بسم اللهِ الرَّحْمَنِ الرَّحِيمِ

1. بسم اللهِالرَّحْمَنِالرَّحِيمِ

2. Ain-Shams university Faculty of Medicine Department of Anesthesiology, ICU, and Pain management CME Program – ICU course

3. Parenteral NutritionByAhmed El-Shaer, MD

4. 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.

5. THE GOLDEN RULE OF NUTRITION The gut should always be the preferred route for nutrient administration. • So, parenteral nutrition is indicated when there is severe gastro-intestinal dysfunction(patient can’t take sufficient food or feeding formulas by the enteral route) .

6. Categories of PN • If enteral feeding is completely stoppedor ineffective, Total Parenteral Nutritionis used (TPN). • If enteral feeding is just “not enough”, supplementation with Partial Parenteral Nutrition(PPN) is indicated.

7. INDICATIONS • In well-nourished adults, 5 - 7 daysof 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.

8. Indications for TPN 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 • Malnourished patients with high risk of aspiration Long-term use (HOME PN) • Prolonged Intestinal Failure • Crohn’s Disease • Bowel resection

9. Partial ParenteralNutrition PPN can be used to supplement Ordinary or Tube feeding esp. in malnourished patients. Indications: Short bowel syndrome Malabsorption disorders Critical illness or wasting disorders

10. Enteral versus parenteral nutrition • As far as GIT failureis concerned, long termparenteralnutritionis a life-saving procedure. • Enteral nutritionhas the advantage over parenteral nutrition of lower % of infectious complications. • Parenteral nutritionhas been shown to lead to changes in intestinal morphologyandfunction and an increase in permeability (with higher % of bacterial translocation)

11. Nutritional Requirements • Energy: Glucose Lipid • Amino acids (Nitrogen) • Water and electrolytes • Vitamins • Trace elements

12. Requirements • Energy • Basal energy requirementsare a function of the individual'sweight, age, gender, activity leveland 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 greaterin patients withinjuryorinfection.

13. Energy Requirements

14. Requirements • Energy Sources: Glucose • The most common source of parenteral energy supply is glucose, being: • Readily metabolized in most patients, • provides the obligatory needs of the substrate , thus reducing 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.

15. Requirements • Energy Sources: Glucose Route • Glucose in 5%solution can be safely administered via aperipheral vein, but higher concentrationsrequire acentral venous line. • 20, 25, or even 50 %solutions are needed to administer meaningful amounts of energy to most patients for proper volume administration.

16. Requirements • Energy Sources: Lipid • Fat mobilization is a major response to stress and infection. • Triacylglycerols are an important fuel source in those conditions, even when glucose availability is adequate. • Need to be restricted in patients withhypertriglyceridemia.

17. Requirements • Energy Sources: Lipid • Lipids are also a source for the essential fatty acidswhich 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%).

18. Requirements • Energy Sources: Lipid • Fat emulsions can be safely administered via peripheral veins, provide essential fatty acids, and are concentrated energy sourcesfor fluid-restricted patients. • They are available in 10, 20 and 30%preparations. • Though lipids have a calorific value of 9Kcal/g, the value in lipid emulsions is 10Kcal/gdue to the contents of glycerol and phospholipids.

19. Requirements • Nitrogen • Protein (or amino acids, the building blocks of proteins) is the functional and structural component of the body, so fulfilling patient’s caloric needs with non-protein calories (fat and glucose) is essential. • Protein requirementsfor most healthy individuals are0.8 g/kg/day.

20. Requirements • Nitrogen • With disease, poor food intake, and inactivity, body protein is lost with the resultant weakness and muscle mass wasting. • Critically ill patientsmay need as high as 1.5-2.5 g protein/kg/daydepending on the disease process: (major trauma or burn > infection or after surgery > standard) • The amount should be reduced in patients with kidney or liver disease.

21. Requirements • Nitrogen Daily Protein requirements

22. Requirements • Nitrogen Nitrogen Balance = Protein intake in grams ÷ 6.25 – UUN (in grams) + 3 • The nitrogen 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. • It is a way to assess the sufficiency of protein intake for the patient.

23. Requirements • Nitrogen • Parenteral amino acid solutions provide all known essential amino acids. • Available a.a. preparations are 3.5 - 15 %(ie contains 3.5-15 gms of protein or a.a.s/100 mL solution). • 1gm of protein = 0.16 gmof N2.

24. Requirements • Nitrogen • Special a.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.

25. Requirements • Nitrogen • Arginine was added to enteral formulae claiming positive effects on immune functionand length of hospital stay. • In some clinical trials,glutamine-enrichedsolutions improved nitrogen balance and gut morphology.

26. Requirements • Fluids and electrolytes • 20–40 mL/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

27. Requirements • Fluids and electrolytes

28. Requirements • Fluids and electrolytes • Normalization of acid-base balance is a priorityand constant concern in the management of critically ill patients. • Most electrolytes can be safely added to the parenteral amino acid/dextrose solution. • Sodium bicarbonate in high concentrations will tend to generate carbon dioxide at the acidic pH of the amino acid/glucose mix.

29. Requirements • Vitamins • These requirements are usually met when standard volumes of a nutrient mix are provided. • Increased amounts of vits are usually provided to severely ill patients. • Vitamins are either fat soluble (A,D,E,K) or water soluble (B,C). Separate multivitamin commercial preparations are now available for both.

30. Requirements • Vitamins • Multivitamin formulations 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. • Most adult vitamin formulae do not contain vitamin K, which is added according to the patient’s coagulation status.

31. Requirements • Trace minerals • These are essential component of the parenteral nutrition regimen. • A multi-element solution is available commercially, and can be supplemented with individual minerals. • may betoxic at high doses. • Iron is excluded, as it alters stability of other ingredients. So it is given by separate injection (iv or im).

32. Requirements • Trace minerals • minerals excreted via the liver, such as copper and manganese, should be used with caution in patients with liver disease or impaired biliary function.

33. Osmolarity • PPN: Maximum of 900 milliosmoles / liter • TPN: as nutrient dense as necessary(>900m.osmol and up as high as 3000). • Amino acids (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.

34. Application • The Solution • Manually mixed in hospital pharmacy or nutrition-mixing service, • premixed solutions, • Separate administration for every element alone in a separate line.

35. Application • Venous access • PPN: (<900 m.osmol/L): a peripheral linecan be enough. • TPN: Central venous access is fundamental, Ideally, the venous line should be used exclusively for parenteral nutrition. Catheter can be placed via the subclavian vein, the jugular vein (less desirable because of the high rate of associated infection), or a long catheter placed in an arm vein and threaded into the central venous system (a peripherally inserted central catheter line) Once the correct position of the catheter has been established (usually by X ray), the infusion can begin.

37. Application • Initiation of Therapy TPN infusion is usually initiated at a rate of 25 to 50 mL/h. This rate is then increased by 25 mL/h until the predetermined final rate is achieved. • Administration To ensure that the solution is administered at a continuous rate, an infusion pumpis utilized to administer the solution. In hospitalized patients, infusion usually occurs over 22-24 h/day. In ambulatory home patients, administration usually occurs overnight (12-16 h).

38. Monitoring • Policy: to monitor: 1-Effecacy:electrolytes (S. Na, K, Ca, Mg, Cl, Ph), acid-base, Bl. Sugar, body weight, Hb. 2-Complications: ALT, AST, Bil, BUN, total proteins and fractions. 3-General:Input- Output chart. 4-Detection of infection: Clinical (activity, temp, symptoms) WBC count (total & differential) Cultures

39. Monitoring Monitoring

40. Complications of TPN • Sepsis • Pneumothorax • Air embolism • Clotted catheter line • Catheter displacement • Fluid overload • Hyperglycemia • Rebound Hypoglycemia

41. Complications of TPN • Catheter-related complications • Catheter sepsis:which can be localized or systemic (skin portal, malnutrion, poor immunity). ccc by: fever, chills, ±drainage around the catheter entrance site, Leukocytosis, +ve cultures (blood & catheter tip). ttt:1- exclusion of other causes of fever 2- short course of anti-bacterial and antifungal therapy (acc. to C&S) 3- Catheter removal may be required

42. Complications of TPN Catheter sepsis (Cont.): Prevention:a rigorous program of catheter care: • Only i.v. nutrition solutions are administered through the catheter, no blood may be withdrawn from the catheter. • Catheter disinfection and redressing 2 to 3 times weekly. • The entrance site is inspected for signs of infection and if present, culture is taken or the catheter is removed. • Other catheter-related complications: Thromboembolism, pneumothorax, vein or artery perforation, and superior vena cava thrombosis

43. Complications of TPN • Metabolic Complications • Hyperglycemia(an elevated blood sugar): Associated with the infusion of excess glucose in the feeding solution or the diabetic-like state in the patient associated with many critical illnesses. It can result in an osmotic diuresis (abnormal loss of fluid via the kidney), dehydration, and hyperosmolar coma. ttt: decrease the amount of infused glucose (to<4 mg/kg/min) OR insulin can be administered (either S.C. inj. or incorporation in the infusion bag).

44. Complications of TPN • Metabolic Complications • Hypertriglyceridemia(High S. Triglycerides) Associated with excess infusion of fat emulsion. N.B.Infusion of both glucose and fat emulsion in excess may result in pulmonary insufficiency. Excess glucose infusion –> excess carbon dioxide (CO2) production a result of glucose metabolism. Excess lipid infusion --> the lipid particles may accumulate in the lungs and reduce the diffusion capacity of respiratory gases.

45. Complications of TPN • Metabolic Complications • liver 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.

46. Complications of TPN • Metabolic Complications • Intestinal bacterial translocation: The lack of direct provision of nutrients to the intestinal epithelia during total parenteral nutrition Trophismand altered permeability of the GI mucosa, thus compromising any potential recovery of the patient’s ability for enteral feeding, and allowing bacterial entery to blood stream  sepsis Preventionis to provide a minimal enteral nutrition supply to avoid or minimize this risk.

47. Complications of TPN • Metabolic Complications • Other metabolic complications: Electrolyte imbalance, mineral imbalance, acid-base imbalance, toxicity of contaminants of the parenteral solution.

48. Complications of TPN • Mechanical Complications Catheters and tubing may become clotted or twist and obstruct. Pumps may also fail or operate improperly.

49. HOME PARENTERAL NUTRITION • Patients who 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. • patients must be able to master the techniques associated with this support system, be motivated, and have adequate social support at home.

50. HOME PARENTERAL NUTRITION • A patient who is judged to be a candidate for home parenteral nutrition requires an indwelling Silastic catheter designed for long-term permanent use. • The nutrient solutions are prepared weekly and delivered to the patient's home. • The patient 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.