Gastric Point-of-Care Ultrasound in Acutely and Critically Ill Children (POCUS-ped): A Scoping Review.

Introduction: Point-of-care ultrasound (POCUS) use is increasing in pediatric clinical settings. However, gastric POCUS is rarely used, despite its potential value in optimizing the diagnosis and management in several clinical scenarios (i.e., assessing gastric emptying and gastric volume/content, gastric foreign bodies, confirming nasogastric tube placement, and hypertrophic pyloric stenosis). This review aimed to assess how gastric POCUS may be used in acute and critically ill children. Materials and Methods: An international expert group was established, composed of pediatricians, pediatric intensivists, anesthesiologists, radiologists, nurses, and a methodologist. A scoping review was conducted with an aim to describe the use of gastric POCUS in pediatrics in acute and critical care settings. A literature search was conducted in three databases, to identify studies published between 1998 and 2022. Abstracts and relevant full texts were screened for eligibility, and data were extracted, according to the JBI methodology (Johanna Briggs Institute). Results: A total of 70 studies were included. Most studies (n = 47; 67%) were conducted to assess gastric emptying and gastric volume/contents. The studies assessed gastric volume, the impact of different feed types (breast milk, fortifiers, and thickeners) and feed administration modes on gastric emptying, and gastric volume/content prior to sedation or anesthesia or during surgery. Other studies described the use of gastric POCUS in foreign body ingestion (n = 6), nasogastric tube placement (n = 5), hypertrophic pyloric stenosis (n = 8), and gastric insufflation during mechanical ventilatory support (n = 4). POCUS was performed by neonatologists, anesthesiologists, emergency department physicians, and surgeons. Their learning curve was rapid, and the accuracy was high when compared to that of the ultrasound performed by radiologists (RADUS) or other gold standards (e.g., endoscopy, radiography, and MRI). No study conducted in critically ill children was found apart from that in neonatal intensive care in preterms. Discussion: Gastric POCUS appears useful and reliable in a variety of pediatric clinical settings. It may help optimize induction in emergency sedation/anesthesia, diagnose foreign bodies and hypertrophic pyloric stenosis, and assist in confirming nasogastric tube placement, avoiding delays in obtaining confirmatory examinations (RADUS, x-rays, etc.) and reducing radiation exposure. It may be useful in pediatric intensive care but requires further investigation.

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.

Planned Peri-Extubation Fasting in Critically Ill Children: An International Survey of Practice.

Introduction: Cumulative energy/protein deficit is associated with impaired outcomes in pediatric intensive care Units (PICU). Enteral nutrition is the preferred mode, but its delivery may be compromised by periods of feeding interruptions around procedures, with peri-extubation fasting the most common procedure. Currently, there is no evidence to guide the duration of the peri-extubation fasting in PICU. Therefore, we aimed to explore current PICU fasting practices around the time of extubation and the rationales supporting them. Materials and Methods: A cross sectional electronic survey was disseminated via the European Pediatric Intensive Care Society (ESPNIC) membership. Experienced senior nurses, dieticians or doctors were invited to complete the survey on behalf of their unit, and to describe their practice on PICU fasting prior to and after extubation. Results: We received responses from 122 PICUs internationally, mostly from Europe. The survey confirmed that fasting practices are often extrapolated from guidelines for fasting prior to elective anesthesia. However, there were striking differences in the duration of fasting times, with some units not fasting at all (in patients considered to be low risk), while others withheld feeding for all patients. Fasting following extubation also showed large variations in practice: 46 (38%) and 26 (21%) of PICUs withheld oral and gastric/jejunal nutrition more than 5 h, respectively, and 45 (37%) started oral feeding based on child demand. The risk of vomiting/aspiration and reducing nutritional deficit were the main reasons for fasting children [78 (64%)] or reducing fasting times [57 (47%)] respectively. Discussion: This variability in practices suggests that shorter fasting times might be safe. Shortening the duration of unnecessary fasting, as well as accelerating the extubation process could potentially be achieved by using other methods of assessing gastric emptiness, such as gastric point of care ultrasonography (POCUS). Yet only half of the units were aware of this technique, and very few used it.

Pre-operative fasting in children: A guideline from the European Society of Anaesthesiology and Intensive Care.

Current paediatric anaesthetic fasting guidelines have recommended conservative fasting regimes for many years and have not altered much in the last decades. Recent publications have employed more liberal fasting regimes with no evidence of increased aspiration or regurgitation rates. In this first solely paediatric European Society of Anaesthesiology and Intensive Care (ESAIC) pre-operative fasting guideline, we aim to present aggregated and evidence-based summary recommendations to assist clinicians, healthcare providers, patients and parents. We identified six main topics for the literature search: studies comparing liberal with conservative regimens; impact of food composition; impact of comorbidity; the use of gastric ultrasound as a clinical tool; validation of gastric ultrasound for gastric content and gastric emptying studies; and early postoperative feeding. The literature search was performed by a professional librarian in collaboration with the ESAIC task force. Recommendations for reducing clear fluid fasting to 1 h, reducing breast milk fasting to 3 h, and allowing early postoperative feeding were the main results, with GRADE 1C or 1B evidence. The available evidence suggests that gastric ultrasound may be useful for clinical decision-making, and that allowing a 'light breakfast' may be well tolerated if the intake is well controlled. More research is needed in these areas as well as evaluation of how specific patient or treatment-related factors influence gastric emptying.

Effect of patient head position on the aspirated volume of regurgitated clear fluid. A fresh human cadaver study.

INTRODUCTION: The relationship between regurgitated and aspirated volume of clear fluids remains undetermined and may depend on anatomical factors and patient position. We aimed to assess whether head position (sniffing vs. extension position) affected this relationship in fresh human cadavers. We also determined the critical volume of water regurgitated that led to pulmonary aspiration of volume ≥ 0.8 mL kg-1 and ≥ 1.5 mL kg-1 for each head position. MATERIAL AND METHODS: Six volumes of water (40, 80, 100, 120, 150, and 200 mL) were injected each twice, in a randomised order, at a flow rate of 20 mL per second, into the oesophagus of seven fresh human cadavers lying in the supine position on a non-tilted table, with the head in the sniffing position and in the extension position. Aspirated volume was measured in the trachea, blindly to the volume injected. RESULTS: Overall, more than 85% of the regurgitated volume was aspirated into the trachea. The volume of aspirated water was significantly greater in the sniffing position than in the extension position. The cut-off volumes of water injected into the oesophagus leading to aspirated volume ≥ 0.8 mL kg-1 and ≥ 1.5 mL kg-1 were, respectively, 0.8 mL kg-1 and 1.5 mL kg-1 in the sniffing position, and 1.2 mL kg-1 and 1.8 mL kg-1 in the extension position. CONCLUSIONS: These results confirm that most of the regurgitated clear fluid enters the trachea in humans lying in the supine position on a non-tilted table, especially when the head is in the sniffing position.

Relationship between the regurgitated and the aspirated volume of water. A manikin study.

BACKGROUND: The relationship between gastric fluid volume, volume of fluid regurgitated, and aspirated fluid volume remains unclear. Using a life-like manikin suitable for a pulmonary aspiration model, we aimed to assess the relationship between regurgitated and aspirated clear fluid volumes, and to determine the minimal value of the volume of liquid regurgitated that may lead to pulmonary aspiration of fluid volume ≥ 0.8 mL kg-1 (around 60 mL) that is likely to cause lung injury. METHODS: Several volumes of water ranging from 30 to 150 mL were injected in a randomized order, at a flow rate of 20 mL per second, into the esophagus of a manikin lying in the supine position on a non-tilted table, with the manikin head in the extension or in the sniffing position. Aspirated volumes were measured in the manikin bronchi, by an investigator blinded to the volume injected. Aspiration was defined as positive when the volume of collected water was ≥ 60 mL for at least one of the five injections of each volume of water. RESULTS: The minimal volume of water injected into the esophagus for an aspirated volume ≥ 0.8 mL kg-1 was 85 mL in the sniffing position, and was 150 mL in the extension position. CONCLUSIONS: These results suggest that the critical cut-off value of gastric fluid volume to be considered for the risk of significant pulmonary aspiration would be ≥ 85 mL (≥ 1 mL kg-1), in the sniffing position. These results should however be confirmed in further studies using other models.

Prevalence and prediction of higher estimated gastric content in parturients at full cervical dilatation: A prospective cohort study.

BACKGROUND: Emergent obstetrical procedures may require general anaesthesia in parturients at full cervical dilatation or immediately after vaginal birth. This study aimed to determine the prevalence and the predictive factors of higher estimated gastric content in parturients at full cervical dilatation with epidural analgesia and allowed to drink during the labour, and to assess the ability of the antral area measured in the semirecumbent position (SR-CSA) to identify higher estimated gastric content in this setting. METHODS: This prospective observational study was conducted between December 2016 and July 2017. Ultrasonographic examination of the antrum was performed at full cervical dilatation, within the hour preceding the beginning of expulsive efforts. Higher estimated gastric content was defined when solid content was observed and/or if the calculated gastric fluid volume was >1.5 mL/kg. RESULTS: Seventeen of 62 parturients (27%) presented higher estimated gastric content. Maximal pain intensity during the last hour of labour and time interval between the insertion of the epidural catheter and ultrasonographic examination were significantly increased in parturients with higher estimated gastric content. The threshold value of the SR-CSA to identify a higher estimated gastric content was 393 mm2 , with sensitivity = 88% and specificity = 87%. CONCLUSION: Around a quarter of parturients with epidural analgesia and free access to clear fluids during labour presented higher estimated gastric content at full cervical dilatation. The SR-CSA may be of interest for the fast ultrasound assessment of the gastric content status in case of emergent obstetrical procedures at full cervical dilatation.