The What, Why and When of Permissive Ainsley Malone, MS, RD, CNSD Nutrition Support Team Mt. Carmel West Hospital Mt. Carmel West 500 bed academic center Non-physician based NST Dietitian, pharmacist and nurse What to Expect Review rationale for underfeeding Discuss research with parenteral nutrition and enteral nutrition Not always mutually exclusive In critically ill population Include obese population Offer recommendations for practice
Minimize loss Promote clinical improvement Positive outcomes Caloric Intake Quandary??? Overfeeding and its associated complications Paradigm Shift A change in basic assumptions within the ruling theory of science History of Energy Intake Early PN Regimens 175% to 200% of BEE VA Cooperative Trial 46 kcals/kg Energy Requirements Long, et al. Activity/injury factors High estimation of requirements Kcals/kg 35 45 kcals/kg Obese patients using actual weight
Adverse Effects? Ventilatory complications reported Case reports Askanazi, et al. 1981 Increased work of breathing, ventilator weaning failure VA Cooperative Trial Increased infectious complications seen in those with mild or moderate malnutrition Relationship to energy intake and/or substrate? Rationale for Based upon hormesis concept (Zaloga-1994) Less is more theory Beneficial effect of low dose vs toxic effect of high dose In setting of inflammation cytokine release, oxidant production damage Critical Illness Metabolic Response Flow phase - catabolism Increased counter-regulatory hormones Favors catabolic processes Increased gluconeogenesis General duration of 3-10 days Flow phase anabolism Decreased glucagon, epi and norepi Increased growth hormone, IGF Favors anabolic processes Duration of 10 to 60 days
Catabolic Phase Ability to tolerate traditional nutrient regimens? Can endogenous glucose production be suppressed? Hyperglycemia common Potential Benefits Reduced nutrient oxidation Reduced free radical and cytokine production Reduced DNA damage Reduced metabolic demands Potential for reduced CO2 production Potential Benefits Energy/carbohydrate restriction Reduced hyperglycemia Lower n-6 fatty acids Reduced substrate for pro-inflammatory mediator synthesis Decreased Ca, Fe, Zn levels May decrease inflammatory response and cell injury
Animal Models for Alexander, Ann Surg 1989 Animals with peritonitis Kcal range 100 to 15 per kg Increased infections in higher calorie group Increased survival when provided fewer calories 100% mortality in high group vs 43% in low group Berg and Simms, J Nutr 1990 Rats with restricted diets lived 20% longer Peck, JPEN 1992 Significantly improved mortality in mice fed 50% normal caloric intake in Parenteral Nutrition Patino, World J Surg 1999 Retrospective of 107 ICU patients Grouped by use of PN (early versus late) 22-24 kcals/kg day (IBW) Lack of statistical analysis Nitrogen balance -8.5 and -9.7 Glucose levels 122 mg/dl and 135 mg/dl Concluded results much improved from earlier hypercaloric regimens in Parenteral Nutrition McGowan, CCM 2000 PRCT in acute care hospital Compared a hypocaloric and eucaloric regimen 1000 kcals/day or 20-25 kcals/kg/day Protein provided at 1.5 g/kg/day Initiated less than total dextrose goal Nutrient intake 913 ± 90 vs 1192 ± 212 kcals/day No difference in glucose levels or infections Nitrogen balance more negative in hypocaloric group Concluded that hypocaloric PN regimen not superior
Enteral Nutrition and Krishnan, Chest 2003 Prospective trial in ICU patients (n=187) Compared energy intakes with AACP guidelines 25 kcals/kg/day Divided energy intakes into tertiles Average intake 50.6% of the ACCP Tertile II with likelihood of discharge alive compared to I or III Criticism of PN use in up to 39% of patients Enteral Nutrition and Ibrahim, JPEN 2002 PRCT with ICU patients Compared early versus late feeding group 100% estimated EE on Day 1 versus Day 5 Late group to receive 20% of EEE Days 1-4 Total caloric intake = 2370 ± 2000 kcals/day versus 629 ± 575 kcals (p<0.001) Increased ICU LOS (p=0.02), VAP (p=0.04) and antibiotic therapy (p=0.001) in the early group No difference in mortality Conclusions and caveats
Enteral Nutrition and Ash, JPEN 2005 (abstract) Retrospective review of trauma patients (n=128) Non-obese Evaluated caloric intakes in quartiles Kcals/kg/day Highest hospital LOS in Quartile IV Enteral Nutrition and Hise, JADA 2007 Prospective evaluation in MICU and SICU Mean percent of goal energy intake per ICU day calculated Energy intake from all sources Higher ICU LOS with >82% of goal intake SICU population of >67% of goal intake Higher ICU and hospital LOS Conclusions Limit energy intake to 80% or less in severe critical illness Rationale for in Obesity Obese associated with metabolic changes Insulin resistance Hyperglycemia Obstructive sleep apnea Fatty infiltration Provide nutrients without exacerbating metabolic issues Protect lean body mass
Obese Patient Dickerson, AJCN 1986 Pilot study (n=14) Prospective evaluation with PN Received 51% of non-protein kcals 2.1 g/protein/kg Weight loss occurred Nitrogen balance +2.4±1.9 g/day Wounds and fistulas healed Obese Patient Burge, JPEN 1994 Prospective trial in acutely ill patients (n=16) Randomized to receive 50% or 100% nonprotein kcals 2 g protein/kg Nitrogen balance 1.3 ± 3.62 hypocaloric group 2.8 ± 6.9 control group Conclusion hypocaloric PN can result in a comparable nitrogen balance Obese Patient Choban, 1997 AJCN Prospective evaluation in acute/critically ill patients (n=30) 22 kcals/kg IBW hypocalorie 36 kcals/kg IBW control No difference in weight change or nitrogen balance ICU patients with no difference Trend toward lower glucose levels in hypocaloric group Conclusion
Obese Patients Dickerson, Nutrition 2002 Retrospective evaluation in critically ill patients (n=40) Hypocaloric = < 20 kcals/kg adj BW Eucaloric = 20 kcals/kg adj BW Actual energy intake - Average at week 4 22 kcals/kg/ibw hypocaloric 29 kcals/kg/ibw - eucaloric No significant differences in nitrogen balance Obese Patient Dickerson, Nutrition 2002 Clinical outcomes Decreased ICU stay (p=0.03) Decreased antibiotic therapy (p=0.03) No difference in glucose levels May be related to EN versus PN Conclusion Hypocaloric EN feeding approach at least AS favorable is eucloric feeding May provide a clinical benefit Obese Patient Choban and Dickerson, NCP 2005 Combined data sets Evaluated morbidly obese (Class III = BMI 40) N = 70 44 provided hypocaloric regimen 26 provided eucaloric regimen Via regression determined higher protein intake is needed 1.9-2.5 g/kg/ibw in critically ill patients Trend toward worsening hyperglycemia in Class III compared to less obese
Recommendations ADA Evidence Analysis Library 2007 summary on EN delivery in critical illness Recommends 14-18 kcals/kg actual weight (non-obese) Caloric intake preview: energy intake of 9 to 18 kcal per kg may be associated with decreased mortality Canadian Clinical Practice Guidelines Recommend low dose PN Short duration and in those not malnourished Refer to lack of prospective trials http://ada.portalxm.com/eal/topic.cfm?cat=3368 Is with EN Occurring? McClave, et al, 1999 44 MICU and CCU patients Nasogastric tubes Data recorded q 4 hrs 78% of ordered TF delivered 11% - 102% Feeding disruption High residual volume Procedures Is with EN Occurring? Petros, Clin Nutr 2006 Observational study of ICU patients At least 7 days of EN Assess EE via indirect calorimetry Caloric target minimum of 20 kcals/kg/day EN interrupted in 32% of feeding days Daily infused volume = 86.2 ± 30.4% of prescribed Mean energy intake 39.2% on Day 1 83.1% on Day 6 Conclusion Caloric delivery much less than MEE Clin Nutr 2006;25:51-59
Contribution to Marshall, Intensive Crit Care Nurse 2006 Descriptive survey of 376 critical care nurses on enteral feeding practices Response rate = 50.5% Gastric residual volume measurement 65.4% Reason to delay feeding Patient positioning (21%) and tube placement issues (25%) Decreased enteral feeding intakes Conclusion Practice Recommendations Populations for permissive underfeeding Sepsis, ARDS, trauma, surgical patients Suggested energy intakes 14-18 kcals/kgday in the non-obese 22 kcals/kg/day in the obese Recommended goal for PN not for EN Monitor energy intake via EN Length of underfeeding Recommendations are for 7-10 days or when metabolic response abates Take Home Messages Permissive underfeeding an alternative concept Preventing overfeeding essential Animal models supportive Research with PN and EN and patient suggests benefit Actively pursue with PN patient but not EN
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