Enteral Nutrition vs Total Parenteral Nutrition (TPN)
Clinical Efficacy
Systematic Review of Enteral vs Parenteral Nutrition in the ICU (Nutrition, 2004) [MEDLINE]
Enteral Nutrition Decreases Infectious Complications, as Compared to Parenteral Nutrition
Enteral Nutrition is Less Expensive than Parenteral Nutrition
British CALORIES Trial Comparing Early Enteral vs Parenteral Nutrition in the ICU (NEJM, 2014) [MEDLINE]: randomized trial in 33 English ICU’s comparing enteral vs parenteral nutrition (n = 2388)
No Difference in 30-day Mortality Between the Groups
Caloric Intake was Similar in the Groups, with the Target Intake Not Achieved in Most Patients
Significant Reduction in the Parenteral Group in Rates of Hypoglycemia (44 patients [3.7%] vs. 74 patients [6.2%]; P=0.006) and Vomiting (100 patients [8.4%] vs. 194 patients [16.2%]; P<0.001), as Compared to the Enteral Group
No Difference in Rate of Infectious Complications or Other Adverse Events
Recommendations (Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) 2016 Guidelines) [MEDLINE]
Enteral Nutrition Should Be Used Over TPN (Quality of Evidence: Very Low-Low): enteral nutrition is associated with decreased infectious complications (pneumonia and central line infections in most patients/abdominal abscess in trauma patients) and decreased ICU length of stay
In Patients with Low Nutrition Risk (NRS 2002 ≤3 or NUTRIC score ≤5), Exclusive TPN Should Be Withheld for the First 7 Days Following ICU Admission, if PO Intake and Enteral Nutrition are Not Adequate/Possible (Quality of Evidence: Very Low)
In Patients with High Nutrition Risk (NRS 2002 ≥5 or NUTRIC score ≥5) or Severely Malnourished, Exclusive TPN Should Be Started as Soon as Possible Following ICU Admission, if PO Intake and Enteral Nutrition are Not Adequate/Possible (Quality of Evidence: Expert Consensus)
In Patients with Low or High Nutrition Risk, Supplemental TPN Should Be Considered AFter 7-10 Days if Unable to Meet >60% of Energy and Protein Requirements by Enteral Route Alone (Quality of Evidence: Moderate): initiating supplemental TPN prior to 7-10 days may be harmful
Caloric Content of Total Parenteral Nutrition Formulations
D5 (Peripheral/Central): 170 kcal/L
D10 (Peripheral/Central): 340 kcal/L
D25 (Central): 850 kcal/L
D30 (Central): 1020 kcal/L
D35 (Central): 1190 kcal/L
Typical Total Parenteral Nutrition (TPN) Formulations
NaCl: 40 mEq/L
KCl: none
Trace Elements: 3 mEq/L
NaAcet: 10 mEq/L
MVI: 1 amp/L
Protein Content of Amino Acids
3.5% AA: 35 g protein/L
4.25% AA: 42.5 g protein/L (170 kcal/L)
5% AA: 50 g protein/L (200 kcal/L)
Calorie Content of Lipid Formulations
10% Intralipid: 1100 kcal/L
20% Intralipid: 2000 kcal/L
Initiating Total Parenteral Nutrition (TPN) in the High Risk or Severely Malnourished Patient
Recommendations (Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) 2016 Guidelines) [MEDLINE]
Hypocaloric TPN Dosing (≤20 kcal/ kg/d or 80% of Estimated Energy Needs) with Adequate Protein (≥1.2 g Protein/kg/day) is Suggested Initially Over the First Week of Hospitalization in the ICU (Quality of Evidence: Low)
Trials Examining Use of Total Parenteral Nutrition (TPN) in the Intensive Care Unit
EPaNIC Trial Comparing Early vs Late Initiation of TPN (NEJM, 2011) [MEDLINE]: Belgian randomized multi-center trial comparing early initiation of TPN (European guidelines: within 48 hrs of ICU admission; n = 2312) with late initiation (American and Canadian guidelines: within 8 days of ICU admission; n = 2328) in adults in the ICU
No Difference in ICU Mortality Rate, Hospital Mortality, and 90-Day Mortality Rate Between the Groups
Late-Initiation Group Had a 6.3% Increase in Likelihood of Being Discharged Alive Earlier from the ICU and Hospital
Late-Initiation Group Had Fewer ICU Infections (22.8% vs. 26.2%, p = 0.008)
Late-Initiation Group Had a Lower Incidence of Cholestasis (p < 0.001)
Late-Initiation Group Had a Relative Reduction of 9.7% in the Proportion of Patients Requiring >2 Days of Mechanical Ventilation (p = 0.006)
Late-Initiation Group Had a Median Reduction of 3 Days in the Duration of Renal Replacement Therapy (p = 0.008)
Late-Initiation Group Had a Mean Reduction in Health Care Costs of About $1,600 (p = 0.04)
Late-Initiation Group Had No Decrease in Functional Status at Hospital Discharge
Study of Early Parenteral Nutrition in Critically Ill Patients with Short-Term Relative Contraindications to Early Enteral Nutrition (JAMA, 2013) [MEDLINE]: n = 1372 patients
No Impact on 60-Day Mortality Rate, as Compared to Standard Care
Early Parenteral Nutrition Strategy Resulted in Fewer Invasive Ventilation Days, But Had No Effect on ICU or Hospital Stay
Swiss Randomized Trial of Supplemental TPN in Critically Ill Patients (Lancet, 2013) [MEDLINE]: n = 305 patients
Supplemental TPN (in Addition to Enteral Nutrition) Starting 4 Days After ICU Admission Decreased Nosocomial Infection Rates
British CALORIES Trial Comparing Early Enteral vs Parenteral Nutrition in the ICU (NEJM, 2014) [MEDLINE]: randomized trial in 33 English ICU’s comparing enteral vs parenteral nutrition (n = 2388)
No Difference in 30-day Mortality Between the Groups
Caloric Intake was Similar in the Groups, with the Target Intake Not Achieved in Most Patients
Significant Reduction in the Parenteral Group in Rates of Hypoglycemia (44 patients [3.7%] vs. 74 patients [6.2%]; P=0.006) and Vomiting (100 patients [8.4%] vs. 194 patients [16.2%]; P<0.001), as Compared to the Enteral Group
No Difference in Rate of Infectious Complications or Other Adverse Events
Recommendations
“Choosing Wisely” Campaign Five Recommendations (Am J Resp Crit Care Med, 2014) [MEDLINE]
Do not order diagnostic tests at regular intervals (such as every day), but rather in response to specific clinical questions
Do not transfuse red blood cells in hemodynamically stable, nonbleeding ICU patients with an Hb concentration greater than 7 g/dl
Do not use parenteral nutrition in adequately nourished critically ill patients within the first 7 days of an ICU stay
Do not deeply sedate mechanically ventilated patients without a specific indication and without daily attempts to lighten sedation
Do not continue life support for patients at high risk for death or severely impaired functional recovery without offering patients and their families the alternative of care focused entirely on comfort
Adverse Effects of Total Parenteral Nutrition (TPN)
Endocrinologic Adverse Effects
Hyperglycemia (see Hyperglycemia, [[Hyperglycemia]])
Epidemiology: associated with opiate administration
Elevated Liver Function Tests (LFT’s) (see xxxx, [[xxxx]])
Other Adverse Effects
xxxx
References
Nutritional effect of continuous hemodiafiltration. Nutrition 1995; 11:388–393
Impact of the nutritional regimen on pro-tein catabolism and nitrogen balance in pa-tients with acute renal failure. JPEN J Parenter Enteral Nutr 1996; 20:56-62
Enteral compared with parenteral nutrition: a meta-analysis. Am J Clin Nutr. 2001;74(4):534-542 [MEDLINE]
High protein intake during continuous hemodiafiltration: Impact on amino acids and ni-trogen balance. Int J Artif Organs 2002; 25:261–268
Prospective randomized trial to assess caloric and protein needs of critically Ill, anuric, ventilated patients requiring continuous renal replacement therapy. Nutrition 2003; 19:909–916
Does enteral nutrition compared to parenteral nutrition result in better outcomes in critically ill adult patients? A systematic review of the literature.
Nutrition. 2004;20(10):843-848 [MEDLINE]
Metabolic and nutritional aspects of acute renal failure in critically ill patients requiring continuous renal replacement therapy. Nutr Clin Pract 2005; 20:176–191
Effects of different energy intakes on nitrogen balance in patients with acute renal failure: A pilot study. Nephrol Dial Transplant 2005; 20:1976–1980
Nutrition therapy in the critical care setting: what is “best achievable” practice? An international multicenter observational study. Crit Care Med. 2010;38:395–401. doi: 10.1097/CCM. 0b013e3181c0263d [MEDLINE]
EPaNIC Trial. Early versus Late Parenteral Nutrition in Critically Ill Adults. NEJM 2011; 365;6 [MEDLINE]
OMEGA Trial. Enteral omega-3 fatty acid, gamma-linolenic acid, and antioxidant supplementation in acute lung injury. JAMA. 2011;306:1574–1581 [MEDLINE]
Optimisation of energy provision with supplemental parenteral nutrition in critically ill patients: a randomised controlled clinical trial. Lancet 2013;381:385–393 [MEDLINE]
Early parenteral nutrition in critically ill patients with short-term relative contraindications to early enteral nutrition: a randomized controlled trial. JAMA 2013;309:2130–2138 [MEDLINE]
A randomized trial of glutamine and antioxidants in critically ill patients. N Engl J Med. 2013;368:1489–1497 [MEDLINE]
Trial of the Route of Early Nutritional Support in Critically Ill Adults. N Engl J Med. 2014 Oct 1 [MEDLINE]
An official American Thoracic Society/American Association of Critical-Care Nurses/American College of Chest Physicians/Society of Critical Care Medicine policy statement: the Choosing Wisely® Top 5 list in Critical Care Medicine. Am J Respir Crit Care Med. 2014 Oct 1;190(7):818-26. doi: 10.1164/rccm.201407-1317ST [MEDLINE]
The Canadian Critical Care Nutrition Guidelines in 2013: an update on current recommendations and implementation strategies. Nutr Clin Pract. 2014;29:29–43. doi: 10.1177/0884533613510948 [MEDLINE]
Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.). JPEN J Parenter Enteral Nutr. 2016 Feb;40(2):159-211. doi: 10.1177/0148607115621863 [MEDLINE]
