1
Q
What are some characteristics of malnutrition?
A
- Independent risk factor for patient morbidity and mortality in hospitalized patients
- Prevalence as high as 40% among critically ill adults due to lack of proper evaluation and failure to optimize nutritional support early in hospitalization
- Associated with increased healthcare costs
- No standard methods of screening or diagnostic criteria
- Inflammation/infection has been identified as risk factor for malnutrition due to a marked increase in metabolism, leading to greater energy (caloric) requirements and loss of lean body mass
- Independent of type and severity of disease, duration of hospitalization impacts the risk of malnutrition; longer the stay = increase risk
- Laboratory markers are NOT reliable by themselves, should be used in conjunction with a thorough physical exam.
2
Q
What are 6 laboratory measures of malnutrition?
A
1. Serum albumin
- Produced by the liver
- Half-life 14-20 days (synthesis requires amino acids and adequate liver function)
- Functions as a carrier molecule for certain minerals, hormones, fatty acids and assists in maintaining oncotic pressure in the capillaries
- Low in malnutrition (<3.5 grams/dl), infection, burns, fluid overload, liver failure, cancer and nephrotic syndrome
- Unreliable as a stand-alone marker for nutritional status since it is affected by a multitude of disease processes.
- Older adults: in functionally impaired elderly, albumin has a low specificity for identifying nutritional status.
2. Pre-Albumin
- Produced by the liver
- Half-life 2-3 days (reflects changes in nutritional status sooner than albumin)
- Affected by the same inflammatory states as albumin- infections and liver disease
- Low in malnutrition:< 10 gm/dl severe depletion, 10-15 grams/dl moderate depletion
- Can be low in liver failure and elevated in renal failure
- More reliable indicator of acute changes in a patient’s nutritional status
- Since it is degraded by the kidneys, any renal dysfunction causes an increase in pre-albumin serum levels.
3. Transferrin or Total Iron Binding Capacity (TIBC)
- Half-life 10 days
- Serum protein synthesized in the liver
- Low in protein energy malnutrition (can also be affected by iron status as in chronic blood loss anemia causing an elevated transferrin level due to increased iron absorption)
- Mild depletion 151-200 mg/dl
- Moderate depletion 100-150mg/dl
- Severe depletion, < 100 mg/dl
- Transferrin also increases in renal failure. Oral contraceptives and estrogen also alter serum transferrin levels.
- Poor serum marker for assessing nutritional status
4. Hemoglobin
- Low hemoglobin leads to inadequate oxygen perfusion to cells resulting in decreased energy production affecting multi-functions-including healing and growth
5. Hematocrit
- A volume measurement that verifies hemoglobin level
6. Lymphocyte count
- Low lymphocyte count indicates decreased ability to fight off infections/increased susceptibility to infections
- Chronic steroid use can decreased lymphocyte count
3
Q
When evaluating malnutrition what should you focus on when conducting a history & physical assessment?
A
Focus on general characteristics, such as:
- Edema, ankle and sacral
- Subcutaneous fat loss
- Muscle wasting
- Ascites
- Skin, mucous membranes, hair, nails
History should include:
- Weight loss in past 6 months
- Changes in dietary intake
- Gastrointestinal symptoms (n,v, change in bowel habits)
- Functional capacity (poor exercise tolerance, reduced mobility/endurance)
- Disease and its relation to nutritional requirements (hx of cancer, crohn’s disease, rheumatoid arthritis. Cardiopulmonary disease, infection)
4
Q
How do you determine a patient’s calorie needs?
A
Kilocalories per kilogram of body weight (may use actual or desired weight depending upon goal of therapy)
- Average adult: 30kcal/kg or 13 kcal/lb of body weight/24 hours
- For weight gain: 35 or more kcal/kg is appropriate
- For weight loss: 25 kcal/kg
- 1 lb of body weight = 3500 kcal
- For fever: 7% increase in kcal/24 hours needed for each degree > 37.0C
5
Q
How do you determine a patient’s fluid requirements?
A
- One mL (cc) of fluid/kcal/24 hours (30-35 ml/kg of body weight) is usual- decaffeinated beverages
- Elevation in vital signs, placements of drains, nausea/vomiting, diarrhea etc. requires an increase of 150mL/24 hours for each degree rise in body temperature above normal (37.0C)
6
Q
How do you determine a patient’s protein requirements?
A
- Protein required per day ranges from 0.8-2 grams/kg of body weight
- Renal and hepatic diseases necessitate lower levels of protein due to inability of body to convert ammonia to urea in liver or to excrete urea via the kidneys
- Protein is primary source of all nitrogenous waste products
- Protein should account for 20% of daily kcal intake- needed for tissue growth
7
Q
How do you determine a patient’s carbohydrate requirements?
A
- Accounts for largest proportion of kcal in most diets- approx. 50% of daily kcal need
- Patients with compromised respiratory function should eat less than average carbohydrate amounts since more oxygen (and release of co2) is required than for protein and fat metabolism
8
Q
How do you determine a patient’s fat requirements?
A
- Substituting fat for carbohydrates can reduce stress on the respiratory system since fat uses less oxygen and produces the least amount of carbon dioxide.
9
Q
How do you determine a patient’s vitamin/mineral requirements?
A
- Use recommended dietary allowance (RDA) as guided
- Consult dietician for individual needs
- Avoid over supplementation since the liver and kidneys excrete excess vitamins
10
Q
How do you determine a patient’s electrolyte requirements?
A
- Replace deficits as per laboratory results
- Avoid excessive amounts, especially in renal disease
11
Q
What are the 2 types of nutritional support?
A
1. Parenteral (vascular feeding): appropriate when GI tract is non-functional
2. Oral/Enteral feeding: appropriate when GI tract is functioning; the preferred method of feeding
12
Q
When should patients begin receiving entral feeding?
A
- Start early within the first 24-48 hours following admission
- Withhold in setting of hemodynamic compromise
- Gastric or small bowel feeding is acceptable
- If high risk for aspiration, enteral access tube feeds should take place in small bowel
- If enteral feeding > 6 weeks, refer for gastrostomy tube placement
- If enteral feeding < 6 weeks, feed through trans-nasal tube
- Withhold feeds for repeated high gastric residual volumes and place tip in small bowel
13
Q
What are the 6 enteral routes of nutritional support?
A
1. Nasogastic tube:
- Tip of tube in stomach
- Most similar to route of normal digestion
- Acid reflux common
- Lack of integrity of gastric mucosa contradicts use
2. Nasoduodenal tubes:
- End of tube located in duodenum
- Acid reflux/aspiration less common
- May require partially predigested form of formula
3. Nasojejunal tube:
- End of tube located in jejunum
- Formula type depends on area of jejunum that is used; intact for upper portion and hydrolyzed for mid to lower portion
4. Enterostomies: surgically created openings from exterior GI tract for long-term use (> 6 weeks) or when trans-nasal tube is contraindicated (ENT cancer)
- Types include esophagostomy (distal tip in stomach)
- Intact or blenderized formulas appropriate
5. Gastrostomy:
- 2 types:
- Percutaneous endoscopic gastrostomy (PEG)
- Placed by GI endoscopy
- Intact formula appropriate
- Can be used 24 hours after placement
- Percutaneous Gastrostomy (G tube)
- Placed by Interventional Radiology using fluoroscopy
- Intact formula appropriate
- May be used in 24 hours
- Percutaneous endoscopic gastrostomy (PEG)
6. Jejunostomy:
- Percutaneous endoscopic jejunostomy is an extension of percutaneous or endoscopic placed gastrostomy tube
- Distal tip lies in jejunum
14
Q
What are some complications with enteral feeding?
A
- GI complications: diarrhea, cramping, constipation, gastric retention
- Monitor for electrolyte imbalances and hyperglycemia
- Consult a dietitian for formula and kilocalorie needs
15
Q
How is parenteral nutritional support initiated?
A
- Consult dietitian, nutritional support team, to include pharmacist
- In patients who are not malnourished prior to acute illness, only initiate after first 7 days of hospitalization- if enteric nutrition not available or contraindicated
- If evidence of malnutrition exists on admission and enteric nutrition contraindicated, begin parenteral nutrition following admission and stabilization.
- Parenteral nutrition provided for a short duration (< 7 days) is not shown to produce outcome effect and can actually increase risks to patient.
- Concentrations of dextrose > 10% require use of central line dedicated to parenteral nutrition.
16
Q
What should you monitor on patients with parenteral nutrition?
A
- Monitor blood glucose every 6 hours
- Monitor electrolytes cbc, ca, mg, phos, lft’s and triglyceride levels
- Infuse fat emulsions slowly
- Involve parenteral nutrition team
- Trend lab results weekly at minimum
17
Q
What are some complications associated with parenteral nutrition?
A
- Metabolic complications, hyperglycemia, hypercapnia
- High risk for infection due to glycemic content
- Risk of pancreatitis with lipid infusion
