Effect of Feeding-Tube Properties on Residual Volume Measurements in Tube-Fed Patients

The Japanese Critical Care Nutrition Guideline 2024

Nutrition therapy is important in the management of critically ill patients and is continuously evolving as new evidence emerges. The Japanese Critical Care Nutrition Guideline 2024 (JCCNG 2024) is specific to Japan and is the latest set of clinical practice guidelines for nutrition therapy in critical care that was revised from JCCNG 2016 by the Japanese Society of Intensive Care Medicine. An English version of these guidelines was created based on the contents of the original Japanese version. These guidelines were developed to help health care providers understand and provide nutrition therapy that will improve the outcomes of children and adults admitted to intensive care units or requiring intensive care, regardless of the disease. The intended users of these guidelines are all healthcare professionals involved in intensive care, including those who are not familiar with nutrition therapy. JCCNG 2024 consists of 37 clinical questions and 24 recommendations, covering immunomodulation therapy, nutrition therapy for special conditions, and nutrition therapy for children. These guidelines were developed in accordance with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system by experts from various healthcare professionals related to nutrition therapy and/or critical care. All GRADE-based recommendations, good practice statements (GPS), future research questions, and answers to background questions were finalized by consensus using the modified Delphi method. Strong recommendations for adults include early enteral nutrition (EN) within 48 h and the provision of pre/synbiotics. Weak recommendations for adults include the use of a nutrition protocol, EN rather than parenteral nutrition, the provision of higher protein doses, post-pyloric EN, continuous EN, omega-3 fatty acid-enriched EN, the provision of probiotics, and indirect calorimetry use. Weak recommendations for children include early EN within 48 h, bolus EN, and energy/protein-dense EN formulas. A nutritional assessment is recommended by GPS for both adults and children. JCCNG 2024 will be disseminated through educational activities mainly by the JCCNG Committee at various scientific meetings and seminars. Since studies on nutritional treatment for critically ill patients are being reported worldwide, these guidelines will be revised in 4 to 6 years. We hope that these guidelines will be used in clinical practice for critically ill patients and in future research.

Strategies to Maximize the Benefits of Evidence-Based Enteral Nutrition: A Narrative Review

Enteral nutrition (EN) has been reported to have some physiological importance for critically ill patients. However, the advantage of EN over parenteral nutrition remains controversial in recent paradigms. To maximize the benefits and efficiency of EN, implementing measures based on comprehensive evidence is essential. Here, we systematically reviewed EN-related studies and integrated them into the best and most up-to-date EN practices. We extracted studies from 13 systematic reviews during the development of Japanese Critical Care Nutrition Guidelines, summarizing findings on the assessment of enteral feeding intolerance (EFI), the timing of EN, formula composition and nutrients, and method of administration in critically ill adult patients. Multifaceted EFI assessment may be needed in patients for high-risk patients. Early EN may reduce infectious complications, and initiating EN even earlier may offer an additional advantage. High protein intake (≥1.2 g/kg/day) could maintain muscle mass and physical function without increasing gastrointestinal complications. Probiotics, prebiotics, and synbiotics may serve as beneficial options for preventing infection and gastrointestinal complications, although their efficacy depends on the strains, types, and combinations used. For patients with EFI, post-pyloric feeding could be an effective approach, while intermittent feeding may be a safer approach. Both methods should be utilized to achieve nutritional targets. Integrating these nutritional interventions into EN strategies may help maximize their effectiveness and minimize complications. However, careful consideration regarding timing, dosage, nutrient selection, administration methods, and patient selection is required.

Prokinetic effect of erythromycin in the management of gastroparesis in critically ill patients-our experience and literature review

Introduction

Gastroparesis is a disorder characterized by impaired gastric emptying and the accumulation of food in the intestines without any clear mechanical cause. Gastroparesis in critical care patients is a prevalent issue in the intensive care unit. The disruption of normal gastrointestinal motility in critically ill patients is linked to a significant risk of intolerance to enteral feeding, colonization of the gastrointestinal tract with pathogenic bacterial strains, increased permeability of the intestinal wall, translocation of the intestinal microbiota, leading to progressive malnutrition, and potential development of bacterial infection.

Materials and methods

The literature was reviewed to assess the benefits and risks associated with the use of this medication.

Aim

The aim of the study was to treat the symptoms of gastroparesis and stimulate gastrointestinal motility. Consequently, the aim was to reduce the amount of backed-up food content in the stomach, accelerate gastrointestinal motility, and return to intestinal feeding.

Results

Gastroparesis is a frequent issue among patients in the intensive care unit. Critical illness can lead to gastrointestinal motility disorders, causing slowed gastric emptying. This increases the risk of problems such as intolerance to enteral feeding, regurgitation, and aspiration of gastrointestinal contents into the respiratory tract, as well as colonization of the gastrointestinal tract by pathogens. Over time, impaired intestinal absorption can result in malnutrition, necessitating the initiation of parenteral nutrition.

Conclusion

After analysis of the literature and published scientific reports, as well as considering their own research, it is evident that erythromycin, as a prokinetic drug, effectively enhances gastrointestinal motility. This contributes to stimulating gastric emptying in critically ill patients with gastroparesis who are hospitalized in an intensive care unit. The use of erythromycin in combination with metoclopramide and/or itopride hydrochloride allows for a synergistic effect, leading to the quickest possible return to enteral feeding.

Assessment the knowledge, care, and experiences of neonatal nurses about enteral nutrition

Enteral-feeding refers to any nutritional method throughout the gastrointestinal tract, including oral feeding. This qualitative study examined the information, experiences, and records of neonatal nurses of enterally fed patients. The study was conducted between 05.04.2018 and 05.05.2018 with 22 nurses (73.3%) working in the neonatal intensive care clinic of Çukurova University Balcali Hospital, Adana, Turkey. The data were collected by "Observation and Interview Form" developed based on the literature. Nurses were observed, and interviews were conducted depending on their appointments. Data were collected by observing each nurse on 2 different days. In all observations; it was determined that the nurses changed the feeding set daily, regularly checked the location of the feeding tube and amount of residue, and administered medication through the feeding tube. In 22.7% of the observations, nurses did not securely fix the feeding tube, 27.2% did not write a daily date on the injector with the residual volume measured, and 31.8% did not wash the injector. All the nurses recorded the amount of feed, residual amounts, and content. At the end of the interviews, 9% of the nurses stated that they had experienced aspiration among the complications encountered during enteral feeding. During the interview, they stated that all nurses were educated about enteral nutrition, had control of whether the probe was in place before feeding, performed residual control, washed their hands before the procedure, fixed the food injector to 1 place, and allowed the food injector to flow spontaneously with negative pressure. According to the results of the interviews and observations, nurses could not reflect on their nursing practices correctly. Nurses working in neonatal intensive care units should be regularly trained to share the results of evidence-based studies on enteral nutrition.

Impact of Routine Gastric Aspirate Monitoring on Very Low Birth Weight Early Preterm Infants

OBJECTIVES

Routine gastric aspirate (RGA) monitoring is a common yet controversial practice intended for early identification of gastrointestinal pathology in infants receiving gavage feeds. Our objectives were to evaluate the association of ceasing RGA monitoring on the incidence of necrotizing enterocolitis (NEC) as well as nutritional outcomes in a large population of very low birth weight (VLBW) and very preterm neonates.

METHODS

Retrospective record review of neonates born ≤32 weeks and/or VLBW from 2 cohorts: (1) during pre-feed RGA monitoring (September 2015 to June 2018) and (2) after cessation of RGA ("non-RGA") monitoring (July 2018 to December 2020). We compared incidence of NEC, time-to-full enteral feeds, central line duration, and duration of parenteral nutrition (PN) in bivariate and multivariable models accounting for changes in feeding protocols over time.

RESULTS

We identified 617 subjects, 53% in the RGA monitoring cohort (n = 327) and 47% in non-RGA cohort (n = 290). The non-RGA cohort had feeds initiated earlier ( P < 0.0001), achieved full enteral feeds more rapidly ( P < 0.0001), received a shorter duration of PN ( P = 0.0003), and had shorter central access duration ( P < 0.0001) without increasing NEC risk. In fact, the non-RGA cohort had a lower incidence of NEC ( P = 0.0345) compared to the RGA cohort. Even after adjusting for changes in feeding protocols over time in a multivariable model, the RGA cohort had significantly higher odds of NEC.

CONCLUSIONS

Pre-feed RGA monitoring in the absence of concerning clinical exam findings is not indicated for neonates receiving gavage feeds as it does not improve NEC incidence but instead may delay important nutritional outcomes such as feed initiation and central line removal.

Gastric ultrasound, citrulline, and intestinal fatty acid-binding protein as markers of gastrointestinal dysfunction in critically ill patients: A pilot prospective cohort study

BACKGROUND

Gastrointestinal (GI) dysfunction is common in the intensive care unit (ICU), although there is no consensus on biomarkers of GI dysfunction. We aimed to evaluate ultrasound-based gastric antrum measurements and serum intestinal fatty acid-binding protein (IFABP) and citrulline levels in relation to GI dysfunction in critically ill patients.

METHODS

Adult critically ill patients receiving enteral nutrition and stayed for in the ICU for ≥48 h was included. GI dysfunction was described using Gastrointestinal Dysfunction Score (GIDS). Gastric antrum measurements, including craniocaudal (CC) diameter, anteroposterior diameter, and antral-cross sectional area (CSA), as well as serum levels for IFABP and citrulline, were prospectively recorded at baseline and on day 3 and day 5 of enteral nutrition. The receiver operating characteristic (ROC) analysis was performed to evaluate gastric ultrasound parameters, serum IFABP, and citrulline concentrations in predicting GI dysfunction.

RESULTS

Thirty-nine participants with a median age of 60 years were recruited and 46.2% of participants had GI dysfunction. ROC analysis revealed that the cutoff value of CSA score to predict GI dysfunction was 4.48 cm² , which provided 72.7% sensitivity and 77.2% specificity (area under the curve = 0.768, 95% CI: 0.555-0.980). At baseline, gastric residual volume was highly correlated with CC diameter and CSA (r = 0.764, P < 0.001 and r = 0.675, P < 0.001, respectively). Serum IFABP and citrulline levels had no correlation with GI dysfunction or gastric ultrasound parameters (P > 0.05).

CONCLUSION

CSA was associated with GI dysfunction in critically ill patients. Serum IFABP and citrulline concentrations were poor in predicting GI dysfunction.

Nurses' and Physicians' Rationale Behind Clinical Performance and Interpretation of Routine Prefeed Gastric Aspiration in Preterm Infants: A Cross-sectional Study

This study aims at understanding the rationale behind performing prefeed gastric aspirations in preterm infants, how nurses and physicians interpret the gastric aspiration and variations between them, and illuminating potential barriers for omitting routine prefeed aspiration. Nurses and physicians from all Danish neonatal intensive care units completed a questionnaire. Of 682 participants, the majority (94%) indicated that they routinely performed prefeed aspiration, primarily to check the feeding tube placement (nurses: 88%, physicians: 46%). Nurses feared necrotizing enterocolitis when observing a large gastric residual (GR) volume (31%) and green-stained GR (63%). Fewer nurses relative to physicians had "no worries" related to large volumes (15% vs 34%) or green-stained GR (14% vs 24%, both P < .01). More nurses than physicians intended to pause enteral feeding when observing green-stained GR (31% vs 16%, P < .01) and more nurses were concerned of completely omitting routine gastric aspirations (90% vs 46%, P < .05). The rationale behind the clinical use of GR volume and color as markers of necrotizing enterocolitis and feeding intolerance differs markedly between nurses and physicians in Denmark. If routine prefeed gastric aspiration should be omitted, special focus on information about early signs of necrotizing enterocolitis and methods to check tube placement is needed.

Gastrointestinal Dysmotility in Critically Ill Patients: Bridging the Gap Between Evidence and Common Misconceptions

Disruption of normal gastrointestinal (GI) function in critical illness is linked to increased morbidity and mortality, and GI dysmotility is frequently observed in patients who are critically ill. Despite its high prevalence, the diagnosis and management of GI motility problems in the intensive care unit remain very challenging, given that critically ill patients often cannot verbalize symptoms and the general lack of understanding of underlying pathophysiology. Common clinical presentations of GI dysmotility issues among critically ill patients include: (1) high gastric residual volumes, acid reflux, and vomiting, (2) abdominal distention, and (3) diarrhea. In this review, we discuss the differential diagnosis for intensive care unit patients with symptoms and signs concerning GI motility issues. There are many myths and longstanding misconceptions about the diagnosis and management of GI dysmotility in critical illness. Here, we uncover these myths and discuss relevant evidence in each subject area, with the goal of re-conceptualizing GI motility disorders in critical care and providing evidence-based recommendations for clinical care.

Prevalence and risk factors of enteral nutrition intolerance in intensive care unit patients: a retrospective study

BACKGROUND

Feeding intolerance (FI) among intensive care unit (ICU) patients undergoing early continuous enteral nutrition (EN) is related to poor outcomes. This study aimed to explore the prevalence and risk factors of FI in ICU patients.

METHODS

We retrospectively enrolled 1057 patients who received early continuous EN via a nasogastric tube between January 2014 and August 2019. The prevalence of FI during the first 7 days of ICU stay was calculated, and the risk factors were investigated using multivariate logistic regression analysis.

RESULTS

The prevalence of FI during the first 7 days of ICU stay was 10.95%. FI occurred in 159 of 1057 (15.04%) patients on ICU day 2, 114 of 977 (11.67%) patients on ICU day 3, and 86 of 715 (12.03%) patients on ICU day 7. Mechanical ventilation (MV) (odds ratio [OR]: 1.928, 95% confidence interval [CI]: 1.064-3.493, P  = 0.03) was an independent risk factor for FI defined by a gastric residual volume (GRV) of 200 mL and/or vomiting, and acute renal failure (OR: 3.445, 95% CI: 1.115-10.707, P  = 0.032) was an independent risk factor of FI defined by a GRV of 500 mL and/or vomiting. Continuous renal replacement therapy (CRRT) was an independent predictor regardless of the FI defined by a GRV of 200 mL (OR: 2.064, 95% CI: 1.233-3.456, P  = 0.006) or 500 mL (OR: 6.199, 95% CI: 2.108-18.228, P  = 0.001) in the ICU patients.

CONCLUSIONS

FI occurs frequently in early ICU days, especially in patients receiving MV and CRRT. However, further investigation of a consensus definition of FI and risk factors is still warranted in future studies.

Point-of-Care Gastric Ultrasound Confirms the Inaccuracy of Gastric Residual Volume Measurement by Aspiration in Critically Ill Children: GastriPed Study

Introduction

No consensus exists on how to define enteral nutrition tolerance in critically ill children, and the relevance of gastric residual volume (GRV) is currently debated. The use of point-of-care ultrasound (POCUS) is increasing among pediatric intensivists, and gastric POCUS may offer a new bedside tool to assess feeding tolerance and pre-procedural status of the stomach content.

Materials and Methods

A prospective observational study was conducted in a tertiary pediatric intensive care unit. Children on mechanical ventilation and enteral nutrition were included. Gastric POCUS was performed to assess gastric contents (empty, full of liquids or solids), and gastric volume was calculated as per the Spencer formula. Then, GRV was aspirated and measured. The second set of gastric POCUS measurements was performed, similarly to the first one performed prior to GRV measurement. The ability of GRV measurement to empty the stomach was compared to POCUS findings. Both GRV and POCUS gastric volumes were compared with any clinical signs of enteral feeding intolerance (vomiting).

Results

Data from 64 children were analyzed. Gastric volumes were decreased between the POCUS measurements performed pre- and post-GRV aspiration [full stomach, n = 59 (92.2%) decreased to n = 46 (71.9%), p =0.001; gastric volume: 3.18 (2.40-4.60) ml/kg decreased to 2.65 (1.57-3.57), p < 0.001]. However, the stomach was not empty after GRV aspiration in 46/64 (71.9%) of the children. There was no association between signs of enteral feeding intolerance and the GRV obtained, nor with gastric volume measured with POCUS.

Discussion

Gastric residual volume aspiration failed to empty the stomach and appeared unreliable as a measure of gastric emptiness. Gastric POCUS needs further evaluation to confirm its role.

Monitoring of gastric residual volume during enteral nutrition

BACKGROUND

The main goal of enteral nutrition (EN) is to manage malnutrition in order to improve clinical outcomes. However, EN may increase the risks of vomiting or aspiration pneumonia during gastrointestinal dysfunction. Consequently, monitoring of gastric residual volume (GRV), that is, to measure GRV periodically and modulate the speed of enteral feeding according to GRV, has been recommended as a management goal in many intensive care units. Yet, there is a lack of robust evidence that GRV monitoring reduces the level of complications during EN. The best protocol of GRV monitoring is currently unknown, and thus the precise efficacy and safety profiles of GRV monitoring remain to be ascertained.

OBJECTIVES

To investigate the efficacy and safety of GRV monitoring during EN.

SEARCH METHODS

We searched electronic databases including CENTRAL, MEDLINE, Embase, and CINAHL for relevant studies on 3 May 2021. We also checked reference lists of included studies for additional information and contacted experts in the field.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), randomized cross-over trials, and cluster-RCTs investigating the effects of GRV monitoring during EN. We imposed no restrictions on the language of publication.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for eligible studies and extracted trial-level information from each included study, including methodology and design, characteristics of study participants, interventions, and outcome measures. We assessed risk of bias for each study using Cochrane's risk of bias tool. We followed guidance from the GRADE framework to assess the overall certainty of evidence across outcomes. We used a random-effects analytical model to perform quantitative synthesis of the evidence. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous and mean difference (MD) with 95% CIs for continuous outcomes.

MAIN RESULTS

We included eight studies involving 1585 participants. All studies were RCTs conducted in ICU settings. Two studies (417 participants) compared less-frequent (less than eight hours) monitoring of GRV against a regimen of more-frequent (eight hours or greater) monitoring. The evidence is very uncertain about the effect of frequent monitoring of GRV on mortality rate (RR 0.91, 95% CI 0.60 to 1.37; I² = 8%; very low-certainty evidence), incidence of pneumonia (RR 1.08, 95% CI 0.64 to 1.83; heterogeneity not applicable; very low-certainty evidence), length of hospital stay (MD 2.00 days, 95% CI -2.15 to 6.15; heterogeneity not applicable; very low-certainty evidence), and incidence of vomiting (RR 0.14, 95% CI 0.02 to 1.09; heterogeneity not applicable; very low-certainty evidence). Two studies (500 participants) compared no GRV monitoring with frequent (12 hours or less) monitoring. Similarly, the evidence is very uncertain about the effect of no monitoring of GRV on mortality rate (RR 0.87, 95% CI 0.62 to 1.23; I² = 51%; very low-certainty evidence), incidence of pneumonia (RR 0.70, 95% CI 0.43 to 1.13; heterogeneity not applicable; very low-certainty evidence), length of hospital stay (MD -1.53 days, 95% CI -4.47 to 1.40; I² = 0%; very low-certainty evidence), and incidence of vomiting (RR 1.47, 95% CI 1.13 to 1.93; I² = 0%; very low-certainty evidence). One study (322 participants) assessed the impact of GRV threshold (500 mL per six hours) on clinical outcomes. The evidence is very uncertain about the effect of the threshold for GRV at time of aspiration on mortality rate (RR 1.01, 95% CI 0.74 to 1.38; heterogeneity not applicable; very low-certainty evidence), incidence of pneumonia (RR 1.03, 95% CI 0.72 to 1.46; heterogeneity not applicable; very low-certainty evidence), and length of hospital stay (MD -0.90 days, 95% CI -2.60 to 4.40; heterogeneity not applicable; very low-certainty evidence). Two studies (140 participants) explored the effects of returning or discarding the aspirated/drained GRV. The evidence is uncertain about the effect of discarding or returning the aspirated/drained GRV on the incidence of vomiting (RR 1.00, 95% CI 0.06 to 15.63; heterogeneity not applicable; very low-certainty evidence) and volume aspirated from the stomach (MD -7.30 mL, 95% CI -26.67 to 12.06, I² = 0%; very low-certainty evidence) We found no studies comparing the effects of protocol-based EN strategies that included GRV-related criteria against strategies that did not include such criteria.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effect of GRV on clinical outcomes including mortality, pneumonia, vomiting, and length of hospital stay.

Can they stomach it? Parent and practitioner acceptability of a trial comparing gastric residual volume measurement versus no gastric residual volume in UK NNU and PICUs: a feasibility study

BACKGROUND

Routine measurement of gastric residual volume (GRV) to guide feeding in neonatal and paediatric intensive care is widespread. However, this practice is not evidence based and may cause harm. As part of a feasibility study, we explored parent and practitioner views on the acceptability of a trial comparing GRV measurement or no GRV measurement.

METHODS

A mixed-methods study involving interviews and focus groups with practitioners and interviews with parents with experience of tube feeding in neonatal and/or paediatric intensive care. A voting system recorded closed question responses during practitioner data collection, enabling the collection of quantitative and qualitative data. Data were analysed using thematic analysis and descriptive statistics.

RESULTS

We interviewed 31 parents and nine practitioners and ran five practitioner focus groups (n=42). Participants described how the research question was logical, and the intervention would not be invasive and potential benefits of not withholding the child's feeds. However, both groups held concerns about the potential risk of not measuring GRV, including delayed diagnosis of infection and gut problems, increased risk of vomiting into lungs and causing discomfort or pain. Parent's views on GRV measurement and consent decision making were influenced by their views on the importance of feeding in the ICU, their child's prognosis and associated comorbidities or complications.

CONCLUSIONS

The majority of parents and practitioners viewed the proposed trial as acceptable. Potential concerns and preferences were identified that will need careful consideration to inform the development of the proposed trial protocol and staff training.

Small-bore feeding tube versus large-bore sump tube for early enteral nutrition in mechanically ventilated patients: A nationwide inpatient database study

BACKGROUND & AIMS

When physicians start nasogastric tube feeding in mechanically ventilated patients, they have two choices of feeding tube device: a large-bore sump tube or a small-bore feeding tube. Some physicians may prefer to initiate enteral nutrition via the large-bore sump tube that is already in place, and others may prefer to use the small-bore feeding tube. However, it remains unknown whether small-bore feeding tubes or large-bore sump tubes are better for early enteral nutrition. The present study aimed to compare outcomes between these two types of feeding tubes in mechanically ventilated patients.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018, we identified adult patients who underwent invasive mechanical ventilation for ≥2 days in intensive care units and received nasogastric tube feeding within 2 days of starting mechanical ventilation. We categorized these patients as receiving early enteral nutrition via small-bore feeding tube (8- to 12-Fr single-lumen tubes) or via large-bore sump tube. Propensity score-matched analyses were performed to compare 28-day in-hospital mortality and hospital-acquired pneumonia between the two groups.

RESULTS

A total of 79,656 patients were included. Of these patients, 20,178 (25%) were in the small-bore feeding tube group. One-to-one propensity score matching created 20,061 matched pairs. Compared with those in the large-bore sump tube group, patients in the small-bore feeding tube group had significantly higher 28-day in-hospital mortality (17.0% versus 15.6%; hazard ratio, 1.08; 95% confidence interval, 1.03 to 1.14) and a significantly higher prevalence of hospital-acquired pneumonia (9.3% versus 8.5%; odds ratio, 1.11; 95% confidence interval, 1.02 to 1.21).

CONCLUSIONS

This nationwide observational study suggests that small-bore feeding tubes may not be associated with better clinical outcomes but rather with increased mortality and hospital-acquired pneumonia. Because of the uncertainty regarding the mechanism of our findings, further studies are warranted.

Gastric Residual to Predict Necrotizing Enterocolitis in Preterm Piglets As Models for Infants

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious intestinal inflammatory disease in preterm infants. High volume of gastric residual (GR) after oral feedings is often used as a predictor of NEC, but evidence is limited. Using NEC-sensitive preterm piglets as models, we hypothesized that GR mass and related plasma biomarkers predict early onset of NEC.

METHODS

In total, 258 newborn preterm piglets were fed bovine milk-based formulas for 5 days. At euthanasia, the stomach, small intestine, and colon were evaluated for NEC lesions. Mass, acidity, gastrin, and bile acid levels were determined for GR content, together with gastrin, glucagon-like peptide 2 (GLP-2), and gastric inhibitory polypeptide (GIP) levels in plasma.

RESULTS

In total, 48% of piglets had NEC lesions in the small intestine and/or colon. These piglets had higher GR mass (+32%, P < 0.001) and lower gastric bile acid concentrations (-22%, P < 0.05) than piglets without NEC lesions. The positive and negative predictive values for these markers were 34%-61%. Gastric acidity, gastrin, GLP-2, and GIP levels were similar for piglets with and without NEC lesions.

CONCLUSION

Elevated GR mass correlates positively with NEC lesions but may be a poor predictor of NEC, even when combined with other biomarkers. More knowledge about gastric emptying and gut transit in preterm neonates is required to understand how GR volume and composition relate to morbidities, such as NEC, in preterm neonates.

Do we control gastric residuals unnecessarily in premature newborns? AGRA study: avoidance of gastric residual aspiration

Aspiration and evaluation of gastric residuals are commonly performed interventions before each feeding in intensive care units, especially in very low birthweight infants. However, there is no sufficient evidence about the necessity of routine gastric residual aspiration. In this study, we aimed to investigate the time to full enteral intake and the incidence of necrotizing enterocolitis (NEC) in preterm infants in the period with gastric residual aspiration performed before each feeding, and those in the period without gastric residual aspiration.

Methods

Preterm infants with a gestational week ≤33 were included in the study. The group with gastric residual control before each feeding consisted of 169 infants, and the group without routine gastric residual aspiration included 122 infants.

Results

The mean gestational week was 30.37±2.58 and 29.31±3.37 in the group with gastric residual control and in the group without routine residual control, respectively (p<0.05). Birth weight, male gender, and mode of delivery were similar between both groups. The time to full enteral intake was shorter in the group without routine residual control (p<0.05). Total durations of parenteral nutrition, ≥grade 2 NEC, weight at discharge and duration of hospitalization were similar between the groups. Duration of invasive mechanical ventilator support was shorter in the group without routine residual control.

Conclusion

Avoidance of routine gastric residual aspiration in preterm infants shortens the time to full enteral intake without increasing the incidence of NEC.

Effect of Gastric Residual Evaluation on Enteral Intake in Extremely Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Evaluating prefeed gastric residuals is considered routine care but has little supporting evidence.

OBJECTIVE

To determine the effect of omitting prefeed gastric residual evaluation on nutritional outcomes in extremely preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

This single-center randomized clinical trial compared the omission of gastric residual evaluation with prefeed gastric residual evaluation. Infants were recruited from a level 4 neonatal intensive care unit and were enrolled from October 17, 2013, to October 8, 2016, and then followed up for 6 weeks after birth. Eligible participants were infants born at 32 or fewer weeks' gestation with a birth weight of 1250 g or less; they were enrolled within 72 hours after birth and within 24 hours after feeding initiation. All participants (N = 143) were included in the modified intent-to-treat analysis, which was conducted from March to July 2018.

INTERVENTIONS

The residual group underwent prefeed gastric residual evaluation; the no residual group did not. Feeding decisions were made according to nutritional guidelines, and infants received only human milk.

MAIN OUTCOMES AND MEASURES

The primary outcome was weekly enteral nutrition intake in mL/kg for 6 weeks after birth.

RESULTS

Of 143 infants, 74 (51.7%) were randomized to undergo gastric residual evaluation (residual group) and 69 (48.3%) to omitted gastric residual evaluation (no residual group). The residual group comprised an even number of male and female infants (37 [50.0%]) with a mean (SD) gestational age of 27.1 (2.4) weeks and a mean (SD) birth weight of 888.8 (206.6) grams, whereas the no residual group had more male infants (36 [52.17%]), a mean (SD) gestational age of 27 (1.2) weeks, and a mean (SD) birth weight of 915.2 (180) grams. The no residual group had feedings that advanced more quickly compared with the residual group (mean weekly increase, 20.7 mL/kg/d vs 17.9 mL/kg/d; P = .02) and consumed more feedings at weeks 5 (137.2 [95% CI, 128.6-145.8]; P = .03) and 6 (141.6 [95% CI, 133.2-150.0]; P = .03). Among the secondary outcomes, the no residual group had higher mean estimated log weights (7.01 [95% CI, 6.99-7.02] vs 6.98 [95% CI, 6.97-7.00]; P = .03), had fewer episodes of abdominal distention (0.59 [95% CI, 0.34-1.01] vs 1.79 [95% CI, 1.27-2.53]; P = .001), and were discharged 8 days earlier (4.21 [95% CI, 4.14-4.28] vs 4.28 [95% CI, 4.19-4.36]; P = .01). Odds for necrotizing enterocolitis (0.058 [95% CI, 0.018-0.190] vs 0.026 [95% CI, 0.006-0.109]), death (0.004 [95% CI, 0.0003-0.046] vs 0.012 [95% CI, 0.001-0.131]), late-onset sepsis (0.970 [95% CI, 0.67-1.40] vs 1.38 [95% CI, 0.97-1.94]), and ventilator-associated pneumonia (0.084 [95% CI, 0.033-0.214] vs 0.056 [95% CI, 0.019-0.168]) were similar between groups.

CONCLUSIONS AND RELEVANCE

Among extremely preterm infants, the omission of gastric residual evaluation increased the delivery of enteral nutrition as well as improved weight gain and led to earlier hospital discharge; these results may translate into evidence-based practice.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01863043.

Gastric Residual Volume in Feeding Advancement in Preterm Infants (GRIP Study): A Randomized Trial

OBJECTIVE

To evaluate the effect of not relying on prefeeding gastric residual volumes to guide feeding advancement on the time to reach full feeding volumes in preterm infants, compared with routine measurement of gastric residual volumes. We hypothesized that not measuring prefeeding gastric residual volumes can shorten the time to reach full feeds.

STUDY DESIGN

In this single-center, randomized, controlled trial, we included gavage fed preterm infants with birth weights (BW) 1500-2000 g who were enrolled within 48 hours of birth. Exclusion criteria were major congenital malformations, asphyxia, and BW below the third percentile. In the study group, the gastric residual volume was measured only in the presence of bloody aspirates, vomiting, or an abnormal abdominal examination. In the control group, gastric residual volume was assessed routinely, and feeding advancement was based on the gastric residual volume. The primary outcome was the time to reach feeding volumes of 120 mL/kg per day. Secondary outcomes were time to regain BW, episodes of feeding interruptions, sepsis, and necrotizing enterocolitis.

RESULTS

Eighty-seven infants were enrolled. There were no differences between the study and control groups with respect to time to reach full feeds (6 days [95% CI, 5.5-6.5] vs 5 days [95% CI, 4.5-5.5]; P = .82), time to regain BW, episodes of feeding interruptions, or sepsis. Two infants in the control group developed necrotizing enterocolitis.

CONCLUSIONS

Avoiding routine assessment of gastric residual volume before feeding advancement did not shorten the time to reach full feeds in preterm infants with BW between 1500 and 2000 g.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01337622.

Gastric Residual Volumes Versus Abdominal Girth Measurement in Assessment of Feed Tolerance in Preterm Neonates: A Randomized Controlled Trial

BACKGROUND

Preterm neonates often have feed intolerance that needs to be differentiated from necrotizing enterocolitis. Gastric residual volumes (GRV) are used to assess feed tolerance but with little scientific basis.

PURPOSE

To compare prefeed aspiration for GRV and prefeed measurement of abdominal girth (AG) in the time taken to reach full feeds in preterm infants.

METHODS

This was a randomized controlled trial. Infants with a gestational age of 27 to 37 weeks and birth weight of 750 to 2000 g, who required gavage feeds for at least 48 hours, were included. Infants were randomized into 2 groups: infants in the AG group had only prefeed AG measured. Those in the GRV group had prefeed gastric aspiration obtained for the assessment of GRV. The primary outcome was time to reach full enteral feeds at 150 mL/kg/d, tolerated for at least 24 hours. Secondary outcomes were duration of hospital stay, need for parenteral nutrition, episodes of feed intolerance, number of feeds withheld, and sepsis.

RESULTS

Infants in the AG group reached full feeds earlier than infants in the GRV group (6 vs 9.5 days; P = .04). No significant differences were found between the 2 groups with regard to secondary outcomes.

IMPLICATIONS FOR PRACTICE

Our research suggests that measurement of AG without assessment of GRV enables preterm neonates to reach full feeds faster than checking for GRV.

IMPLICATIONS FOR RESEARCH

Abdominal girth measurement as a marker for feed tolerance needs to be studied in infants less than 750 g and less than 26 weeks of gestation.

Comparison of Two Different Methods for the Measurement of Gastric Residual Volume

The objective of this study was to determine the difference between gastric residual volume measurements without giving air compared to giving 30 ml of air via the feeding tube. This experimental study was on 60 subjects fed enterally at a university hospital. Data collection was with the 12-item "Gastric Residual Volume Measurement Instructions" and "Gastric Residual Volume Observation Form." The same subjects composed experimental and control groups. Gastric residual volume measurements were taken before feedings at 10:00 a.m., 1:00 p.m., and 4:00 p.m. with a 60-ml syringe. First measurement was taken without giving air by withdrawing the syringe piston at 2-3 ml/second. Second measurement was applied by giving 30 ml of air and withdrawing the piston at the same speed. Student's t test was used for data analysis. A total of 180 measurements were made for each method. Gastric residual volume averages were 3.71 ± 7.97 ml without air and 3.78 ± 8.08 ml with air. The difference between averages was statistically significant (p < .05). Difficulties withdrawing the syringe piston without giving air occurred in 85% of the intermittently enterally fed patients and 22.8% of those fed continuously. Gastric residual volume measurements with air were higher than those without air. The aspiration procedure with air was easier. Gastric residual volume measurements should be made with 30 ml of air and by withdrawing the syringe piston at 2-3 ml/minute.

Comparison of Two Different Enteral Nutrition Protocol in Critically Ill Patients

OBJECTIVE

In this study, two enteral nutrition protocols with different gastric residual volumes (GRVs) and different monitoring intervals were compared with respect to gastrointestinal intolerance findings in intensive care unit (ICU) patients.

METHODS

The study was carried out prospectively in 60 patients in the anaesthesiology and reanimation ICU under mechanical ventilation support, who were scheduled to take enteral feeding. Patients were sequentially divided into two groups: Group 1, GRV threshold of 100 mL, and monitoring interval of 4 hours, and Group 2, GRV threshold of 200 mL, monitoring interval of 8 hours. To test the significant difference between the groups, Student's t test, chi-square text and Fisher exact test were used.

RESULTS

In Group 1, 3.3% vomiting, 6.6% diarrhoea was observed; in Group 2, 16.6% vomiting, 10% diarrhoea. In terms of total intolerance (vomiting and/or diarrhoea) of the two groups, the incidence was significantly higher in Group 2 (33.3%) than in Group 1 (10%) (p=0.02).

CONCLUSION

According to the results of the study, a lower gastrointestinal intolerance rate was detected in the GRV threshold 100 mL, monitoring interval for 4 hours protocol (Group 1) than in GRV threshold 200 mL, monitoring interval for 8 hours protocol (Group 2); Group 1 may be preferred renovation.

Evaluation of the effect on patient parameters of not monitoring gastric residual volume in intensive care patients on a mechanical ventilator receiving enteral feeding: A randomized clinical trial

PURPOSE

This study aimed to evaluate the effects of not measuring gastric residual volume (GRV) in intensive care patients on a mechanical ventilator and receiving enteral feeding on the feeding intolerance, gastroesophageal reflux (GER) risk, and nutritional adequacy.

METHODS

This randomized clinical study was performed in 2 medical intensive care units of 2 university hospitals in Ankara, Turkey. The patients were randomized into 2 groups. In the group with GRV monitoring, GRV was measured 3 times a day, and the GRV threshold was accepted as 250 mL. In addition, 24-hour pH monitoring was used in this group to assess the risk of GER. In the group without GRV monitoring, GRV was not measured. The patients were followed-up for 5 days.

RESULTS

The feeding targets were reached more quickly in the group without GRV monitoring (n = 26) with no increase in the complication rate (P < .05). No significant relationship was found between GRV and GER in the group with GRV monitoring (n = 25) (P > .05).

CONCLUSION

The discrepancies in GRV measurement make it unreliable for monitoring feeding intolerance and GER. The use of GRV measurements may therefore be discontinued as part of the standard care protocol in medical intensive care units.

A breath of fresh air: a quality-improvement study comparing an air-circulating technique versus conventional technique to prevent nasogastric tube dysfunction

Background

Nasogastric tubes are an important component of care in patients with gastrointestinal obstructions. However, they are prone to malfunction despite conventional flushing techniques, with potentially severe consequences. There is no widely accepted, gold-standard way to ensure that a nasogastric tube succeeds in maintaining an empty stomach following flushing.

Methods

We have developed a flushing technique to better ensure successful tube function. We compared this technique to conventional flushing both in vitro (using a plastic stomach model) and in vivo (in a pig model), and we provide a didactic video.

Results

The mean gastric residual volume following our novel flushing technique is nearly 25-fold lower than following conventional flushing (13 mL vs. 330 mL).

Conclusions

Our simple technique is more effective than conventional techniques in maintaining nasogastric tube function and therefore should prevent dangerous vomiting and aspiration pneumonia better than conventional techniques.

Gastric Dysmotility in Critically Ill Children: Pathophysiology, Diagnosis, and Management

OBJECTIVE

We aimed to review gastric dysmotility in critically ill children: 1) its pathophysiology, with a focus on critical care diseases and therapies that affect gastric motility, 2) diagnostic methodologies, and 3) current and future potential therapies.

DATA SOURCES

Eligible studies were identified from PubMed and MEDLINE.

STUDY SELECTION

Literature search included the following key terms: "gastric emptying," "gastric motility/dysmotility," "gastrointestinal motility/dysmotility," "nutrition intolerance," and "gastric residual volume."

DATA EXTRACTION

Studies since 1995 were extracted and reviewed for inclusion by the authors related to the physiology, pathophysiology, diagnostic methodologies, and available therapies for gastric emptying.

DATA SYNTHESIS

Delayed gastric emptying, a common presentation of gastric dysmotility, is present in up to 50% of critically ill children. It is associated with the potential for aspiration, ventilator-associated pneumonia, and inadequate delivery of enteral nutrition and may affect the efficacy of enteral medications, all of which may be result in poor patient outcomes. Gastric motility is affected by critical illness and its associated therapies. Currently available diagnostic tools to identify gastric emptying at the bedside have not been systematically studied and applied in this cohort. Gastric residual volume measurement, used as an indirect marker of delayed gastric emptying in PICUs around the world, may be inaccurate.

CONCLUSIONS

Gastric dysmotility is common in critically ill children and impacts patient safety and outcomes. However, it is poorly understood, inadequately defined, and current therapies are limited and based on scant evidence. Understanding gastric motility and developing accurate bedside measures and novel therapies for gastric emptying are highly desirable and need to be further investigated.

Aspiration and evaluation of gastric residuals in the neonatal intensive care unit: state of the science

The routine aspiration of gastric residuals (GR) is considered standard care for critically ill infants in the neonatal intensive care unit (NICU). Unfortunately, scant information exists regarding the risks and benefits associated with this common procedure. This article provides the state of the science regarding what is known about the routine aspiration and evaluation of GRs in the NICU focusing on the following issues: (1) the use of GRs for verification of feeding tube placement, (2) GRs as an indicator of gastric contents, (3) GRs as an indicator of feeding intolerance or necrotizing enterocolitis, (4) the association between GR volume and ventilator-associated pneumonia, (5) whether GRs should be discarded or refed, (6) the definition of an abnormal GR, and (7) the potential risks associated with aspiration and evaluation of GRs. Recommendations for further research and practice guidelines are also provided.

Gastric residual volume in critically ill patients: a dead marker or still alive?

Early enteral nutrition (EN) is consistently recommended as first-line nutrition therapy in critically ill patients since it favorably alters outcome, providing both nutrition and nonnutrition benefits. However, critically ill patients receiving mechanical ventilation are at risk for regurgitation, pulmonary aspiration, and eventually ventilator-associated pneumonia (VAP). EN may increase these risks when gastrointestinal (GI) dysfunction is present. Gastric residual volume (GRV) is considered a surrogate parameter of GI dysfunction during the progression of enteral feeding in the early phase of critical illness and beyond. By monitoring GRV, clinicians may detect patients with delayed gastric emptying earlier and intervene with strategies that minimize or prevent VAP as one of the major risks of EN. The value of periodic GRV measurements with regard to risk reduction of VAP incidence has frequently been questioned in the past years. Increasing the GRV threshold before interrupting gastric feeding results in marginal increases in EN delivery. More recently, a large randomized clinical trial revealed that abandoning GRV monitoring did not negatively affect clinical outcomes (including VAP) in mechanically ventilated patients. The results have revived the discussion on the role of GRV monitoring in critically ill, mechanically ventilated patients receiving early EN. This review summarizes the most recent clinical evidence on the use of GRV monitoring in critically ill patients. Based on the clinical evidence, it discusses the pros and cons and further addresses whether GRV is a dead marker or still alive for the nutrition management of critically ill patients.

Gastric residual evaluation in preterm neonates: a useful monitoring technique or a hindrance?

It is routine practice in most neonatal intensive care units to measure the volume and color of gastric residuals (GRs) prior to enteral bolus feedings in preterm very low birth weight infants. However, there is paucity of evidence supporting the routine use of this technique. Moreover, owing to the lack of uniform standards in the management of GRs, wide variations exist as to what constitutes significant GR volume, the importance of GR color and frequency of GR evaluation, and the color or volume standards that dictate discarding or returning GRs. The presence of large GR volumes or green-colored residuals prior to feeding often prompts subsequent feedings to be withheld or reduced because of possible necrotizing enterocolitis resulting in delays in enteral feeding. Cessation or delays in enteral feeding may result in extrauterine growth restriction, a known risk factor for poor neurodevelopmental and growth outcomes in preterm very low birth weight infants. Although some neonatal intensive care units are abandoning the practice of routine GR evaluation, little evidence exists to support the discontinuation or continuation of this practice. This review summarizes the current state of GR evaluation and underlines the need for a scientific basis to either support or refute the routine evaluation of GRs.

Current issues on safety of prokinetics in critically ill patients with feed intolerance

Feed intolerance in the setting of critical illness should be treated promptly given its adverse impact on morbidity and mortality. The technical difficulty of postpyloric feeding tube placement and the morbidities associated with parenteral nutrition prevent these approaches being considered as first-line nutrition. Prokinetic agents are currently the mainstay of therapy for feed intolerance in the critically ill. Current information is limited but suggests that erythromycin or metoclopramide (alone or in combination) are effective in the management of feed intolerance in the critically ill and not associated with significant cardiac, haemodynamic or neurological adverse effects. However, diarrhoea is a very common gastrointestinal side effect, and can occur in up to 49% of patients who receive both erythromycin and metoclopramide. Fortunately, the diarrhoea associated with prokinetic treatments has not been linked to Clostridium difficile infection and settles soon after the drugs are ceased. Therefore, prolonged or prophylactic use of prokinetics should be avoided. If diarrhoea occurs, the drugs should be stopped immediately. To minimize avoidable adverse effects the ongoing need for prokinetic drugs in these patient should be reviewed daily.

Examination of accuracy in the assessment of gastric residual volume: a simulated, controlled study

BACKGROUND

Increased gastric content from enteral nutrition intolerance is thought to place patients at risk for pulmonary aspiration. Although considered a questionable practice, blind gastric tube aspiration is the most common approach to measure gastric content. This simulated study evaluated the accuracy of residual volume (RV) assessment via tube aspirations made from known volumes by controlling the syringe pull technique, feeding tube properties, fluid viscosity, and placement of tubes in the fluid.

MATERIALS AND METHODS

This study was conducted in a metrology laboratory. Aspirates were obtained using a force measurement test system to control force of the syringe pull technique using 3 different procedures (slow 10 inches per minute [ipm], intermittent 10 ipm, and fast 40 ipm). Four different feeding tubes, 10 Fr and 18 Fr, each made of polyurethane and polyvinyl chloride, were placed in varying depths of 100 mL of either water or formula. The effect of fluid viscosity was also examined.

RESULTS

Overall, 108 RVs were analyzed using a force measurement test system. Actual content of RV was underestimated 19% on average and varied across tube size and viscosity. Intermittent and slow syringe pull techniques yielded greater aspirate quantities, although neither technique aspirated the full amount of volume available. The 10 Fr feeding tubes yielded larger RVs in more viscous fluid, yet the 18 Fr tubes performed better with fluids of lower viscosity.

CONCLUSIONS

Based on this simulation, RV assessment does not accurately reflect the total volume of the contents available and, therefore, the clinical utility of this assessment should be further investigated.

Use of gastric residual volume to guide enteral nutrition in critically ill patients: a brief systematic review of clinical studies

OBJECTIVE

In critically ill patients, the optimal procedure to monitor upper gastrointestinal function is controversial. Several authors have proposed gastric residual volume (GRV) as a tool to guide enteral nutrition. The aim of this contribution is to briefly discuss corresponding studies.

METHODS

We electronically searched MEDLINE, EMBASE, and CINAHL for studies relevant to the subject.

RESULTS

Six randomized controlled trials (RCTs) and six prospective observational studies were identified. Each analyzed different thresholds of GRV to guide enteral nutrition and to avoid complications (e.g., vomiting, aspiration, nosocomial pneumonia) in artificially ventilated patients. Due to heterogeneity in outcome measures, patient populations, type and diameter of feeding tubes, and randomization procedures, combination of the results of the six RCTs into a meta-analysis was not appropriate. High-quality RCTs studying medical patients could not demonstrate an association between complication rate and the magnitude of GRV. The only observational study that adjusted results to potential confounders and that studied surgical patients found, however, that the frequency of aspiration increased significantly if a GRV > 200 mL was registered more than once.

CONCLUSION

For mechanically ventilated patients with a medical diagnosis at admission to the intensive care unit, monitoring of GRV appears unnecessary to guide nutrition. Surgical patients might profit, however, from a low GRV threshold (200 mL).

Comparison of postpyloric tube feeding and gastric tube feeding in intensive care unit patients: a meta-analysis

BACKGROUND AND OBJECTIVE

Enteral feeding is vital in the critical care setting; however, the optimal route of enteral feeding (postpyloric vs gastric feeding) remains debated. We aimed to systematically review the current evidence to see whether postpyloric feeding could provide additional benefits to intensive care unit (ICU) patients.

METHOD

Randomized controlled trials (RCTs) comparing the efficacy and safety of postpyloric feeding vs gastric feeding were included in our systematic review. Odds ratio (OR) was used for binary outcome data and weighted mean difference (WMD) was used for continuous outcome data. Summary effects were pooled using a fixed or random effects model as appropriate.

RESULTS

Seventeen RCTs were included in our meta-analysis. Postpyloric tube feeding could deliver higher proportions of estimated energy requirement (WMD, 12%; 95% confidence interval [CI], 5%-18%) and reduce the gastric residual volume (GRV) (WMD, -169.1 mL; 95% CI, -291.995 to -46.196 mL). However, the meta-analysis failed to demonstrate any benefits to critically ill patients with postpyloric tube feeding in terms of mortality (OR, 1.05; 95% CI, 0.77-1.44), new-onset pneumonia (OR, 0.77; 95% CI, 0.53-1.13), and aspiration (OR, 1.20; 95% CI, 0.64-2.25). There was no significant publication bias as represented by an Egger's bias coefficient of 0.21 (95% CI, -1.01 to 1.43; P = .7).

CONCLUSION

As compared with gastric feeding, postpyloric feeding is able to deliver higher proportions of the estimated energy requirement and can help reduce the GRV.

Nasogastric tube feedings and gastric residual volume: a regional survey

OBJECTIVES

To maintain adequate nutrition for patients who are in need, enteral feeding via nasogastric tube (NGT) is necessary. Although the literature suggests the safety of continued NGT feeding at a gastric residual volume of <400 mL, inconsistencies in withholding tube feeding based on residual volume have been observed in clinical practice. We performed a regional survey to determine the range of current practice among nursing staff regarding the decision to withhold NGT feeding based on residual volume and the factors that influence the decision-making process.

METHODS

A questionnaire was designed to evaluate nursing practice patterns regarding the decision of withholding NGT feeding based on a certain residual volume, which was distributed to the nursing staff at all major hospitals in the Oklahoma City metropolitan area. Statistical analysis was done with the Fisher exact test. All of the statistical tests were carried out at α = 0.05.

RESULTS

A total of 582 nurses completed the survey. Residual volumes (milliliters) resulting in the termination of NGT feeding occurred in 89% of nurses at volumes <300 mL and only 3% of nurses at volumes >400 mL. Three main reasons for nurses to withhold NGT feeding were risk of aspiration (90%), potential feeding intolerance (81%), and risk of regurgitation (67%). Other less common concerns were abdominal distension and abdominal discomfort.

CONCLUSIONS

The decision of withholding NGT feeding varied among the nursing staff that were surveyed. A consensus is necessary for the standardization of withholding NGT feeding in clinical practice among nursing staff.

Monitoring for intolerance to gastric tube feedings: a national survey

BACKGROUND

Confusion about how to assess for intolerance to feedings often results in unnecessary feeding interruptions.

OBJECTIVES

To report findings from a national survey of methods used by critical care nurses to assess tolerance to gastric tube feedings and to discuss the findings in light of current enteral nutrition guidelines.

METHODS

A paper-and-pencil survey was mailed to 1909 members of the American Association of Critical-Care Nurses. In addition, the same survey was posted online in a newsletter circulated to association members. Results from both surveys were pooled for data analysis.

RESULTS

A total of 2298 responses were obtained; most respondents reported using a combination of methods to assess tolerance to gastric tube feedings (listening for bowel sounds, measuring gastric residual volumes, observing for abdominal distention/discomfort and for nausea and vomiting). More than 97% of the nurses reported measuring gastric residual volumes; the most frequently cited threshold levels for interrupting feedings were 200 mL and 250 mL. About 25% of the nurses reported interrupting feedings for gastric residual volumes of 150 mL or less; only 12.6% of the respondents reported allowing gastric residual volumes of up to 500 mL before interrupting feedings.

CONCLUSIONS

Practice among the 2298 critical care nurses varied widely. Many of the survey respondents are practicing in ways that can unnecessarily diminish the delivery of calories to patients. Protocols based on current enteral nutrition guidelines must be developed and implemented in practice settings.

Impact of disease severity on gastric residual volume in critical patients

AIM: To investigate whether illness severity has an impact on gastric residual volume (GRV) in medical critically ill patients.

METHODS: Medical intensive care unit (ICU) patients requiring nasogastric feeding were enrolled. Sequential Organ Failure Assessment (SOFA) score was assessed immediately preceding the start of the study. Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded on the first, fourth, seventh, and fourteenth day of the study period. GRV was measured every 4 h during enteral feeding. The relationship between mean daily GRV and SOFA scores and the correlation between mean daily GRV and mean APACHE II score of all patients were evaluated and compared.

RESULTS: Of the 61 patients, 43 patients were survivors and 18 patients were non-survivors. The mean daily GRV increased as SOFA scores increased (P < 0.001, analysis of variance). Mean APACHE II scores of all patients correlated with mean daily GRV (P = 0.011, Pearson correlation) during the study period. Patients with decreasing GRV in the first 2 d had better survival than patients without decreasing GRV (P = 0.017, log rank test).

CONCLUSION: GRV is higher in more severely ill medical ICU patients. Patients with decreasing GRV had lower ICU mortality than patients without decreasing GRV.

Jejunal tube placement in critically ill patients: A prospective, randomized trial comparing the endoscopic technique with the electromagnetically visualized method

OBJECTIVE

Head-to-head comparison of the success rate of jejunal placement of a new electromagnetically visualized jejunal tube with that of the endoscopic technique in critically ill patients.

DESIGN

: Prospective, randomized clinical trial.

SETTING

Two intensive care units at a university hospital.

PATIENTS

: A total of 66 critically ill patients not tolerating intragastric nutrition.

INTERVENTIONS

Patients were randomly assigned (2:1 ratio) to receive an electromagnetically visualized jejunal feeding tube or an endoscopically placed jejunal tube. The success rate of correct jejunal placement after 24 hrs was the main outcome parameter.

MEASUREMENTS AND MAIN RESULTS

The correct jejunal tube position was reached in 21 of 22 patients using the endoscopic technique and in 40 of 44 patients using the electromagnetically visualized jejunal tube (95% vs. 91%; relative risk 0.9524, confidence interval 0.804-1.127, p = .571). In the remaining four patients, successful endoscopic jejunal tube placement was performed subsequently. The implantation times, times in the right position, and occurrences of nose bleeding were not different between the two groups. The electromagnetically visualized technique resulted in the correct jejunal position more often at the first attempt. Factors associated with successful placement at the first attempt of the electromagnetically visualized jejunal tube seem to be a higher body mass index and absence of emesis. This trial is registered at ClinicalTrials.gov, number NCT00500851.

CONCLUSIONS

In a head-to-head comparison correct jejunal tube placement using the new electromagnetically visualized method was as fast, safe, and successful as the endoscopic method in a comparative intensive care unit patient population.

Gastric residual volumes in critical illness: what do they really mean?

The practice of measuring gastric residual volumes (GRVs) has become a routine part of enteral feeding protocols in the critical care setting. However, little scientific evidence indicates that their use improves patient outcomes. The use of GRVs is more of a tradition, which unfortunately guides the delivery of enteral nutrition (EN). The practice of GRVs is predicated on several flawed assumptions. Using GRVs in hospitalized patients assumes that the practice is well standardized, that GRVs reliably and accurately measure gastric contents, and that they sufficiently distinguish normal from abnormal emptying. The practice also assumes that GRVs are easy to interpret, that a tight correlation exists between GRVs and aspiration, and that continuing EN after a high value for GRV is obtained leads to pneumonia and adverse patient outcomes. And finally, clinicians assume that GRVs are an inexpensive "poor man's test" for determining tolerance of EN. This article reviews studies showing the fallacies of these assumptions. Although clinicians are unlikely to stop using GRVs, interpretation of these must be modified so as not to interrupt the delivery of EN. Using a protocol that directs appropriate responses to elevated GRVs should promote the delivery of EN and improve patient outcome.

An Update on Nutrition Support in the Critically Ill

Nutrition support in the critically ill patient has shifted from adjunctive toward fundamental therapy with the publication of high-grade evidence. Early enteral nutrition (EN) is recommended because it is associated with decreased infectious complications and use of EN is associated with decreased mortality and infections compared with parenteral nutrition (PN). EN is not without risks, such as diarrhea or aspiration, but use of prokinetic agents, head of bed elevation, and use of feeding protocols can maximize benefits and minimize risks. Although recently high-grade evidence on nutrition support in the critically ill population has been published, many controversies still exist. In obese patients, use of hypocaloric feedings with increased protein has been demonstrated to promote weight loss and improved glucose management. In nonobese patients, small studies have demonstrated that providing more than 70% or less than 30% of goal caloric intake may be associated with worse outcomes, but more studies are needed. Additional research is also needed to conclude whether withholding intravenous fat emulsions for the first 7 to 10 days of PN reduces infectious complications. Finally, more high-quality studies are needed to define the role of immune-enhancing nutrients such as arginine, glutamine, omega-3 fatty acids, zinc, and selenium.

The impact of enteral feeding protocols on nutritional support in critically ill children

BACKGROUND

Studies have shown that feeding protocols may assist in achieving optimal nutritional care in critically ill children. The present study aimed to assess the impact of enteral feeding protocols on nutritional support practices through a continuous auditing process over a defined period.

MATERIALS AND METHODS

A prospective audit on nutritional practice was initiated in 1994-1995 on all ventilated patients who were admitted for more than a complete 24-h period in the paediatric intensive care unit. The audit was repeated 1997-1998, 2001 and 2005. The collection of data on outcomes included the time taken to initiate nutritional support, the proportion of patients fed via the enteral versus parenteral route, and the proportion of children reaching 50% and 70% of the estimated average requirement (EAR) by day 3. Feeding algorithms and protocols were introduced after each audit with a view to improving practices.

RESULTS

Over the study period, time taken to initiate nutrition support was reduced from 15 h (1994-1995), 8 h (1997-1998), 5.5 h (2001) to 4.5 h (2005). The proportion of patients on parenteral feeds was reduced from 11% (1994-1995) to 4% (2005). An increase was also documented in the percentage of patients receiving a daily energy provision of 50% and 70% of the EAR by day 3 after the initiation of nutritional support (6% in 1994-1995 to 21% in 2005 for 70% of EAR).

CONCLUSION

The present study demonstrates that feeding protocols improve nutritional practices in a paediatric intensive care unit. However, protocol introduction needs to be monitored regularly through audit.

Impact of not measuring residual gastric volume in mechanically ventilated patients receiving early enteral feeding: a prospective before-after study

BACKGROUND

Monitoring of residual gastric volume (RGV) to prevent aspiration is standard practice in mechanically ventilated patients receiving early enteral nutrition (EN). No data are available to support a correlation between RGV and adverse event rates. We evaluated whether not measuring RGV affected EN delivery, vomiting, or risk of nosocomial pneumonia.

METHODS

Two hundred and five eligible patients with nasogastric feeding within 48 hours after intubation were included in a 7-day prospective before-after study. Continuous 24-hour nutrition was started at 25 mL/h then increased by 25 mL/h every 6 hours, to 85 mL/h. In both groups, intolerance was treated with erythromycin (250 mg IV/6 h) and a delivery rate decrease to the previously well-tolerated rate. RGV monitoring was used during the first study period (n = 102), but not during the subsequent intervention period (n = 103). Intolerance was defined as RGV >250 mL/6 h or vomiting in the standard-practice group and as vomiting in the intervention group.

RESULTS

Groups were similar for baseline characteristics. Median daily volume of enteral feeding was higher in the intervention group (1489; interquartile range [IQR], 1349-1647) than in the controls (1381; IQR, 1151-1591; P = .002). Intolerance occurred in 47 (46.1%) controls and 27 (26.2%) intervention patients (P = .004). The vomiting rate did not differ between controls and intervention group patients (24.5% vs 26.2%, respectively; P = .34), and neither was a difference found for ventilator-associated pneumonia (19.6% vs 18.4%; P = .86).

CONCLUSION

Early EN without RGV monitoring in mechanically ventilated patients improves the delivery of enteral feeding and may not increase vomiting or ventilator-associated pneumonia.

Methods for the assessment of gastric emptying in critically ill, enterally fed adults

Critically ill patients may experience delayed gastric emptying. Patients receiving enteral feeding are monitored closely to detect a delay of gastric emptying, assess feeding tolerance, and prevent aspiration pneumonia. The most common practice for assessing gastric emptying is to measure the aspirated gastric residual volume; however, this is an unreliable method that lacks standardization, fails to differentiate normal digestive secretions from enteral formula, and results in unnecessary interruptions of enteral nutrition. The aim of this review is to identify an alternative method to assess gastric emptying, which should be reliable, sensitive, harmless, feasible, and inexpensive. Several techniques are discussed: scintigraphy, paracetamol absorption test, breath tests, refractometry, ultrasound, and gastric impedance monitoring. Refractometry seems to be the most appropriate tool for the regular assessment of enteral nutrition; however, standardization and validation of this method are needed before it can be routinely used to monitor critically ill patients receiving enteral nutrition.