Gastroenteric tube feeding: Techniques, problems and solutions

Table 1 Tube-related complications of enteral tube feeding[203]

Mechanical complications	Tube obstruction
	Primary malposition
	Perforation of the intestinal tract
	Secondary displacement of the feeding tube
	Knotting of the tube
	Accidental tube removal
	Breakage and leakage of the tube Leakage and bleeding from insertion site
	Erosion, ulceration and necrosis of skin and mucosa
	Intestinal obstruction (ileus)
	Hemorrhage
	Inadvertent IV infusion of enteral diet
Infectious complications	Infection at the tube insertion site
	Aspiration pneumonia
	Nasopharyngeal and ear infections
	Peritonitis
	Infective diarrhea
Metabolic complications	Electrolyte disturbances
	Hyper- and hypoglycemia
	Vitamin and trace element deficiency
	Tube feeding syndrome (“Refeeding syndrome”)

Table 2 Techniques for delivery of feeds in enteral tube feeding

Method of feeding	Indication	Comments
Bolus intermittent (by syringe or bulb)	Ambulatory patients	100-400 mL over 5-10 min multiple times, high risk of aspiration and diarrhea, cheap and convenient for NGT
Cyclic intermittent (by gravity or pump)	Partially recumbent	Higher infusion rate for a shorter period (8-16 h); while changing from tube feeds to oral
Intermittent drip	Home enteral feeding	1.5-2 L over 8-12 h overnight, no daytime feeds
(by gravity or pump)
Constant infusion (by gravity or pump)	Bedridden patients ICU patients	Initiate with 20-50 mL/h, altered periodically depending on gastric residual volume, increased chances of aspiration and metabolic abnormalities; incline head end of bed to 45° to reduce aspiration and regurgitation

NGT: Nasogastric tube; ICU: Intensive care unit.

Table 3 Gastrointestinal complications of enteral nutrition; causes, prevention and treatment

Complication	Cause	Prevention/treatment
Diarrhea	Too rapid increase in amount of feed per day	Observe adaptation phase
	Too rapid infusion rate	Reduce/control infusion rate
	Feed temperature too cold	Increase to room temperature
	Hyperosmolar feedings (> 300 mOsm)	Use isotonic feeding solution, initially
		dilute hyperosmolar feeding solutions
	Lactose intolerance	Use low-lactose or lactose-free diet
	Fat malabsorption	Use low-fat or MCT-containing diet
	Hypoalbuminemia	Use chemically defined diet and/or feed
	Antibiotic therapy or medications	Review medications
	Chemotherapy/radiotherapy	Prescribe antidiarrheal medications
Nausea/vomiting	Too rapid infusion rate	Reduce/control infusion rate
	Bacterial contamination of formula feed/delivery equipment contamination	Handle administration systems hygienically, change delivery equipment every 24 h, keep opened bottles of formula no more than 24 h in refrigerator
Cramps/bloating	Too rapid infusion rate	Reduce/control infusion rate
	Lactose intolerance	Use low-lactose or lactose-free diet
	Fat malabsorption	Use low-fat or MCT-containing diet
Regurgitation/aspiration	Gastric retention	Reduce/control infusion rate, use duodenal tubes, incline patient during food administration
Constipation	Inadequate fluid intake	Increase fluid intake, check fluid balance
	Fiber intake too low	Use fiber-containing formulas
	Fecal impaction	Enemas
	Electrolyte and hormonal derangement	Osmotic laxatives (lactulose 15-60 mL),
		peristaltic agents (e.g., prostigmine 0.25-0.5 mg iv)

MCT: Medium-chain triglyceride.

Table 4 Randomized controlled trials measuring the impact of probiotics on enteral nutrition-related diarrhea

Ref.	Study population	Treatment groups	Sample size (placebo)	Daily dose	Outcome
					Probiotics	Controls
Heimburger et al[204]	Adults starting EN	Lactobacillus acidophilus and L. bulgaricus	41 (23)	3000 CFU/d	31% developed diarrhea	11% developed diarrhea
Alberda et al[205]	Adults startingEN on ICU	VSL#3 - live cells	10/9 (9)	9 × 1011 mg/d	14%/12%1 of days with diarrhea	23% of days with diarrhea
Frohmader et al[206]	Adults startingEN on ICU	VSL#3	45 (25)	9 × 1011 mg/d	0.5 liquid stools/d	1.1 liquid stools/d
Ferrie et al[207]	Adults with diarrhea during EN on ICU	L. rhamnosus GG	36 (18)	(2 × 1010 cells/d) and inulin (560 mg/d)	3.8 d duration of diarrhea	2.6 d duration of diarrhea
Barraud et al[208]	Adults starting EN on ICU	Ergyphilus	167 (80)	(2 × 1010 CFU/d	55% developed diarrhea	53% developed diarrhea
Bleichner et al[209]	Adults starting EN on ICU	Saccharomyces boulardii	128 (64)	4 × 1010 CFU/d	7.7% of days with diarrhea	9.1% of days with diarrhea
Schlotterer et al[210]	Burnt adults	Saccharomyces boulardii	18 (9)	4 × 1010 CFU/d	1.5% of days with diarrhea	14% of days with diarrhea
Tempe et al[211]	Adults in ICU	Saccharomyces boulardii	40 (20)	1 × 1010 CFU/d	8.7% of days with diarrhea	16.9% of days with diarrhea

¹Viable probiotics/probiotic sonicates. VSL#3 consists of Lactobacillus casei, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus delbrueckii, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, and Streptococcus salivarius. Ergyphilus consists of mainly Lactobacillus rhamnosus GG, Lactobacillus casei, Lactobacillus acidophilus, and Bifidobacterium bifidum.

Table 5 Patients at high risk of refeeding syndrome

Patients with anorexia

Patients with chronic alcoholism

Oncology patients

Postoperative patients

Elderly patients (comorbidities, decreased physiological reserves)

Patients with uncontrolled diabetes mellitus (electrolyte depletion, diuresis)

Patients with chronic malnutrition:

Marasmus

Prolonged fasting or low energy diet

Morbid obesity with profound weight loss

High stress unfed for > 7 d

Malabsorptive syndromes (inflammatory bowel disease, cystic fibrosis, short bowel syndrome)

Adapted from reference[188].

Table 6 Therapy and prevention of refeeding syndrome

Careful evaluation of cardiovascular system, check for any electrolyte abnormalities before initiating refeeding

In severe cases, an initial starting volume of 50%-75% of daily requirements should be used

< 7 yr old: 80-100 kcal/kg bw/d

7-10 yr: 75 kcal/kg bw/d

11-14 yr: 60 kcal/kg bw/d

15-18 yr: 50 kcal/kg bw/d

> 18 yr: 25 kcal/kg bw/d (or an average 1000 kcal/d initially)

If the initial food challenge is tolerated, caloric intake may be increased over the next 3-5 d. Each requirement should be tailored to the individual’s needs, and the above values may need to be adjusted by as much as 30%. Frequent administration of small feeds is recommended. Feeds should provide a minimum of 1 kcal/mL to minimize volume overload

Protein

Initial regimen for malnourished patients: 0.8-1.0 g/kg bw/d

The feed should be rich in essential amino acids, and should gradually be increased, as an intake of 1.2-1.5 g/kg bw/d is needed for anabolism to occur

Vitamins/trace elements

Thiamine, folic acid, riboflavin, ascorbic acid and pyridoxine should be supplemented, as well as the fat-soluble vitamins A, D, E, and K

300 mg thiamine should be given IV at least 30 min. before refeeding is initiated, and should be continued with 100 mg iv for at least 7 d. Later on, oral thiamine can be supplemented as 100 mg tablets

Iron should be supplemented iv according to the Ganzoni formula {iron deficit (mg) = bw (kg) × [(target Hb - actual Hb (g/L )] × 2.4 + depot iron (500 mg)}

Minerals

Sodium should be restricted (about 1 mmol/kg bw/ or 1.5 g/d), but liberal amounts of phosphorus, potassium and magnesium should be given to patients with normal renal function

Magnesium (normal range: 0.8-1.6 mmol/L )

Mild to moderate hypomagnesemia (0.5-0.7 mmol/L )

→Initially 0.5 mmol/kg bw/d over 24 h iv, then 0.25 mmol/kg bw/d for 5 d iv

Maintenance requirement

→0.2 mmol/kg bw per day iv or 0.4 mmol/kg bw per day orally

Phosphate (normal range: 0.85-1.40 mmol/L)

Mild hypophosphatemia (0.6-0.85 mmol/L)

→0.3-0.6 mmol/kg bw per day orally

Moderate hypophosphatemia (0.3-0.6 mmol)

→0.3-0.6 mmol/kg bw per day orally

Severe hypophosphatemia (< 0.3 mmol/L )

iv supplementation with either potassium phosphate or sodium phosphate (e.g., 0.8 mmol/kg bw monobasic potassium phosphate in half-normal saline by continuous infusion over 8-12 h)

Plasma phosphate, calcium, magnesium and potassium should be monitored, and the infusion should be stopped once plasma phosphate concentration exceeds 0.30 mmol/L

Adapted from references[185,191].