In this lecture we will be talking about energy and its needs for patients in the
hospital. First ,however, let's have a look at the difference between energy needs for
healthy person, and hospitalized person.
When we are calculating energy needs for healthy person, we are using formula that
takes into account three variables - BMR (short cut 21.9/24 x wt(kg)
- Activity factor (AF)
- Factor for digestion (TEF)
This formula ,however, is not particularly accurate for people who are for most of
their lives on their lover weight range (slightly underweight), people on their upper
range, or for professional athletes . It fits only an average person.
For the above reasons we are using in clinical nutrition formula, that is more
precise. It consists of -BMR (Haris Benedict Formula)
-Activity factor (AF) in the hospital always 1.2
-Injury factor (IF) It is usually between 1.0-1.7 but in some
facilities it may go over 1.7
By using this formula and calculating energy need of the patient, we are trying to
prevent Prot-Kcal malnutrition. Malnutrition we define as a deficiency, deficiency that
causes Pt to stay in the hospital for a longer time.
Next thing we want to look at, is how we determine protein needs for hospitalized
patients. We know from normal nutrition that to calculate protein need for normal healthy
non hospitalized individual, we used RDA for protein which is 0.8gm/kg of body weight and
we multiply that by actual wt(kg). This is however different when we calculate protein
need for hospitalized patients. First thing we need to realize is that protein need for
hospitalized Pt is always going to be higher then for a healthy individual. The minimum
Prot. requirement is going to be 1.0/(Kg) actual body weight. There are however two ways
how we can determine protein need more precisely.
a) We look at injury factor(IF). This If is protein IF, but it is essentially the
same as Kcal IF. It is usually around 1.2, unless
patient has undergone any trauma,has high fevers, or
surgery where multiple organ damage was involved. For
that reason it will not include for example,an open
heart surgery. Weight used in this calculation is actual
weight, unless pt is obese, in that case we need to use
adjusted wt.
Formula is then actual BW x IF
b) Based on number of Kcal needed for nitrogen (N) to be utilized. What we are
trying to accomplish by this, is to make
sure that we use protein to make protein,
not to make energy. This will happen when
there is insufficient amount of Kcal-
coming predominantly from carbohydrates
(CHO)and fat- to spare the protein. For
that reason many hospitals are calculating
ratio between nitrogen and Kcal in diet.
The rule is: For every gram of nitrogen to be spared, we need 150kcal. any
less kcal will cause the nitrogen to be used for energy.
Kcal : N
150 : 1
In order to calculate protein needs by this method, we need to follow these steps
1) Calculate Pt kcal need- using any method ( average energy need of hospital Pt is 2000-
2200 kcal.
2) For every gram of Nitrogen they need 150 Kcal = eg calculated kcal need is 2200 Kcal
2200 : 150 = 14.66
3) For each gram of protein it is about 16% of Nitrogen= 16% out of 1gm = 6.25 gm of
nitrogen
4) 14.66 x 6.25 = 91.6 gm of protein is what the actual protein need is for an
individual requiring 2200 kcal
Eg: Short cut method : male 5'8:"
IF=1.2
age = 52
wt = 154 lb = 70kg
70 x 1.2 = 84 gm of protein
Haris benedict 66 + (13.7 x 70) + (5 x 172.72) - ( 6.8 x 52)
1889 - 354 = 1535 x 1.2(AF)
1842 x 1.2(IF) = 2200 kcal
protein need : 2200 : 150 = 14.66 x 6.25 = 91.6 gm = 92 gm of protein
Anthropometric
Here is where we are looking at how we measure body. Generally we can measure it in
two ways:
a) Fat
b) Somatic ( body) protein
When we are doing anthropometric measurements, we are looking only at somatic
protein,not visceral- protein in the blood (albumin, globulin atc.)
We are looking at height and weight. It is very important to measure people,
especially the elder individuals, since their reported height may not be accurate due to
bone shrinkage( individuals over 65 years old)
To measure a hospitalized Pt you can either bring a scale to the pt's room
and ask him/her to weight themselves if they are ambulatory ( have bathroom privileges
and can move on their own), or you can measure the span between their arms from point
finger to point finger by means of tape measure. This will give you an estimate height.
When we are looking at growth chard, what is considered normal is if child is in
between 5-95 percentile. This chart is however based on Northen-European standards, and
in such diverse cities as New York City, it may not necessary apply. For that reason many
facilities are using range of 3-97 percentile.
When we are plotting data into the growth chart, we should see height -weight-head
circumference in the same percentile (5-95%) As children grow they should still stay in
the same percentile. One thing to keep in mind is that it is perfectly normal for
children to be born with mother's physique, it is only later, that children grow up to
the fathers physique. This is a measure that mother nature has taken to allow for easier
birth process-imagine baby being born with fathers shoulders !!!