Effectiveness of Intermittent Feeding Combined with Right Lateral Position on Gastric Residual Volume in Critically Ill Patients: A Randomized Controlled Study

Objective To investigate the current status of monitoring gastric residual volume (GRV) and enteral nutrition (EN) tolerance in critically ill elderly patients in ICU nationwide, so as to provide evidence for finding the best assessment method of EN tolerance in critically ill elderly patients and standardizing the operation procedure. Methods A total of 724 ICU critically ill elderly patients from 22 provinces, 5 autonomous regions and 4 municipalities were selected by convenience sampling method and investigated for EN strategy management, EN pipeline maintenance, EN tolerance assessment and GRV monitoring. Results During the period of enteral nutrition in critically ill elderly patients, 461 (63.7%) of the 724 ICUs surveyed performed routine GRV monitoring, 166 (22.9%) used the EN tolerance scoring too, 156 (21.5%) used ultrasound to monitor gastric residual volume. There was no statistical difference in use of EN tolerance score tool and B-mode ultrasound monitoring among different types of ICU (P>0.05) . The incidence of vomiting and dominant aspiration in routine monitoring departments was lower than that in unconventional monitoring departments, and the difference was statistically significant (P<0.05) . Conclusions The elderly critically ill patients should be evaluated EN tolerance every day during the implementation of EN, and routine and feasible GRV monitoring should be carried out. Key words: Aged; Intensive Care Units; Tolerance of enteral nutrition; Gastric residual volume

Children undergo a preoperative fast in an attempt to minimize the fluid and solid food component of gastric contents. The importance of a preoperative fast was acknowledged early in the evolution of anesthesia as a discipline of medicine. In response to concerns about the aspiration of gastric contents, a prolonged fast presumably came into vogue. With this practice, it was not unusual to have hungry, irritable children who were prone to hypoglycemia after fasts of 8 ‐12 h or even longer. The purpose of this article is to provide the reader with a narrative review of the literature pertaining to preoperative fasting in children. This article is primarily focused on randomized controlled trials (RCTs), but when not available, literature of lesser intensity was used. We present the physiology of gastric emptying with an emphasis on studies focusing on children in the perioperative period. These studies of gastric emptying were, when possible, divided into studies involving solid food and those involving clear fluids. We then present preoperative fasting of children, which was subdivided by age (neonates, infants, toddlers, and adolescents) and by health (elective versus emergent surgery and healthy versus medically compromised patients). In the concluding portions of this review, we present recommendations for the management of perioperative fasting and recommendations with respect to the need for more research, as more questions remain unanswered than those that have been answered. During preparation of this article, we accepted several links. The linkage between gastric fluid volume and aspiration pneumonia for healthy patients has recently been examined by an ASA taskforce, which concluded that the available data were insufficient to confirm or deny a relationship. Although this means that gastric fluid volume is a surrogate end point for aspiration pneumonia, virtually all studies examining preoperative feeding practices have gastric residual volume as their primary end point. For the purpose of this review, we focus on the end point of gastric residual volume, which is the almost exclusive choice of numerous peer-reviewed investigations. Furthermore, in the practice of anesthesia, patients undergoing emergency surgery have increased gastric contents and are at increased risk of aspiration pneumonia. This is an established link, and if we were to refute it, we would deny the need for rapid-sequence induction plus appropriate airway management during general anesthesia for emergency surgery. Although increased gastric contents increase the risk of aspiration pneumonia, there is no known gastric fluid volume that places a particular patient at clinically relevant risk or eliminates all risk.

Preoperative Fasting in Children

Objective To evaluate the feeding effect of not monitoring gastric residual volume in ICU patients receiving continuous enteral feeding,including complications and calorie intake. Methods We searched for relevant studies in China national knowledge internet(CNKI), Wanfang Data, PubMed, Embase, Cochrane library. We included all Randomized controlled trials (RCTs) and pre-post studies related to the feeding effect of not monitoring gastric residual volume in ICU patients receiving continuous enteral feeding. Two researchers independently screened, appraised and extracted data, and meta-analysis was conducted via RevMan 5.3 software. Results 3 RCTs and 2 pre-post studies with 1 000 patients were included. Not monitoring gastric residual volume increase the rate of vomiting [OR=1.35, 95%CI(1.02, 1.80), Z=2.08, P=0.04], decrease the proportion of intolerance to enteral nutrition [OR=0.35, 95%CI(0.26, 0.46), Z=7.29, P<0.01], there were no significant differences in diarrhea [OR=1.14, 95%CI(0.78, 1.67), Z=0.67, P=0.51] and distention[OR=1.24, 95%CI(0.76, 2.03), Z=0.87, P=0.38]. The cumulative calorie deficit between targeted volume and provided volume in not monitoring gastric residual volume group was significantly lower than the control group[MD=-0.29, 95%CI(-0.47, -0.11), Z=3.23, P=0.001], daily provided calorie amount was also significantly higher than the control group [MD=0.35, 95%CI(0.10, 0.59), Z=2.75, P=0.006]. Conclusions Not monitoring gastric residual volume in ICU patients increase calorie intake and have better enteral nutrition provision, decrease the proportion of intolerance to enteral nutrition. Monitoring gastric residual volume should not be taken as a routine task in critical care nursing. Key words: Not monitoring; gastric residual volume; Enteral nutrition; Intensive care units; Meta-analysis

Objective To discuss the application of bedside ultrasound monitoring of gastric residual volume in ICU patients complicated with enteral nutrition support via nasogastric tube. Methods November 2017 to May 2018, 120 patients with enteral nutrition support via nasogastric tube who admitted in ICU of our hospital were randomly divided into the observation group and the control group. The observation group used bedside ultrasound monitoring to determine the gastric residual volume, while the control group was estimated by withdrawn with 50 ml syringe. Reflux, pulmonary aspiration and the time of enteral nutrition were observed in both groups. Results Reflux and pulmonary aspiration were present in 2, 3 in the observation group and 10, 11 in the control group, with significant difference between them (χ2=4.53, 3.96, P<0.05). The time of enteral nutrition in the observation group was (13.98±3.20) h, and (15.54±3.54) h in the control group, which had a statistically difference (t=-10.49, P<0.05). Conclusion The application of bedside ultrasound monitoring of gastric residual volume in ICU patients complicated with enteral nutrition support via nasogastric tube can significantly reduce the risk of reflux and pulmonary aspiration which can ensure the safety of enteral nutrition, and decrease time of enteral nutrition. Key words: Ultrasound; Gastric residual volume; Enteral nutrition

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. 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. A total of seven RCTs involving 1240 enteral nutritionpatients 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). Not monitoring gastric residual volume is associated with reduced unnecessary interruptions of enteral nutrition related to inadequate feeding and increased risk of vomiting.

Objective To explore the variation trend of gastric residual volume (GRV) during continuous enteral nutrition (EN) in critical patients by ultrasonic monitoring so as to provide a basis for standardizing GRV monitoring. Methods From November 2015 to January 2016, we selected 85 critical patients with continuous EN from three ICU in a Class Ⅲ Grade A hospital. The GRV was dynamically monitored by ultrasonic during continuous EN at different time points (0, 4, 8, 12, 16, 24 h) of feeding so as to explore its variation trend. Results The GRV of patients with continuous EN increased with the extension of feeding time. The GRV reached the peak at twelfth hour and showed a downtrend after that. There were no significant differences in GRVs at 4, 8, 12, 16 h between patients with and without mechanical ventilation (P=0.055, 0.169, 0.193, 0.154) . Conclusions The twelfth hour of feeding by daily was the important time point for GRV monitoring in patients with continuous EN. Key words: Intensive care; Critical patients; Enteral nutrition; Gastric residual volume

During tube feeding, it is a common practice to check gastric residual volume frequently for indications of pathologic impairment of gastric emptying. The volume threshold standards for holding feedings are applied nonselectively, disregarding slowing of gastric emptying by nutrient-triggered intestinogastric inhibitory feedback. We developed a computer simulation model considering this feedback to test the hypothesis that gastric residual volume increases with slower gastric emptying and faster formula delivery but reaches a plateau volume (equilibrium between input and output) at volumes commonly seen in the postprandial stomach. A computer simulation model using Microsoft Excel 4.0 calculated the cumulative gastric residual volume over time when the input volume into the stomach is 125 mL/h (endogenous secretions)+ 0 to 125 mL/h (formula delivery rate) and the output volume out of the stomach is equal to gastric emptying rates that varied between 0% and 50%/h. The model simulated nasogastric feeding with nine different rates of gastric emptying and six different rates of formula delivery. Measurements consisted of the cumulative gastric residual volume at the end of each hour for a minimum of 48 hours. (1) Gastric residual volumes 1.5 to 6 times the commonly applied "stop feeding" threshold volume of 150 mL are encountered at gastric emptying rates of 20% to 50%/h; (2) gastric residual volume stabilizes to a plateau of 225 to 900 mL between 3 and 13 hours after start of formula delivery at these rates; and (3) at 0% gastric emptying, gastric residual volume does not reach a plateau. At gastric emptying rates expected with nutrient-triggered inhibitory feedback and at formula delivery rates common in nutrition support, gastric residual volume reaches a plateau rapidly and at volumes commonly encountered in normal postprandial stomachs. On the basis of the results of this model, the current practice of stopping enteral feeding when gastric residual volume exceeds an arbitrarily selected volume threshold may not be physiologically sound. Clinical studies are needed to verify this model.

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. To investigate the efficacy and safety of GRV monitoring during EN. 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. 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. 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. 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. The evidence is very uncertain about the effect of GRV on clinical outcomes including mortality, pneumonia, vomiting, and length of hospital stay.

not effective as observed in this case also, phenytoin may worsen the overall toxicity.Hence, phenobarbitone controls pyrethroid-evoked seizure foci through its dual action such as chloride channel agonist and as a membrane stabilizer. [5] As pyrethroid insecticides have come into prominent use in recent years, the incidence of poisoning has increased.Hence, practitioners may be sensitized on the clinical manifestations, course, selection of anticonvulsants and outcome of pyrethroid poisoning, as well as be informed that these cases shall not be considered as simple or taken lightly.

IntroductionNo 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 MethodsA 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).ResultsData 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.DiscussionGastric 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.

Measuring gastric residual volume (GRV) is a standard practice during enteral nutrition (EN) in the Intensive Care Units (ICU). However this practice though customary is marred due to several postulations. It is assumed that GRVs in critically ill patients is a well-standardized practice, GRVs consistently and precisely measures gastric contents, they adequately indicate normal from abnormal emptying. A host of intraluminal and extraluminal causes influences gastric emptying (GE), which may be endogenous or exogenous, and can be modulated by neural and hormonal factors. Factors that may alter GE include osmolarity, volume of feeds, composition of feeds, caloric density, temperature, nature of nutrients, and systemic parameters such as blood sugar levels.[1] The definition of “high” GRV is extremely variable. One survey revealed that GRV definitions ranged from values as low as 50-400 mL.[2] The assumption that high GRV is synonymous in delayed GE is not well supported by evidence.[3] In critically ill patients specified groups are more likely to have delayed GE, these include patients with multitrauma (60%), traumatic brain injury (57%) and sepsis (42%).[4] Feeding intolerance is also related to the severity of illness. Opioids and catecholamines that are widely used in the critically ill will influence GE. A protocol of EN management without GRV monitoring is not inferior to a similar protocol, including GRV monitoring in terms of protection against ventilator associated pneumonia as demonstrated by the CRICS study.[5] Other methods of determining GE is Scintigraphy (which is considered to be a gold standard consists of recording GE by a γ-scintillation camera), paracetamol absorption test (since paracetamol is not absorbed in the stomach), breath tests using nonradioactive isotope, carbon-13 (13C), refractometry (model requires measurement of the Brix value), ultrasound to measure cross-sectional scans of a defined portion of the stomach, Gastric impedance monitoring is based on modifications of electrical resistivity (or impedance) for the estimation of GE and using magnetic resonance imaging. Most of these methods may not be practical to implement in the critically ill.[6]

Effects of not monitoring gastric residual volume in intensive care patients: A meta-analysis

Introduction Nutrition is a core component of care for the critically ill burn patient. The Society for Critical Care Medicine recommends initiating enteral nutrition (EN) within 4–6 hours of injury for burn patients, while simultaneously recommending waiting until hemodynamic stability is achieved for critical care patients. The goal of this analysis was to evaluate tolerance of EN during periods of different pressor requirements and lactate levels. Methods We performed a retrospective evaluation on all burn patients admitted to our intensive care unit in 2018 who received EN. This performance improvement project was approved by our regulatory compliance division. Lactate levels and vasopressor use just prior to EN initiation, the highest EN rates and gastric residual volumes during the 24 hours after initiation, and ischemic bowel and aspiration after EN initiation were recorded. Significance was accepted at p&amp;lt; 0.05. Results EN was initiated at 30 ± 20 hours after admission in 58 patients with the following characteristics: 47 ± 19 years old, 29 ± 24% TBSA burn, 13 mechanical ventilator days (IQR: 5–30), 15% mortality. The highest EN rate reached was 100 ± 49 mL/hr during the first 24 hours after initiation. Lactate levels were 1.9 mmol/L at the time of EN initiation (IQR: 1.6–2.4 mmol/L), with a maximum of 4.9 mmol/L. Lactate levels did not have a significant correlation with gastric residual volumes (p=0.532). Most (59%) patients did not have vasopressor requirements, but 21% required vasopressin only, 2% required norepinephrine only, and 19% required a combination of vasopressin and norepinephrine. Those who received norepinephrine received 3.3 ± 1.7 mcg/min, with a maximum of 7 mcg/min. There was a significant difference in gastric residual volumes between patients who had no vasopressor requirements compared to those who required vasopressors [13 mL (IQR: 0–200 mL) vs. 240 mL (IQR: 21–430 mL), p=0.014)]; however, the number of patients with gastric residual volumes over 500 mL was not significantly different (3% vs. 17%, p=0.149). When examining patients receiving vasopressin alone, there was a significant but weak correlation between vasopressin dose and gastric residual volumes (p=0.047, R2=0.339); however, when examining only patients receiving norepinephrine, there was no correlation between norepinephrine dose and gastric residual volumes (p=0.905, R2=0.002). There was 1 episode of aspiration and 1 episode of ischemic bowel, both of which occurred 3 days after EN initiation. EN was initiated without vasopressors running and lactate levels were normal in both cases. Conclusions The majority of patients tolerated EN initiation with vasopressor dosing of norepinephrine up to 7 mcg/min and lactate up to 4.9 mmol/L. Applicability of Research to Practice We found no indication for holding EN for lactate levels under 5 mmol/L and norepinephrine under 8 mcg/min.

Background: To assess the risk of aspiration, nutrient tolerance, and gastric emptying of patients in ICUs, gastric ultrasound can provide information about the gastric contents. Using established formulas, the gastric residual volume (GRV) can be calculated in a standardized way by measuring the gastric antrum. The purpose of this study was to determine the GRV in a cohort of enterally fed patients using a miniaturized ultrasound device to achieve knowledge about feasibility and the GRV over time during the ICU stay. The findings could contribute to the optimization of enteral nutrition (EN) therapy. Methods: A total of 217 ultrasound examinations with 3 measurements each (651 measurements in total) were performed twice daily (morning and evening) in a longitudinal observational study on 18 patients with EN in the interdisciplinary surgical ICU of Saarland University Medical Center. The measured values of the GRV were analyzed in relation to the clinical course, the nutrition, and other parameters. Results: Measurements could be performed without interrupting the flow of clinical care and without pausing EN. The GRV was significantly larger with sparsely auscultated bowel sounds than with normal and excited bowel sounds (p < 0.01). Furthermore, a significantly larger GRV was present when using a high-caloric/low-protein nutritional product compared to an isocaloric product (p = 0.02). The GRV at the morning and evening measurements showed no circadian rhythm. When comparing the first and last ultrasound examination of each patient, there was a tendency towards an increased GRV (p = 0.07). Conclusion: The GRV measured by miniaturized ultrasound devices can provide important information about ICU patients without restricting treatment procedures in the ICU. Measurements are possible while EN therapy is ongoing. Further studies are needed to establish gastric ultrasound as a management tool in nutrition therapy.