patient conditions, but, in average, never less than 2000-2500/day by enteral feeding if feasible (even more for burn patients)
Depending on the amount of physiologic stress, it's usually around 25 kcal/kg/day; One way to more accurately assess the need of a particular patient, especially once the hyperacute phase of critical illness has resolved, is to perform a "metabolic cart"... that way you can avoid both under-feeding (bad) and prevent over-feeding (sometimes worse).
I agree that after the initial 'acute resuscitation phase has passed', metabolic cart is a good start.
Having 'carted' many patients over the years we have found (unpublished observations) that even with on going sepsis, the resting energy expenditure (REE) is rarely >2000 KCal. Our routine is to feed the required amount (not less, not more) of about 1800 - 2000 KCal as half sugar and half fat with about 9-12 g nitrogen (60- 75 g protein) enetrally (preferred) or intravenously. I have never heard (or practiced) of feeding less than the REE. You have to be careful that so called 'hypercatabolic' patients do not have a very high REE; many of these patients are sedated! Hope this helps.
Thank you Roop Kishen and other colleagues. REE > 2000 is the exception, indeed (we found that too). Some physicians in our metiér are prone to call "hypermetabolic" those whose REE estimated by Harris-Benedict x injury factor are surpassed by the measured REE (one of my mentors was student in 80-90 at John Grant service of parenteral nutrition at Dukes, USA and brought this notion). But I agree that this is somewhat arbitrary and can be masked by interventions, eg. sedatives.. Anyway, this idea does not seems to me a complete non-sense, because of uncertainty in face of recent trials that shows some benefits in hypocaloric feeding.
I am trying to scrutinize that this notion (offer around 80% of REE measured in clinically hypermetabolic patients) some colleagues apply here. I think was once enunciated by Calvin Long in the 70`s or someone among the Founding Fathers of Enteral Nutrition, but I am not sure. Thanks for sharing. Apologies for my English.
Indeed, you should not give the full amount of calories in the acute phase. European recommendations say that you should give 20-25 kcal/kg per day in the acute phase and increase this amount in the recovery phase. I have not precise literature data on why but I'm quite certain it relies on the fact that under high stress conditions, anabolism is not fully operational. The purpose is only to assess a basal supply (to avoid catabolism of our own resources), keep the gut epithelium healthy and not saturate physiological systems. This is especially true in case of sepsis shock and severe hypoperfusion.
Regarding pediatric patients, the main components of energy expenditure are metabolic rate, growth, and activity. During metabolic stress, no growth or physical activity takes place. Therefore, the lack of growth and activicty components in conjunction with sedation reduces energy expenditure to that needed to reach basal metabolic rate. A stress factor may be included, depending on the clinical situation (1.3 to 1.7 in burned children).
The basal metabolic rate in newborns and infants is 50–55 kcal/kg/day and falls steadily until adolescence to 25 kcal/kg/day. This calculation represents only an estimate of energy needs.
We should note that estimating the energy intake of a critically ill child on the predicted requirements of a healthy child lends to a risk of overfeeding.
Most patients with a hypermetabolic phase of criticall illness lose weight, because the calorie requirement exceeds the nutrition offered. I wonder that they should receive only 80% of calorie consumption.
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