Effect of lying position on gastric residual volume in premature infants: A systematic review

Premature infants' gastric residual volume may be affected by position. This systematic review was conducted to examine the effect of lying position on the gastric residual volume of preterm newborns fed by gastric tube. Electronic databases (PubMed, MEDLINE, MEDLINE Complete, Academic Search Ultimate, CINAHL Complete, Cochrane, and Scopus) were searched for randomized controlled experimental or quasiexperimental studies in English published between 2011 and 2022 investigating the effect of one or more lying positions on gastric residual volume in premature newborns. The PICOS strategy was used in preparing and reporting the systematic review. A total of 304 articles were retrieved, and the full texts of 12 articles were evaluated for suitability. After eliminating the excluded articles, 10 articles were included in the analysis. The quality of evidence varied, with four studies judged to have poor quality whereas the remaining six were considered to range from moderate to good in quality. Based on the results obtained from the studies, it was determined that gastric residual volume was the least in the right lateral and prone positions and more in the left lateral and supine positions compared with the other two positions, with no difference between the two latter positions. The methodological differences, such as the evaluation of different positions, the timing of positioning and the duration of maintaining in the same position, and the measurement times of gastric residual volume made it difficult to reach a definitive proof. We concluded that high-evidence studies evaluating all positions are needed.

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.

Assessment of Gastric Residual Volume with Ultrasound in Children at Fasting and after Oral Intake of Carbohydrate-Rich Fluid in the Preoperative Period

Purpose

Despite standard preoperative fasting guidelines, children are subjected to prolonged fasting due to various reasons. This does not reduce gastric residual volume (GRV) further, instead causes hypoglycemia, hypovolemia, and unnecessary discomfort. We calculated the cross-sectional area (CSA) of antrum and GRV in children in fasting state and 2 h after intake of oral carbohydrate-rich fluid, using gastric ultrasound.

Methods

Anteroposterior and craniocaudal gastric antral diameters were measured by ultrasonography in the right lateral decubitus position, at fasting and at 2 h after 8 ml/kg of pulp-free fruit juice ingestion. CSA of antrum and GRV was calculated using validated mathematical models.

Results

Data of 149 children of age >1-12 years were analyzed. Greater than ninety-nine percent of children emptied ≥95% of the ingested pulp-free fruit juice volume within 2 h. One hundred and seven (71.8%) children had reduced CSA and GRV at 2 h after fruit juice ingestion (2.01 ± 1.00 cm2 and 7.77 ± 6.81 ml) as compared to fasting state (3.18 ± 1.40 cm2 and 11.89 ± 7.80 ml). Fourty-nine (28.2%) children had slightly increased CSA and GRV at 2 h after fruit juice (2.46 ± 1.14 cm2 and 10.61 ± 7.26 ml) than at fasting (1.89 ± 0.92 cm2 and 8.61 ± 6.75 ml), but this increased GRV was grossly lower than limit of risk stomach (26.54 ± 8.95 ml).

Conclusion

Carbohydrate-rich drink in the form of pulp-free fruit juice may be safely permitted up to 2 h before anesthetic induction, as it promoted gastric emptying in ≈ 72% of children and 28% of children, although GRV was slightly higher at 2 h after fruit juice ingestion than fasting but remained considerably lower than limit of risk stomach.

Gastrointestinal dysfunction during enteral nutrition delivery in intensive care unit (ICU) patients: Risk factors, natural history, and clinical implications. A post-hoc analysis of The Augmented versus Routine approach to Giving Energy Trial (TARGET)

BACKGROUND

Slow gastric emptying occurs frequently during critical illness and is roughly quantified at bedside by large gastric residual volumes (GRVs). A previously published trial (The Augmented versus Routine approach to Giving Energy Trial; TARGET) reported larger GRVs with energy-dense (1.5 kcal/mL) compared with standard (1.0 kcal/mL) enteral nutrition (EN), warranting further exploration.

OBJECTIVE

To assess the incidence, risk factors, duration, and timing of large GRVs (≥250 mL) and its relation to clinical outcomes in mechanically ventilated adults.

METHODS

A post-hoc analysis of TARGET data in patients with ≥1 GRV recorded. Data are n (%) or median [IQR].

RESULTS

Of 3876 included patients, 1777 (46%) had ≥1 GRV ≥250 mL, which was more common in males (50 compared with 39%; P < 0.001) and in patients receiving energy-dense compared with standard EN (52 compared with 40%; RR = 1.27 (95% CI: 1.19, 1.36); P < 0.001) in whom it also lasted longer (1 [0-2] compared with 0 [0-1] d; P < 0.001), with no difference in time of onset after EN initiation (day 1 [0-2] compared with 1 [0-2]; P = 0.970). Patients with GRV ≥250 mL were more likely to have the following: vasopressor administration (88 compared with 76%; RR = 1.15 [1.12, 1.19]; P < 0.001), positive blood cultures (16 compared with 8%; RR = 1.92 [1.60, 2.31]; P < 0.001), intravenous antimicrobials (88 compared with 81%; RR = 1.09 [1.06, 1.12]; P < 0.001), and prolonged intensive care unit (ICU) stay (ICU-free days to day 28; 12.9 [0.0-21.0] compared with 20.0 [3.9-24.0]; P < 0.001), hospital stay (hospital-free days to day 28: 0.0 [0.0-12.0] compared with 7.0 [0.0-17.6] d; P < 0.001), ventilatory support (ventilator-free days to day 28: 16.0 [0.0-23.0] compared with 22.0 [8.0-25.0]; P < 0.001), and a higher 90-d mortality (29 compared with 23%; adjusted: RR = 1.17 [1.05, 1.30]; P = 0.003).

CONCLUSION

Large GRVs were more common in males and those receiving energy-dense formulae, occurred early and were short-lived, and were associated with a number of negative clinical sequelae, including increased mortality, even when adjusted for illness severity. This trial was registered at clinicaltrials.gov as NCT02306746.

[Preventive Care for Aspiration Pneumonia in Patients With an Indwelling Nasogastric Tube]

More than 190,000 patients have been fitted with an indwelling nasogastric tube in Taiwan. Nasogastric tube feeding is a strategy for temporary or long-term feeding and for preventing aspiration pneumonia in patients with dysphagia. However, aspiration pneumonia is a common complication in patients fitted with a nasogastric tube. Displacement of the nasogastric tube, inappropriate length of the placed nasogastric tube resulting gastroesophageal reflux, inappropriate feeding posture and speed, and excessive gastric residual volume resulting in vomiting are important risk factors associated with aspiration pneumonia. In this article, the literature and clinical practice experiences were reviewed to identify methods used to confirm the length and positioning of nasogastric tubes. We further explored strategies for preventing oral-care and tube-feeding-induced aspiration pneumonia during the period of indwelling nasogastric tube. These strategies included adjusting the patient's positions for receiving tube feedings, feeding techniques, methods and frequency of gastric residual volume measurement, and conditions for stopping nasogastric feeding. This exploration was intended to provide nursing staff with relevant knowledge and skills for preventing aspiration pneumonia in patients with indwelling nasogastric tube to improve patient safety.

Oropharyngeal Dysphagia and Impaired Motility of the Upper Gastrointestinal Tract-Is There a Clinical Link in Neurocritical Care?

Patients in the neurological ICU are at risk of suffering from disorders of the upper gastrointestinal tract. Oropharyngeal dysphagia (OD) can be caused by the underlying neurological disease and/or ICU treatment itself. The latter was also identified as a risk factor for gastrointestinal dysmotility. However, its association with OD and the impact of the neurological condition is unclear. Here, we investigated a possible link between OD and gastric residual volume (GRV) in patients in the neurological ICU. In this retrospective single-center study, patients with an episode of mechanical ventilation (MV) admitted to the neurological ICU due to an acute neurological disease or acute deterioration of a chronic neurological condition from 2011–2017 were included. The patients were submitted to an endoscopic swallowing evaluation within 72 h of the completion of MV. Their GRV was assessed daily. Patients with ≥1 d of GRV ≥500 mL were compared to all the other patients. Regression analysis was performed to identify the predictors of GRV ≥500 mL/d. With respect to GRV, the groups were compared depending on their FEES scores (0–3). A total of 976 patients were included in this study. A total of 35% demonstrated a GRV of ≥500 mL/d at least once. The significant predictors of relevant GRV were age, male gender, infratentorial or hemorrhagic stroke, prolonged MV and poor swallowing function. The patients with the poorest swallowing function presented a GRV of ≥500 mL/d significantly more often than the patients who scored the best. Conclusions: Our findings indicate an association between dysphagia severity and delayed gastric emptying in critically ill neurologic patients. This may partly be due to lesions in the swallowing and gastric network.

Gastric Volume Changes in Preterm Neonates during Intermittent and Continuous Feeding-GRV and Feeding Mode in Preterm Neonates

Background: We aimed to evaluate gastric volume changes during intermittent milk feeds (IMF) and continuous milk feeds (CMF) in very premature neonates (VPN), with gastric residual volume (GRV) based on antral cross-sectional area (ACSA) measurements and to examine if there were differences in GRV between the two feeding methods. Methods: A randomized prospective clinical trial with crossover design was conducted in 31 preterm neonates (gestational age < 30 weeks). Gastric volume was assessed twice in each neonate (during IMF and CMF feeding), at 7 specific time points during a 2-h observation period by measuring ACSA changes via the ultrasound (U/S) method. Results: There was a significantly different pattern of gastric volume changes between the two feeding methods. GRV, expressed as the median percentage of ACSA measurement at 120 min relative to the higher ACSA measurement during IMF, was found to be 3% (range 0–25%) for IMF and 50% (range 15–80%) for CMF. Neonates fed with IMF had a shorter mean gastric emptying time compared to those fed with CMF (p = 0.0032). No signs of feeding intolerance were recorded in either group during the period of observation. Conclusions: Our results showed that gastric volume changes and gastric emptying time in VPN, based on ACSA measurement changes, depend on the milk feeding method. No gastrointestinal complications/adverse events were noted with GRV up to 80% with CMF.

Evaluating a symptom-triggered gastric residual volume policy in a surgical trauma intensive care unit: Simple and safe

BACKGROUND

Routine checking of gastric residual volumes (GRVs) during enteral feeding within surgical trauma intensive care units (STICUs) is a common practice. However, data on the necessity of this practice and its impact on nutrient delivery are limited. We aim to study the association between the replacement of a routine GRV (rGRV) policy with a triggered GRV (tGRV) policy and the safe achievement of daily nutrition goals.

METHODS

We prospectively collected data on patients after we instituted a tGRV policy and compared them with a historical cohort of patients who had rGRV assessments in our STICU at a level 1 trauma center. The primary end point was achieving 80% of prescribed nutrient goals. Secondary end points included aspiration pneumonia, witnessed emesis, and glycemic control.

RESULTS

A total of 145 patients accounting for 1405 STICU days were treated under the tGRV policy, and 156 patients accounting for 1694 STICU days were treated under the rGRV policy. There were no statistically significant differences between the tGRV and rGRV groups with regard to the proportion of days meeting or exceeding protein (56.7% vs 56.2%) or calorie (56.4% vs 56.0%) goals. After adjusting for in-hospital deaths, injury severity score, complications, and STICU time, the predictive margins for meeting caloric and protein goals were higher among the tGRV patients (57% vs 56%), but these differences were not statistically significant.

CONCLUSION

A tGRV policy did not change protein or calorie delivery among patients or increase the risk of emesis compared with traditional monitoring methods.

Efficacy and Safety of Enteral Erythromycin Estolate in Combination With Intravenous Metoclopramide vs Intravenous Metoclopramide Monotherapy in Mechanically Ventilated Patients With Enteral Feeding Intolerance: A Randomized, Double-Blind, Controlled Pilot Study

BACKGROUND

In this pilot study, we aimed to determine the efficacy and safety of enteral erythromycin estolate in combination with intravenous metoclopramide compared to intravenous metoclopramide monotherapy in mechanically ventilated patients with enteral feeding intolerance.

METHODS

This randomized, double-blind, controlled pilot study included 35 mechanically ventilated patients with feeding intolerance who were randomly assigned to receive 10-mg metoclopramide intravenously every 6-8 hours in combination with 250-mg enteral erythromycin estolate (study group) or placebo every 6 hours for 7 days. The primary outcome was an administered-to-target energy ratio of ≥80% at 48 hours, indicating a successful feeding. Secondary, prespecified outcomes were daily average gastric residual volume (GRV), total energy intake, administered-to-target energy ratio, hospital length of stay, in-hospital mortality, and 28-day mortality.

RESULTS

The rate of successful feeding was not significantly different between the study and placebo groups (47.1% and 61.1%, respectively; P = .51). The average daily GRV was significantly lower in the study group than in the placebo group (β = 91.58 [95% Wald CI, -164.35 to -18.8]), determined by generalized estimating equation. Other secondary outcomes were comparable, and the incidence of adverse events was not significantly different between the 2 groups. One common complication was cardiac arrhythmia, which was mostly self-terminated.

CONCLUSION

Although the combination therapy of enteral erythromycin estolate and intravenous metoclopramide reduced GRV, the successful feeding rate and other patient-specific outcomes did not improve in mechanically ventilated patients with feeding intolerance.

Interventions Aimed at Reducing Fasting Times in Acute Hospital Patients: A Systematic Literature Review

Despite current guidelines recommending fasting from solids for ≤6 hours and clear fluids for ≤2 hours prior to surgery, outdated practices endure; patients fast for unnecessarily prolonged periods because of beliefs regarding aspiration risk upon anaesthesia induction. This literature review aimed to identify and evaluate current interventions aiming to reduce preoperative fasting times for acutely ill hospital patients, summarizing effective interventional strategies and associated outcomes. EMBASE, MEDLINE, PreMEDLINE, and CINAHL were systematically searched. Quality of evidence was assessed using Cochrane risk-of-bias tools. Studies, of any type, reporting fasting times as a primary or secondary outcome were included. A total of 1918 potential studies were identified; of these, 16 studies were included. Seven studies investigated the effect of changing fasting protocol on gastric fluid volume/residual gastric volume (GFV/RGV) and gastric pH as surrogate measures for aspiration risk. No significant differences in GFV/RGV and gastric pH due to reduced preoperative fasting were reported, thus no change in aspiration risk. Eight studies documented improvements in patient-reported outcomes with shorter fasting times. However, this review identified a paucity of studies that trialled interventions to reduce fasting times as the primary aim. These interventions were multimodal and multidisciplinary in nature, incorporating principles of implementation science to successfully achieve significant reductions in fasting times. This review highlights that reducing the preoperative fasting period is safe while improving patient's physical and psychological well-being. Further high-quality studies that investigate multimodal interventions, and that utilize implementation science principles, are required in this area.

Elimination of Routine Gastric Residual Volume Monitoring Improves Patient Outcomes in Adult Critically Ill Patients in a Community Hospital Setting

BACKGROUND

A community hospital updated its nutrition support practices in 2016 through the elimination of monitoring gastric residual volume (GRV) in accordance with the 2016 Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition.

METHODS

This retrospective analysis (N = 61) compared incidence of feeding intolerance in 2 cohorts of adult critically ill patients pre-implementation (n = 36) and post-implementation (n = 25) of these guidelines into a nutrition support team's standard of practice policy. Differences in kilocalories and protein (gm) received and percent of daily prescribed kilocalories and protein received were also compared between the 2 cohorts.

RESULTS

Mean episodes of gastrointestinal intolerance over the number of eligible days of receiving enteral nutrition in the critical care unit did not differ between the pre-implementation and post-implementation groups (P = 0.46). Compared with the pre-implementation group, the post-guideline implementation cohort was significantly more likely to meet higher percentages of both prescribed protein (71.8 ± 22.2% vs 55.9 ± 24.0%; P = 0.01) and energy requirements (93.4 ± 36.9% vs 69.6 ± 35.3%; P = 0.01), even after adjusting for potential confounders (age, body mass index, sex, and primary comorbid medical condition).

CONCLUSION

Elimination of routine monitoring of GRV may result in a greater percentage of prescribed daily nutrient requirements met by patients in the critical care setting, without adverse effects on feeding intolerance.

Evaluation of gastric residual volume in fasting diabetic patients using gastric ultrasound

BACKGROUND

Diabetic patients are claimed to have high risk of delayed gastric emptying; however, the evidence concerning residual gastric volume in fasting diabetic patients is not consistent. The aim of this work is to evaluate residual gastric volume in fasting diabetic patients for elective surgery.

METHODS

Fifty patients scheduled for elective surgery under general anaesthesia were included in the study. The study included 25 patients with at least 6-year history of diabetes and 25 healthy controls. Gastric ultrasound was performed to measure antral cross-sectional area in semi-sitting and right lateral positions. Nasogastric tube was inserted after induction of anaesthesia to aspirate and calculate the volume of gastric contents. Both study groups were compared according to antral cross-sectional area, residual gastric volume, risk of aspiration, in addition to demographic data.

RESULTS

The diabetic group showed higher median (quartiles) antral cross-sectional area (13.8 [9.5-19.5] mm² versus 8.8 [5.5-10.5] mm² , P < 0.001), and higher calculated gastric residual volume, (177 [96-275] mL versus 83 [50-109] mL, P < 0.001) compared to the control group. The diabetic group also showed higher aspirated volume through the nasogastric tube compared to the control group (150 [85-210] mL versus 75 [35-87] mL, P < 0.001). The correlation was very good between calculated residual gastric volume using ultrasound measures and volume of aspirated gastric contents through nasogastric tube.

CONCLUSION

Patients with long standing diabetes showed higher residual gastric volume compared to healthy controls after fasting 8 hours for elective surgery.

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 Emptying in Critically Ill Children

BACKGROUND

Delayed gastric emptying (GE) impedes enteral nutrient (EN) delivery in critically ill children. We examined the correlation between (a) bedside EN intolerance assessments, including gastric residual volume (GRV); (b) delayed GE; and (c) delayed EN advancement.

MATERIALS AND METHODS

We prospectively enrolled patients ≥1 year of age, eligible for gastric EN and without contraindications to acetaminophen. Gastric emptying was determined by the acetaminophen absorption test, specifically the area under the curve at 60 minutes (AUC₆₀). Slow EN advancement was defined as delivery of <50% of the prescribed EN 48 hours after study initiation. EN intolerance assessments (GRV, abdominal distension, emesis, loose stools, abdominal discomfort) were recorded.

RESULTS

We enrolled 20 patients, median 11 years (4.4-15.5), 50% male. Sixteen (80%) patients had delayed GE (AUC₆₀ <600 mcg·min/mL) and 7 (35%) had slow EN advancement. Median GRV (mL/kg) for patients with delayed vs normal GE was 0.43 (0.113-2.188) vs 0.89 (0.06-1.91), P = .9635. Patients with slow vs rapid EN advancement had median GRV (mL/kg) of 1.02 mL/kg (0.20-3.20) vs 0.27 mL/kg (0.06-1.62), P = .3114, and frequency of altered EN intolerance assessments of 3/7 (42.9%) vs 5/13 (38.5%), P = 1. Median AUC₆₀ for patients with slow vs rapid EN advancement was 91.74 mcg·min/mL (53.52-143.1) vs 449.5 mcg·min/mL (173.2-786.5), P = .0012.

CONCLUSIONS

A majority of our study cohort had delayed GE. Bedside EN intolerance assessments, particularly GRV, did not predict delayed GE or rate of EN advancement. Delayed gastric emptying predicted slow EN advancement. Novel tests for delayed GE and EN intolerance are needed.

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.

Should intensivist do routine abdominal ultrasound?

Roundworm infestation is common in tropical climate population with a low socioeconomic status. We describe a case of a young male with polytrauma accident who presented with small bowel dysfunction with a high gastric residual volume during enteral feeding. While searching the etiology, the intensivist performed bedside abdominal ultrasound (USG) as a part of whole body USG screening along with clinical examination using different frequency probes to examine bowel movement and ultimately found ascariasis to be the cause. This case report will boost up the wide use of bedside USG by critical care physicians in their patient workup.

Abdominal signs and symptoms in intensive care patients

Abdominal problems, both as a primary reason for admission or developing as a part of multiple organ dysfunction syndrome during an ICU stay, are common in critically ill patients. The definitions, assessment, incidence and outcome of different abdominal signs, symptoms and syndromes are assessed in the current review. General abdominal signs and symptoms include abdominal pain and distension, as well as other signs assessed during the physical examination (e.g. palpation, percussion). Gastrointestinal (GI) symptoms include vomiting, high gastric residual volumes, diarrhoea, GI bleeding, paralysis of the lower GI tract, bowel dilatation and absent bowel sounds. Although around half of patients suffer from these symptoms, the reported incidences of single symptoms vary within a large range due to variable definitions and case-mix. In a few studies, the total number of coincident GI symptoms was associated with increased mortality. Although acute abdomen is a well-recognized severe syndrome in emergency medicine, its incidence in ICUs is not known. Next to subjective clinical evaluation, intra-abdominal pressure, as a reproducible numerical variable, provides useful assistance in the assessment of the abdominal compartment, whereas intra-abdominal hypertension has been shown to impair the outcome of the critically ill. In conclusion, abdominal symptoms occur in half of patients in ICUs. Clinical evaluation, albeit largely subjective, remains the main bedside tool to detect abdominal problems and to assess GI function in the critically ill. IAP is a useful additional tool in the assessment of abdominal complications in ICUs.

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.

Evaluation of potential factors predicting attainment of full gavage feedings in preterm infants

BACKGROUND

The clinical measures of gastric residuals and abdominal distention are often used to guide feeding in preterm infants, but there are few data demonstrating their usefulness. Similarly, techniques are now available to investigate gastrointestinal (GI) function noninvasively and safely, but their ability to predict attainment of full gavage feedings and/or feeding volume in preterm infants is unclear.

OBJECTIVE

We sought to determine prospectively the potential relationships of attainment of full gavage feedings and feeding volume with clinical measures and noninvasive GI tests.

METHODS

Fifty preterm infants were followed prospectively. Daily tally was taken of gavage feeding intake, gastric residual volumes (GRVs; milliliters per day, number of GRVs >50% of the previous feeding volume, and number of GRVs >2 ml/kg), and abdominal distention. Infants underwent repeated measurement of lactase activity, GI permeability, fecal calprotectin concentration, and gastric emptying.

RESULTS

The number of GRVs >2 ml/kg tended to decrease with postnatal age (p = 0.06). Lactase activity and feeding volume in milliliters per kilogram per day prior to achieving full feedings were correlated (p = 0.007, β = 0.164). There was no correlation between feeding outcomes and GRV (ml/day), GRV >50%, GRV >2 ml/kg, small bowel, colonic, or whole bowel permeability, fecal calprotectin concentration, gastric emptying, or abdominal distention.

CONCLUSIONS

GRV is unreliable in predicting attainment of full gavage feeding. Lactase activity is related to feeding volume. However, other noninvasive GI tests utilized were not predictive. These data cast doubt upon the utility of GRV in guiding feeding therapy. Randomized trials of different GRV management protocols are needed.

Enteral feeding in the critically ill: comparison between the supine and prone positions: a prospective crossover study in mechanically ventilated patients

INTRODUCTION

Prone position is effective in mechanically ventilated patients to improve oxygenation. It is unknown if prone position affects gastric emptying and the ability of continued enteral feeding.

AIM

To determine tolerance of enteral feeding by measuring gastric residual volumes in enterally fed patients during supine and prone positions.

METHODS

Consecutive mechanically ventilated intensive care patients who were turned to prone position were included. All patients were studied for 6 hours in supine position, immediately followed by 6 hours in prone position, or vice versa. The rate of feeding was unchanged during the study period. Gastric residual volume was measured by suctioning the naso-gastric tube after 3 and 6 hours in the same position. Wilcoxon test and regression analysis were used for analysis.

RESULTS

The median volume of administered enteral feeds was 95 ml after 6 hours in supine position and 110 ml after 6 hours in prone position (P = 0.85). In 10 patients, a greater gastric residual volume was found in prone position. In eight others a greater volume was found in supine position. In 18 of 19 patients, gastric residual volumes in both positions were > or = 150 ml in 6 hours or < or = 150 ml in 6 hours. Significantly more sedatives were used in prone position. Regression analysis excluded dopamine dose and the starting position as confounders.

CONCLUSION

Our results suggest that enteral feeding can be continued when a patient is turned from supine to prone position or vice versa. The results indicate that patients with a clinically significant gastric residual volume in one position are likely to have a clinically significant gastric residual volume in the other position.