Total enteral nutrition and total parenteral nutrition in critically ill patients
Total Enteral Nutrition &Total Parenteral Nutrition in Critically Ill Patients
Dr. M. M. PANDITRAO CONSULTANT DEPARTMENT OF ANESTHESIOLOGY & INTENSIVE CARE PUBLIC HOSPITAL AUTHORITY’S RAND MEMORIAL HOSPITAL FREEPORT, GRAND BAHAMA THE BAHAMAS
Normal Energy & Protein RequirementsProteins 10-20%Carbohydrates & 80-90% Fats
Normal Energy & Protein Requirements (Contd.)• Energy supply by 3 components• Exception:- Some organs viz. central nervous system, red blood cells, marrow tissue• Traumatized/Damaged issues• These tissues are absolutely and obligatory demanders of glucose for their energy derivation.
Starvation DefinitionLack of exogenous energy substrateand may be relative or absolute.
Hospital Malnutrition: Prevalence• Numerous studies on hospital malnutrition have been published.• Prevalence of malnutrition in U.S. hospitals today ranges from 30% to 50%.• Patient‘s nutritional status declines with extended hospital stay. Coats KG et al. J Am Diet Assoc 1993
Malnutrition Among Hospitalized Patients: A Problem of Physician Awareness• Up to 50% of hospitalized patients may be malnourished on admission• Before nutritional assessment training: – Only 12.5% of malnourished patients are identified• After 4 hours of training: – 100% of patients are identified Roubenoff et al. Arch Intern Med 1987
Prevalence of Malnutrition in Hospitalized Patients 10% Severely Malnourished 21% Moderately Malnourished69%AdequateNutritionalState Detsky et al. JPEN 1987
Prevalence of Malnutrition in Hospitalized Patients In a published British study:• 46% of general medicine patients• 45% of patients with respiratory problems• 27% of surgical patients• 43% of elderly patients Percentage of malnourished patients at time of admission McWhirter et al. Br Med J 1994
Malnutrition and its Consequences• Changes in intestinal barrier• Reduction in glomerular filtration• Alterations in cardiac function• Altered drug pharmacokinetics Roediger 1994; Green 1999; Zarowitz 1990
Malnutrition and its Consequences• Loss of weight• Slow wound healing• Impaired immunity• Increase in length of hospital stays• Increased treatment costs• Increase in morbidity & mortality
Malnutrition and Increased ComplicationsMany studies have shown thatcomplications are 2 to 20 times morefrequent in malnourished patientsthan in well-nourished patients. Buzby et al. Am J Surg 1980 Hickman et al. JPEN 1980 Klidjian et al. JPEN 1982
Marasmic starvation/ malnutrition• Conservation of energy and proteins• Stored substrates are utilized sparingly• Fate is depending upon availability of energy and proteins
Starvation• Muscles derive energy by the Oxidation of lipids• Glycogen depletion augments lipolysis• Glycerol and free fatty acids are released• The liver synthesizes acetoacetate and beta hydroxybutyrate• Keto-adaptation
Starvation• Gluconeogenesis• Proteins are catabolised to form glucose viz. carbohydrate residues of amino acids• Glycerol and lactate from Lipid Pathway
Starvation Ketoadaptation is followed by :• Breakdown of proteins decreases• Utilization of glucose as main substrate decreases• Ketones are used by tissues like brain• Urea is replaced by mainly ammonia• Excretion of ammonia rises, with help of glutamine
Critically ill patientsWhen these processes are correlated in responseto the injury (trauma) &/ or sepsis, we candifferentiate them in 2 classical phases: 1) Ebb phase 2) Flow phase.
Metabolic Response to Trauma Ebb Phase Flow Phase Energy Expenditure Time Cutherbertson DP, et al. Adv Clin Chem 1969;12:1-55
Ebb phaseAs happens in normal response tostarvation, there is no dearth of availabilityof substrate but actually an inability ordecreased ability to utilize it.Gluconeogenetic activity takes over,leading to increased protein breakdownand decrease in lean body mass.
Metabolic Response to Trauma: Ebb Phase • Characterized by hypovolemic shock • Priority is to maintain life/homeostasis Cardiac output Oxygen consumption Blood pressure Tissue perfusion Body temperature Metabolic rateCuthbertson DP, et al. Adv Clin Chem 1969;12:1-55Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. 1997
Flow phaseAfter duration of days to weeks, increasedmetabolic activity, process of repair /regeneration is initiated and recovery phasestarts with increased energy demand. If thesupply is well maintained, then the organfunction and structure is restored and normalcyis achieved.
Metabolic Response to Trauma: Flow Phase • Catecholamines • Glucocorticoids • Glucagon • Release of cytokines, lipid mediators • Acute phase protein productionCuthbertson DP, et al. Adv Clin Chem 1969;12:1-55Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. 1997
Necrobiosis• Massive trauma / overwhelming sepsis / infection.• Improper, inadequate or inappropriate measures of correction, shock.• Inherent failure of homeostatic mechanism.• Any additional systemic / metabolic disorders, burns. Then as a result of failure of multiple organ systems – death ensues as the final outcome
Stress starvation Hypoalbuminemia & Oedema• Severe acute inflammatory response mediated through the cytokines• Transmigration of proteins (albumin) to extra vascular compartment• Oedema, hypovolemia and haemodynamic instability
Stress starvation (Contd.)• Adaptative strategies as in ―normal‖ starvation glycogenolysis, lipolysis and ketoadaptation: fail• ―Gluoneogenesis‖ is the only alternative pathway : especially by catabolising proteins (muscles) leading to severe negative nitrogen balance & grave sequelae
What’s to be done?• Metabolic response to critical illness• Supportive strategies• Adequate nutritional support at right time via right route in a right proportion Outcome• Significantly decreasing morbidity and mortality in critically ill patients
Nutrition : Basic Principles1. Critically ill : Prone for high energy expenditure and rapid protein breakdown. E N initiated within 24 hours of admission significantly reduces morbidity.2. Parenteral support to be administered to all patients who cannot tolerate enteral regimen within 5 days of starvation.3. Factors to be taken into consideration: preoperative fasting status/ level of starvation before ICU admittance, number of days anticipated on ventilator and any associated systemic problems.
Nutrition : Basic Principles4. Intra-operative Jejunal access for enteral nutrition: better option5. Optimization of protein and energy requirement (avoid over/ under feeding) Protein input - 1.5-2.5 g/kg/day with 50% of total administered enterally Total caloric intake of 1500-2000 kcal/ day is to be achieved (25 kcal/kg/day ) as per BEE6. Appropriate electrolyte supplementation : Na P, K & Mg supplementation
Nutrition : Basic Principles7. Substrate for provision of energy is carbohydrates and lipids in the ratio of 70:30. Peripheral insulin resistance and hyperglycemic state, mainly due to impaired glucose utilization and gluconeogenesis. Overzealous administration of glucose ( eg: > 5 mg/kg/day) will increase the susceptibility to infection.8. Proper selection of volume, composition and route of administration, for patients with Renal & hepatic insufficiency Cardio-pulmonary diseased
Nutrition : Basic Principles9. Critical monitoring essential10. High degree of suspicion and constant ―looking out‖ for complications11. Immunonutriton is still a contentious issue, especially in terms of final outcome!
Pre requisites:1. Routine history taking2. Assessment of physical status3. Comparative assessment of approximate weight & weight loss4. Periods of fasting/ starvation5. Investigations:- blood urea, serum creatinine, serum electrolytes and serum proteins Albumin level of less than 3.5g/dl is indicative strongly of sepsis and associated with high post- abdominal surgical morbidity and mortality.
Pre requisites: (Contd.)6. Nutritional requirements : Protein requirements in terms of ‗Nitrogen balance‘ (NB) N.B. = N (in) – N (out)* = Protein _ N (out) 6.25 (gm/day) * N (out) = Urine Urea N/0.8 (gm/day) + GI losses (2 – 4 gms/ day) + cutaneous losses (0-4 gm/day) = Urine Urea N + 4 -- as a constant factor 0.8 NB =(Protein intake) – (Urine urea nitrogen + 4) 6.25 0.8 keep positive nitrogen balance of 2 – 4 gm / day
Pre requisites: (Contd.) Calculating Basal Energy Expenditure (BEE) • Harris-Benedict Equation – Variables gender, weight (kg), height (cm), age (years)Men: 66.47 + (13.75 x weight) + (5 x height) – (6.76 x age) Women: 65.51 + (9.56 x weight) + (1.85 x height) – (4.67 x age)Calorie requirement = BEE x Activity factor x Stress factor
Pre requisites: (Contd.)7. Resting Energy Eexpenditure (REE) REE = BEE x 1.1 – 1.4 Old Concept :Injury, sepsis and burns increase energy requirements by 30%, 60% and 100%. Actual requirement rises only by 14% more than calculated BEE Calories to be supplied are not more than calculated REE Asknazi J. et al Ann Surg 1980 Frankenfield D C et al Crit Care Med 1994
Pre requisites: (Contd.) 9. Micro NutrientsAgent Requirement/day Agent Requirement/dayIron 0 – 2 mg Vit K 10 mg/weekZinc 1 – 15 g Thiamine 50 – 250 mgCopper 1 -5 g Riboflavin 5 mgChromium 10 – 20 g Niacin 50 mgSelenium 20 – 100 g Pantothenate 15 mgManganese 150 -800 mgVit E 10 – 50 IU Pyridoxine 5 mgVit A 2500 IU Folic acid 600 gVit C 300 – 500 mg BIZ 12 gVit D 250 IU Biotin 60 g
Routes & Technologies of Administration ENTERAL PARENTERAL
The Total Enteral Nutrition (TN) DEFINED : Delivery of all the necessary substrates (Amino acids + Carbohydrates + Lipids) via an access either through the natural anatomical GI route or surgically created one
Benefits of Enteral Nutrition Therapy • Maintains GIT structure, integrity and function • Easier, more Physiological • Enhances intestinal immune function • Reduces bacterial translocation • Decreases risk of sepsis • Fewer complications than with parenteral nutrition • Lower costs, Less expensive
Benefits of Enteral Nutrition Therapy Improved Patient Outcomes Improved wound healing Decreased risk of complications – Nosocomial infection Decreased length of stay Decreased healthcare costs
Benefits of Enteral Nutrition Therapy Early Intervention as Part of Initial Care Enteral Nutrition • Oral supplements • Tube feeding Parenteral Nutrition • Total • PeripheralIf the gut works, use it!”
Complications of TEN Complications Complications of GI access:- Dislodgements Small bowel volvulus, infarction Catheter/tube occlusion Leakage/skin breakdown Tube malposition Gastric distention and aspiration Diarrhea and GI complications Other infections
Protocol for TEN• Tube placement, confirmed with X ray• Raise HOB to 30• Start with 15 ml/hr with increments of 15 ml/hr every 12th hourly to 60 ml/hr.• Continue 60 ml/hr for 24 hrs.• Increments 15 ml/hr every 12 hrly. After that to reach TEN max of 100 – 120 ml/hr.• Intermittent aspiration (every 4th hourly) assess if <150 Continue, if < 150 – 300 Prokinetic like Metaclopramide, if > 300 ml reduce rate by 50% & try other alternative.• Irrigate tube 4th hourly with 30 ml of water, 12th hourly with 10 ml of sodabicarb.
The Total Parenteral Nutrition (TPN) DEFINED: Delivery of all the necessary, required substrates (combination of amino acids + concentrated glucose + lipids) via central vein (to overcome high osmolarity of the preparation due to high concentration of glucose) with the help of a pump for prolonged duration as required in critically ill patients.
The Total Parenteral Nutrition Access • Subclaviabn ( Right one preferred) • Internal JugularRarely and to be avoided:- • Femoral vein • Median cubital • Any peripheral veins
The Total Parenteral Nutrition Formulations• Multiple preparations• Energy providers:- Glucose + lipids (a combination of medium chain + long chain – MCT / LCT : triglyceride) in the ratio of 60% - 70% + 30% - 40%• Proteins in the form of amino acid preparation provides nitrogen up to 8 – 16 g/lit• Micro nutrients, electrolytes and other additives like anticoagulants
Complications of TPN• Procedure complications Pneumothorax, chylothorax, haemothorax, air embolism, hydrothorax Carotid arterial puncture Subclavian arterial puncture• Mechanical Wrong position in to the peripheral vein. Blockade of catheter• Metabolism related to all electrolytes & glucose• Infection / Sepsis
Protocol for starting TPN• Confirm proper placement of central venous catheter• Absolutely thorough aseptic precautions while handling• Carbohydrates at rate of – Not more than 4 mg/kg/min – Lipids not more than 0.1 gm/kg/hr• Infusion pump to be used ―all in one‖ system• Calculate nitrogen requirement and titrate• Continuous monitoring
The recent reviews Meta analysis of 5, level 2 randomized controlled trials carried out by Hemdon (1987)8 , Hemdon (1989) 9, Dunham (1994) 10 , Chiarelli (1996) 11 and Bauer (2000) 12 revealed• Parenteral nutrition in combination with enteral nutrition in critically ill provides no added benefit to enteral nutrition alone• Parenteral nutrition with enteral nutrition is associated with high cost to enteral nutrition alone
The recent reviewsSame findings were confirmed by, Dhaliwal R ,Jurewitsch B et al,13 after doing systematicreview of the evidence
The recent reviews Latest guidelines about the enteral nutrition and parenteral nutrition in terminally ill cancer patients by Dy SM (2006) 14 confirm• Enteral and parenteral nutrition combined may help improve survival, functional status and quality of life• These benefits appear to be primarily limited to the patients with good functional status• The risks and the complications as mentioned in the past are confirmed
Summary• Recognize when nutritional support is warranted• Choose route of nutrition (enteral vs. parenteral)• Plan nutrient prescription• Discuss benefits vs. complications of enteral and parenteral nutrition• Describe how to monitor patients receiving nutrition support
Conclusion• A Few, Basic & Fundamental Concepts• ―Critically ill‖: a Misleading word• Multiple Factors have multiple roles!• Magnitude of Malnutrition—Unimaginable!• Understand, Estimate, Strategize and Execute!• EN or PN ?????• Use Your own Discretion!!!!!!