Topic C-Medical Nutrition Therapy

1. Planning and intervention

(a)Identify desired outcomes and actions

(b)Relationship of physiology and pathology to treatment of primary nutrition-related disorders

Critical Care

Trauma:

Injury results in profound metabolic alterations beginning at the time of injury and persisting until wound healing and recovery are complete
Whether the event is sepsis (infection), trauma (including burns), or surgery, once the systematic response is activated, the physiologic and metabolic changes that follow are similar
Accelerated catabolism of lean body or skeletal mass that clinically results in negative nitrogen balance and muscle wasting
The goals of nutritional support during sepsis and after injury include minimization of starvation, prevention or correction of specific nutrient deficiencies, provision of adequate calories to meet energy needs, and fluid and electrolyte management to maintain adequate urine output and normal homeostasis
Response to critical illness, injury, and sepsis involves both the ebb and flow phase
Ebb phase-occurring immediately following injury is associated with hypovolemia, shock, and tissue hypoxia. This phase is manifested by decreased cardiac output, oxygen consumption, and body temperature. Insulin levels fall in direct response to the increase in glucagons, most likely as a signal to increase hepatic glucose production
Flow phase-follows fluid resuscitation and restoration of oxygen transport, is characterized by increased cardiac output, oxygen consumption, body temperature, energy expenditure, and total body protein catabolism
The mobilization of acute-phase proteins results in rapid loss of lean body mass and an increased negative nitrogen balance, which continues until the cause of stress is relieved
Breakdown of protein tissue also causes increased urinary losses of potassium, phosphorus, and magnesium
Starvation differs from stress in that starvation is aimed at preserving lean body mass

Surgery

A well-nourished patient usually tolerates major surgery better than a severly malnourished pt b/c malnutrition is associated with a high incidence of operative complications and death

Preop-improve nutrition whenever possible-Vit C
Nutritional support has been used for pts with inadequate intake who require a major operation but cannot undergo immediate surgery, and for candidates for immediate surgery who have sig nutritional defecits
It is important that the stomach be empty of food at the time of the operation to avoid the danger of vomitus aspiration during the induction of anesthesia or on awakening
Postop-hypermetabolic state, negative nitrogen balance, increased energy needs
Oral feeding is often delayed for the first 24 to 48 hours following surgery to await the return of bowel sounds or passage of flatus.
A general practice has been to progress over a period of several meals from clear liquids to full liquids, and finally to solid foods.

Burns

Immediate shock period-catabolism; BMR rises 50-100%

(1)replace fluids and electrolytes

(2)recovery period-increase calories

(3)secondary period-1.5-3 grams protein/KG, high calories

(a)vitamin C-wound healing; 500 mg x 2

(b)B vitamins-increased metabolic needs

(c)Vitamin K if on antibiotics

(d)Zinc for wound healing if zinc deficient; 220 mg zinc sulfate

For adults and children with burn wound size of more than 10% total body surface area (TBSA), protein should comprise 20% of the total caloric requirement or up to 2.0 g/kg body weight per day
For burn wound size that is 1%-10% TBSA, 15% of the total caloric requirement should come from protein
Twice weekly measurement of prealbumin level or weekly transferrin level is recommended during the acute phase of recovery

(2) Eating Disorders

Anorexia Nervosa

The first goal of treatment is to stop weight loss and establish the highest possible level of medical stability
The second phase is to initiate wt gain with a long-term goal of restoring body weight to a level where normal metabolism and body fxn return

Anorexia nervosa (AN)

Refusal to maintain body weight at or above 85% of expected
Intense fear of gaining wt…even though under wt
Disturbed perception of body image
Amenorrhea in postmenarcheal females
Restricting type: during the current episode of AN, patient has not regularly engaged in binge-eating or purging behavior
Binge-eating/purging type: during the current episode of AN, pt has regularly engaged in binge eating or purging

Bulimia Nervosa

Recurrent episodes of binge eating
Eating in a discrete time period amount of food definitely larger than most people would under similar circumstances
Sense of lack of control over eating during these episodes
Recurrent inappropriate compensatory behavior to prevent weight gain: self-induced vomiting; misuse of laxatives; diuretics; enemas; fasting; excessive exercise
Purging type: regularly engaged in self-induced vomiting or other inappropriate behaviors
Non-purging type: uses inappropriate compensatory behaviors-such as fasting or excessive exercising, but does not purge

Other types of eating disorders: binge eating disorder and orthoexia

Medical Complications and Laboratory Findings in Anorexia and Bulimia

Organ System / Signs / Laboratory Findings
Dermatologic / Calluses on dorsum of hand
Dry scaly skin
Lanugo
Perioral irritations
Gastrointestinal / Enlarged parotids
Abdominal cramps, flatulence, constipation
Nausea / Elevated amylase
Delayed gastric motility
Cardiovascular / Bradycardia
Hypotension
Arrhythmias / ECG abnormalities
T wave and ST changes
Elevated CPK
Renal and electrolyte / Edema
Dehydration / Hypokalemia
Hyponatremia
Hypochloremia
Alkalosis or acidosis
Hematologic / Pallor / Mild anemia
Leukopenia
Thrombocytopenia
Metabolic / Hypercholesterolemia
Hypercarotenemia
Decreased plasma zinc
Endocrine / Amenorrhea
Oligomenorrhea / Eleved GH
DST nonsuppression
Euthyroid sick syndrome
Central Nervous System / EEG abnormalities
CAT scan abnormalities
Musculo-skeletal / Muscular Weakness
Short stature / Osteoporosis
Pathologic fractures
Dental / Caries
Erosion of tooth enamel

Refeeding Syndrome

Excessive rapid refeeding, especially with tube feeds or TPN, is dangerous since it can lead to severe fluid restriction, cardiac arrhythmias, cardiac failure, delirium, or seizures…esp for those at the lowest weights

Hypophophatemia which can be life-threatening can occur

Anorexia: 1200-1400 calories

(3) Food allergies and intolerance

Ag-Ab reaction: when antigen enters body, antibody reacts
In an allergic person system goes awry and antibodies interact with normally harmless substances
Protein component is causative factor
Common allergens-wheat, fish, nuts, milk, eggs
Diagnosis-diet hx, skin tests, elimination diet, food challenge
Rice is least likely to cause an allergy

Immediate hypersensitivity, which involves IgE, is the most common allergic rxn and has the most clearly understood mechanism
The combination of an allergen with allergen-specific IgE fixed to tissue mast cells or circulating basophils causes the release of chemical mediators, including histamine, serotonin, kinins, and others.
When released these inflammatory mediators can cause itching, contraction of smooth muscle, vasodilation, and secretion of mucus
Anaphylaxis: an acute, often severe, and sometimes fatal immune response that may affect one or more organ systems
Peanuts are the most common cause of death from anaphylaxis in the United States

(4) Immune system disorders, infections, and fevers

BMR increases 7% for each degree rise in F temp

AIDS (Acquired immune deficiency syndrome (AIDS)

Virus debilitates immune system by attacking lymphocytes
Diarrhea, malabsorption, nausea, vomiting, weight loss
High calories, high protein, high fluids immediately
BEE x 1.3-1.5 for weight gain
1-1.4 g protein maintenance; 1.5-2 g protein repletion
Vitamin/Mineral supplements 100% RDA
Drug AZT-Retravir-causes megaloblastic anemia
Educate pt about food safety-low bacterial diet-neutropenic diet
Avoid raw foods
HIV infected women should be counseled NOT to breast-feed
Follow appropriate universal precautions; need not wear gloves, gowns or masks with general care

System / Nutritional Considerations
Endocrine / Loss of lean body mass and/or inability to replete, weight loss, inanition, fatigue
Hyponatremia
Hypoglycemia/hyperglycemia
Central Nervous / Potential for dysphagia, aspiration pneumonia, inability to comply with nutrition regimen due to dementia
Respiratory / Increased nutrient needs
Acceleration of wasting and side effects related to cancer therapy
GI / Dysgeusia, dysphagia, abdominal pain
Renal / Electrolyte abnormalities
Hemtologic / Anemia, leukopenia
Hepatic / Anorexia, cirrhosis, edema, hepatic encephalopathy

Topic C-1(d) Determine specific feeding needs

Enteral Nutrition is indicated by the presence of the following:

Dysphagia

Poor oral intake

Malnutrition

Inability to consume needed calories, protein, and other nutrients by mouth

Severe weight loss

Higher nutrient needs than can be consumed orally

Nutritional losses (via pleural fluids, fistulas, etc) leading to higher nutrient needs than client can consume orally

Type of Tube / Use
Nasogastric (NG) / Extends form the nose into the stomach
Chosen when the stomach is intact and empties normally
Resident has a normal gag reflex
Used for a short period of time (usually less than 30 days) due to possible irritation of the nostrils
Additional tubes that may be used are the nasoduodenal and naso-jejunal tubes (ND tube and NJ tube)
Enterostomies / Surgically placed into the gastrointestinal tract
Most common site of placement is the stomach
Neck (pharyngostomy or esophagostomy)
Small intestine (jejunostomy)
Preferred for long term feedings
PEG / Placed quickly and simply
Less cost
Less risk to the resident
Major surgery and general anesthesia can be avoided by placing enterostomies through the skin under local anesthesia

*Aspiration pneumonia

Cause: delayed gastric emptying; gastroparesis

Treatment:

Reduce infusion rate

Select isotonic or lower-fat formula

Regularly check gastric residuals

Keep head of bed elevated 30 to 45 deg during and after feedings

Consider jejunal feeding for high-risk pts

Calculation

Ex. Isocal 60 cc X 24 h + H2O flush 100 cc q3h

60 cc/hr x 24 hrs= 1440 cc

1.06 kcal/cc x 1440 cc= 1526.4 kcal

32 g Pro/1000 kcal x 1526.4 kcal= 49 g Pro

1440 cc x 840/1000 mL=1209.6 cc fluid + (8 x 100 cc)=2009.6 cc fluid

TPN

Indications: When the GI tract is nonfunctional (severe malabsorption, short-bowel syndrome, bowel obstruction, GI bleed, intractable diarrhea or vomiting, radiation enteritis, bowel ischemia and high out-put fistula). When bowel rest is indicated as with severe pancreatitis or when the GI tract in non-accessible or safe for enteral nutrition support

Dextrose: provides carbohydrate and available in 5%, 10%, 20%, 50%, and 70% concentrations. To calculate the gms of dextrose

1000 ml x 70%= 700 gms of dextrose x 3.4 kcal/g= 2380 kcals

Protein: is provided in the form of AA and is available in 3%, 7%, 8.5%, 10% and 15% concentrations. To calculate the gms of protein:

500 ml x 8.5 % =42.5 gms of protein x 4=170 kcals

Lipids: are provided as LCT, available in 10%, 20%, and 30% concentrations, provide a source of EFA and may be admixed with the dextrose and protein or infused separately

10% lipids provides 1.1 kcal/ml

20% lipids provides 2.0 kcal/ml

*Venous access is established before initiating therapy. Central veins, including the subclavian, internal jugular, and femoral veins, or peripheral veins in the extremities, usually the hands or forearms, are used to provide nutrition support. However, femoral catheters are generally not used b/c of the association with increased risk of complications, such as infection or thrombophlebitis