Practical Hospital Nutrition for Third-Year Medicine Students

Susan Bussell, R.D., Susan DeHoog, R.D., Susan Billingsley R.D., John Amory, M.D.

Malnutrition has been associated with a variety of adverse patient outcomes such as: increased risk of infection and sepsis, impaired skeletal and respiratory muscle strength and poor wound healing, increased morbidity and mortality, longer ICU and hospital stays and increased costs. Regulatory agencies such as JCAHO now require screening of every newly admitted patients nutritional status.

Overview

  1. Nutrition Screening/Assessment
  2. Regular and Soft Textured Diets
  3. Dysphagia Diet
  4. Renal Failure
  5. Diabetes (ADA Diet)
  6. Congestive Heart Failure
  7. Hepatic Dysfunction and Liver Function
  8. Gastro Intestional Disease
  9. Nutrition Support: Enteral Nutrition (EN)
  10. Nutrition Support: Total Parenteral Nutrition (TPN)
  11. Re-feeding Syndrome

A. Nutrition Screening/Assessment

Nutritional screening is completed by nursing within the first 24 hours a patient is admitted.

Criteria for nutritionally at risk:

  • Involuntary weight loss of more than 10 pounds in 1 month
  • Nausea/Vomiting/Diarrhea for greater than 5 days
  • Alternate nutrition support (parenteral / enteral nutrition)
  • Trauma, burns, major surgery, anticipated NPO greater than 5 days
  • BMI <20 or >40
  • Major organ dysfunction/transplant
  • Severe dysphagia
  • Prolonged NPO status (eg: intubation)

A Nutritional Assessment (consult): is completed by a registered dietitian or diet tech. It evaluates and reviews acute or chronic illness, nutritional deficiencies, medications, weight changes, swallowing issues, psychosocial issues (eg. alcohol, drugs ), diagnostic procedures, surgeries and other therapies that affect nutrition status (radiation, chemotherapy, transplantation).

The nutrition recommendations are then documented in the patients' charts. Nutrition consults also can be requested by MDs for patients who are nutritionally compromised or who need nutritional education.

How Does a Nutritionist Estimate a Patient's Caloric Requirements?

Approach 1: Harris-Benedict Equation: Basal Energy Needs

For men:
66.5 + (13.75 x kg*) + (5.003 x cm) - (6.775 x age)
For women:
655.1 + (9.563 x kg*) + (1.850 x cm) - (4.676 x age)

*Weight (kg) is based on ideal body weight (IBW) using Hamway Equation:
Hamway Equation:
Males: [106# (first 5 feet) + 6# per additional inch]/2.2
Females: [100# (first 5 feet) + 5# per additional inch]/2.2

Stress Factors that increase calorie needs above calculated value of Harris-Benedict Equation:

Condition Factor
Minor injury, minor surgery, open (clean) wound
1.2
Fracture, major surgery, open (infected) wound
1.3
Major trauma, severe infection
1.5
Burn or combinations of above
2.0

 

Approach 2: (Weight based)
Normal: 15-25 kcal/kg/day
Catabolic: 25-30 kcal/kg/day
Obese: 20-25 kcal/kg/day
Morbidly obese: Consult dietitian

Estimating Protein needs:

Normal 1.0 g protein/kd/d
Mild to moderate depletion 1.2-1.5 g protein/kg/day***
Post-operative/stressed/trauma/burns 1.2-2.0 g protein/kg ***
***ADJUST FOR LIVER OR RENAL DYSFUNCTION***

Where does the Nutritionist Put the Recommendations?

  • The patient's Nutritional Assessment documented in the chart as well as recommendations for TPN or Tube Feeding.
  • If enteral / parenteral feeding recommendations are not already documented in the patient's chart, call the dietitian as needed to initiate nutrition support, of call with questions.

B. Regular and Soft Textured Diets

General or Regular Diet

Purpose: to maintain optimal nutritional status in persons who do not require a therapeutic diet. All foods are allowed.

Soft/Textured-Modified/Mechanical Soft

Indications for diet:

  • Patients with poor dentition, limited teeth, or other chewing problems
  • Patients who are progressing from liquid diets
  • Postoperative patients unable to tolerate a general diet
  • Patients with mild gastrointestinal problems
  • N.B. Soft textured diets are not for use by dysphagia patients in whom a specific "dysphagia diet" should be ordered.

Modifications: to fiber, texture, and seasoning.

  • Fluids and solid foods are lightly seasoned and moderately low in fiber and easy to chew.
  • Excluded: Raw fruits and vegetables, course breads and cereals, highly seasoned foods, strong-smelling foods, and fried foods.

Examples: macaroni and cheese, ice cream, puddings

C. Dysphagia Diets

Patients at risk for aspiration should have a speech pathology evaluation for swallowing. The diet order should specify the texture for solids and the consistency of fluids (see below).

Solid Textures:

Dysphagia Pureed: Smooth blended foods that do not require chewing and that form a cohesive bolus. Examples: pudding, applesauce, pureed meats, vegetables, and fruits.

Dysphagia Mechanical: Moist soft-textured foods, easy to chew foods that form a cohesive bolus. Some entrees will be chopped. Moist soft breakfast breads, such as pancakes, muffins, and French toast are allowed. This diet excludes sandwiches, breads, and rolls, unless specified by the Speech Therapist to be safe for a particular patient. Smooth hot cereals are allowed. Cold cereals are omitted. The Speech Therapist will specify if a patient needs to have "all textures chopped."

Dysphagia Advanced: This consists of soft textured foods. This diet excludes dry, crumbly, or crunchy foods, such as raw fruits and vegetables, crackers, chips, and cookies. Breads are safe. All foods from the Dysphagia Pureed and Mechanical diets are safe.

Fluid Consistency:

Spoon Thick Liquids: Highly viscous liquids that are too thick to be taken by a straw.

Nectar Thick Liquids: Medium viscosity liquids that may be taken through a straw and have a nectar-like consistency. Example: apricot nectar.

Thin Liquids: Liquids with a viscosity similar to water.

D. Renal Diet

Renal diet:

  • 2g Na, 2-3g K+, 1000-1200mg PO4
  • Adjust protein based on renal function, nutritional status, and need for/type of dialysis. Basic guidelines for estimating protein needs are as follows:
    • Pre-dialysis: .8-1.2g/kg, ideal body weight
    • Hemodialysis: 1.0-1.4g/kg, ideal body weight
    • Peritoneal Dialysis: 1.2-1.5g/kg, ideal body weight
  • Supplements: Nephrovitamins; Vitamin D, Calcium, Iron as needed
  • Individualized restrictions as needed per patient renal function and labs

E. Diabetic Diet

First, discuss food plan first then integrate insulin regimen into the eating plan and consider exercise. Diabetics with insulin pumps have more flexibility with diet.

Then, recording and evaluating blood glucose levels. Adjust insulin regimens as needed. Individualize each patient's meal plan and teach carbohydrate counting as indicated. Plan for adjustments for illness, exercise, and provide appropriate treatment for hypoglycemia and/or hyperglycemia.

Write "ADA diet"only. There is no need to write for calories (e.g. 2000kcal ADA), this allows for more appropriate individualization of the diet.

F. Congestive Heart Failure

Background:

CHF compromises a patient's ability to meet nutrition requirements. It is estimated that greater than 50% of hospitalized patients with CHF have some degree of cardiac cachexia. It involves depletion of lean body mass with declines in strength, performance status and possible immune competence due to impaired nutrient absorption, hypermetabolism, insufficient food intake, anorexia, taste changes associated with medications, and abdominal distension.

Nutrition Approach:

  • Reduce sodium intake to <2500 mg/day
  • Promote adequate calorie and protein intake to maintain BMI >= 20 and Alb > 3.5
  • Avoid excessive fluid intake and implement fluid restriction if severe hyponatremia is present
  • Encourage MVI with minerals and liquid nutritional beverages if oral intake suboptimal
  • Encourage activity
  • Encourage adherence to all diet/medication/fluid regimens
  • Encourage 2 or more fatty fish meals/week

G. Hepatic Dysfunction and Liver Failure

Liver patients can have malnutrition, muscle wasting, fluid imbalance, encephalopathy, nutrient deficiencies, decreased appetite secondary to disease and ascites, malabsorption, anorexia, low albumin, elevated ammonia levels due to:

  • Malabsorption (diarrhea secondary to meds-- i.e. lactulose)
  • Anorexia
  • Encephalopathy
  • Early satiety secondary to ascites
  • Dietary restrictions

Nutritional Approach:

To prevent further nutritional compromise especially pending transplant or if lactulose ordered:

  • Avoid protein restriction (Ideally, recommend 1.3 grams protein per kg IBW, but not less than 1.0g/kg,Ibw)
  • Fluid restriction may be appropriate depending on electrolytes and ascites.
  • Sodium restriction- usually 2g Na with fluid retention and hyponatremia.
  • Supplements: Multivitamins should contain Folic Acid, but not iron. Also, recommend 1500mg calcium, preferably calcium carbonate or calcium citrate + 800IU Vitamin D. They should be instructed to not take additional Vitamin A or Beta-Carotene supplements.
  • Monitor for deficiencies of thiamin, folate, fat soluble vitamins, and zinc.

 

H. Gastro Intestinal Disease

Background

Patients with GI disease may have malabsorption, ileus, fistulas, poor wound healing, protein losing enteropathy, dumping syndrome, malnutrition, weight loss, muscle wasting, nutrient deficiencies, poor appetite, inability to tolerate nutrition intake

Nutritional Interventions

  • Provide enteral or parenteral nutrition support for patients who cannot meet their nutritional needs by oral diet.
  • Provide high protein along with adequate calorie support:
    • 1.5 - 2.0 gm/ kg for patients with fistulas and protein losing enteropathies;
    • 1.4 - 1.5 gm/ kg for patients with large wounds
  • Monitor and replace key wound healing nutrients: Vitamin C, Vitamin A, Zinc.
    • Provide Vitamin -mineral supplementation if ileum is removed.
    • Multivitamin with Iron, Calcium, and Vitamin B-12.
  • Replace electrolytes for GI losses. Provide adequate fluid.
  • Order Diets to accommodate patients GI tolerance and to meet their nutritional needs:
    • General or low / high fiber diets as needed for patients with colon diseases
    • Gastrectomy Diet for patients who are prone to dumping syndrome and have limited capacity for intake s/p gastrectomy.
    • Esophageal Diet for patients s/p esophagus surgery needing moist soft textures.
    • Gastric Bypass Diet for patients who are s/p bariatric surgery.
    • Low Fat Diet for patients with malabsorption syndromes.

I. Nutrition Support: Enteral Nutrition (EN)

Enteral feeding is the preferred route of Nutritional Support for the following reasons:

  • Maintains gut integrity, promotes immune function, and decreases risk of bacterial translocation
  • No line complications (infection, thrombosis)

Indications for Use

  • Unable to meet nutritional needs via po intake secondary to malabsorption, high risk aspiration with a diet.
  • Hypermetabolic state. Example: trauma, burns
  • Neurologic impairments. Example: CVA, head injury, dementia, altered mental status
  • Medications or treatments that induce anorexia. Example: chemotherapy, radiation
  • Ventilated patients with functioning gastrointestinal tract.

Contraindications

  • GI obstruction or inability to gain access
  • Persistent post-operative ileus or bowel ischemia
  • Aggressive care not indicated or desired
  • Massive GI bleed

Feeding tube options

Type Use Advantages Risk Method of Feeding
Nasogastric Short-term, Less than 4 weeks No surgical procedure Aspiration risk, easily pulled by pt Continuous, intermittent, bolus, or nocturnal
Nasoduodenal Short-term, Less than 4 weeks No surgical procedure, decreased risk of aspiration Easily pulled out by patient, cannot bolus Continuous or nocturnal
Gastrostomy tube (PEG, G-tube) Greater than 4 weeks, Pts at low aspiration risk Flexibility of feeding method Wound Infection, wound complications, surgically placed Bolus, continuous, or nocturnal
Jejunostomy tube (PEJ, J-tube) Greater than 4 weeks Low risk for aspiration, Gastric motility disorders Wound infection, enteral feeding pump needed, surgically placed Continuous, intermittent nocturnal

Example of Tube Feeding Formulas

Characteristics

Indications

Cal/mL

Osmolality

mOsm/kg H20)

% Water

ML to meet 100% daily vitamins

1.0 Cal/cc, isotonic, very high protein

Low osmolality, wound healing

1.0

340

84

1000

High Protein; low residue

Standard tube feeding without fiber

1.2

360

82

1000

Calorically dense; volume restriction

Fluid retention

2.0

725

70

948

Initiation

  • Continuous feeds: Begin full strength formula. Start 10-30 ml per hour. Increase by 10-20 ml as tolerated every 8-12 hours until goal rate. (usually 70-110 cc/hour)
  • Bolus feeds: Begin with 120 ml (1/2 can) 3-4x/day. Advance by 120 ml every 2-3 feeds as tolerated to goal
  • Jejunostomy feeding: Use low osmolality, fiber-free formula. Start at 10 -20mL and advance slowly 10-20 mL every 12 to 24 hours until goal rate is reached.

Checking Residuals for Continuous Tube Feeding

  • Check gastric residuals (definition: measured amounts of gastric contents taken at timed intervals determined by MD); usually every 4-6 hours (after one hour of holding feeds)
  • Hold tube feeding if residuals are greater than 200 ml on 2 consecutive assessments. It is not necessary to check residuals in a J-tube.

Monitoring

  • As feedings advance, monitor patient for complaints of pain, abdominal distention and high residuals, diarrhea or nausea (can be signs of intolerance)
  • Monitor daily weight and daily Ins and Outs (I/O)
  • Metabolic panel including calcium and phosphorus
  • Albumin /prealbumin, C-reactive protein weekly
  • Use IV replacement for abnormal electrolytes

 

Medications

  • Use liquid form of medication whenever possible
  • Be aware of drug-nutrient interactions (Ex. tetracycline, fluoroquinolones)
  • Avoid time release capsules because they become immediate release (Ex. MS Contin, Morphine) when crushed
  • Flush feeding tube before and after each use with minimum 30-60mL water based on patient's fluid status

J. Nutrition Support: Total Parenteral Nutrition (TPN)

Intravenous administration of nutrients should only be used when the gastrointestinal tract is not functional, accessible, or safe to use. TPN is appropriate only when enteral feeding is contraindicated. "When the gut works, use it!"

Total Parenteral Nutrition is utilized for patients requiring nutritional support greater than 7 days or with moderate to severe malnutrition. TPN requires PICC or central line.

Peripheral parenteral nutrition (PPN) is utilized for patients requiring short-term support (7 days or less). Need good peripheral access.

Venous Access Selection

Selection of a central vs. peripheral venous access site depends on nutrient requirements and duration of parenteral nutrition.

Central venous access defined by:

  • Catheter tip in the superior or inferior vena cava
  • Types
    • Non-tunneled CVCs (subclavian, jugular,PICC)
    • Tunneled percutaneous catheters
    • Hickman, Groshong on implanted subcutaneous infusion ports

Peripheral access:

  • Tip position outside the centeral vessels.
  • Osmolarity of PPN cannot exceed 900 mOsmls
  • Peripheral catheters include peripheral cannulas, midline catheters, and mid-clavian catheters.

Calculating TPN Requirements:

  • Three macronutrients are used in parenteral nutrition selections:
    • Amino Acid 4.0 kcal per gram
    • Carbohydrate 3.4 kcal per gram
    • Fat 9.0 kcal per gram
  • Calculate protein needs first: 1.0 to 1.5 grams per kg/day (consider renal function).
  • Carbohydrate: CHO tolerance ranges between 2-5 mg/kg/min (do not exceed 5 mg/kg/min). CHO utilization 4 mg/kg/min. 4x (wt in kg) x 1.44 = gm CHO/day
  • Lipids: At least 2-3 times/week to prevent essential fatty acid deficiency. Total fat should not exceed 1.0 to 1.5 g/kg/day. No more than 20-30% of calories.
  • Example: Male post-op patient 175 cm tall, 82kg in weight needs 2400 kcal/day with 125g protein
    • 125g x 4 kcal/g = 500 kcal (Still have additional 1900 kcals needed as fat and carbohydrate)
    • Calculate fat: Determine what percentage of total calories (20-30%). So if need 25% kcals, need 600 kcals = 300mL 20% Lipid solution every day.
    • Carbohydrate tolerance: Determine kcals needed to fill total daily requirements: 2400 (total needed)-1100 (what we have in protein and fat) =1300 kcal. Determine what dextrose solution you want to use. Calculate how much of that solution you need to get the rest of the kcals. Divide calories left by 3.4 to get grams of carbohydrates needed. (1300/3.4=382 grams carbohydrates needed). Divide by concentration of dextrose solution (divide by 0.5 if using 50% dextrose solution). Round as needed. (382g carbohydrate/ 0.5 =764 mL of 50% dextrose solution).
  • Note "%" = mg/dl so 50%= 50 mg/dl or 500 mg/L

Other Elements that can be added to TPN:

  • Check electrolytes before initiating TPN or PPN
  • Order 1 package and add additional electrolytes under custom additives prn
  • Add vitamin trace element package daily (check renal and hepatic function)
  • Add vitamin C 500 mg daily for wound healing (adjust for renal dysfunction)
  • Add Vitamin K 150 mcg in the daily vitamin package (unless on coumadin)
  • Check if patient is on pantoprazole or ranitidine (adjust for renal function).
  • Consult with pharmacist or dietician before adding insulin to TPN support.

Fluid Requirements:

  • 35 cc/kg/day (adjust for renal function, liver function, and CHF)
  • 25-30 cc/kg/day if pt is elderly or has fluid restrictions
  • Check IV Fluids: the amount and type of IV fluids can be reduced as needed when TPN/PPN initiated.

Monitoring:

  • Day 1-Before initiating parenteral nutritional support:
    • Metabolic panel + calcium and phosphorus
    • Prealbumin + CRP
    • Triglycerides (fasting)
    • Liver enzymes
  • Daily:
    • Metabolic panel + calcium and phosphorus
    • Blood glucose every 6 hours
  • Weekly:
    • Prealbumin + CRP
    • TG (hold lipids for 4 hours before checking)
    • Liver enzymes

K. Re-feeding Syndrome

A syndrome of hypophosphatemia, hypomagnesemia, hypocalcemia, and fluid retention seen in severely malnourished patients. During starvation, total body loss of these minerals is compensated by ion movement out of cells into plasma, which maintains normal plasma levels. When feeding is started, the increase of insulin encourages intracellular shifts of ions and plasma concentrations of these ions fall.

Patients at Risk for Re-feeding:

  • Alcoholic
  • Chronic GI disease (including gastric bypass)
  • Cancer cachexia
  • Unintentional significant weight loss
  • Elderly

Monitoring:

  1. Check plasma K, Ca, PO4, Mg in all patients before initiating feeding and correct abnormalities
  2. Start feeds at 20 kcal/kg (approximately 1000 kcal for first two days)
  3. Recheck K, Ca, PO4, Mg daily and replete with advancement of nutrition support