High Gastric Residual Volume Research Articles

Erythromycin is more effective than metoclopramide in the treatment of feed intolerance in critical illness*

This study aimed to a) compare the efficacy of metoclopramide and erythromycin in the treatment of feed intolerance in critical illness; and b) determine the effectiveness of "rescue" combination therapy in patients who fail monotherapy. Randomized controlled trial. Level III mixed medical and surgical intensive care unit. Ninety mechanically ventilated, medical patients with feed-intolerance (gastric residual volume>or=250 mL). Patients received either metoclopramide 10 mg intravenously four times daily (n=45) or erythromycin 200 mg intravenously twice a day (n=45) in a double-blind, randomized fashion. After the first dose, nasogastric feeding was commenced and 6-hourly nasogastric aspirates were performed. If a gastric residual volume>or=250 mL recurred on treatment, open-label, combination therapy was given. Patients were studied for 7 days. Successful feeding was defined as 6-hourly gastric residual volume<250 mL with a feeding rate>or=40 mL/hr. Demographic data, blood glucose levels, and use of inotropes, opioids, and benzodiazepines were similar between the two groups. After 24 hrs of treatment, both monotherapies reduced the mean gastric residual volume (metoclopramide, 830+/-32 mL to 435+/-30 mL, p<.0001; erythromycin, 798+/-33 mL to 201+/-19 mL, p<.0001) and improved the proportion of patients with successful feeding (metoclopramide=62% and erythromycin=87%). Treatment with erythromycin was more effective than metoclopramide, but the effectiveness of both treatments declined rapidly over time. In patients who failed monotherapy, rescue combination therapy was highly effective (day 1=92%) and maintained its effectiveness for the study duration (day 6=67%). High pretreatment gastric residual volume was associated with poor response to prokinetic therapy. In critical illness, erythromycin is more effective than metoclopramide in treating feed intolerance, but the rapid decline in effectiveness renders both treatments suboptimal. Rescue combination therapy is highly effective, and further study is required to examine its role as the first-line therapy.

Outcomes Associated With Enteral Tube Feedings in a Medical Intensive Care Unit

BACKGROUND Underfeeding of patients reliant on enteral tube feedings most likely is due primarily to interruptions in the infusions. Strategies to improve energy intake require an understanding of such interruptions and associated outcomes. To compare daily energy intake with goal energy intake; to ascertain frequency, duration, and reasons for interruptions in feedings, and to determine occurrences of feeding intolerance. A prospective, descriptive study of a convenience sample of patients admitted during a 3-month period to a medical intensive care unit. Patients were included who were expected to receive continuous enteral tube feedings for at least 48 hours. Patients were studied until discontinuation of feedings, discharge from the unit, or death. Thirty-nine patients were studied for 276 feeding days. Patients received a mean of 64% of goal energy intake. Mean length of interruptions in feeding was 5.23 hours per patient per day. Interruptions for performance of tests and procedures accounted for 35.7% of the total cessation in feeding time. Next most time-consuming interruptions occurred with changes in body position (15%), unstable clinical conditions (13.5%), high gastric residual volume (11.5%), and nausea and vomiting (9.2%). Patients had diarrhea 105 (38%) of 276 feeding days. Gastric residual volumes exceeded 150 mL on 28 measurements in 11 patients. Five patients experienced episodes of nausea and vomiting. Four patients experienced an episode of feeding aspiration. CONCLUSIONS Precautionary interruptions in enteral feedings to decrease presumed risk of aspiration occurred frequently and resulted in underfeeding. Episodes of vomiting and of aspiration were uncommon.

Monitoring bolus nasogastric tube feeding by the Brix value determination and residual volume measurement of gastric contents

Critically ill patients do not always tolerate nasogastric tube feeding. Gastric residual volumes (GRVs), obtained by aspiration from a nasogastric tube, are widely used to evaluate feeding tolerance and gastric emptying, but controversy exists about what constitutes the true GRV (diet formula or digestive juice) and how it should affect management. In this pilot study, we used the Brix value (BV) measurement of gastric contents to monitor both GRV and food content in patients receiving nasogastric feeding. Forty-three patients receiving bolus nasogastric feeding were monitored for 24 hours before entry into the study and then divided into 2 groups according to traditional use of GRV; patients with low GRVs (< 75 mL) were placed in group 1, whereas patients with higher GRVs (> 75 mL) were placed in group 2. All subjects were given 250 mL of polymeric formula by bolus nasogastric infusion, followed by BV measurement of gastric contents at 0, 30, 60, 120, and 180 minutes. All gastric fluid was aspirated after 180 minutes of feeding; the volume was recorded and BV measurement made, then reinstilled with an added 30 mL of dilutional water, after which a final aspiration and BV measurement was performed. Calculated GRV and volume of formula remaining in the stomach was determined by derived equations. Serial BV measurements decreased in both groups after bolus feeding. For patients in group 2, the decrease was less such that at 180 minutes, the mean BV for gastric contents was significantly higher than for those patients in group 1 (10.1 vs 5.1, respectively; p < .01). Aspirated GRV, calculated GRV, and volume of formula remaining in the stomach at 180 minutes were significantly greater for patients in group 2 compared with those in group 1. Use of refractometry in combination with traditional use of GRV identified 4% (1/25) of patients in group 1 with low GRVs who might have possible gastric dysmotility (> 20% of initial 250-mL volume of formula remaining at 180 minutes) and ensured that 72% (13/18) of patients in group 2 with higher GRVs had sufficient gastric emptying (< 20% of initial 250 mL volume of formula remaining). This pilot study raises the feasibility that refractometry and the BV measurement of gastric juice may be a promising tool for bedside monitoring of tolerance and gastric emptying in patients receiving nasogastric feeding, providing valuable complementary information to traditional use of GRV.

Risk factors for esophagitis in extreme acid hypersecretors with and without Zollinger-Ellison syndrome

Background & aims Whereas severe duodenal ulcer is the hallmark of acid hypersecretion in Zollinger-Ellison syndrome (ZE) and similar states, the esophagus also is at high risk. We quantified the incidence of esophagitis and various risk factors that might contribute to it. Methods Sixty-eight acid hypersecretors (basal acid output >15 mmol/h), 50 patients with ZE, and 18 patients without ZE with normal gastrin levels were studied by gastric analysis, serum gastrin levels, and endoscopy. In 44 of 68 patients, esophageal manometry was performed after the esophagus had healed. Results Erosive esophagitis, grade 2 or worse, was found in 65%; an additional 15% had heartburn only, for a total reflux disease incidence of 80%. ZE accounted for 95% of severe esophagitis. Patients with and without esophagitis had the same high overnight fasting gastric residual volume and acidity, as well as basal and peak acid and pepsin outputs. However, patients with esophagitis had a lower median lower esophageal sphincter pressure (LESP) of 15.5 vs. 23 mm Hg in those without symptoms; the critical discriminator threshold was 16 mm Hg. Multivariate analysis further identified frequent vomiting and obesity as positive predictors of esophagitis, whereas Helicobacter pylori was a strong negative predictor (odds ratio, 0.16), possibly related to an elevated LESP in patients infected with H. pylori. Conclusions Erosive esophagitis is very common in acid hypersecretors. Identified risk factors that could promote abnormal esophageal exposure to the high acid and pepsin levels in our population of hypersecretors were vomiting, LESP < 16 mm Hg, and obesity, whereas H. pylori appeared to protect the esophagus not by reduced acid, but through an elevated LESP.

Enteral nutrition in patients with acute renal failure

Systematic studies on safety and efficacy of enteral nutrition in patients with acute renal failure (ARF) are lacking. We studied enteral nutrition-related complications and adequacy of nutrient administration during 2525 days of artificial nutrition in 247 consecutive patients fed exclusively by the enteral route: 65 had normal renal function, 68 had ARF not requiring renal replacement therapy, and 114 required renal replacement therapy. No difference was found in gastrointestinal or mechanical complications between ARF patients and patients with normal renal function, except for high gastric residual volumes, which occurred in 3.1% of patients with normal renal function, 7.3% of patients with ARF not requiring renal replacement therapy, 13.2% of patients with ARF on renal replacement therapy (P= 0.02 for trend), and for nasogastric tube obstruction: 0.0%, 5.9%, 14%, respectively (P < 0.001). Gastrointestinal complications were the most frequent cause of suboptimal delivery; the ratio of administered to prescribed daily volume was well above 90% in all the three groups. Definitive withdrawal of enteral nutrition due to complications was documented in 6.1%, 13.2%. and 14.9% of patients, respectively (P= 0.09 for trend). At regimen, mean delivered nonprotein calories were 19.8 kcal/kg (SD 4.6), 22.6 kcal/kg (8.4), 23.4 kcal/kg (6.5); protein intake was 0.92 g/kg (0.21), 0.87 g/kg (0.25), and 0.92 g/kg (0.21), the latter value being below that currently recommended for ARF patients on renal replacement therapy. Median fluid intake with enteral nutrition was 1440 mL (range 720 to 1960), 1200 (720 to 2400), and 960 (360 to 1920). Enteral nutrition is a safe and effective nutritional technique to deliver artificial nutrition in ARF patients. Parenteral amino acid supplementation may be required, especially in patients with ARF needing renal replacement therapy.

Continuous nasogastric tube feeding: monitoring by combined use of refractometry and traditional gastric residual volumes

Background & aims: Traditional use of gastric residual volumes (GRVs) is insensitive and cannot distinguish retained enteral formula from the large volume of endogenous secretions. We designed this prospective study to determine whether refractometry and Brix value (BV) measurements could be used to monitor gastric emptying and tolerance in patients receiving continuous enteral feeding. Methods: Thirty-six patients on continuous nasogastric tube feeding were divided into two groups; patients with lower GRVs (<75 ml) in Group 1, patients with higher GRVs (>75 ml) in Group 2. Upon entry, all gastric contents were aspirated, the volume was recorded (Asp GRV), BV measurements were made by refractometry, and then the contents were reinstilled but diluted with 30 ml additional water. Finally, a small amount was reaspirated and repeat BV measurements were made. Three hours later, the entire procedure was repeated a second time. The BV ratio, calculated (Cal) GRV, and volume of formula remaining were calculated by derived equations. Results: Mean BV ratios were significantly higher for those patients in Group 2 compared to those in Group 1. All but one of the 22 patients (95%) in Group 1 had a volume of formula remaining in the stomach estimated on both measurements to be less than the hourly infusion rate (all these patients had BV ratios <70%). In contrast, six of the 14 patients in Group 2 (43%) on both measurements were estimated to have volumes of formula remaining that were greater than the hourly infusion rate (all these patients had BV ratios >70%). Three of the Group 2 patients (21%) whose initial measurement showed evidence for retention of formula, improved on repeat follow-up measurement assuring adequate gastric emptying. The remaining five patients from Group 2 (35%) had a volume of formula remaining that was less than the hourly infusion rate on both measurements. The pattern of Asp GRVs and serial pre- and post-dilution BVs failed to differentiate these patients in Group 2 with potential emptying problems from those with sufficient gastric emptying. Conclusions: Refractometry and measurement of the BV may improve the clinical utilization of GRVs, by its ability to identify the component of formula within gastric contents and track changes in that component related to gastric emptying.

Clinical use of gastric residual volumes as a monitor for patients on enteral tube feeding.

The use of gastric residual volumes (GRVs) as a clinical monitor for patients receiving enteral tube feeding (ETF) is based on presumptions that are not physiologically sound and practice that is poorly standardized. This systematic review of the medical literature summarizes results from studies that evaluate the practice, interpretation, and impact on patient outcome from use of GRV. Little data exist to support a correlation of GRV with gastric emptying, volume of gastric contents, or changes in the infusion of ETF. GRVs do not correlate to regurgitation or aspiration, and their use cannot be relied on to protect patients against aspiration pneumonia. Although recent reports suggest that elevated GRVs correlate to "intolerance" of ETF, use as a marker of impending clinical deterioration is limited by the fact that the timing of increases in GRV is unpredictable and high GRVs do not correlate independently to adverse outcome. The practice of GRV may in fact impede delivery of ETF by promoting inappropriate cessation and reducing potential infusion time. Modifying interpretation and the response by healthcare providers to GRV data are needed to preserve any clinical use for this practice.

Comparison of 2 methods of managing gastric residual volumes from feeding tubes

Research-based standards do not exist for the management of gastric residual volumes from feeding tubes. Withdrawing and returning residual volumes can lead to clogged tubes and exposes patients to possible contamination of the feeding system. However, discarding residual volumes may place patients at risk for electrolyte imbalance and may alter fluid or nutritional balance. To investigate the effects of discarding versus returning gastric residual volumes on body weight, serum electrolyte levels, and the rate of complications associated with tube feeding. Thirty-five subjects receiving enteral feedings were recruited from intensive care units at 3 Midwest hospitals and randomized to a discard group or a return group. Eighteen sets of usable data were obtained. Repeated-measures analysis of variance indicated no significant differences between the 2 groups for any of the variables. Complications related to enteral feedings were more common in the return group (n = 8), which had 2 episodes of tube clogging and 1 episode of diarrhea and nausea. None of these complications were experienced by patients in the discard group (n = 10). Both groups had significant numbers of complications, including a total of 15 episodes, 7 in the discard group and 8 in the return group, of feeding delays due to high gastric residual volumes. Although serum electrolyte levels did not differ significantly between the 2 groups, potassium levels tended to be lower in the discard group. Considerations for the care of critically ill patients with feeding tubes are discussed in light of these findings.

The paracetamol absorption test: a useful addition to the enteral nutrition algorithm?

Background: Enteral nutrition in critically ill patients given via the nasogastric route is often decreased or stopped because of large gastric residual volumes. Aim: To assess the effect of continuing enteral nutrition in patients with an elevated gastric residual volume but normal gastric emptying by the paracetamol absorption test.Methods: The paracetamol absorption test was performed on all patients receiving enteral nutrition via a nasogastric tube who had a residual volume (assessed every 8 hours) of >150 ml or more than twice the hourly infusion rate. Patients were then divided into 2 groups according to the result of the test: Group 1 (n=8), normal gastric emptying; and Group II (n=24), abnormal gastric emptying. Group I continued to receive enteral nutrition. In Group II feeding was interrupted in 18 patients and prokinetic agents administered, while a subgroup of six patients continued to receive enteral nutrition without prokinetic agents. All patients were followed for evidence of delayed gastric emptying and aspiration.Results: Residual volumes were similarly elevated in both groups (p=0.25). Enteral nutrition was continued in Group I with no adverse effects. Prokinetic agents allowed enteral nutrition to be resumed in 88% of the 18 Group II patients. Enteral nutrition in the subgroup had to be stopped because of persistently elevated residual volumes.Conclusion: The paracetamol absorption test may be normal in patients with relatively high gastric residual volumes. These patients may continue to receive enteral nutrition.

Endoscopic placement of nasoenteric feeding tubes in critically ill patients: a reliable alternative.

Spontaneous transpyloric passage of nasoenteric feeding tubes is often unsuccessful in critically ill patients due to gastric ileus. The purpose of this study was to evaluate the success rate of endoscopic placement of postpyloric nasoenteric tubes and the time required to achieve goal enteral nutritional support in critically ill patients with gastric ileus. Surgical ICU patients with gastric ileus, documented by recorded high gastric residual volumes via a nasogastric tube, were identified for placement of a nasoenteric postpyloric tube via esophagogastroduodenoscopy (EGD). EGD was performed bedside in the ICU, using intravenous sedation, for placement of a 43-inch (109 cm) 8 French tungsten-weighted nasoenteric tube with an inner stylet into the duodenum, and the tube was advanced as far distally as possible. Abdominal radiograph was obtained to confirm final tube position postprocedure. Enteral feedings were initiated immediately with a full-strength formula and increased to the goal enteral feeding rate as tolerated. Thirty-four patients underwent successful placement of postpyloric nasoenteric tubes by EGD. One procedure was aborted in a patient with adult respiratory distress syndrome (ARDS) who developed hypoxemia with gastric insufflation during the EGD. The mean time to achievement of goal enteral nutritional support was 20.8 hours. Tubes remained in place for a range of 6 to 37 days. Endoscopic placement of postpyloric enteral feeding tubes is highly successful, and allows for prompt achievement of goal enteral nutritional requirements. It has two main advantages: it eliminates the risk of patient travel to radiology for fluoroscopic placement, and allows for earlier initiation of enteral feedings because spontaneous passage of weighted nasoenteric tubes into the duodenum in critically ill patients is often unsuccessful.

Randomized prospective trial of early versus delayed feeding after percutaneous endoscopic gastrostomy placement

By convention, most clinicians delay feeding through the gastrostomy tube until 24 h after placement. However, evidence is lacking to support the rationale for such a delay in PEG use. This randomized, prospective study was designed to assess the safety of early feeding after PEG placement.One hundred-twelve patients referred for PEG were randomized to begin tube feedings at 4 h (group A) or at 24 h (group B) after placement. All patients received prophylactic antibiotics. Full-strength Isocal was administered with the following schedule: day 1, 100 ml every 4 h for six feedings; day 2, 200 ml every 4 h for six feedings. Immediately before each scheduled feeding, gastric residual volume was recorded and the next feeding was withheld if the residual volume was > 50 percent (gastric retention). Patients were evaluated on day 1, day 2, day 7, and day 30 for major and minor complications.The two groups were similar with regard to age, gender, baseline nutritional status, and indications for PEG placement. On the first day of feeding, 14 of 57 patients (25%) in group A, but only five of 55 patients (9%) in group B, had evidence of gastric retention, p = 0.029. The proportion of patients with high gastric residual volumes was not significantly different on day two. In group B, one death occurred because of aspiration of gastric contents on day 2. All other complications were minor and did not differ significantly between the two groups.Early initiation of PEG feedings is safe, well tolerated, and reduces cost by decreasing hospital stay.