Artificial Nutritional Support

Artificial Nutritional Support

The Artificial nutrition support includes:

• Parenteral: It is an intravenous route to provide total parenteral nutrition.
• Enteral: It uses GIT to provide nutrition to the patient. It is the preferred nutritional support.

We will read about their details in this blog. Keep reading to enhance your knowledge about this topic.

Enteral Nutrition

Advantages of Enteral Nutrition

• Maintains gut integrity/ preserves gut mucosal barrier. 
• More physiological
• Prevents bacterial translocation.
• Maintains villi and prevents villous atrophy.
• Maintains gut microbiome.
• Maintains enterohepatic circulation.
• Decreased release of pro-inflammatory cytokines
• Low-cost

Indications of Enteral Nutrition

It can be provided only if the integrity of the bowel (especially its proximal part) is maintained.

• Protein Energy Malnutrition with inadequate oral intake
• CA of the upper aerodigestive tract
• Dysphagia
• Inflammatory bowel diseases
• Major trauma or surgery when returning to prolonged dietary intake. 
• Distal low output enterocutaneous fistula.

Contraindications to Enteral Nutrition

• Paralytic ileus
• Intestinal Obstruction/Ischemia
• High output fistula
• Proximal small bowel fistula
• Short bowel syndrome- Acute phase
• Severe pancreatitis
• Intractable vomiting/ diarrhea
• Severe malabsorption
• Severe GI He/Shock/Hemodynamic instability

Methods of Enteral Nutrition

• Oral supplements
  • 200 kcal and 2g of nitrogen per 200 ml
  • Increase daily calorie intake in addition to diet.
• Nasogastric/ nasojejunal tube feeding.
• Feeding gastrostomy or jejunostomy
  • Percutaneous endoscopic gastrostomy
  • Radiologically inserted gastrostomy
• Surgical
  • Surgical Feeding Jejunostomy and surgical feeding gastrostomy.

Comparison between different Methods of Tube Feeding

Nasogastric Tube Feeding

• Tube feeding can be nasogastric tube feeding.
• It can be used for the short term, and the GI tract must be functional.
• The patient should have intact mentation and protective laryngeal reflexes to decrease the risk of aspiration.
• It can be inserted blind at the bedside or under fluoroscopic guidance.
• But after insertion, it must be checked first, and then feeding should be started.
• Advantages of tube feeding
  • It is easy to insert and replace.
  • Gastric pH can be monitored.
  • Can calculate residual gastric volume.
  • Capable of bolus feeding, drugs, or medications
• Disadvantages of Tube Feeding
  • Misplacement 
  • Aspiration risk 
  • Esophageal erosion
  • Insertion can cause epistaxis, nasal necrosis, and esophageal strictures.

Nasoduodenal Tube Feeding

• The other mode of feeding is nasoduodenal or nasojejunal.
• It is used for the short term.
• It is used for patients with functional GI tract but poor gastric emptying reflex and has a risk for aspiration.
• It has a better insertion result if inserted under endoscopic or fluoroscopic guidance.
• Advantages of Tube Feeding
  • It has 25% less aspiration risk compared to nasogastric insertion.
  • Some tubes enable decompression of the stomach while feeding into the jejunum.
• Disadvantages of Tube Feeding
  • It can be clogged easily.
  • Risk of aspiration.
  • Misplacement or displacement can happen in the stomach.
  • It cannot be used for bolus feeding.
  • It is mainly used for continuous infusion.
  • It cannot check gastric residual volume.

Gastrotomy

• Gastrotomy is a long-term method.
• It is used in patients with good gastric emptying.
• It should be avoided in patients with an increased chance of reflux or aspiration.
• It can be done surgically by laparoscopic or laparotomy.
• The other techniques are percutaneous, endoscopic or radiological.
• Advantages of Gastrotomy
  • It can be used for bolus feeding.
  • A large bore tube is used so there is less chance of blocking.
• Disadvantages of Gastrotomy
  • It can cause bleeding, and perforation.
  • It also has aspiration risk.
  • Dislodgement with peritoneal contamination can happen.
  • The wound site might get infected.

Jejunostomy

• Jejunostomy is used for the long term in patients with functional GI tract.
• It is preferred in patients with poor gastric emptying, aspiration risk, and risk of reflux.
• It can be used in patients with gastroparesis or gastric dysfunction.
• For example, a feeding jejunostomy can be implemented in a patient with a pseudocyst of the pancreas compressing the stomach.
• It can be surgical with a small laparotomy incision, percutaneous, or endoscopic.
• Advantages of Jejunostomy
  • It has comparatively reduced aspiration risk.
• Disadvantages of Jejunostomy
  • It can cause bleeding, perforation, infection, and nasal necrosis.
  • Dislodgement and perforation into the peritoneal cavity can happen.
  • Rare - Pneumatosis of the intestine can cause a problem.
  • The residual cannot be checked.
  • It requires continuous infusion.

Full Feeding or Trophic Feeding

• Full feeding is continuous - daily total intake and hourly rates are estimated.
• Initially, it is given at 20-30ml /hr and gradually increases it.
• Aspiration should be done before feeding.
• It should be skipped when the residual volume is more than 200cc in a 4–6 hour period or when abdominal distension occurs.
• Bolus feeding replicates the physiology of meals.
  • It can be given through a nasogastric tube and gastrotomy tube.
• Trophic feeding can be defined as a small amount of balanced enteral nutrition.
  • It prevents the disuse of GIT.

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Complications of Enteral Nutrition

Tube-related

• Malposition, disposition, and dislodgement.
• The tube can also get blocked.
• Sinusitis, Rhinitis, nasal necrosis, esophageal, or gastric erosion
• Breakage or leakage

GI

• Osmotic diarrhea is the most common complication.
• Bloating or abdominal cramps
• Aspiration, nausea, and vomiting 

Metabolic and Biochemical

• Electrolyte imbalance 
• Vitamin, mineral, and trace element deficiency 
• These are more commonly seen with total parenteral nutrition.

Infective

• Infection can be endogenous or exogenous.

Parenteral Nutrition

It is the infusion of nutrients in elemental form, bypassing the usual digestion process. This nutrition can be provided in two ways: central and peripheral.

• Central nutrition is when a larger diameter vein (subclavian vein, internal jugular vein, femoral vein) is used. The most common route is the subclavian vein (SV). The advantage of central nutrition is that It can be given for a longer time (> 1-2 weeks), and a high osmolarity solution can be provided in this nutrition (25% dextrose).
• Peripheral PN - Small-diameter peripheral veins are used. It can be given for <1-2 weeks. In this case, high osmolarity solutions cannot be given. High osmolarity solutions can cause thrombophlebitis.  Dextrose (5-10%) can be provided. It is not recommended for severely malnourished patients. It is given only to supplement nutrition or if a central route is not possible.

Indications of parenteral nutrition

• According to the Society of Critical Care Medicine
  • NRS 2002 is ≥ 3, and the NUTRIC score is ≥ 5.
  • Energy and protein needs cannot be met with EN.
  • After one week of use of EN if it cannot meet >70% of energy requirements.
  • GI dysfunction is unsuitable for EN.
  • The integrity of the proximal bowel is impaired.
    • Enterocutaneous fistulas are present, especially proximal/high-output fistulas.
    • In the case of short bowel syndrome (especially the acute phase), massive bowel resection occurs.
    • Severe acute pancreatitis
    • Prolonged ileus
    • Acute chemotoxicity or radiation enteritis

Complications of Parenteral Nutrition

• It can be catheter or feeding-related.
• Catheter- related complications
  • The most common catheter-related complication is sepsis.
    • It can even lead to systemic sepsis.
    • The earliest sign of systemic sepsis is hyperglycemia.
  • Using multi-lumen catheters can increase the risk of infection.
  • Indwelling time is > 7 days.
  • The risk is higher when provided in the femoral vein > Jugular vein > subclavian vein.
  • Pneumothorax
    • It is the most dangerous catheter-related complication.
    • Occurrence: When nutrition is provided through the subclavian vein > internal jugular vein > femoral vein.
    • Ideally, the central line should be placed under the guidance of USG, and after insertion, an X-ray should be performed to see the placement of the line and any pneumothorax.
  • Other complications include air embolism, A/V injury, occlusion, and thrombosis.
• Feeding-related complications
  • It can be caused due to overfeeding or underfeeding.
  • Overfeeding, fluid retention, or overload can cause problems.
    • If there is a weight gain of more than 1kg/day, then that indicates fluid overload.
    • The overall most common complication is hyperglycemia or glucose intolerance.
    • Hyperosmolar dehydration.
    • Cholestasis or hypertriglyceridemia.
    • Hypercholesterolemia/ Hypertriglyceridemia 
    • Increased infusion of amino acids leads to hyperchloremic metabolic acidosis.
    • Azotemia, metabolic bone disease, and neutrophil dysfunction.
  • Underfeeding causes chronic deficiency syndrome.
  • Essential fatty acids, trace elements (Zn, Se, Mo, Mn), minerals, and vitamins are deficient.
  • Electrolyte abnormalities.
    • It can be hypo (more common) and hyper of particulate electrolyte. 
  • Hyperchloremic metabolic acidosis
• Other complications include gallstones, bacterial translocation (which can lead to infections), intestinal atrophy, and pulmonary dysfunction.

Summary

• Enteral nutrition(EN) is preferred over parenteral nutrition.
• When EN is contraindicated or not possible, parenteral nutrition can be given.
• A central pathway should be chosen if the expected use is for more than 1-2 weeks and high osmolarity mixtures are more than 850 mmol/L.
• Choose peripheral pathways for less time and lower osmolar content.

Frequently Asked Questions: 

Q: Which artificial nutrition is preferred more in the patients?

Answer: Enteral nutrition(EN) is preferred over parenteral nutrition.

Q: Which radiographic method is used to check the correct placement of the nasogastric tube?

Answer: X-Ray

Q: Which is the most common route of central nutrition?

Answer: The most common route is the subclavian vein (SV).

Also read: High-Yield GIT, Hepatobiliary and Pancreatic Surgery Questions

Hope you found this blog helpful for your NEET SS Surgery Perioperative preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.