Flashcards in Nutrition Parenteral Nutrition Deck (53):
What is the advantage of using Glycerol over Dextrose?
Doesn't stimulate Insulin release
How many Cals/gm does Dextrose have?
How many Cals/gm does Glycerol have?
How much do you need to limit dextrose to initially?
What is the maximal glucose oxidation rate?
7-9mg/kg/min (need to make sure you administer below this, ~5-7mg/kg/min)
For patients previously treated with insulin or oral agents with fasting glucose > 150, what should the initial insulin dose be?
0.1 units insulin/gram dextrose (ex. 1L D25W/4.25% AA = 250gm dextrose, use 25 units of insulin)
How should you monitor someone on glucose infusion?
Monitor serum glucose levels daily, until stable. Monitor fingersticks for glucose Q4-6h around the clock (not AC and HS)
What are the goal levels for people on glucose infusion?
What are some potential contributing factors that can cause a patient to have hyperglycemia when on glucose infusion?
History of DM. Glucose intolerance. Pancreatic pathology. Metabolic stress (infections, sepsis, trauma). Glucose-containing dialysis therapy. Overfeeding with carbohydrates: all sources. Medications. Factitious hyperglycemia d/t site of blood sampling
What are the goals of intensive insulin therapy in critically ill patients?
Maintain blood glucose at or below 110
What are some potential contributing factors for hypoglycemia in patients in the hospital?
Exogenous insulin administration. Reduction in dextrose administered without reduction in insulin administered via PN. Resolution of metabolic stress. Dosage reduction or discontinuation of medications that contribute to hyperglycemia. Renal dysfunction: prolonged insulin effect. Rebound hypoglycemia - related to abrupt discontinuation of high dextrose solution
What are potential complications of hypoglycemia?
Seizures. Coma. Death
What is the caloric density of 10% fat TPN?
What is the caloric density of 20% fat TPN?
What is the caloric density of 30% fat TPN?
What are the essential fatty acids?
Linoleic Acid --> arachidonic acid (omega-6). Linolenic Acid --> docosahexonoic acid (omega-3)
What are the Practice Recommendations for how many calories the fatty acids can contribute?
25-30% of nonprotein calories. 30-35% of total calories
What needs to be monitored while giving free fatty acids?
Serum triglyceride levels. Obtain baseline level prior to initiating PN. Follow-up levels at least once a week. Goal: TG < 400 (if TG > 400, reduce amount of lipid emulsion administered)
What can essential free fatty acid deficiency (EFAD) lead to?
Hair loss, desquamative dermatitis, thrombocytopenia
What are the Cals/gm in protein?
How do you get the grams of nitrogen?
(grams protein) / 6.25
When might you need to reduce protein dose?
Renal dysfunction, if significantly elevated BUN and no dialysis. Hepatic dysfunction, if hepatic encephalopathy present
What needs to be monitored while on protein infusion?
BUN, serum creatinine levels. Mental status for possible hepatic encephalopathy
What are possible complications with protein infusion?
Increase in BUN level. Hepatic encephalopathy
What can cause an increase in BUN level with protein infusion?
Renal dysfunction (decrease protein intake, dialysis therapy). Perenal Azotemia (hydration, decrease protein intake)
What can cause Hepatic Encephalopathy with protein infusion?
Intolerance to protein load (decrease protein intake). Amino acid imbalance (consider use of hepatic AA solutions, avoid use of essential AA solutions)
What Cations are used for electrolyte infusions?
Sodium, Potassium, Calcium, Magnesium
Which type of Calcium is used? Why?
Calcium Gluconate (Calcium chloride precipitates easily with phosphate)
What Anions are used for electrolyte infusions?
Phosphate, Chloride, Acetate
What is Refeeding Syndrome?
Related mainly to CHO load administered. Significant drops in K, Phos, Mg --> may lead to respiratory dysfunction, death. Initiate and increase PN cautiously for patients at risk. Monitor electrolytes closely, including phosphate. Supplement PRN. Do not increase PN rate (CHO load) until K, Phos, Mg levels corrected
What electrolyte losses happen with gastric issues?
Sodium, Potassium, Chloride
What electrolyte losses happen with small bowel issues?
Potassium, Magnesium, Bicarbonate
What electrolyte losses happen with renal failure?
Potassium, Phosphate, Magnesium, Bicarbonate
Which multivitamins should be given daily, unless otherwise clinically indicated?
Thiamine (B-1) 6mg. Folate 0.6mg. Ascorbic acid 200mg. Pyridoxine 6mg
Why is Vitamin K not included in the usual MVI-12?
Because of its potential interactions with anticoagulation therapy
What can happen to patients who have Thiamine (B-1) deficiency?
Lactic acidosis. Wernicke-Korsakoff syndrome. Wet beribert (cardiac failure, edema). Dry beriberi (peripheral neuropathy, muscle wasting). Hyperglycemia. Possible death
What are the common trace elements used?
Zinc, Copper, Chromium, Manganese, Selenium, Iodide, Molybdenum
What happens with Zinc deficiency?
Skin lesions, dermatitis, alopecia, diarrhea, impaired wound healing, decreased serum alkaline phosphate, impaired white blood cell chemotaxis, impaired T lymphocyte function, behavioral changes
What deficiency can be induced with Zinc supplementation?
When do patients usually have an increased requirement for zinc?
With increased GI losses (e.g. diarrhea, fistula)
When do patients usually have an increased requirement for copper?
Intestinal fluid losses
What can Copper deficiency cause?
Anemia (microcytic, hypochromic), neutropenia, leukopenia, thrombocytopenia, skeletal demineralization in infants
When do patients usually have an increased requirement for chromium?
Intestinal fluid losses may increase requirements
What can chromium deficiency cause?
Impaired glucose tolerance, increased insulin requirements, high triglyceride levels, weight loss, peripheral neuropathy, metabolic encephalopathy-like confusional state
When do patients usually have an increased requirement for Selenium?
Intestinal fluid losses may increase requirements
What can Selenium deficiency cause?
Skeletal muscle weakness, tenderness, pain; cardiomyopathy; elevated transaminase, CPK levels; biochemical and functional abnormalities of erythrocytes and granulocytes; abnormalities in T lymphocyte function; loss of skin and hair pigmentation; whitened fingernail beds
What are the four main trace elements used in TPN?
Zinc, Copper, Chromium, Manganese
Which trace element should be avoided during bacterial infection?
What complications might occur in patients receiving parenteral nutrition therapy?
Infections. Mechanical. Metabolic. Allergic reactions
What are some of the mechanical complications that might occur in patients receiving parenteral nutrition therapy?
Pneumothorax. Arterial puncture. Catheter tip misplacement. Air embolism. Thrombosis. Phelbitis. Extravasation/infiltration
What are some possible causes of hepatic dysfunction in patients receiving parenteral nutrition therapy?
Overfeeding with total calories. Overfeeding with carbohydrate calories. Essential fatty acid deficiency. Oxidative stress. Soybean based lipid emulsions. Micronutrient deficiencies
What are some compatibility considerations when giving calcium and phosphate together?
pH. Amino acids (more AAs will decrease precipitation). Use proper calcium salt. Cooler temperature is less likely to precipitate