Chapter 073. Enteral and Parenteral Nutrition (Part 8)

Trace MineralIntakeZinc2.5–4 mg/d, an additional 10–15 mg/d per L of stool or ileostomy outputCopper0.5–1.5 mg/d, possibility of retention in biliary tract obstructionManganese0.1–0.3 mg/d, possibility of retention in biliary tract obstructionChromium10–15 µg/dSelenium20–100 µg/d, necessary for long-term PN, optional for short-term TPNMolybdenum20–120 µg/d, necessary for long-term PN, optional for short-term PNIodine75–150 µg/d, necessary for long-term PN, optional for short-term PNaCommercial products are available that have the first four, first five, andall seven of these metals in recommended amounts.Note: PN, parenteral nutrition; TPN, total parenteral nutrition. ...
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Chapter 073. Enteral and Parenteral Nutrition (Part 8) Chapter 073. Enteral and Parenteral Nutrition (Part 8) Table 73-6 Parenteral Trace Metal Supplementation for Adultsa Trace IntakeMineral Zinc 2.5–4 mg/d, an additional 10–15 mg/d per L of stool or ileostomy output Copper 0.5–1.5 mg/d, possibility of retention in biliary tract obstruction Manganese 0.1–0.3 mg/d, possibility of retention in biliary tract obstruction Chromium 10–15 µg/d Selenium 20–100 µg/d, necessary for long-term PN, optional for short-term TPN Molybdenum 20–120 µg/d, necessary for long-term PN, optional for short-term PN Iodine 75–150 µg/d, necessary for long-term PN, optional for short-term PN a Commercial products are available that have the first four, first five, andall seven of these metals in recommended amounts. Note: PN, parenteral nutrition; TPN, total parenteral nutrition. Parenteral Nutrition Infusion Technique and Patient Monitoring Parenteral feeding through a peripheral vein is limited by osmolality andvolume constraints. Solutions that contain more than 3% amino acids and 5%glucose (290 kcal/L) are poorly tolerated peripherally. Parenteral fat (20%) can begiven to increase the calories delivered. The total volume required to provide amarginal protein intake of 60 g and 1680 total kcal is 2.5 L. However, the risk ofsignificant morbidity and mortality from incompatibilities of calcium andphosphate salts is greatest in these low-osmolality, low-glucose regimens.Parenteral feeding via a peripheral vein is generally intended as a supplement tooral feeding and is not optimal for the critically ill. Peripheral parenteral nutritionmay benefit from small amounts of heparin at 1000 U/L and co-infusion withparenteral fat to reduce osmolality, but volume constraints still limit the value ofthis therapy. Peripherally inserted central catheters (PICCs) can be used for theshort term to provide concentrated glucose parenteral solutions of 20–25%dextrose and 4–7% amino acids, while avoiding some of the complications ofcatheter placement via a large central vein. With PICC lines, however, flow can beposition-related, and the lines cannot be exchanged over a wire for infectionmonitoring. For these reasons, in the critically ill, centrally placed catheters arepreferred. The subclavian approach is best tolerated by the patient and is theeasiest to dress. The jugular approach is less likely to lead to a pneumothorax. Thefemoral approach is discouraged because of the greater risk of catheter infection.For long-term feeding in the home, tunneled catheters and implanted ports reduceinfection risk and are more acceptable to patients. However, tunneled cathetersrequire placement in the operating room. Catheters are made of silastic, polyurethane, or polyvinyl chloride. Silasticcatheters are less thrombogenic and are best for tunneled catheters. Polyurethane isbest for temporary catheters. Dressing changes with dry gauze at regular intervalsshould be performed by nurses skilled in catheter care to avoid infection.Chlorhexidine solution is more effective than alcohol or iodine compounds.Appropriate monitoring for patients receiving PN is summarized in Table 73-7. Table 73-7 Monitoring the Patient on Parenteral Nutrition Clinical Data Monitored Daily General sense of well-being Strength as evidenced in getting out of bed, walking, resistance exercise asappropriate Vital signs including temperature, blood pressure, pulse, and respiratoryrate Fluid balance: weight at least several times weekly, fluid intake (parenteraland enteral) vs fluid output (urine, stool, gastric drainage, wound, ostomy) Parenteral nutrition delivery equipment: tubing, pump, filter, catheter,dressing Nutrient solution composition Laboratory Daily Finger-stick glucose Three times daily until stable Blood glucose, Na, K, Cl, HCO3, Daily until stable and fullyBUN advanced, then twice weekly Serum creatinine, albumin, PO4, Baseline, then twice weeklyCa, Mg, Hb/Hct, WBC INR Baseline, then weekly Micronutrient tests As indicated Note: Hb, hemoglobin; Hct, hematocrit; INR, international normalizedratio; WBC, white blood cell count. Source: A ...