Chapter 073. Enteral and Parenteral Nutrition (Part 11)

InfectiousInfections of the central access catheter rarely occur in the first 72 h. Fever during this period is usually from infection elsewhere or another cause. Fever that develops during PN can be addressed by checking the catheter site and, if the site looks clean, exchanging the catheter over a wire with cultures taken through the catheter and at the catheter tip. If these cultures are negative, as they are most of the time, the new catheter can continue to be used. If a culture is positive for a relatively nonpathogenic bacteria like Staphylococcus epidermidis, consider a second exchange over...
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Chapter 073. Enteral and Parenteral Nutrition (Part 11) Chapter 073. Enteral and Parenteral Nutrition (Part 11) Infectious Infections of the central access catheter rarely occur in the first 72 h. Feverduring this period is usually from infection elsewhere or another cause. Fever thatdevelops during PN can be addressed by checking the catheter site and, if the sitelooks clean, exchanging the catheter over a wire with cultures taken through thecatheter and at the catheter tip. If these cultures are negative, as they are most ofthe time, the new catheter can continue to be used. If a culture is positive for arelatively nonpathogenic bacteria like Staphylococcus epidermidis, consider asecond exchange over a wire with repeat cultures or replace the catheter dependingon the clinical circumstances. If cultures are positive for more pathogenic bacteria,or for fungi like Candida albicans, it is generally best to replace the catheter at anew site. Whether antibiotic treatment is required is a clinical decision, but C.albicans grown from the blood culture in a patient receiving PN should always betreated because the consequences of failure to treat can be dire. Catheter infections can be minimized by dedicating the feeding catheter toPN, without blood sampling or medication administration. Central catheterinfections are a serious complication with an attributed mortality of 12–25%.Infections in central venous catheters dedicated to feeding should occur lessfrequently than 3 per 1000 catheter-days. Home PN catheters that become infectedmay be treated through the catheter without removal of the catheter, particularly ifthe offending organism is S. epidermidis. Clearing of the biofilm and fibrin sheathby local treatment of the catheter with indwelling alteplase may increase thelikelihood of eradication. Antibiotic lock therapy with high concentrations ofantibiotic, with or without heparin in addition to systemic therapy, may improveefficacy. Sepsis with hypotension should precipitate catheter removal in either thetemporary or permanent PN setting. Enteral Nutrition Tube Placement and Patient Monitoring The types of enteral feeding tubes, methods of insertion, their clinical uses,and potential complications are outlined in Table 73-9. The different types ofenteral formulas are listed in Table 73-10. Patients receiving EN are at risk formany of the same metabolic complications as those who receive PN and should bemonitored in the same manner. EN can be a source of similar problems, but not tothe same degree, because the insulin response to EN is about half of that seen withPN. Enteral feeding formulas have fixed electrolyte compositions that aregenerally modest in sodium and somewhat higher in potassium content. Acid-basedisturbances can be addressed to a more limited extent with EN. Acetate salts canbe added to the formula to treat chronic metabolic acidosis. Calcium chloride canbe added to treat mild chronic metabolic alkalosis. Medications and other additivesto enteral feeding formulas can clog the tubes (e.g., calcium chloride may interactwith casein-based formulas to produce insoluble calcium caseinate products) andmay reduce the efficacy of some drugs (e.g., phenytoin). Since small-bore tubesare easily displaced, tube position should be checked at intervals by aspirating andmeasuring the pH of the gut fluid (6 in the jejunum). Table 73-9 Enteral Feeding Tubes Type/Insertion Clinical Uses PotentialTechnique Complications NASOGASTRIC TUBE External measurement: Short-term Aspiration;nostril, ear, xiphisternum; tube clinical situation ulceration of nasal andstiffened by ice water or (weeks) or longer esophageal tissues,stylet; position verified by periods with leading to strictureinjecting air and auscultating, intermittent insertion;or by x-ray bolus feeding simpler, but continuous drip with pump better tolerated NASODUODENAL TUBE External measurement: Short-term Spontaneousnostril, ear, anterior superior clinical situations pulling back into stomachiliac spine; tube stiffened by where gastric emptying (position verified bystylet and passed through impaired or proximal aspirating content, pH >pylorus under fluoroscopy or leak suspected; requires 6); diarrhea common,with endoscopic loop continuous drip with fiber- ...