In general, one may refer to these as "feeds" in the context of an informal semi-educational website, or in the company of understanding colleagues during rounds. However, the use of the verb "feed" as a noun serves to identify one as an uneducated oaf, and elicits derision from senior examiners.

Anyway.

There are 5 major formulae available to me at present, and I will focus on these. They are Jevity, Jevity HiCal, Nepro, Pulmocare, and Promote.

The available enteral supplements

properties Jevity Jevity HiCal Nepro Pulmocare Promote
Calories per ml 1.06 1.5 2.0 1.5 1.0
% calories from carbohydrate 54.3% 53.6% 43% 28.2% 50%
% calories from protein 16.7% 17% 14% 16.7% 25%
% calories from fat 29% 29.4 43% 55.1% 25%
           
calorie:nitrogen ratio 150:1 147:1 179:1 125:1 100:1
Osmolality 300 mOsm/Kg 525 mOsm/Kg 665 mOsm/Kg 475 mOsm/Kg 380 mOsm/Kg
Volume to supplement the recommended daily intake of vitamins, mineral and protein 1316 ml 1176 ml 1200 ml 1000 ml 1100 ml
Carbohydrate content
(per 100 ml)
14 g 20.1 g 20.6 g 10.6 g 0.124 g
Protein content (per 100 ml) 4.0 g 6.4 g 7.0 g 6.3 g 0.063 g
Fat content (per 100 ml) 3.5 g 4.9 g 9.6 g 9.3 g 0.028 g
Water content (per 100 ml) 83 g 76 g 70 g 79 g 0.83 g
           
Fibre (per 100 ml) 1.76 g 2.2 g 1.26 0 1.4
Sodium (mmol/L) 40.5 60.9 46.1 56.98 56.54
Potassium (mmol /L) 40.2 42.2 27.1 50.13 53.72
Chloride (mmol/L) 37 40.9 23.8 47.67 35.54
Calcium (mg/L) 920 1000 1060 1060 1200
Phosphorus (mg/L) 720 1000 720 1060 1200
Magnesium (mg/L) 220 310 210 425 400
           
Iron (mg/L) 14 22 19 19 18

More detailed data regarding important features (eg. whether the nutrient fluid is kosher, and how much molybdenum is in it) can be found in the manufacturer's own propaganda pamphlet, and via MIMS.

What the hell are we feeding them?

Well. Lets unfocus from the electrolyte and micronutrients content.

The carbohydrate is provided by maltodextrin, a polysaccharide derived from starch (which originates in either wheat or corn). It is a familiar component of many different confectionaries. There are also some fructooligosaccharides and soy polysaccharides.

The protein and amino acid content is provided by sodium and calcium caseinates. Casein is a milk protein with little tertiary structure.

The fatty calories are supplies by sunflower oil, corn oil and canola oil.

Gum arabic and oat fibre complete the cocktail.

References

All this stuff I got from the Abbott Nutrition Product Brochure.