[INFLUENCE OF THE NUTRITIONAL COMPOSITION OF DIFFERENT FIBER-ENRICHED ENTERAL NUTRITION FORMULAS ON THE ADMINISTRATION TIME BY GRAVITY AND THE RISK OF TUBE FEEDING OBSTRUCTION].
BACKGROUND
the administration of enteral nutrition by gravity is a very useful method in clinical practice; nevertheless, it may not be very precise. Indeed, this method presents some important limitations, such as the difficulty in establishing a precise dripping rate and the possibility for the dripping rate decrease depending on the formula.


OBJECTIVE
assess the administration time and the risk of clogging of 5 fiber-enriched enteral nutrition formulas with different protein concentrations and caloric density, all administered by gravity through nasogastric (NG) tubes of different sizes. Assess the influence of the composition on the dripping rate, by gravity, of the tested formulas.


METHODS
5 fiber-enriched EN formulas were compared by using nasogastric tubes of the calibers 8, 10 and 12 Fr. The fluidity of these gravity-administered NE formulas was estimated by timing the complete passage of each formula at full speed, thus allowing one to calculate the mean time of free fall (MTFF) and to register any possible obstruction. Subsequently, an in vitro simulation of a 1 500 ml administration was performed for each formula at a particular speed, so that the administration time was 5 hours. Slowing flow and stagnated flow were detected as indicators of the risk of obstruction.


RESULTS
the two products that especially differed in MTFF were the ones with the highest energy concentration. The passage time in free fall of these two products through the 8 Fr tube exceeded four hours. For the rest of the products and NG tubes used, this time was less than 2 hours and 5 minutes. No slowing flow or tube obstruction was detected in free fall and at maximum speed. When the dripping was adjusted to be administered in 5 hours, three of the studied products (those with the least caloric concentration and viscosity) showed slowing flow and, in some cases, the dripping stopped completely. The most important factor associated to the MTFF was the lipid content, followed by viscosity, energy and protein content. The MTFF measured was not significantly related to the fiber content of the nutritional formula.


CONCLUSIONS
all studied products can be administered by gravity via nasogastric tubes in free fall without any risk of obstruction, even though the free fall time was very variable. The lowest caliber tubes, the highest energy content and the viscosity of the EN mixture turn-out to be the limiting factors when fiber-enriched formulas are to be administered by gravity.
Unidad de Nutrición Clínica. Servicio de Medicina Interna. IISPV. Hospital Universitari Sant Joan de Reus. Universitat Rovira i Virgili, Reus.. ambonada@grupsagessa.com.
Anna
A
Bonada Sanjaume
Unidad de Nutrición Clínica. Servicio de Medicina Interna. IISPV. Hospital Universitari Sant Joan de Reus. Universitat Rovira i Virgili, Reus.. annagilsc@gmail.com.
Anna
A
Gils Contreras
Unidad de Nutrición Clínica. Servicio de Medicina Interna. IISPV. Hospital Universitari Sant Joan de Reus. Universitat Rovira i Virgili, Reus. CIBERobn (Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid (España).. jordi.salas@urv.cat.
Jordi
J
Salas-Salvadó
D004043:Dietary Fiber; D002149:Energy Intake; D004750:Enteral Nutrition / Q000379:methods; D005526:Food, Formulated; D006112:Gravitation; D006801:Humans; D007441:Intubation, Gastrointestinal / Q000379:methods; D013997:Time Factors