1. Def. :a method of feeding patients by infusing a mixture of all necessary nutrients into the circulatory system, thus bypassing the GIT. Also referred to as: intravenous nutrition, parenteral alimentation, and artificial nutrition.

2. The gut should always be the preferred route for nutrient administration. Therefore,parenteral nutrition is indicated generally when there is severe gastrointestinal dysfunction (patients who cannot take sufficient food or feeding formulas by the enteral route) . 3. Ifenteral feeding is completely stopped or ineffective, Total Parenteral Nutrition is used (TPN).enteral feeding is just not enough , supplementation with Partial Parenteral Nutrition (PPN) is indicated. If 4. Inwell-nourished adults, 7 - 10 days of starvation with conventional intravenous support (using 5% dextrose solutions) is generally accepted. If the period of starvation is to extend beyond this time, or the patient is not well-nourished, Total Parenteral Nutrition (TPN) is necessary to prevent the potential complications of malnutrition. 5. Short-term use Bowel injury, surgery, major trauma or burns Bowel disease (e.g. obstructions, fistulas) Severe malnutrition Nutritional preparation prior to surgery. Malabsorption - bowel cancer Severe pancreatitis Malnourishedpatients who have high risk ofaspiration Long-term use (HOME PN) Prolonged Intestinal Crohns Disease Bowel resectionFailure 6. PPNcan be used to supplement Ordinary or Tube feeding esp. in malnourished patients.Indications: Short bowel syndrome Malabsorption disorders Critical illness or wasting disorders 7. Asfar as gastrointestinal failure is concerned, long term parenteral nutrition is a life-saving procedure. Enteral nutrition has the advantage over parenteral nutrition of lower % of infectious complications. Parenteral nutrition has been shown to lead to changes in intestinal morphology and function and an increase in permeability (with higher % of bacterial translocation) 8. Energy:Glucose Lipid Amino acids (Nitrogen) Water and electrolytes Vitamins Trace elements 9. Energy Basalenergy requirements are a function of the individual's weight, age, gender, activity level and the disease process. The estimation of energy requirements for parenteral nutrition relies on predictive equations. Hospitalized adults require approximately 25-30 kcal/ kgBW/day. However, these requirements may be greater in patients with injury or infection. 10. Patient conditionBasal metabolic rateApproximate energy Requirement (kcal/kg/day)No postoperative complications, GIT fistula without infectionNormal25-30Mild peritonitis, long-bone fracture, mild to moderate injury, malnourished25% above normal30-35Severe injury or infection50% above normal35-45Burn 40-100% of total body Up to 100% 45-80 surface above normal 11. EnergySources: Glucose Themost common source of parenteral energy supply is glucose, being: Readily metabolized in most patients, provides the obligatory needs of the substrate , thusreducing gluconeogenesis and sparing endogenous protein. 1 gm of glucose gives 4 Kcals. Most stable patients tolerate rates of 4-5 mg.kg-1.Min-1,but insulin resistance in critically ill patients may lead to hyperglycemia even at these rates, so insulin should be incorporated acc. to blood sugar levels. 12. EnergySources: GlucoseRoute Glucosein 5% solution can be safely administered via a peripheral vein, but higher concentrations require a central venous line. 20,25, or even 50 % solutions are needed to administer meaningful amounts of energy to most patients for proper volume administration. 13. EnergySources: Lipid Fatmobilization is a major response to stress and infection. Triacylglycerolsare an important fuel source in those conditions, even when glucose availability is adequate. Needto be restricted in patients withhypertriglyceridemia. 14. EnergySources: Lipid Lipidsare also a source for the essential fatty acids which are the building blocks for many of the hormones involved in the inflammatory process as well as the hormones regulating other body functions. Ideally,energy from fat should not exceed 40% of the total (usually 20-30%). 15. EnergySources: Lipid Fatemulsions can be safely administered via peripheral veins, provide essential fatty acids, and are concentrated energy sources for fluid-restricted patients. Theyare available in 10, 20 and 30% preparations. Thoughlipids have a calorific value of 9Kcal/g, the value in lipid emulsions is 10Kcal/g due to the contents of glycerol and phospholipids. 16. Nitrogen Protein(or amino acids, the building blocks of proteins) is the functional and structural component of the body, so fulfilling patients caloric needs with non-protein calories (fat and glucose) is essential. Proteinrequirements for most healthy individuals are 0.8 g/kg/day. 17. Nitrogen Withdisease, poor food intake, and inactivity, body protein is lost with the resultant weakness and muscle mass wasting. Criticallyill patients may need as high as 1.5-2.5 g protein/kg/day depending on the disease process: (major trauma or burn > infection or after surgery > standard) Theamount should be reduced in patients with kidney or liver disease. 18. NitrogenDaily Protein requirements ConditionBasic requirements Slightly increased requirements Moderately increased requirements Highly increased requirements Reduced requirementsExamplerequirementNormal person Post-operative, cancer, inflammatory Sepsis, polytrauma0.5-1g/Kg 1.5g/KgPeritonitis, burns,2.5g/KgRenal failure, hepatic encephalopathy0.6g/Kg2g/Kg 19. NitrogenNitrogen Balance = Protein intake in grams6.25 UUN (in grams) + 3 Thenitrogen lost in urine derives primarily from amino acids released by protein breakdown in response to catabolic mediators that include stress hormones (corticosteroids, catecholamines) and cytokines. Itis a way to assess the sufficiency of protein intake for the patient. 20. Nitrogen Parenteralamino acid solutions provide all known essential amino acids. Availablea.a. preparations are 3.5 - 15 % (ie contains 3.5-15 gms of protein or a.a.s/100 mL solution). 1gmof protein = 0.16 gm of N2. 21. Nitrogen Speciala.a. solutions are also available containing higher levels of certain a.a.s, most commonly the branched-chain ones (valine, leucine and isoleucine), aimed at the management of liver diseases, sepsis and other stress conditions. Conversely,solutions containing fewer a.a.s (primarily the essential ones) are available for patients with renal failure. 22. Nitrogen Argininewas added to enteral formulae claiming positive effects on immune function and length of hospital stay. Insome clinical trials, glutamine-enriched solutions improved nitrogen balance and gut morphology. 23. Fluidsand electrolytesmL/kg - daily young adults 30 mL/kg daily older adults Sodium, potassium, chloride, calcium, magnesium, and phosphorus ( as per the table) Daily lab tests to monitor electrolyte status 2040 24. Fluidsand electrolytesNutrient Water Sodium Potassium Magnesium Calcium Phosphate Chloride/AcetateRequirements (/Kg/day) 20-40 mL 0.5-1.0 mmol 0.5-1.0 mmol 0.1-0.2 mmol 0.05-0.15mmol 0.2-0.5mmol So a to maintain acid-base balance (normally 0.5 mmol for Cl- , & 0.1mEq for Acetate) 25. Fluidsand electrolytes Normalizationof acid-base balance is a priority and constant concern in the management of critically ill patients. Mostelectrolytes can be safely added to the parenteral amino acid/dextrose solution. Sodiumbicarbonate in high concentrations will tend to generate carbon dioxide at the acidic pH of the amino acid/glucose mix. 26. Vitamins Theserequirements are usually met when standard volumes of a nutrient mix are provided. Increasedamounts of vits are usually provided to severely ill patients. Vitaminsare either fat soluble (A,D,E,K) or water soluble (B,C). Separate multivitamin commercial preparations are now available for both. 27. Vitamins Multivitaminformulations for parenteral use for adult patients usually contain 12 vitamins at levels estimated to provide daily requirements.Additional amounts can be provided separately when indicated. Mostadult vitamin formulae do not contain vitamin K, which is added according to the patients coagulation status. 28. Traceminerals Theseare essential component of the parenteral nutrition regimen.Amulti-element solution is available commercially, and can be supplemented with individual minerals. may Ironbe toxic at high doses.is excluded, as it alters stability of other ingredients. So it is given by separate injection (iv or im). 29. Traceminerals mineralsexcreted via the liver, such as copper and manganese, should be used with caution in patients with liver disease or impaired biliary function. MineralZinc CopperRecommended dietary allowance (RDA) for daily oral intake (mg) 15 2-3Suggested daily intravenous intake (mg) 2.5-5 0.5-1.5Manganese Chromium Iron2.5-5 0.05-0.2 10 (males)-18 (females)0.15-0.8 0.01-0.015 3 30. PPN:Maximum of 900 milliosmoles / liter TPN:as nutrient dense as necessary (>900 m.osmol and up as high as 3000). Aminoacids (10 m.osmol/gm), dextrose (5 m.osmol/gm) and electrolytes (2 m.osmol /mEq) contribute most to the osmolarity, while lipids give 1.5 m.osmol/gm. 31. TheSolution Manuallymixed in hospital pharmacy or nutrition-mixing service, premixed Separatesolutions,administration for every element alone in a separate line. 32. Venous PPN:access( the lipid particles may accumulate in the lungs and reduce the diffusion capacity of respiratory gases. 46. Metabolic oComplicationsliver toxicity (also know as parenteral nutrition cholestasis): It causes severe cholestatic jaundice, elevation of transaminases, and may lead to irreversible liver damage and cirrhosis. Multiple causes have been proposed, including high infusion rates of aromatic amino acids, high proportion of energy intake from glucose, e.t.c.. There is no specific treatment, other than anticholestatic therapy. 47. Metabolic oComplicationsIntestinal bacterial translocation: The lack of direct provision of nutrients to the intestinal epithelia during total parenteral nutrition Trophism and altered permeability of the GI mucosa, thus compromising any potential recovery of the patients ability for enteral feeding, and allowing bacterial entery to blood stream sepsisPrevention is to provide a minimal enteral nutrition supply to avoid or minimize this risk. 48. Metabolic oComplicationsOther metabolic complications: Electrolyte imbalance, mineral imbalance, acid-base imbalance, toxicity of contaminants of the parenteral solution. 49. MechanicalComplicationsCatheters and tubing may become clotted or twist and obstruct. Pumps may also fail or operate improperly. 50. Patientswho are unable to eat and absorb adequate nutrients for maintenance over the long term may be candidates for home parenteral nutrition e.g. extensive Crohn's disease, mesenteric infarction, or severe abdominal trauma. patientsmust be able to master the techniques associated with this support system, be motivated, and have adequate social support at home. 51. Apatient who is judged to be a candidate for home parenteral nutrition requires an indwelling Silastic catheter designed for long-term permanent use. Thenutrient solutions are prepared weekly and delivered to the patient's home. Thepatient sets up the infusion system and attaches the catheter to the delivery tubing in the evening for infusion over the next 12-16 h. The intravenous nutrition is terminated by the patient the next morning. 52. Among the indications for parentral nutrition Short bowl syndrome, True Surgical GIT resection followed by more than 5 days fasting in a cachectic patient, True Polytrauma, False Intractable malabsorption, True Prolonged mechanical ventilation False 53. For energy requirements hospitalized adults require approximately 25-30 kcal/kg/day True A single measurement of energy expenditure by indirect calorimetry will provide a reliable estimate of average requirements. False The most common source of parenteral energy supply is glucose. True Glucose in 5% solution can be safely administered via a peripheral vein, True With severe infection or injury, basal metabolic rate rises about 25% above normal False 54. Regarding Nitrogen balance A 70 Kgs normal adult male requires about 60 gms of protein daily True Stress induces catabolic state and hence, a positive Nitrogen balance False Special amino acid solutions containing higher levels of branched-chain amino acids (valine, leucine and isoleucine) are useful in the management of liver diseases. True With renal failure, reduction of the amino acid load is recommended. True Glutamine is essential for gut function. False 55. During Monitoring of TPN Hyperglycemia can be tolerated so long as there is no ketosis False New-onset glucose intolerance in patients receiving TPN may represent an early sign of sepsis. True Serum levels of electrolytes including magnesium and phosphorus should be checked daily until stabilized, then two times daily. False Overfeeding the patients markedly increases metabolic and respiratory complications. True Indirect calorimetry is very useful in mechanically ventilated patients with an FiO2 greater than 50%. False 56. Complications of parentral nutrition The most frequent catheter-related complication is SVC thrombosis False Catheter sepsis is characterized by the classic signs of infection: chills, fever, and white blood cell count is usually elevated True Hyperglycemia is a very serious, relatively common, problem True Excessive infusion of aromatic amino acids, glucose, and lipids may lead to the development of liver toxicity (cholestasis). True Excess glucose infusion leads to excess O2 consumption, while with lipid infusion, the lipid particles may accumulate in the lungs and reduce the diffusion capacity of respiratory gases. False