nutrition in critical ill patients 2.pptx

Nutrition in critical care and critical ill patients

1. The fundamental goal of nutritional support is to provide the daily nutrientand energy needs of each patient. NUTRITION SUPPLEMENTATION IN CRITICALLY ILL PATIENTS MODERATOR:DR POOJA MONGIA PRESENTER : DR VARDAAN BHARDWAJ

2. Oxidation of Nutrient Fuels Oxidative metabolism captures the energy stored in nutrient fuels (carbohydrates, lipids, and proteins) Indirect Calorimetry It is not possible to measure metabolic heat production in hospitalized patients, but if the whole-body O2 consumption (VO2) and CO2 production (VCO2) are known, the relationships can be used to determine the metabolic heat production. This is the principle of indirect calorimetry which measures the RESTING ENERGY EXPENDITURE (REE) using the following relationships REE( kal /min)= (3.6*vo2) +(1.1*vco2) - 61

3. ESTIMATING DAILY ENERGY REQUIREMENTS = REE( Kal /day)= 25 *body weight (kg) Protein Requirements The daily protein requirement is dependent on the rate of protein catabolism. The normal daily protein intake is 0.8 – 1 grams/kg , but in ICU patients, the daily protein intake is higher at 1.2 – 1.6 grams/kg because of hypercatabolism .

4. VITAMIN REQUIREMENTS Thiamine Deficiency Thiamine (vitamin B1) plays an essential role in carbohydrate metabolism, where it serves as a coenzyme (thiamine pyrophosphate) for pyruvate dehydrogenase , the enzyme that allows pyruvate to enter mitochon dria and undergo oxidative metabolism to generate high-energy ATP molecules Thiamine deficiency can thus have an adverse effect on cellular energy production, particularly in the brain, which relies heavily on glucose metabolism.

5. ESSENTIAL TRACE ELEMENTS A trace element is a substance that is present in the body in amounts less than 50 μ g per gram of body tissue

6. Guidelines for nutrition support therapy in adult critically ill patients . Jointly formulated (2009) by of Society of critical Care Medicine and American Society for Parenteral and Enteral Nutrition. Traditionally nutritional support was regarded as adjunctive care with the objectives:- a. to preserve lean body mass. b. to maintain immune function c. to avert metabolic complications.

7. Recently these goals have become more focused on nutrition therapy attempting to- attenuate the metabolic response to stress prevent oxidative cellular injury favorably modulate the immune response. Focus is on- 1.early EN. 2. appropriate macro and micro nutrient delivery 3. glycemic control.

8. ENTERAL TUBE FEEDING For patients who are unable to eat, the preferred method of nutrition support is the infusion of liquid feeding formulas into the stomach or small bowel This mimics the normal process of nutrition support, and also serves as an infection control measure The presence of bowel sounds is not required to initiate enteral tube feedings Tube feedings should be started within 24 – 48 hours of admission to the ICU to take advantage of the protective effects of tube feedings. There is evidence that early institution of enteral nutrition is associated with fewer septic complications and a shorter hospital stay

9. Contraindications Absolute contraindications to enteral tube feedings include complete bowel obstruction, bowel ischemia, ileus, and circulatory shock with high-dose vasopressor requirements Gastric feedings can be at tempted in stable patients on low doses of vasopressors but any signs of intolerance should prompt immediate cessation of feedings

10. FEEDING FORMULAS Feeding formulas are available with caloric densities of 1 kcal/mL, 1.5 kcal/mL, and 2 kcal/ mL. Most tube feeding regimens use formulas with 1 kcal/ mL. The high-calorie formulas (2 kcal/mL) are intended for patients with severe physiological stress (e.g., multisystem trauma and burns),

11. Creating an Enteral Feeding Regimen

12. Initiate enteral feeding Traditional tools of assessment (albumin, prealbumin , anthropometry) are not validated. Assessment includes – weight loss , nutrient intake before admission , disease severity, comorbid condition & function of GI tract. Initiated in patients who is unable to maintain volitional intake of food. EN is preffered over PN. Early EN (24 to 48 hours of admission)to be initiated and should be advanced towards energy goal over next 48 to 72 hrs.

13. 5. In the setting of haemo -dynamic compromise EN to be withheld until fully resuscitated. 6. In ICU setting neither presence nor absence of Bowel sounds and evidence of passage of flatus and stool is required for initiation of EN. 7. Either gastric or small bowel feed is acceptable. Switch to small bowel feed in patient with high risk of regurgitation and aspiration and intolerance to gastric feed.

14. Dosing of Enteral Feeding Target goal of EN should be set using predictive equations or by indirect calorimetry (preferable). Effort to be made to provide at least 50 to 65% of goal calories to achieve clinical benefit of EN. If unable to meet energy requirement (100% of target) after 7 to 10 days of EN alone consider supplemental PN. Ongoing assessment of adequacy of protein provision. Additional modular protein supplementation for pts with BMI < 30 ( requires 1.2 to 2 g/kg actual BW). In critically ill obese patient permissive underfeeding is recommended ( goal should not exceed 60 to70 % of target energy, or 11 to 14.5 kcl /kg actual BW)

15. Monitoring tolerance and adequacy of EN :- Evidence of bowel motility not required in ICU to initiate EN. Monitor for tolerance – c/o pain, distension on physical examination , passage of flatus / stool and abdominal radiograph. inappropriate cessation should be avoided-for gastric residual volume < 500 ml in absence of other sign of intolerance EN should be continued. Enteral feeding protocols to be adopted. To asses for risk of aspiration and steps to reduce risk. Blue food coloring and glucose oxidase strips as markers for aspiration are not recommended. Development of diarrhea further warrants for evaluation of etiology.

16. Measures to reduce risk of aspiration . The head of the bed to be elevated by 30 to 45⁰ for high risk pt showing intolerance to gastric feeding EN to be switched over to continuous infusion AGENTS TO PROMOTE MOTILITY SUCH AS prokinetics(metoclopramide , erythromycin) or narcotic antagonists ( naloxone , alvimopan ) should be initiated whenever feasible diverting the level of feeding by post pyloric tube placement should be considered.

17. Selecting appropriate enteral formulation ; Immune modulating formulations to be reserved for appropriate sub population :- major elective surgery, major trauma, burns, head and neck cancer . To be cautious in patients with severe sepsis. Patient with ARDS and severe ALI should be placed on an enteral formulation with anti inflammatory lipid profile (omega- 3 fish oil, borage oil) and anti oxydents . To get benefit of immune modulating supplements at least 50 to 60% of target calory to be given enterally. In case of diarrhea – soluble fibre containing or small peptide formulations to be considered.

18. Adjunct therapy Probiotics has shown improved outcome in specific groups (involving transplantation, major abdominal surgery, severe trauma. Not recommended for general ICU use. Combination of antioxidant vitamins and trace minerals (specifically selenium) should be provided to patients receiving specialized nutrient therapy. Addition of enteral glutamine to patients of burn and trauma. soluble fibers for patients with diarrhea is recommended. Both soluble and insoluble fibers to be avoided in patients at high risk of bowel ischemia or severe dysmotility.

19. When to use Parenteral Nutrition ? When EN could not be initiated or feasible within first 7 days of admission & protein calorie malnutrtion is detected . Patient planned for upper GI surgery When full nutritional support is not possible in the alimentary canal, the I ntravenous route is available for nutrient delivery.

20. SUBSTRATE SOLUTIONS Standard nutrition support regimens use carbohydrates to supply approximately 70% of the daily (nonprotein) caloric requirements. The carbohydrate source for total parenteral nutrition (TPN) is dextrose glucose (The standard solution is 50% dextrose, or D50.) These solutions are hyperosmolar, and must be infused through large central veins. Amino acid solutions Protein is provided as amino acid solutions that contain varying mixtures Of essential Amino acids. These solutions are mixed with dextrose solutions in a 1:1 Volume ratio Standard Solutions Standard amino acid solutions (e.g., Aminosyn ) balanced mixtures of 50% essential amino acids and 50% nonessential and semi-essential amino acids. Available concentrations range from 3.5 % up to 10%, but 7% solutions (70 g/L) are used most often.

21. Specialty Solutions Specially designed amino acid solutions are available for patients with severe metabolic stress (e.g., from multisystem trauma or burns), and for patients with renal or liver failure. 1. Solutions designed for metabolic stress (e.g., Aminosyn -HBC ) are enriched with branched chain amino acids ( isoleucine,leucine , and valine), which are preferred fuels in skeletal muscle when metabolic demands are high. 2. Renal failure solutions (e.g., Aminosyn RF ) are rich in essential amino acids, because the nitrogen in essential amino acids is partially recycled to produce nonessential amino acids, which results in smaller increments in blood urea nitrogen (BUN) when compared with breakdown of nonessential amino acids. 3. Solutions designed for hepatic failure (e.g., HepaticAid ) are enriched with branched chain amino acids, which block the transport of aromatic amino acids across the blood-brain barrier (which is implicated in hepatic encephalopathy).

22. When indicated ,maximize efficacy of PN If the patient is deemed to be candidate for PN steps to maximize efficacy (dose, content ,monitoring, choice of additive etc.) should be taken. Initial mild permissive underfeeding (80% of estimated energy). For obese patient recommendation is same as in EN. If PN has to be given in the 1 st week of hospitalization formulation without soy-based lipid to be used. Protocol to control moderately strict control of serum glucose (110 to 150 mg/dl) to be adopted. Consideration for Parenteral glutamine. Once stabilized on PN , effort to be made periodically to start EN.

23. Pulmonary failure :- High-lipid ,low carbohydrate formulations designed to manipulate respiratory quotient and reduce CO2 production are not recommended in ICU patient with acute Respiratory failure. Fluid restricted calorically dense formulation to be considered. Serum phosphate level to be monitored closely and replaced appropriately.

24. Renal failure ICU patients with ARF or AKI should be placed on standard enteral formulation. If significant electrolyte abnormalities occur – specialized formulation to be considered. Patient on hemodialysis or CRRT should receive increased protein upto 2.5 gm/kg/day . Protein should not be restricted in patients with renal insufficiency as a measure to delay initiation of dialysis.

25. Hepatic failure: Traditional assesment tools are less effective due to presence of ascites, intravascular volume depletion , edema, portal hypertension and hypoalbuminemia. EN is preferred route. Regimes should not be protein restricted. Standard enteral formulation for acute and chronic liver disease. Branched chain amino-acids formulations to be reserved for rare encephalopathic patients refractory to standard therapy with luminally active antibiotics and lactulose.

26. Acute pancreatitis At admission: to be evaluated for disease severity. For severe acute pancreatitis naso -gastric tube EN should be initiated as soon as fluid volume resuscitation is complete. Patient with mild to moderate acute pancreatitis does not require nutrition support therapy, unless there is failure to advance to oral diet within 7 days. Acute severe pancreatitis patients may be feed enterally by gastric and jejunal route.

27. 4. Tolerance to EN may be enhanced by : minimising the period of ileus by early initiation of EN. displacing the level of infusion more distally in the GI T. changing the content of EN from intact protein to small peptides, and long chain fatty acid to medium chain triglycerides or fat free elemental formulation. - switching from bolus to continuous infusion. 5. When EN is not feasible in severe disease PN to be initiated but not before first 5 days of hospitalisation .