Nutrition Assessment Flashcards
Supplementation of vitamin A (3,000-15,000/day) should usually be given for a maximum of
7 days
Vitamin A has multiple functions in wound healing including cellular differentiation, enhancement of epithelialization and collagen synthesis. A wide dosage range of 3000 to 15,000 RAE/d orally for 7 days has been recommended to counteract the inhibitory effects that steroids have on collagen synthesis and connective tissue repair. Oral administration of 3,000 to 4,500 RAE/d is recommended to enhance wound healing with concurrent corticosteroid therapy.
Which of the following is common in both acute illness or injury-related and social or environmental related malnutrition?
lipolysis
Catabolism of endogenous substrate including fat stored in adipose tissue (lipolysis) is common in both forms of malnutrition. Hypoglycemia and ketosis are characteristic of starvation. Hypermetabolism and hyperglycemia are characteristic of stress-related malnutrition.
Which of the following nutrition tools includes evaluating subcutaneous fat and muscle wasting at multiple body sites to determine nutrition status?
The Subjective Global Assessment (SGA)
The SGA is a nutrition assessment tool using five historical (weight history, dietary intake, gastrointestinal symptoms, functional status, and metabolic demand) and three components focusing on physical examination (fat depletion, muscle wasting, and nutrition related edema).
The data are subjectively weighted to classify the patient as well nourished, moderately malnourished, or severely malnourished. The SGA has been found to be a good predictor of complications in patients undergoing gastrointestinal surgery, liver transplantation, and dialysis. For critically ill patients, the SGA may have limited use. ASPEN and the Society of Critical Care Medicine recommend the use of the NRS-2002 or the NUTRIC tool to determine nutrition risk in this patient population. The NRS-2002 includes unintentional weight loss, BMI, disease severity, impaired general condition and age > 70. The NUTRIC score includes APACHE II score, SOFA (with or without IL-6), number of comorbidities and days from hospital to ICU admission. The NRI uses serum albumin and the ratio of current weight to usual weight.
Which of the following compromises the reliability of urinary urea nitrogen to calculate nitrogen balance?
Creatinine clearance <50 mL/min
Urine urea nitrogen is used primarily to monitor protein intake during nutrition support. Urine is usually collected for a 24-hour period in order to quantify the amount of urinary urea nitrogen. Compromised renal function, as indicated by a creatinine clearance <50 mL/min, low urine output, and muscle atrophy can alter urinary urea nitrogen, resulting in unreliable results.
Which of the following has been shown to reduce plasma homocysteine concentrations?
Folic acid
Hyperhomocysteinemia has been linked to an increased risk for coronary artherosclerosis. Studies have shown that folic acid, vitamin B6, and vitamin B12 supplementation can reduce plasma homocysteine concentrations. It is not known whether hyperhomocysteinemia is a causative factor of artherosclerosis or simply a marker of vascular disease.
In persons with phenylketonuria(PKU), tyrosine becomes an essential amino acid due to
a deficiency in the phenylalanine hydroxylase enzyme.
PKU is an inborn error of phenylalanine metabolism caused by a deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH). PAH catalyzes the hydroxylation of phenylalanine to tyrosine. In the absence of PAH, phenylalanine levels become extremely high and tyrosine becomes deficient. Treatment with a phenylalanine-free diet and tyrosine supplementation is used for chronic management.
Conditionally essential amino acids
arginine, cysteine, glutamine, glycine, proline and tyrosine
Conditionally essential amino acids are synthesized from other amino acids under normal conditions but require a dietary source in order to meet increased needs caused by metabolic stress. For example, arginine becomes conditionally essential for wound healing.
EFAD deficiency from TPN without ILE
Provision of fat free PN for three weeks has resulted in essential fatty acid deficiency (EFAD). EFAD usually results after 4 week of fat free PN, although signs of deficiency can be seen as early as 10-20 days in adults although deficiency can occur more rapidly in infants and children. Signs of EFAD include scaly dermatitis, alopecia, thrombocytopenia, anemia and impaired wound healing. Provision of 4-10% of total calories from soy or soy/safflower ILE should be sufficient to prevent essential fatty acid deficiency. Trace elements deficiencies need to be monitored in the light of shortages. Using ASPEN guidelines should reduce the risk. Hypocaloric PN actually may benefit patient on fat free PN as it is thought that EFA are released as a result of lipolysis of endogenous fat stores in response to reduction in insulin levels. Cholestasis is usually associated with high ILE doses.
Which of the following IV fluids most closely resemble jejunal and ileal electrolyte content?
LR
The electrolyte content of gastrointestinal secretions changes according to their location along the GI tract. The composition of jejunal and ileal fluids is listed below. Jejunum: Sodium = 95-120 mEq/L; Potassium = 5-15 mEq/L; Chloride = 80-130 mEq/L; Bicarbonate = 10-20 mEq/L. Ileum: Sodium = 110-130 mEq/L; Potassium = 10-20 mEq/L; Chloride = 90-110 mEq/L; Bicarbonate = 20-30 mEq/L. IV electrolyte content is as follows: Lactated Ringer's: Glucose = 0; Sodium = 130 mEq/L; Chloride = 109 mEq/L; Potassium = 4 mEq/L; Lactate = 28 mEq/L; Calcium = 2.7 mEq/L. Normal saline (0.9% Sodium Chloride) contains only: Sodium - 154 mEq/L and Chloride 154 mEq/L. ½ Normal saline (0.45% Sodium Chloride) contains only: Sodium = 77 mEq/L and Chloride = 77 mEq/L. D5 0.45% Sodium Chloride contains: Glucose = 50 grams/L; Sodium = 77 mEq/L; Chloride = 77 mEq/L.
Lactic acidosis can be a result of which vitamin deficiency?
Thiamin is necessary for the metabolism of glucose, specifically, the conversion of pyruvate to acetyl CoA. In the absence of thiamin, the resultant inhibition of pyruvate dehydrogenase drives carbohydrate metabolism toward lactic acid fermentation, resulting in a build-up of lactic acid. Untreated thiamin deficiency can result in fatal lactic acidosis
The risk of metastatic calcification in soft tissues begins to increase when the product of serum calcium and phosphorus exceeds
55
A primary complication of hyperphosphatemia is soft tissue and vascular calcification. Calcification occurs when the product of serum calcium and phosphorus exceeds 55 mg2/dL2. Additional symptoms of hyperphosphatemia include secondary hyperparathyroidism and renal osteodystrophy.
A respiratory quotient (RQ) of 0.87 most likely suggests
mixed substrate
RQ = CO2 produced/O2 consumed. An RQ <0.7 or >1.0 may result from hypoventilation or hyperventilation. While there are several metabolic causes for an RQ < 0.7 or > 1.0, traditional interpretation of RQ is as follows: RQ of 0.71 is primarily fat oxidation, 0.82 is primarily protein oxidation, 0.85 suggests mixed substrate utilization, and 1.0 is carbohydrate oxidation.
Cheilosis is a physical symptom associated with a deficiency of
riboflavin
Cheilosis, cracking of the corners of the mouth, is observed with a deficiency of riboflavin. Other symptoms of riboflavin deficiency include: hyperemia and edema of pharyngeal and oral mucosa, angular stomatitis, and glossitis (magenta tongue). Vitamin D deficiency is most often characterized by a loss of bone density. A classic feature of folic acid deficiency is megaloblastic or macrocytic anemia. A deficiency in Vitamin C can lead to scurvy.
Dietary fat is predominately absorbed in what part of the gastrointestinal tract?
Duodenum and proximal jejunum
Dietary fat is absorbed in the proximal small bowel. Lingual lipase released in the mouth and gastric lipase produced in the stomach have a limited role in fat digestion in healthy adults. Bile acids secreted by the liver as well as lipase and colipase produced by the pancreas aid in the micellar solubilization and absorption of dietary fat.
Which of the following areas of the gastrointestinal tract has the LEAST impact on nutrient absorption and intestinal adaptation following significant intestinal resection?
Jejunum
Resections of the proximal bowel, including the duodenum and proximal jejunum, are generally better tolerated because of ileal compensation and adaptation. In general, ileal resection is poorly tolerated because adaptive hyperplasia in the remaining jejunum is limited. The ileocecal valve slows intestinal transit allowing for greater absorption of nutrients. The colon has critical roles in fluid and nutrient absorption. Therefore, patients lacking a colon are at greater risk of dehydration. Furthermore, the colon is capable of salvaging calories through anaerobic bacterial fermentation of undigested carbohydrates into absorbable short-chain fatty acids (SCFAs).
