Assessing Energy and Protein Needs Slides

Assessing Energy and Protein Needs Slides - ESTIMATING...

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Unformatted text preview: ESTIMATING ENERGY AND PROTEIN NEEDS FOR HOSPITAL PATIENTS Consequences of Underfeeding Loss of muscle mass Reduced immune response Impaired organ function Poor wound healing and increased infection Consequences of Overfeeding Hyperglycemia Insulin resistance Fatty liver Hypertriglyceridemia yp gy Failure to wean from mechanical ventilation Assessing Hospital Energy Needs Direct measurement using indirect calorimetry g y Calculation from pulmonary artery catheter measurement t Fick equation Estimation using equations based on body size degree size, of injury or inflammatory response Weir equation Mifflin-St. Jeor Harris Benedict Harris-Benedict Ireton-Jones Penn State Rule f thumb R l of th b Estimating Hospital Energy Needs using: Indirect Calorimetry Pulmonary gas exchange measurements are used to determine cellular metabolism (energy expenditure) Energy usage calculated by measuring: CO2 exhaled O2 consumed urea nitrogen (rarely) Relies on known constant energy expenditure associated with all ratios of O2 consumption and CO2 production Indirect Calorimetry Abbreviated Weir Formula REE = [3.94 (VO2) + 1.11 (VCO2)] 1.44 VO2 = oxygen consumption (mL/min) VCO2 = carbon dioxide production (mL/min) Indirect Calorimetry Advantages “Gold Standard” Most accurate method for establishing energy needs Disadvantages Expensive equipment Requires trained personnel Some patients can’t be measured Recommended Energy Intake for Hospital Patients using Indirect Calorimetry Non-ambulatory Patients EER = REE x 1.2 Ambulatory Patients EER = REE x 1.4 Pulmonary Artery Catheter (Swan Ganz Catheter) Bedside measurement of pressure and flow within the cardiocardio pulmonary system Used to characterize fluid status in complex patients and evaluate response t therapeutic to th ti manipulations Estimating Hospital Energy Needs using: PAC (Fisk Equation) VO2 = cardiac output x 10 (CaO2 – CvO2) REE = VO2 x 7 Calculation based on d t C l l ti b d determination of wholei ti f h l body oxygen consumption Method of opportunity Invasive nature precludes its use of anything other than its intended purpose th th it i t d d One study demonstrated this method was accurate (± 20% of IC) in only 30% of subjects Estimating Hospital Energy Needs using: Mifflin-St. Mifflin-St Jeor Equations Male: REE = 10(W) + 6.25 (H) – 5(A) + 5 Female: REE = 10(W) + 6.25 (H) – 5(A) – 161 W = weight in kg (2.2 lb/kg) H = height in cm (2.54 cm/in) A = age in years Estimating Hospital Energy Needs using: Mifflin-St. Mifflin-St Jeor Equations Equations estimate basal requirement only (REE) EER = REE x Activity Weight Gain/Loss Must adjust by: multiplying by an stress factor May l M also adjust b dj t by: adding for pregnancy or lactation adding for weight gain weight loss is not a suitable goal for hospital patients No research to validate in hospital p p p population Effect of various stresses on REE in hospitalized patients Adjustment for Stress/Activity/Hypermetabolism Condition Degree of Increase Stress Factor Elective Surgery/ Serious Medical Problems 110 – 120% REE 1.1 – 1.2 Trauma 135 – 150% REE 1.35 – 1.5 Sepsis 150% - 170% REE 1.5 – 1.7 ASPEN, 2007 Estimating Hospital Energy Needs using: HarrisHarris Benedict Equations H i -B di t E ti Males: Females: BEE/REE = 66.5 + 13.8(W) + 5(H) – 6.8(A) BEE/REE = 655 + 9.6(W) + 1.9(H) – 4.7(A) W = weight in kg (2.2 lb/kg) H = height in cm (2.54 cm/in) A = age in years Research listed formula as estimating BEE Conditions more consistent with measuring REE Adjust for stress, weight gain, pregnancy/lactation EAL Evaluation of HarrisHarris-Benedict Equations Without added factors (13 papers) ( p p ) One study reported 97% results were more than 15% above/below RMR Mean difference between RMR and predicted value range from 250-900 kcal/day With added factors (13 papers) Using stress factor of 1.3 21% were within 10% of measured values 56% were more than 15% above/below RMR Using stress factor of 1.6 51% were within 10% of measured values 27% were more than 15% above/below RMR Estimating Hospital Energy Needs using: IretonIreton-Jones Equations 1992 Formula for ventilator dependent patients: IJEEV = 1925 - 10(A) + 5(W) + 281(S) + 292(T) + 851(B) 1997 Formula for ventilator dependent patients: IJEEV = 1784 - 11(A) + 5(W) + 244(S) + 239(T) + 804(B) A = age in years W = actual weight in kg S = sex (male = 1 female = 0) 1, T = trauma (present = 1, absent = 0) B = burns (present = 1, absent = 0) EAL Evaluation of IretonIreton-Jones Equations 1992 formula (7 papers) MacDonald & Hildebrandt reported 52% of nonobese subjects fell within 10% RMR and 34% were >15% RMR above or b l b below RMR Frankenfield reported 28% within ±10% RMR and 57% were >15% RMR above/below RMR 1997 formula (3 papers) Only O l one study reported accuracy rates: 36% within t d t d t ithi ±10% RMR and 40% >15% above/below RMR Estimating Hospital Energy Needs using: Penn State Equation PSU (BMI<30) = HBE (0.85) + Tmax (175) + Ve (33) – 6344 ( ) ( ) ( ) ( ) Use actual weight in Harris-Benedict Equation PSU (BMI ≥30) = HBE (1.1) + Tmax (140) + Ve (32) – 5340 Use adjusted weight in Harris-Benedict Equation Harris Benedict PSU (BMI<30) = Mifflin (0.96) + Tmax (167) + Ve (31) – 6212 Use actual weight in Mifflin-St. Jeor Equation Tmax – maximum b d t T i body temperature i previous 24 h t in i hr. Ve – minute ventilation at the time of measurement, read from ventilator, not calorimeter Developed from a mixed ICU population (1992-1997) Based on variables related to body size (HBE MSJ) (HBE, MSJ), inflammatory response (temperature, minute ventilation) Limitations of Predictive Equations Normal physiologic range of individual variations in RMR p y g g Typical factors (sex, height, weight, age) account for only about 80% of energy expenditure Differences in body composition accounts some of the individual variation Variation in the effect of trauma and disease on RMR Small increase due to diseases (except hyperthyroidism ) Increase due to traumatic injury can be very large Estimating Hospital Energy Needs using: “Rule of Thumb Rule Thumb” Healthy, H l h nonhospitalized h i li d 30 k l/k kcal/kg Adjust for activity and weight loss/gain No stress 20-25 kcal/kg Mild stress 25 30 25-30 kcal/kg Pneumonia, elective surgery Moderate t M d t stress 30-35 kcal/kg 30 35 k l/k Major surgery, long-bone fractures ASPEN, 2007 Assessing Hospital Protein Needs Grams per kilogram Kcal:N ratio Effect of various stresses on urinary nitrogen excretion in hospitalized patients Estimating Protein Needs using: grams/kg Protein Stress Condition (g/day) Normal Hospitalized without stress 1.0 Mild g y, Minor surgery, mild infection 1.0 – 1.2 Moderate Major surgery, moderate infection, moderate skeletal trauma 1.2 – 1.5 Severe Severe infection, multiple injuries, severe trauma major burns trauma, 1.6 – 2.0 Estimating Protein Needs using: Kcal:N Ratio Kcal requirement = g N x 6.25 = g protein Desired ratio Ratio for anabolism: 150:1 100:1 standard recommendation when limiting energy intake Assessing Hospital Fluid Needs Energy Age/Weight Estimating Fluid Needs based on: Energy Needs 1 mL fluid per 1 kcal estimated energy Estimating Fluid Needs using: Age/Weight Method Age Fluid Requirement 16 – 30 years, active 40 mL/kg/day 20 – 55 years 35 mL/kg/day 55 – 75 years y 30 mL/kg/day g y > 75 years 25 mL/kg/day Factors Increasing Fluid Requirements Factors F t Increase I Fever 12% per 1° C Sweating 10 – 25% Hyperventilation 10 – 60% Hyperthyroidism 25 – 50% Elevated GI losses Replace mL/mL based on 24 hr output Elevated renal losses p Replace mL/mL based on 24 hr output Feeding Recommendations for ICU patients Begin feeding within 24o if possible Use enteral feeding rather than parenteral if at all possible ll ibl Consider limiting energy in most critical p g gy patients ...
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