Enteral Nutrition Support Therapy for AdultsManual of Clinical Nutrition Management B- 45 Copyright © 2013 Compass Group, Inc.
intermittently during continuous pump feedings, or when there are signs of feeding intolerance (eg,
abdominal distention or vomiting). Guidelines for GRV cut-off values vary among organizations (3,5). The
Academy of Nutrition and Dietetics recommends against holding enteral nutrition when the GRV is less
than 500 mL in the absence of signs of intolerance (e.g., abdominal distention, nausea, vomiting) in
critically ill adult patients (3). Holding enteral nutrition when the GRV is less than 500 mL is associated
with delivery of less enteral nutrition (Fair, Grade III) (3,52). The ASPEN guidelines recommend that GRVs in
the range of 200 to 500 mL should raise concern and lead to the implementation of measures to reduce
the risk of aspiration; however, feedings should not automatically be stopped if the GRV is less than 500
mL and there are no other signs of intolerance (5). These ASPEN guidelines are based on studies that
demonstrated no greater risk for regurgitation, aspiration, or pneumonia when a 250-mL to 500-mL cut-
off value for GRV was used (5). In any case, the clinician should consider the individual patient
circumstance and adhere to organization-specific policies when determining cut-off values for GRV. If a
patient has reoccurring elevated GRVs that exceed target cut-off goals, the underlying causes should be
evaluated, and preventive interventions should be provided. For example, consider a small-bowel tube
placement in patients who have more than 250 mL GRV or formula reflux in two consecutive measures
(Grade II) (3). Small-bowel tube placement (postpyloric position) is associated with reduced GRV (Grade I) (3).
Adequately powered studies have not been conducted to evaluate the impact of GRV on aspiration
pneumonia (3). Patients with GRVs ranging from 200 to 500 mL may benefit from medications that
stimulate gastric motility (eg, metoclopramide, erythromycin, or narcotic antagonists such as naloxone
and alvimopan) (Grade II) (3,5). Patients with consistently high GRVs must be evaluated to exclude
underlying medical problems (eg, ileus, bowel impaction, gastroparesis, or pancreatitis) that may cause
feeding intolerance.
Blue dye should not be added to enteral formulas to detect aspiration. The risk of using blue dye
outweighs any perceived benefit. The presence of blue dye in tracheal secretions is not a sensitive
indicator for aspirations (Grade III) (3,5,60).
If not contraindicated, maintain the head of the patient’s bed at a 30 - 45 angle during feedings to
reduce the risk of aspiration pneumonia (Grade II) and the reflux of gastric contents into the esophagus and
pharynx (Grade I) (3,4). If bolus feeding, keep the head of the bed in this position for 30 to 60 minutes after
feeding.
If the patient has a history of gastroparesis or repeated high GRVs ranging from 200 to 500 mL, then
consider the use of a promotility agent, if there are no contraindications (Grade II) (3). Promotility agents
(eg, metoclopramide or others listed above (5)) have been associated with increased gastrointestinal
transit, improved feeding tolerance, improved enteral nutrition delivery, and possibly a reduced risk of
aspiration (Grade II) (3).
Use of chlorhexidine mouthwash twice a day should be considered to reduce the risk of ventilator-
associated pneumonia (5). Two studies have demonstrated that the use of chlorhexidine mouthwashes
twice daily reduced the incidence of respiratory infection and nosocomial pneumonia in patients
undergoing heart surgery (5).
Diarrhea and Probiotics
Diarrhea in the ICU patient receiving enteral nutrition should prompt an investigation to distinguish
between infectious diarrhea, osmotic diarrhea, or malabsorption. Check for excessive intake of
hyperosmolar medications and substances, such as sorbitol; the use of broad-spectrum antibiotics that
can cause pseudomembranous colitis due to an overpopulation of Clostridium difficile; and other
infectious etiologies. Clostridium difficile is prevalent and increasingly severe nosocomial infection that
presently accounts for 15% to 25% of hospital cases of antibiotic-associated diarrhea (61). S. Boulardii has
been effective as an adjunctive therapy for the treatment and reoccurrence of C. difficile (62, 63, 64). The
dosage of 250 mg twice daily for prevention and 250 mg four times daily to prevent recurrent C difficile
toxins as an adjunct to antibiotic treatment with metronidazole or vancomycin has been suggested (61).
Most episodes of nosocomial diarrhea are mild and resolve independently (5). Soluble fiber (eg, guar
gum) may be beneficial for fully resuscitated, hemodynamically stable, critically ill patients who receive
enteral nutrition and develop diarrhea (5).
Metabolic/laboratory data monitoring guidelines: Serum protein levels are no longer considered to be
reliable or valid as an indicator of a critical care patient’s nutritional status or response to nutrition therapies
(64). Evidence has shown that serum protein levels are markers of the stress response and disease severity,
rather than indicators of nutritional status or protein requirements. For monitoring the adequacy of protein
intake, the most useful (although still limited) laboratory indicator may be nitrogen balance, which reflects
the adequacy of protein intake in matching catabolic demand (64). (Refer to Section II: Estimation of Protein