Nutrition Support Guideline

               

                  Critical illness is associated with a catabolic stress state demonstrated as SIRS, coupled with complications of infectious morbidity, MSOF/dysfunction, prolonged hospitalization, and disproportionate mortality. Traditionally, nutrition support in the critically ill population was regarded as adjunctive care, with simple goals of preserving lean body mass, maintaining immune function and averting metabolic complications.

                  Recently, the broad concept of critical care nutrition has changed to one of nutrition as specific therapy with the following goals: attenuate the metabolic response to stress, prevent oxidative cellular injury, favorably modulate the immune response and nutritionally modulate the stress response. To accomplish these goals, 3 fundamentals must be in place:  1) early enteral nutrition, 2) appropriate macro- and micronutrient delivery and 3) meticulous glycemic control.  Specifically, early EN is a proactive therapeutic strategy that may reduce disease severity, diminish complications, decrease ICU LOS, and favorably impact patient outcome.        

General Guidelines for NON-CRITICALLY ILL:

1.     Most general trauma patients can tolerate regular diet if no GI injury. Avoid clear liquids unless it appears clinically that they will not be tolerated.

2.     If Registered Dietitian has entered a note, follow the recommendations unless reasons not to do so, in which case communicate directly with RD or re-consult, if appropriate.

3.     If risks of dysphagia present, order ‘Dysphagia Screen’ (performed by RN at bedside) or Dysphagia Team Consult. Ice chips might be appropriate until screen complete.

4.     Enteral nutrition is superior to parenteral.

5.     If feeding tube indicated because of dysphagia or feeding difficulty, use Cortrak to aid placement when possible and initiate Impact 1.5 peptide unless another formula and/or rate are indicated.

General Guidelines for CRITICALLY ILL (see complete ASPEN guidelines below):

1.     All critically ill patients who are anticipated to have insufficient nutritional intake should be screened to determine nutritional risk using NUTRIC score.

2.     Nutrition assessment includes evaluation of comorbid conditions, function of the GI tract, and risk of aspiration.

3.     Traditional nutrition indicators or surrogate lab markers are not validated in critical care.

4.     Indirect calorimetry should be used to determine energy requirements when available and of reliable accuracy.

5.     In the absence of indirect calorimetry a predictive equation or simple weight-based equation (25-30 kcal/kg/d) may be substituted to calculate energy requirements.

6.     EN is the preferred route over TPN for the critically ill patient who requires nutrition support therapy.  It reduces infectious morbidity and significantly reduces LOS & cost.

7.     EN supports gut function & integrity, maintains tight cell junctions, stimulates gut blood flow & release of trophic endogenous agents (such as CCK , gastrin, & bile salts), supports secretory production of IgA-producing immunocytes which comprise the GALT.

8.     “Early” EN should be initiated in the critically ill or injured patient unable to maintain intake.  “Early” = within 24-48 hours of admission. 

9.     Initial formula and rate should be Impact 1.5 peptide at 20cc/hr unless otherwise indicated by situation or RD. Increase to goal unless RD note indicates otherwise.  All new ICU admits are evaluated by nutrition within 24hrs. 

10.  If RD has entered a note follow the recommendations unless specific reason not to do so.  This requires communication directly with the RD or re-consult with comments/concerns.   

11.  In the setting of hemodynamic compromise (patients requiring high dose vasoactive agents, alone or in combination with large volume fluid or blood product resuscitation to maintain cellular perfusion), EN should be withheld until the patient is fullly resuscitated and/or stable.  At UK, a trophic rate TF @ 20ml/hr is appropriate if low dose pressors, lactate <2.0 and good oxygen saturation.

12.  In ICU, evidence of bowel motility is not required in order to initiate EN .

13.  Gastric enteral nutrition is appropriate for most critically ill patients.  Therefore at UK initial feeding may be via Nasogastric tube until Flexible/Dobhoff tube is placed.

14.  Post-pyloric feeding is recommended in patients at high risk for aspiration or who have demonstrated prior intolerance to enteral nutrition or who are at high risk for aspiration.

15.  Goal > 80% estimated energy needs delivered within the first 48-72h of ICU admission.  > 50% of goal calories over the first week of hospitalization.

16.  Patients deemed high nutritional risk should have early goal enteral nutrition as soon as possible while monitoring for refeeding syndrome.

17.  Avoid bolus tube feeding in patients who exhibit intolerance to enteral nutrition or are at high risk for aspiration.

18.  Reglan or erythromycin may be beneficial to enhance gastric motility.

19.  Minimize tube feeding ‘holds’. Decisions to hold TF for OR should involve SGB resident/fellow/faculty… NOT a specialty service alone.

20.  Monitor daily for intolerance of enteral nutrition.  ASPEN 2016 guidelines recommend against use of routine GRV monitoring in ICU patients receiving EN, however, UK policy requires avoidance of holding TF’s for gastric residual volumes < 500mL absent other signs of intolerance. 

21.  Refer to institutional protocol for guidelines regarding assessment of gastric residual volumes.

22.  Timing of NPO status prior to, during, and after OR or other procedures should be minimized to prevent inadequate delivery of nutrition.  Ileus may be propagated by NPO status.  See UK Guideline: Cessation of Pre-operative Enteral Feeding For Adult ICU Patients

23.  High dose protein should be provided (1.2-2 g/kg/day).  Higher protein requirements are needed for burn or multi-trauma patients.

24.  Continually assess patients receiving EN for risk of aspiration. 

25.  Proactive use of ventilator bundle protocol (HOB > 40deg, oral care, suctioning, GI prophylaxis, etc) to reduce aspiration pneumonia should be followed.

26.  A combination of antioxidant vitamins and trace minerals (specifically including selenium) should be provided to all critically ill patients receiving specialized nutrition therapy.  NOTE-EFFICACY QUESTIONED BY REDOX TRIAL (Heyland et al. N Eng J Med 2013;368;16).

27.  The addition of enteral glutamine to an EN regimen is recommended in the ASPEN guideline for burn, trauma, and mixed ICU patients.  REDOX TRIAL SHOWED INCREASED MORTALITY WHEN USED IN SEVERE SIRS/INJURY/SEPSIS.

28.  Target blood glucose range of 140 or 150-180 mg/dL in the general ICU population.

29.  Recommendation against the use of special high-fat/low-carbohydrate formulations designed to reduce CO2 production in critically ill patients with acute respiratory failure.

30.  Fluid restricted energy-dense EN formulas should be considered for patients with acute respiratory failure and volume overload.

31.  Close monitoring and repletion of serum phosphate is indicated.

Specific Situations in both CRITICALLY ILL and NON-CRITICALLY ILL:

Parenteral Nutrition (TPN) Indications, Specific Recommendations

1. In previously healthy (nutritionally optimized) patients, initiate TPN only after the first 7 days of hospitalization if patient cannot maintain volitional intake and early EN is not feasible. 
2. In patients who are determined to be previously ill or malnourished, and EN is not feasible, initiate PN as soon after ICU admission as possible.
3. Regardless of nutritional status, initiate supplemental PN only if unable to meet > 60% of energy and protein requirements via enteral route after 7-10 days.

4.      Protocols and nutrition support teams necessary to guide PN efficiency and safety.

5.     In previously healthy patients, initiate TPN only after the first 7 days of hospitalization.  (Grade: E)

6.     Hypocaloric PN dosing (< 20kcal/kg/day or 80% estimated energy needs) with adequate protein supplement (>1.2g/kg/d) for patients requiring PN initially over the first week in the ICU.

7.     Limit or withhold soybean oil-based IV fat emulsions over the first week of PN in the critically ill.

8.     No significant difference in clinical outcomes between standardized commercially available PN versus custom compounded PN.

9.     Recommend against parenteral glutamine supplementation in the critical care population.

10.  As tolerance to EN improves, reduce (wean) PN and discontinue when patient is receiving > 60% of goal energy requirement from EN.

11.  In patients undergoing major upper GI surgery in which EN is not feasible, TPN should be provided under very specific conditions: If malnourished, PN should be initiated 5-7 days preoperatively and continued into the postoperative period.  TPN should not be initiated in the immediate postoperative period but delayed for 5-7 days (should EN continue not to be feasible).

12.  TPN of < 7 day duration would be expected to have no outcome effect and may result in increased risk to the patient. TPN should be initiated only if the duration of therapy is anticipated to be ≥7 days.

Enteral Nutrition in Obese Patients

1. Initiate early EN (24-48h of admission) in obese patients who cannot maintain adequate volitional intake.
2. Nutritional assessment in the obese patient should include assessment/screening for metabolic syndrome, evaluation of co-morbidities, and determination of severity of inflammation.
3. Patients with BMI <30, protein requirements 1.2-2.0 g/actual kg.
4. In the critically ill obese patient, permissive underfeeding or hypocaloric feeding with EN is recommended. (Grade: D). If BMI  >30, EN goal should not exceed 65%-70% of target energy requirements as measured by indirect calorimetry.  Provide 11-14 kcal/ actual kg or 22-25 kcal/IBW. For protein, if BMI 30-40, provide ≥2.0 g/IBW kg. If BMI ≥ 40, provide ≥2.5 g/IBW kg.
5. Obese patients with history of bariatric surgery should receive thiamine supplementation prior to receiving dextrose-containing IV fluids or nutrition therapy.
6. Micronutrients (calcium, thiamin, vitamin B12), fat-soluble vitamins (A,D,E,K), folate, and trace minerals (iron, selenium, zinc, copper) should be supplemented.

Renal Dysfunction

1. ICU patients with acute renal failure (ARF) or acute kidney injury (AKI) should be placed on standard enteral formulations, and standard ICU recommendations for protein and calorie provision should be followed. If significant electrolyte abnormalities exist or develop, a specialty formulation designed for renal failure (with appropriate electrolyte profile) may be considered.
2. Patients receiving hemodialysis or continuous renal replacement therapy (CRRT) should receive increased protein, up to a maximum of 2.5 g/kg/d.
3. Protein should not be restricted in patients with renal insufficiency as a means to avoid or delay initiation of dialysis therapy.

Hepatic Dysfunction

1.  Traditional assessment tools should be used with caution in patients with cirrhosis and hepatic failure, as these tools are less accurate and less reliable due to complications of ascites, intravascular volume depletion, edema, portal hypertension, and hypoalbuminemia.
2. Dry or usual weight should be used instead of actual weight in predictive equations to determine energy/protein requirements. 
3. EN is the preferred route of nutrition therapy in ICU patients with acute and/or chronic liver disease.
4. Nutrition regimens should avoid restricting protein in patients with liver failure.  
5. Standard enteral formulations should be used in ICU patients with acute and chronic liver disease.
6. No evidence has demonstrated benefit from using branched-chain amino acid (BCAA) formulations in patients with hepatic encephalopathy who are already receiving appropriate treatment.

Pancreatitis

1.  On admission, patients with acute pancreatitis should be evaluated for disease severity.  Frequent re-evaluation for EN tolerance and need for specialized therapy is indicated.
2. Patients with severe acute pancreatitis should have a nasoenteric tube placed and EN initiated as soon as fluid volume resuscitation is complete.
3. Patients with mild to moderate acute pancreatitis do not require nutrition support therapy (unless an unexpected complication develops or there is failure to advance to oral diet within 7 days).
4. Patients with severe acute pancreatitis may be fed enterally by the gastric or jejunal route and EN should initiate and advance to goal within 48-72 hours of admission, or when fluid resuscitation is completed.
5. EN superior to PN in patients with severe acute pancreatitis who require nutrition therapy.
6. Standard polymeric formula is, at present, sufficient for EN in severe acute pancreatitis.
7. Tolerance to EN in patients with severe acute pancreatitis may be enhanced by the following measures:   

-        Minimizing the period of ileus after admission by early initiation of EN.

-        Displacing the level of infusion of EN more distally in the GI tract.

-        Changing the content of the EN delivered from intact protein to small peptides, and long-chain fatty acids to medium-chain triglycerides or a nearly fat-free elemental formulation. 

-        Switching from bolus to continuous infusion.

8. Probiotics may be useful in patients with severe acute pancreatitis who are receiving early EN and are recommended.
9. Parenteral Nutrition should be initiated in patients with severe acute pancreatitis of one week’s duration when EN is not feasible or tolerated.

Miscellaneous Situations

1. Arginine-containing immune-modulating EN is potentially beneficial in patients with TBI.
2. Early EN (24-48h post-injury) should be initiated in patients treated with open abdomen in the absence of a bowel injury.
3. Early EN (24-48h post-injury) should be initiated in trauma patients once hemodynamically stable.
4. An additional 15-30g of protein per liter of exudate lost from the open abdomen should be provided each day in addition to calculated energy needs.
5. Very early EN (within 4-6h post-injury) should be provided to burn patients with functional GI tracts who cannot meet estimated energy needs with volitional intake.  PN should be reserved for intolerance of EN.
6. Indirect calorimetry should be used to assess energy needs in burn patients on a weekly basis.
7. Burn patients require 1.5-2 g/kg/day protein.
8. Regardless of nutritional status or risk, do not use exclusive PN or supplemental PN in conjunction with EN early in acute phases of septic shock.
9. Immune-modulating EN should not be routinely used in patients with severe sepsis.
10. Routine use of immune-modulating EN (arginine and fish oils) in post-operative patients is recommended.
11. Though early EN is recommended, individualization is required in each specific case for situations such as prolonged, ileus, anastomosis, vasopressor usage.
12. Chronically critically-ill patients (ICU LOS > 21 days) should receive aggressive high-protein EN in addition to a resistance exercise program.
13. Specialized nutrition therapy is not obligatory in cases of futile care or end-of-life situations. The decision to provide nutrition therapy should be based on effective patient/family communication, realistic goals, and respect for patient autonomy.

Finally……a word on feeding while on neuromuscular blockade:

Not a lot has been published regarding enteral nutrition tolerance and neuromuscular blockade. Several related papers have been published in pediatrics. UK published data on tolerance of EN in pentobarb coma which creates a similar clinical result. To summarize:

·       Patients will tolerate EN while on NMB

·       A small bowel feeding tube is critical (D1 often refluxes to the stomach).

·       Often the goal rate is 20% below the non-NMB goal.

·       Aggressive bowel regimen should be used including a hyperosmotic agent because the stimulants (Dulcolax) are useless with NMB.

·       ASPEN Guidelines for Parenteral and Enteral Nutrition (https://nutritioncare.org)