أسئلة الثالثة جراحة ثالثة الدلتا

Surgical Nutrition

• Surgical nutrition is for those unable/unwilling to eat enough by mouth to maintain health.
• When possible, the enteral route is preferred over others unless contraindicated.

Supplements Chart

• Carbohydrates: 2 gm/kg/day, 4 Kcal/g
  • Primary energy source for RBCs, brain, leukocytes, and renal medulla
  • IV Dextrose (glucose 5%) provides 3.4 Kcal/g.
• Fats: 100-200 gm/week, 9 Kcal/g
  • Advantages: Less CO2 production, Provides essential fatty acids and fat-soluble vitamins.
  • Disadvantages: potential Fat embolism, increased Hepatic dysfunction and increased risk of Sepsis.
• Protein: 1 gm/kg/day, 4 Kcal/g
  • 6.25 gm of protein yields 1 gm of nitrogen
  • Ingested protein is assessed based on its nitrogen content.
    • Positive nitrogen balance (anabolic): Nitrogen intake exceeds nitrogen in urine.
    • Negative nitrogen balance (catabolic): Nitrogen intake is less than nitrogen in urine.

Energy Requirements

• Daily energy requirement: 20-30 Kcal/kg/day.
• Trauma, surgery, or sepsis can elevate kcal needs by 20%-40%.
• Pregnancy needs an additional 300 kcal/day
• Lactation requires 500 kcal/day

Fluid Maintenance

• Use the "4/2/1 rule"

Malnutrition in Surgical Patients

• Effects of malnutrition on surgery outcomes:
  • Impaired wound healing, potentially leading to burst abdomen and intestinal anastomosis failure.
  • Suppressed immune response, increasing susceptibility to infection.
  • Mental and physical exhaustion, delaying recovery, and increasing hospital stay/expenses.
  • Reduced tolerance to chemotherapy and radiotherapy.
• Operative morbidity and mortality are increased when 20% of total body weight is lost.

Indications for Nutritional Support

• Preoperative nutritional depletion like cancer of the esophagus.
• Postoperative complications such as sepsis, fistula, pancreatitis, and ileus.
• Inability to resume oral nutrition after 7 days post-operation.
• Intestinal Fistula: high output > 500 ml/day.
• Intestinal Failure: malabsorption, Crohn's/ulcerative colitis, short bowel syndrome, massive bowel resection.
• Severe Trauma: especially head injuries
• Burns

Diagnosing Malnutrition

• Clinical Assessment
  • Routine history and clinical examination, including grip strength assessment.
  • Dietary history: anorexia, vomiting, weight loss.
  • BMI less than 18.5 kg/m2 indicates underweight condition.
  • Recent weight loss: 20% or more in the last 3 months indicates malnutrition.
• Anthropometric Measures
  • Mid-arm circumference: below 80% of normal (30 cm in males, 28.5 cm in females).
  • Triceps skin fold thickness: indicates fat loss (11 mm in males & 13 mm in females).
• Laboratory Tests
  • Prealbumin: most accurate, half-life is 2 days.
  • Transferrin: half-life is 8 days.
  • Albumin: half-life is 18 days.

Routes of Surgical Nutrition

• Parenteral: nutrition delivered intravenously
• Enteral: liquid nutrition delivered via mouth or feeding tube, terminating in the stomach (nasogastric), duodenum (nasoduodenal), or jejunum (nasojejunal).
• Oral route relies on intact chewing/swallowing mechanisms and mental alertness.

Enteral Route Details

• Oral intake is inadequate or impossible, but the patient has a functional, accessible GIT.
• Appropriate for unconscious, critically ill, or dysphagic patients, those with head and neck surgery, burns, or enterocutaneous fistulae with low output.
• Liquid diet: soup, juice, milk, and blended food.
• Advantages:
  • Preserves mucosal function and IgA secretion, reducing bacterial translocation.
  • Cheaper, with fewer complications.
  • More physiological, as nutrients pass through the liver.
  • Prevents gallstone formation (unlike TPN), stimulates GB contractility.
  • Supplies glutamine (for enterocytes) and Short Chain F.A (for colonocytes).
• Contraindications:
  • Intestinal obstruction, GIT bleeding, or severe diarrhea.
  • Lack of safe access to enteral feeding due to risk of organ perforation.
  • High-output fistulas or proximal/HD unstable patients.
• Complications:
  • Related to route: Dislodgment, malposition, aspiration, discomfort, breakage, wound infection/leak (for gastrostomy/jejunostomy), wrong insertion site/injury.
  • Related to content: Diarrhea (more common than TPN), hyperglycemia/hypokalemia, malnutrition, and refeeding syndrome.

Nasogastric Tube (Ryle)

• Advantages: bedside placement, can be repeated easily.
• Disadvantages: discomfort, epistaxis, not tolerated for long periods.
• Confirmation of position:
  • Best Methods: Chest x-ray (tip below diaphragm), aspirate pH (<5 is safe).
  • Less Reliable Methods: Bubbling method/auscultation, aspirating GIT contents, litmus paper.

Gastrostomy

• Methods: Open, Laparoscopic, or PEG (percutaneous endoscopic gastrostomy).
  • PEG is minimally invasive and most popular. Endoscopic, no traditional surgery is needed.
• Techniques: Stamm (Malecot) or Janeway (mucosal tunneling).
• Types: Temporary (Malecott) or Permanent (mucosal lining).
• Indications: prolonged enteral nutrition (4-6 weeks) Obstruction of the upper GIT above the stomach (Esophageal Atresia / Malignancy)
• Contraindications: previous gastric surgery; GOO or gastric pathology; general contraindication to the enteral route.
• Tube Care: flush with saline twice daily to prevent blockage.
  • Chemotrypsin can be used to unblock a partially obstructed tube.
  • Do not use guidewires due to risk of perforation.

Jejunostomy

• Preferred in cases of pancreatic disease/gastric surgeries (due to GOO risk) or if there is a fear of aspiration.
• Special formulas are preferred, starting slowly with isotonic sterile formulas.

Parenteral Route

• Indications: Patients whose intestines cannot absorb nutrients (failure/inability of enteral nutrition for 7 days).
  • Short bowel syndrome (most common), radiation enteritis, severe IBD/diarrhea, high-output intestinal fistulae (> 500 ml/day), severe pancreatitis, prolonged paralytic ileus.
  • Can be a temporary measure before establishing enteral route (e.g., feeding jejunostomy).
• Types: Partial or total parenteral nutrition (TPN).
• Administration Formulae:
  • Daily requirements estimated according to body weight.
  • CHO provided mainly via glucose.
  • Fat emulsions from intralipid (soya oil).
  • Proteins typically administered as L-amino acids solutions.
    • Central venous catheter: placed percutaneously (US guided preferred) through the subclavian or internal jugular vein, under sterile conditions. Catheter tip position should be checked by chest X-ray, with the tip located at distal superior vena cava.
    • Peripheral venous catheter: Osmolarity is limited to 900 mOsm to avoid phlebitis, so it is mostly fat-based. Usage for short term (14 days), and the site is typically the basilic or cephalic vein, reaching the SVC.
  • Calories from dextrose: 60%
  • Calories from amino acids: 20%
  • Calories from lipids: 20%

Parenteral Nutrition Components

• Carbohydrates:
  • Dextrose is less costly and used in 50-70% concentration.
  • Supplies calories, stimulates insulin release/glucose oxidation, prevents muscle protein breakdown, nitrogen-sparing.
• Fat:
  • High calorie, essential fatty acids.
  • Contains soybean/sunflower oil with egg yolk phospholipids (emulsifying factor), glycerin (isotonic).
  • Available as 10%, 20%, 30% emulsions.
• Amino acids:
  • Source of proteins.
  • Daily protein need: 0.8-1.5 gram/kg.
• Vitamins, electrolytes, trace elements, minerals:
  • Electrolytes: sodium, potassium, magnesium, phosphate, calcium.
  • Fat soluble vitamins: A, D, E, K; water soluble vitamins.
  • Trace elements: chromium, copper, iodine, iron, manganese.

Monitoring Regimens

• Daily: Track pulse, blood pressure, temperature, body weight, fluid balance, food, and urine/intestinal losses.
• Weekly to fortnightly:
  • Plasma levels for sodium, potassium, urea, creatinine, glucose, magnesium, phosphate, liver function tests, and C-reactive protein.
• 3-6 monthly:
  • Plasma levels for full blood count, calcium, zinc, copper, plasma proteins (albumin), thiamine, triglycerides, vitamin B12, folic acid, ferritin, selenium, manganese, and 25-hydroxyvitamin D

Parenteral Nutrition Contraindications

• Severe Cardiac failure.
• Blood dyscrasias (bleeding on insertion).
• Altered fat metabolism.

Parenteral Nutrition Complications

• Pneumothorax (early fatal if unnoticed)
• Hemothorax.
• Air embolism.
• Central venous line infection: Fever after insertion, staph epidermidis.
  • Do Paired cultures from the line and a peripheral site.
  • Hold use if a central venous line infection is suspected.
  • If positive, remove, then confirm by tip culture.

Complications of the Route

• Displacement, blockage, thrombosis, thoracic duct damage (left side).

Complications of the Content

• Electrolyte imbalance: hypokalemia, hyponatremia, hypomagnesemia, hypophosphatemia.
• Hyperosmolarity
• Hyperglycemia or Hypoglycemia
• Dehydration
• Altered immunological and reticuloendothelial function.
• Anemia (Iron and zinc deficiency).
• Severe hepatic steatosis, cholestatic jaundice,Re-feeding Syndrome
• Metabolic acidosis: hyperchloraemic
• Malnutrition or Overfeeding (increase CO2 production, making weaning difficult).

Refeeding Syndrome

• Fluid and electrolyte shifts after TPN or enteral feeding. Occurs after chronic starvation or alcoholism due to a shift of metabolism from mainly fat to CHO.
• Electrolytes are rapidly consumed in metabolic reactions.
• Hallmark of the syndrome: Hypophosphatemia (insulin shifts phosphate intracellular for ATP synthesis) + Hypokalemia + Hypomagnesemia/Hypocalcemia.
• Presentation: Myocardial arrhythmias, muscle weakness, respiratory dysfunction, convulsions (4th day).
• Prevention: Correct electrolytes, gradual feeding (15 kcal/kg, then increase).

Home Parenteral Nutrition

• Indicated for short bowel syndrome or other conditions where enteral feeding is not possible.
• A permanent silastic central venous catheter (tunneled & cuffed) is used for long-term use.
• Parenteral alimentation: typically given at night over 12 hours with a mechanical pump.
• Regular TPN clinic: Weekly follow-up is needed to address complications.