Hemodynamically stable
No nutrition support if hemodynamics are changing
and require high-dose pressor support
Are any of the following present:
• Obstruction/active pseudo-obstruction
• High-output fistula
• Excessive vomiting/
diarrhea
• Bowel perforation or ischemia
Start tube feeding
Evaluate route of delivery (see Table 71.8)
Initiate small bowel feeds Initiate gastric feeds
• Start at 10–20 mL/h
• Advance 10 mL/hr q4–8h until goal achieved
• Minimal flush (water or NS) 30 mL q4h
• If feeding noted in gastric output, recheck tube position via x-ray
• For 1–1.5 cal/mL product, start at 100 mL q4h
• For 2 cal/mL product, start at 50 mL q4h
• Increase 50 mL q4–8h until goal is achieved
• Minimal flush (water or NS) of 30 mL q4h
• Hold for gastric residual volume >150–250 mL, abdominal distention, or emesis
TF held × 2
Unable to achieve TF goal for >7 days
Start TPN Reassess routinely for
TF eligibility
Yes
No
TPN, total parenteral feeding; TF, tube feeding; NS, normal saline.
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TABLE 71.5 Advantages and Disadvantages of Enteral and Parenteral Nutrition
Type of feeding Advantages Disadvantages Enteral nutrition Preserves gut mucosal
integrity
Requires functional GI tract Less costly than TPN More time to reach goal
calories May blunt hypermetabolic
response
Multiple contraindications (e.g., obstruction, fistula) Less infectious complications
Parenteral nutrition
Does not require functioning Intestinal atrophy
GI tract Requires central IV access
Full support in<24 hr Increased rate of infectious complications
TPN, total parenteral nutrition; GI, gastrointestinal; IV, intravenous.
recommended unless symptoms of malabsorption are present, then a peptide-based product should be initiated. Studies using immune-modulating formulas (those enriched with glutamine, arginine, omega-3 fatty acids, antioxidants, or nucleotides) have been found to be positive in elective upper gastrointestinal surgical, head and neck cancer, burn, trauma, and ICU patients. No benefit of immune-modulating formulas has been established in patients with severe sepsis; in fact, caution should be used when providing products containing arginine to these patients. Advantage has been shown with the use of formulas containing antioxidants and omega-3 fatty acids for patients with pulmonary capillary leak syndromes (acute respiratory distress syndrome or acute lung injury). To receive optimal benefit from immune-modulating formulas,
TABLE 71.6 Gastric and Small Bowel Feeding Indications Gastric feeding Small bowel feeding
rMajority of ICU patients rShort gut (to maximize
surface area fed) rTotal laryngectomies
(cannot aspirate)
rDelayed gastric emptying rPostoperative gastric ileus
rSevere gastroesophageal reflux disease rSevere pancreatitis (unable to resume PO in
5–7 days)
rProximal gastrointestinal fistula
rIntolerance to gastric feeds (despite prokinetic use); high gastric residual volumes, emesis rSupine positioning
rPatients unable to protect their airway secondary to heavy sedation (Ramsey>5) ICU, intensive care unit; PO, by mouth.
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TABLE 71.7 Troubleshooting Tube Feeding Complications Residuals:Gastric residual volume of 250 mL or more on more than one
consecutive reading; or 500 mL on one reading.
rClinically examine for signs of intolerance: abdominal distention, fullness, discomfort, or presence of emesis.
rStart a prokinetic agent: IV metoclopramide 10 mg q6h (if no renal failure present), for no>72 hr.
rChange to a more calorically dense product to decrease total volume infused.
rIf aMoss tubeis present, normal gastric output may reach 2 L/day because of drainage of proximal duodenum.
rPresence of a small amount of tube feeding from the gastric port is normal.
rOrder a small bowel feeding tube.
Diarrhea:Quantify amount of stool. It is normal for a patient on tube feedings to have four to five soft formed stools per day.
rReview medications. Diarrhea may be secondary to an enteral medication. Try changing medication route to IV.
rRule out the presence ofClostridium difficile.
rTry adding a soluble fiber to feeds (Benefiber 1 Tbsp TID) if patient fully resuscitated and without risk of bowel ischemia.
rOnce infectious cause is ruled out, use an antidiarrheal agent (loperamide 2–4 mg q6h)
rKEEP FEEDING
Constipation:Difficulty passing or no bowel movement>3 days after feedings are at goal.
rCheck for signs of dehydration, such as hypernatremia, prerenal azotemia, oliguria, low skin turgor, orthostatic hypotension
rIncrease amount of free water.
rRectal examination with disimpaction.
rOrder KUB to rule out obstruction
rOnce obstruction is ruled out, start bisacodyl suppository and/or enemas PRN.
rStart bowel regimen (docusate, 100 mg BID, and/or senna syrup, 5 mL BID).
IV, intravenous; TID, three times a day; KUB, kidney/ureter/bladder x-ray; PRN, as needed;
BID, two times a day.
at least 50% to 60% of the patient’s caloric goal should be provided. At present no recommendation can currently be made for use of probiotics via the enteral feeding route in the general ICU population because of lack of consistent outcome effect and heterogeneity of the bacterial strains studied. Insoluble fiber should be avoided in all critically ill patients and soluble fiber should only be used resuscitated, hemody- namically stable patients. Both forms should be avoided in any patient with severe dysmotility or at risk of bowel ischemia.
Critically ill patients presenting with injuries (traumatic brain injury) or condi- tions (severe dysphagia due to cerebral vascular accident) that will require>4 weeks of enteral support will benefit from early placement of long-term feeding access. For conditions requiring<4 weeks of therapy, placement of short-term feeding access via the nose or mouth should be instituted. Several options of both short- and long-term access and their associated risks are reviewed in Table 71.8.
Nutrition in the ICU rNutrition in the Intensive Care Unit 5 6 7
TABLE 71.8 Short- and Long-Term Enteral Feeding Access
rSalem sump nasogastric or orogastric:a short-term feeding tube generally placed by the bedside nurse for decompression that may be used for feeding.
The patient must have a functioning GI tract, adequate gastric-emptying, and low risk of aspiration. Nasally placed tubes carry the risk of sinusitis and nasal necrosis.
rNasoenteric feeding tubefor gastric or small bowel placement: a short-term, softer, more flexible tube with less risk of causing sinusitis or nasal necrosis, this tube may also be placed orally. Generally placed in patients for comfort.
Small bowel tubes are placed in patients with poor gastric-emptying and have a high risk of reflux.
rG-tubeafor surgical or percutaneous endoscopic gastrostomy: a long-term feeding tube for patients with a functioning GI tract and adequate
gastric-emptying. G-tubes have a lower risk of aspiration when compared with above-the-diaphragm feeding access.
rJ-tubeafor surgical or percutaneous endoscopic jejunostomy: a long-term feeding tube indicated for patients with a functioning GI tract, poor gastric-emptying, and a high risk for reflux and aspiration.
rG-J tubea:a long-term feeding tube placed percutaneously or at time of laparotomy in patients for feeding into the distal duodenum with a gastric port for decompression.
aAll tubes that transverse the two epithelial barriers of the skin and mucosa of the GI tract carry the risk of hemorrhage and infection at the incision site as well as peritonitis and risk of dislodgment.
GI, gastrointestinal.
TABLE 71.9 Catheter Selection for Total Parenteral Nutrition (TPN) rTriple/quad lumen catheter:used for in-hospital patients on TPN. The distal
port is preferred for the infusion of TPN solution to maintain sterility and avoid contamination. Blood is drawn through the medial port and other infusions are performed through the proximal port(s).
rPICC (peripheral inserted central catheter):PICC lines are placed via the brachiocephalic vein. PICC lines have a long catheter (60 cm) with the tip positioned in the superior vena cava.
rTunneled catheter:This is a silastic catheter (single-, double-, or triple-lumen) that is tunneled subcutaneously several centimeters from the insertion site before exiting the skin. If no infection is present, these catheters can stay in place indefinitely.
rHohn:A percutaneously placed catheter used for patients requiring 6 months or less of TPN or IV medication. The distal port (red) is preferred for the infusion of TPN solution to maintain sterility and avoid contamination.
rImplanted venous access device:This is a subcutaneously implanted chamber attached to a silastic central venous catheter, either single- or double-lumen. Because the reservoir is implanted in the SQ, it must be accessed with a needle for drawing blood or administering TPN or other IV infusions. These catheters are generally reserved for patients receiving chemotherapy who require periodic infusions.
IV, intravenous.
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TPN must be administered via a designated port of a central venous catheter to avoid potential complications associated with incompatibilities with intravenous medication administration. Parenteral nutrition via a peripheral intravenous line is not appropriate for the critically ill patient. Subclavian lines are preferred because of the ease in maintaining an occlusive dressing and the lower rate of infections. The least
TABLE 71.10 Electrolytes Administered Via the Total Parenteral Nutrition Solution
Suggested electrolytes (per liter)
Conditions that may require alteration of amount provided
Electrolyte carriers Sodium
60–150 mEq
rRenal function NaCl
rFluid status Na acetate
rGI losses NaPO4
rTraumatic brain injury Potassium
40–120 mEq
rRenal function KCl
rGI losses K acetate
rMetabolic acidosis KPO4 rRefeeding
Phosphate 10–30 mM
rRenal function NaPO4
rRefeeding KPO4
rBone disease rHypercalcemia rRapid healinga rHepatic function Chloride
60–120 mEq
rRenal function NaCl
rGI losses (gastric) KCl rAcid-base status
Acetate 10–40 mEq
rRenal function NaAcetate rGI losses (small bowel) KAcetate rAcid-base status
rHepatic function Calcium
4.5–.2 mEq
rHyperparathyroidism Ca Gluconate
rMalignancy CaCl2
rBone disease rImmobilization rAcute pancreatitis rRenal function Magnesium
8.1–24.3 mEq
rRenal function Mg sulfate rRefeeding
rHypokalemia
aRapid healing examples are burn, and young trauma patients who have rapid tissue generation.
GI, gastrointestinal.
Nutrition in the ICU rNutrition in the Intensive Care Unit 5 6 9
desirable is a femoral line that has been associated with a higher incidence of venous thrombosis. The choice of catheter type depends on the reason for TPN, expected duration of TPN, and the patient’s overall status (Table 71.9).
When TPN is provided, the practitioner must be knowledgeable regarding the form in which electrolytes are provided, the normal amount recommended, and what conditions should precipitate an alteration in the amount provided (Table 71.10). One must be vigilant when prescribing the various electrolytes that are provided in TPN, as there are inherent risks associated with its administration. This is balanced with the need to avoid exceeding amounts, which may lead to precipitation within the TPN solution itself.
Clinicians often underestimate the importance of nutrition support in the ICU patient population. Early intervention by a nutrition support specialist as part of the multidisciplinary team is imperative to ensure that appropriate access is obtained and substrates provided. Understanding the massive catabolic state that exists with critical illness underscores the need for early and precise nutritional support. Early replacement of ongoing losses of micro- and macronutrients will aid in the patient’s recovery once the critical illness has resolved and the anabolic building phase has commenced.
S U G G E S T E D R E A D I N G S
Dabrowski GP, Rombeau JL. Practical nutritional management in the trauma intensive care unit.
Surg Clin North Am.2000;80:921–932.
A practical overview of nutritional management of the trauma patient.
Heyland DK, Dhaliwal R, Drover JW, et al. Canadian clinical practice guidelines for nutri- tional support in mechanically ventilated, critically ill adult patients.J Parenter Enter Nutr.
2003;27:355–373.
Canadian evidence-based practice guidelines for nutrition support in mechanically ventilated patients.
Kreymann KG, Berger MM, Deutz NE, et al. ESPEN guidelines on enteral nutrition: intensive care.Clin Nutr.2006;25:210–223.
Consensus guidelines based on review of the literature for enteral nutrition support in the critically ill with at least one organ failure.
Kudsk KA. Effect of route and type of nutrition on intestine-derived inflammatory responses.
Am J Surg.2003;185:16–21.
This review article looked at the effects on the gastrointestinal from lack of feeding. Findings included an increase in proinflammatory markers and showed that the addition of glu- tamine reverses many of the defects seen in starvation in the critically ill.
Marik PE, Zaloga G. Immunonutrition in high-risk surgical patients: a systematic review and analysis of the literature.J Parenter Enter Nutr.2010;34:378–386.
In surgery patients, immunonutrition is associated with a reduction in risk of acquired infec- tion and wound complications and a shorter LOS. However, there was not a mortality advantage.
Martindale RG, McClave SA, Vanek VW, et al; American College of Critical Care Medicine; and the A.S.P.E.N. Board of Directors. Guidelines for the provision and assessment of nutrition support therapy in the adult critically ill patient: Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition.J Parenter Enter Nutr.2009;33:277.
Executive Summary:Crit Care Med.2009;37:1757.
Review of the literature and evidence based recommendations for nutritional support in the critically ill patient.
Montejo JC, Minambres E, Bordege L, et al. Gastric residual volume during enteral nutrition in ICU patients: the REGANE study.Intensive Care Med.2010;36:1386–1393.
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Pontes-Arruda Alessandro, Aragao AM, Albuquerque JP, et al. Effects of enteral feeding with eicosapentaenoic acid,γ-linolenic acid, and antioxidants in mechanically ventilated patients with severe sepsis and septic shock.Crit Care Med.2006;34:2325–2333.
This study showed that in patients with severe septic shock requiring mechanical ventilation who were tolerating enteral feeding, a diet rich in EPA, GLA, and antioxidants imparted improved ICU and hospital outcomes and was associated with decrease mortality.
Singer P, Berger MM, Van den Berghe G, et al. ESPEN guidelines on parenteral nutrition:
intensive care.Clin Nutr.2009;28:387–400.
Consensus guidelines based on review of the literature for parenteral support in the critically ill patient, covering both parenteral macro- and micronutrients.