Gastric Residual Volume Measurement in U.K. PICUs: A Survey of Practice

Gastric residual volume monitoring practices in UK intensive care units: A web-based survey

Background and aim

Monitoring of gastric residual volume (GRV) to assess for enteral feeding intolerance is common practice in the intensive care unit (ICU) setting; however, evidence to support the practice is lacking. The aim of this study was: (i) to gain a perspective of current practice in adult ICUs in the UK around enteral feeding and monitoring of GRV, (ii) to characterise the threshold value used for a high GRV in clinical practice, (iii) to describe the impact of GRV monitoring on enteral feeding provision and (iv) to inform future research into the clinical value of GRV measurement in the adult ICU population.

Methods

A web-based survey was sent to all UK adult ICUs. The survey consisted of questions pertaining to (i) nutritional assessment and enteral feeding practices, (ii) enteral feeding intolerance and GRV monitoring and (iii) management of raised GRV.

Results

Responses were received from 101 units. Ninety-eight percent of units reported routinely measuring GRV, with 86% of ICUs using GRV to define enteral feeding intolerance. Threshold values for a high GRV varied from 200 to 1000 ml with frequency of measurement also differing greatly from 2 to 12 hourly. Initiation of pro-kinetic medication was the most common treatment for a high GRV. Fifty-two percent of respondents stated that volume of GRV would influence their decision to stop enteral feeds a lot or very much. Only 28% of units stated that they had guidelines for the technique for monitoring GRV.

Conclusions

Measurement of GRV is the most common method of determining enteral feeding intolerance in adult ICUs in the UK. The practice continues despite evidence of poor validity and reproducibility of this measurement. Further research should be undertaken into the benefit of ongoing GRV measurements in the adult ICU population and alternative markers of enteral feeding intolerance.

Is monitoring of gastric residual volume for critically ill patients with enteral nutrition necessary? A meta-analysis and systematic review

BACKGROUND

There are many controversies over the necessity of monitoring gastric residual volume in the nursing care of enteral nutrition. We aimed to conduct an updated meta-analysis to evaluate the effects of monitoring or not monitoring gastric residual volume on patients' outcomes and complications.

METHODS

We searched the Cochrane Library database to 15 April 2021 for randomized controlled trials (RCTs) on the effects of gastric residual volume and no gastric residual volume monitoring. Review Manager software was used for data analysis.

RESULTS

A total of seven RCTs involving 1240 enteral nutrition patients were included. Gastric residual volume monitoring was associated with reduced incidence of vomiting (OR2.33, 95% CI:1.68-3.24), whereas no gastric residual volume monitoring was associated with reduced incidence of unnecessary interruptions of enteral nutrition (OR0.38,95% CI:0.26-0.55). There were no significant differences on the incidence of abdominal distention (OR1.87, 95% CI:0.82-4.28), diarrhoea (OR1.03,95% CI:0.74-1.43), VAP (OR0.83, 95%CI:0.37-1.89), duration of mechanical ventilation (MD -0.06,95% CI:-1.22-1.10), length of ICU stay (MD -1.33, 95% CI:-3.58-0.91) and mortality (OR0.90,95% CI:0.61-1.34).

CONCLUSIONS

Not monitoring gastric residual volume is associated with reduced unnecessary interruptions of enteral nutrition related to inadequate feeding and increased risk of vomiting.

Optimizing enteral nutrition delivery by implementing volume-based feeding protocol for critically ill patients: an updated meta-analysis and systematic review

BACKGROUND

This study aims to provide an updated assessment of the efficacy of optimized enteral nutrition (EN) delivery by implementing the volume-based feeding (VBF) protocol in critically ill patients.

METHODS

We updated our previous literature retrieval with no language restrictions. The inclusion criteria were:1) Participants: Critically ill patients (Patients who was admitted in ICU; 2) Intervention: The VBF protocol was adopted for EN administration; 3) Comparison: The rate-based feeding (RBF) protocol was adopted for EN administration; 4) Major outcomes: EN nutrition delivery. The exclusion criteria included participants aged < 18 years, duplicated literature, animal and cellular experiments, and studies lacking any of the outcomes mentioned in the inclusion criteria. The databases included MEDLINE (through PubMed), Web of Science, Cochrane Library, Chinese Biomedical Literature Service System (SinoMed), Wanfang Data Knowledge Service Platform, and China National Knowledge Infrastructure.

RESULT

Sixteen studies involving a total of 2896 critically ill patients are included in the updated meta-analysis. Compared with the previous meta-analysis, nine new studies were added that included 2205 more patients. The VBF protocol significantly improved energy (MD = 15.41%, 95% CI: [10.68, 20.14], p < 0.00001) and protein (MD = 22.05%, 95% CI: [10.89, 33.22], p = 0.0001) delivery. The patients in the VBF group stayed in the ICU for a shorter time (MD = 0.78, 95% CI: [0.01, 1.56], p = 0.05). The VBF protocol did not increase the risk of death (RR = 1.03, 95% CI: [0.85, 1.24], p = 0.76) or prolong the mechanical ventilation duration (MD = 0.81, 95% CI: [-0.30,1.92], p = 0.15). In addition, the VBF protocol did not affect EN complications, such as diarrhea (RR = 0.91, 95% CI: [0.73, 1.15], p = 0.43), emesis (RR = 1.23, 95% CI: [0.76, 1.99], p = 0.41), feeding intolerance (RR = 1.14, 95% CI: [0.63, 2.09], p = 0.66), and gastric retention (RR = 0.45, 95% CI: [0.16, 1.30], p = 0.14).

CONCLUSION

Our study revealed that the VBF protocol significantly improved calorie and protein delivery in critically ill patients with no additional risk.

Continuous versus Intermittent Enteral Feeding in Critically Ill Children: A Systematic Review

Administration of enteral nutrition (EN) in critically ill pediatric patients admitted to the pediatric intensive care unit (PICU) constitutes a major challenge due to the increased risk of complications, as well as the lack of well-trained healthcare professionals. EN is usually delivered via cyclic, continuous, or intermittent feeding; however, a number of potential barriers have been reported in the literature regarding different feeding regimens. The purpose of this review was to assess the effectiveness of continuous and intermittent bolus feeding on critically ill children. A systematic search was conducted in PubMed, Scopus Cochrane Central Register of Controlled Trials (CENTRAL) and a clinical trial registry up to September 2022, including randomized controlled trials (RCTs) published in the English language. Four studies met the inclusion criteria with a total population of 288 patients admitted to the PICU. Three studies were rated with a high risk of bias and one with some concerns. There was high heterogeneity between the studies in regard to the reporting of outcomes. Three studies measured the total time needed to reach prescribed caloric intake with conflicting results, while two studies evaluated the length of stay (LOS) in PICU with no difference between the two arms. One study assessed the time weaning from mechanical ventilation, favoring the bolus group. No data were provided for gastric residual volume (GRV), anthropometric measurements, and biochemical markers. Additional randomized trials with better methodology are needed to assess the efficacy of the two enteral feeding regimens in critically ill PICU patients.

Is bolus or continuous enteral feeding better in critically ill children: An evidence-based review

Inadequate nutrition can lead to increased morbidity and mortality for mechanically ventilated children in the paediatric intensive care unit (PICU). Enteral feeding can either be delivered by gravity bolus (intermittent) feeding or continuously via a pump and in UK PICUs variable practice exists. This evidence-based review therefore aimed to examine the evidence surrounding the two feeding methods for ventilated children, to determine whether one provides better enteral nutrition. Four papers were included, three randomized controlled trials and a systematic review, which provide conflicting evidence. There is some suggestion that bolus feeding may be superior in medical children on PICU to achieve their energy and protein goals faster, however, the clinical significance of the results is questionable and further research is needed to identify whether one method of feeding can impact on patient outcomes.

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.

Impact of Nutrition Support Team in Achieving Target Calories in Children Admitted in Pediatric Intensive Care Unit

OBJECTIVE

To determine the impact of nutrition support team (NST) on achieving an early target caloric goal in mechanically ventilated children admitted in pediatric intensive care unit (PICU).

METHODS

An early enteral nutrition protocol (EENP) was implemented by NST to ensure early and adequate nutrition provision to PICU patients. All children (1 month- 18 years) that were admitted in PICU for >2days and received mechanical ventilation, with no contraindications to enteral feed, were included and data was compared with those of pre-intervention. The adequacy of energy intake was defined as 70% achievement of target energy intake on the third day of admission. Chi-square/t-test was used to determine the difference between different variables pre and post intervention.

RESULTS

Total 180 patients (99 and 81 in pre- and post-intervention group, respectively) were included. Overall, 115 (63.9%) received adequate calories (70%) on third day of admission. Of which 69 (85.2%) were from post intervention (P  < 0.001; odds ratio [OR] 6.6, 95% confidence interval [CI] 3.195-13.73). Moreover, NST intervention also promoted adequate protein intake in 62 (76.5%) children compared to 37 (37.4%) in pre-intervention group (P < 0.001, OR 5.468, 95% CI 2.838- 10.534). The median (interquartile range) length of PiCU stay in pre-NST group was 6 (4-9) days and in NST supported group was 4 (3-4) days (OR 0.580, CI 0.473-0.712, P < 0.001). Age, severity of illness, multiorgan dysfunction syndrome, sepsis, need of organ support had no effect in achievement of caloric target in both the groups (P > 0.05).

CONCLUSION

Introduction of EENP with NST helped in the achievement of better and quicker target caloric intake.

Feeding the critically ill child in intensive care units: a descriptive qualitative study in two tertiary hospitals in Ghana

BACKGROUND

Critically ill children require optimum feeding in the intensive care units for speedy recovery. Several factors determine their feeding and the feeding method to adopt to address this phenomenon. The aim of this study was to explore and describe the feeding criteria of critically ill children at the neonatal and paediatric intensive care units.

METHODS

A descriptive qualitative design was used to conduct the study. Six focus group discussions were conducted, and each group had five members. In addition, twelve one-on-one interviews were conducted in two public tertiary teaching hospitals in Ghana and analyzed by content analysis using MAXQDA Plus version 2020 qualitative software. Participants were selected purposively (N = 42).

RESULTS

The decision to feed a critically ill child in the ICU was largely determined by the child's medical condition as well as the experts' knowledge and skills to feed. It emerged from the data that cup feeding, enteral, parenteral, and breastfeeding were the feeding processes employed by the clinicians to feed the critically ill children.

CONCLUSIONS

Regular in-service training of clinicians on feeding critically ill children, provision of logistics and specialized personnel in the ICU are recommended to reduce possible infant and child mortality resulting from suboptimal feeding.

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.

Prospective evaluation of a novel enteral feeding guideline based on individual gastric emptying times: an improvement project in a pediatric intensive care unit

BACKGROUND

On a 20-bed, mixed cardiac and general, UK pediatric intensive care unit (PICU), we aimed to determine if a physiologically based enteral feeding guideline for critically ill children, using feed frequency tailored to individual gastric emptying times, resulted in earlier establishment of full feeds (when 100% of fluid allowance (FA) available to be given as intravenous maintenance fluid or feed, defined as free FA [FFA], is given as enteral nutrition [EN]) and an increase in FFA given as EN.

METHODS

Four prospective audits (totaling 331 patients and 19,771 hours) were conducted at 1 year before guideline introduction and 1, 5, and 10 years after. Patient feeding data were collected from admission until day 4 or discharge, including reasons why feed was withheld.

RESULTS

The median time from admission to establishing full feeds decreased from 18 to 10 hours preguideline and postguideline and was sustained over 10 years. After adjustment for 5 confounders, this represented a reduction in the geometric mean time to full feeds of 30% (2009), 29% (2013), and 48% (2019) compared with 2007 (all P < .01). Nil-per-oral (NPO) hours were categorized as due to modifiable and nonmodifiable factors. Preguideline and postguideline NPO hours from modifiable factors decreased from 21 (2007) to 10 (2009) per 100 audit hours, which was sustained across 10 years (all P < .01). Conversely, NPO hours from nonmodifiable factors ranged from 27 to 36 per 100 audit hours throughout the audits, with no consistent trend over time. Similar inconsistency was shown in the proportion of FFA given as EN: 48% (2007), 71% (2009), 51% (2013), and 64% (2019). Continuous nasogastric and hourly bolus feeds decreased over time; they comprised 66% of feeds in 2007 but only 4%-11% in subsequent periods, being replaced with more 2-6 hour bolus, on-demand, or continuous nasojejunal feeds.

CONCLUSION

The guideline was associated with sustained reduction in the time to establishing full feeds and NPO hours due to modifiable factors and more or no less FFA being given as EN.

Routine gastric residual volume measurement to guide enteral feeding in mechanically ventilated infants and children: the GASTRIC feasibility study

BACKGROUND

The routine measurement of gastric residual volume to guide the initiation and delivery of enteral feeding is widespread in paediatric intensive care and neonatal units, but has little underlying evidence to support it.

OBJECTIVE

To answer the question: is a trial of no gastric residual volume measurement feasible in UK paediatric intensive care units and neonatal units?

DESIGN

A mixed-methods study involving five linked work packages in two parallel arms: neonatal units and paediatric intensive care units. Work package 1: a survey of units to establish current UK practice. Work package 2: qualitative interviews with health-care professionals and caregivers of children admitted to either setting. Work package 3: a modified two-round e-Delphi survey to investigate health-care professionals' opinions on trial design issues and to obtain consensus on outcomes. Work package 4: examination of national databases to determine the potential eligible populations. Work package 5: two consensus meetings of health-care professionals and parents to review the data and agree consensus on outcomes that had not reached consensus in the e-Delphi study.

PARTICIPANTS AND SETTING

Parents of children with experience of ventilation and tube feeding in both neonatal units and paediatric intensive care units, and health-care professionals working in neonatal units and paediatric intensive care units.

RESULTS

Baseline surveys showed that the practice of gastric residual volume measurement was very common (96% in paediatric intensive care units and 65% in neonatal units). Ninety per cent of parents from both neonatal units and paediatric intensive care units supported a future trial, while highlighting concerns around possible delays in detecting complications. Health-care professionals also indicated that a trial was feasible, with 84% of staff willing to participate in a trial. Concerns expressed by junior nurses about the intervention arm of not measuring gastric residual volumes were addressed by developing a simple flow chart and education package. The trial design survey and e-Delphi study gained consensus on 12 paediatric intensive care unit and nine neonatal unit outcome measures, and identified acceptable inclusion and exclusion criteria. Given the differences in physiology, disease processes, environments, staffing and outcomes of interest, two different trials are required in the two settings. Database analyses subsequently showed that trials were feasible in both settings in terms of patient numbers. Of 16,222 children who met the inclusion criteria in paediatric intensive care units, 12,629 stayed for > 3 days. In neonatal units, 15,375 neonates < 32 weeks of age met the inclusion criteria. Finally, the two consensus meetings demonstrated 'buy-in' from the wider UK neonatal communities and paediatric intensive care units, and enabled us to discuss and vote on the outcomes that did not achieve consensus in the e-Delphi study.

CONCLUSIONS AND FUTURE WORK

Two separate UK trials (one in neonatal units and one in paediatric intensive care units) are feasible to conduct, but they cannot be combined as a result of differences in outcome measures and treatment protocols, reflecting the distinctness of the two specialties.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN42110505.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 23. See the NIHR Journals Library website for further project information.

Determining Optimal Outcome Measures in a Trial Investigating No Routine Gastric Residual Volume Measurement in Critically Ill Children

BACKGROUND

Choosing trial outcome measures is important. When outcomes are not clinically relevant or important to parents/patients, trial evidence is less likely to be implemented into practice. This study aimed to determine optimal outcome measures for a trial of no routine gastric residual volume (GRV) measurement in critically ill children.

METHODS

A mixed-methods approach was used: a focused literature review, parent and clinician interviews, a modified 2-round Delphi, and a stakeholder consensus meeting.

RESULTS

The review generated 13 outcomes. Fourteen pediatric intensive care unit (PICU) parents proposed 3 additional outcomes; these 16 were then rated by 28 clinicians in Delphi round 1. Six further outcomes were proposed, and 22 outcomes were rated in the second round. No items were voted "consensus out." The 18 "no-consensus" items were voted in a face-to-face meeting by 30 participants. The final 12 outcome measures were time to reach energy targets, ventilator-associated pneumonia, vomiting, time enteral feeds withheld per 24 hours, necrotizing enterocolitis, length of invasive ventilation, PICU length of stay, mortality, change in weight and markers of feed intolerance (parenteral nutrition administered), feed formula altered, and change to postpyloric feeds all secondary to feed intolerance.

CONCLUSION

We have identified 12 outcomes for a trial of no GRV measurement through a multistage process, seeking views of parents and clinicians.

Review of Outcomes Used in Nutrition Trials in Pediatric Critical Care

BACKGROUND

Generating robust evidence within pediatric intensive care (PIC) can be challenging because of low patient numbers and patient heterogeneity. Systematic reviews may overcome small study biases but are limited by lack of standardization in outcome measures and their definition. Trials of nutrition interventions in PIC are increasing; thus, we wanted to examine the outcome measures being used in these trials.

OBJECTIVE

Our objective was to systematically describe outcome measures used when a nutrition intervention has been evaluated in a PIC randomized controlled trial.

METHODS

A systematic literature review of all studies involving a PIC trial of a nutrition intervention was undertaken from January 1, 1996, until February 20, 2018.

RESULTS

Twenty-nine trials met the criteria and were reviewed. They included a total of 3226 patients across all trials. Thirty-seven primary outcomes and 83 secondary outcomes were found. These were categorized into PIC-related outcomes (infection, intensive care dependency, organ dysfunction, and mortality) and nutrition outcomes (energy targets, nutrition parameters, and feeding tolerance). We found large variation in the outcome measures used. Outcome domains of energy targets, feeding tolerance, and infection were not adequately defined.

CONCLUSIONS

Considerable variation in the outcome measures chosen and their definitions exist within PIC nutrition trials. Optimal nutrition outcomes for PIC must be agreed upon and defined, specifically domains of nutrition efficiency, nutrition tolerance, and non-nutrition PIC outcomes. The next step is to conduct an international Delphi study to gain expert consensus and develop a core outcome set to be reported in future pediatric nutrition trials.