A potential mechanism by which aspiration of duodenogastric fluid augments the risk for bronchiolitis obliterans syndrome after lung transplantation.

OBJECTIVE: Aspiration of duodenogastric refluxate may damage the respiratory epithelium of lung allografts in transplant recipients. We sought to define a mechanism by which aspiration of duodenogastric fluid augments the risk of bronchiolitis obliterans syndrome after lung transplant in a murine model. METHODS: We analyzed the immunological effects of acute aspiration of duodenogastric fluid (0.5 mL/kg) on transplant naive (strain DBA/2J) and transplanted mice (strain B6D2F1/J to strain DBA/2J). Serum antibodies to the lung self-antigens (SAgs) K-alpha1 tubulin and collagen-V were determined by enzyme-linked immunosorbent assay. Exosomes were isolated from serum, and immunoblot membranes were probed for antibodies to lung SAgs. Lung sections were assessed for fibrotic burden and obliterative bronchiolitis lesions by histologic and immunohistochemical analyses, including trichrome staining. RESULTS: Transplanted mice that received duodenogastric fluid developed higher levels of antibodies to the lung SAgs K-alpha1 tubulin and collagen-V and exosomes with lung SAgs on posttransplant days 14 and 28 than transplanted mice with sham aspiration or transplant naive mice (with and without aspiration). All lung allografts demonstrated severe grade A4 rejection on posttransplant day 14, with the highest mean fibrotic burden and mean number of obliterative bronchiolitis-like lesions per microscopic field on day 28 in recipients with aspiration. CONCLUSIONS: This study links aspiration of duodenogastric fluid after lung transplant to higher autoimmune responses to lung SAgs and the release of circulating exosomes with lung SAgs, which together promote sustained immune responses leading to extensive lung parenchymal damage and, ultimately, severe obliterative bronchiolitis-the histologic hallmark of bronchiolitis obliterans syndrome.

Association of enteral feeding with microaspiration in critically ill adults.

AIM: This study explored relationships between enteral feeding and tracheal pepsin A. BACKGROUND: Mechanically ventilated (MV) patients receiving enteral feeding are at risk for microaspiration. Tracheal pepsin A, an enzyme specific to gastric cells, was a proxy for microaspiration of gastric secretions. METHODS: Secondary analysis of RCT data from critically ill, MV adults was conducted. Microaspiration prevention included elevated head of bed, endotracheal tube cuff pressure management, and regular oral care. Tracheal secretions for pepsin A were collected every 12 h. Microaspiration was defined as pepsin A ≥ 6.25 ng/mL. Positive pepsin A in >30 % of individual tracheal samples was defined as abundant microaspiration (frequent aspirator). Chi-squared, Fisher's Exact test, and generalized linear model (GLM) were used. RESULTS: Tracheal pepsin A was present in 111/283 (39 %) mechanically ventilated patients and 48 (17 %) had abundant microaspiration. Enteral feeding was associated with tracheal pepsin A, which occurred within 24 h of enteral feeding. Of the patients who aspirated, the majority received some enteral feeding 96/111 (86 %), compared to only 15/111 (14 %) who received no feeding. A greater number of positive pepsin A events occurred with post-pyloric feeding tube location (55.6 %) vs. gastric (48.6 %), although significant only at the event-level. Frequent aspirators (abundant pepsin A) had higher pepsin A levels compared to infrequent aspirators. CONCLUSIONS: Our findings confirmed the stomach as the microaspiration source. Contrary to other studies, distal feeding tube location did not mitigate microaspiration. Timing for first positive pepsin A should be studied for possible association with enteral feeding intolerance.

Pro-Con Debate: 1- vs 2-Hour Fast for Clear Liquids Before Anesthesia in Children.

Perioperative fasting guidelines are designed to minimize the risk of pulmonary aspiration of gastrointestinal contents. The current recommendations from the American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology and Intensive Care (ESAIC) are for a minimum 2-hour fast after ingestion of clear liquids before general anesthesia, regional anesthesia, or procedural sedation and analgesia. Nonetheless, in children, fasting guidelines also have consequences as regards to child and parent satisfaction, hemodynamic stability, the ability to achieve vascular access, and perioperative energy balance. Despite the fact that current guidelines recommend a relatively short fasting time for clear fluids of 2 hours, the actual duration of fasting time can be significantly longer. This may be the result of deficiencies in communication regarding the duration of the ongoing fasting interval as the schedule changes in a busy operating room as well as to poor parent and patient adherence to the 2-hour guidelines. Prolonged fasting can result in children arriving in the operating room for an elective procedure being thirsty, hungry, and generally in an uncomfortable state. Furthermore, prolonged fasting may adversely affect hemodynamic stability and can result in parental dissatisfaction with the perioperative experience. In this PRO and CON presentation, the authors debate the premise that reducing the nominal minimum fasting time from 2 hours to 1 hour can reduce the incidence of prolonged fasting and provide significant benefits to children, with no increased risks.

Metabolomic profiling of extraesophageal reflux disease in children.

Although respiratory symptoms in children are often attributed to gastroesophageal reflux disease, establishing a clear diagnosis of extraesophageal reflux disease (EERD) can be challenging, as there are no sensitive or specific EERD biomarkers. The aim of this study was to evaluate the metabolite profile in bronchoalveolar (BAL) fluid from children with suspected EERD and assess the impact of reflux treatment on these metabolites. In this prospective pilot study, we performed nontargeted global metabolomic profiling on BAL fluid from 43 children undergoing testing with bronchoscopy, upper endoscopy, and multichannel intraluminal impedance with pH (pH-MII) for evaluation of chronic respiratory symptoms. Twenty-three (54%) patients had an abnormal pH-MII study. Seventeen (40%) patients were on proton pump inhibitors (PPIs) for testing. Levels of histamine, malate, adenosine 5'-monophosphate, and ascorbate were significantly lower in subjects with abnormal pH-MII studies compared to those normal studies. Furthermore, in children off PPI therapy, those with abnormal pH-MII studies had robust increases in a number of glycerophospholipids within phospholipid metabolic pathways, including derivatives of glycerophosphorylcholine, glycerophosphoglycerol, and glycerophosphoinositol, compared to those with normal pH-MII studies. These findings offer insight into the impact of reflux and PPIs on the lungs and provide a foundation for future studies using targeted metabolomic analysis to identify potential biomarkers of EERD.

Modified Reflux Scintigraphy Detects Pulmonary Microaspiration in Severe Gastro-Esophageal and Laryngopharyngeal Reflux Disease.

INTRODUCTION: Previously described methodologies for detecting laryngopharyngeal reflux (LPR) have limitations. Symptoms alone are non-diagnostic, and pH-impedance studies have poor sensitivity. Pulmonary micro-aspiration is under-recognised in LPR and gastro-esophageal reflux disease (GERD). The present study aimed to describe the results of a modified technique for scintigraphic reflux studies in two groups with severe reflux: those with typical reflux symptoms and those with laryngopharyngeal manifestations of reflux. METHODS: A prospective database of severely symptomatic, treatment-resistant reflux patients was grouped based upon predominant symptom profile of typical GERD or LPR. All patients underwent reflux scintigraphy. Results were obtained for early scintigraphic reflux contamination of the pharynx and proximal esophagus, and delayed contamination of the pharynx and lungs after 2 h. RESULTS: 187 patients were studied (82 GERD, 105 LPR). The LPR patients were predominantly female (70.5% vs. 56.1%; p = 0.042) and older than the GERD group (median age 60 years vs. 55.5 years; p = 0.002). Early scintigraphic reflux was seen at the pharynx in 89.2% (GERD 87.7%, LPR 90.4%; p = 0.133), and at the proximal esophagus in 89.7% (GERD 88.9%, LPR 90.4%; p = 0.147). Delayed contamination of the pharynx was seen in 95.2% (GERD 93.9%, LPR 96.2%; p = 0.468). Delayed pulmonary aspiration was seen in 46% (GERD 36.6%, LPR 53.3%; p = 0.023). CONCLUSION: Reflux scintigraphy demonstrated a high rate of reflux-related pulmonary aspiration. Contamination of the proximal esophagus and pharynx was observed frequently in both groups of severe disease. The likelihood of pulmonary aspiration and potential pulmonary disease needs to be entertained in severe GERD and LPR.

Gastric Ultrasound Assessing Gastric Emptying of Preoperative Carbohydrate Drinks: A Randomized Controlled Noninferiority Study.

BACKGROUND: Tools for the evaluation of gastric emptying have evolved over time. The purpose of this study was to show that the risk of pulmonary aspiration is not increased with carbohydrate drink, by demonstrating that the gastric antral cross-sectional area (CSA) of the NO-NPO group is either equivalent to or less than that of the NPO (nil per os) group. METHODS: Sixty-four patients scheduled for elective laparoscopic benign gynecologic surgery were enrolled and randomly assigned to the NPO group (n = 32) or the NO-NPO group (n = 32). After having a regular meal until midnight before surgery, the NPO group fasted until surgery, while the NO-NPO group ingested 400 mL of a carbohydrate drink at midnight and freely up to 2 hours before anesthesia. The primary outcome was the gastric antral CSA by gastric ultrasound in right lateral decubitus position (RLDP). Noninferiority was defined as a mean difference of CSA <2.8 cm2. Secondary outcomes included CSA in supine position, gastric volume (GV), GV per weight (GV/kg), GV/kg >1.5 mL/kg, and Perlas grade. RESULTS: CSA in RLDP was not different between the NPO group (6.25 ± 3.79 cm2) and the NO-NPO group (6.21 ± 2.48 cm2; P = .959). The mean difference of CSA in RLDP (NO-NPO group - NPO group) was 0.04 (95% confidence interval [CI], -1.56 to 1.64), which was within the noninferiority margin of 2.8 cm2. CSA was not different between the 2 groups (4.17 ± 2.34 cm2 in NPO group versus 4.28 ± 1.23 cm2 in NO-NPO group; P = .828). GV in NPO group (70 ± 56 mL) was not different from NO-NPO group (66 ± 36 mL; mean difference, 3.66; 95% CI, -20 to 27; P = .756). GV/kg in the NPO group (1.25 ± 1.00 mL/kg) was not different from the NO-NPO group (1.17 ± 0.67 mL/kg; P = .694). The incidence of GV/kg > 1.5 mL/kg was not different between NPO (31.3%) and NO-NPO group (21.9%; P = .768). The median (interquartile range) of the Perlas grade was 1 (0-1) in NPO group and 0.5 (0-1) in NO-NPO group (P = .871). CONCLUSIONS: Preoperative carbohydrates ingested up to 2 hours before anesthesia do not delay gastric emptying compared to midnight fasting, as evaluated with gastric ultrasound.

Long-Term Radiologic Evaluation of Microaspirations among Patients after Esophagectomy.

OBJECTIVES: Aspirations are common after esophagectomy. Data are lacking regarding its long-term radiological manifestations. The purpose of this study is to determine the incidence and radiological patterns of aspirations among long-term survivors and evaluate their clinical significance. METHODS: The records of all patients who underwent esophagectomy between October 2003 and December 2011 and survived more than 3 years were reviewed. Preoperative, first routine postoperative, and latest chest computed tomography (CT)scans were reviewed. Imaging studies were reviewed for radiological signs suspicious of aspirations, conduit location, anastomotic site, and maximal intrathoracic diameter. Data regarding patients' complaints during clinic visits were also collected. RESULTS: A total of 578 patients underwent esophagectomy during the study period. One-hundred twenty patients met the inclusion criteria. Median follow-up was 83.5 months. Cervical and intrathoracic anastomoses were performed in 103 and 17 patients, respectively. A higher rate of CT findings was found in postoperative imaging (n = 51 [42.5%] vs. n = 13 [10.8%] respectively, p < 0.05). Most of these were found in the lower lobes (61%). A higher rate of lesions was found among patients in whom the conduit was bulging to the right hemithorax compared with totally mediastinal or completely in the right hemithorax (54.5 vs. 35.2% and 34.6%, respectively, p < 0.05). No correlation was found with conduit diameter or anastomotic site. These lesions were more prevalent among patients who complained of reflux or cough during meals (NS). CONCLUSIONS: A significantly higher rate of new CT findings was found in postoperative imaging of this post-esophagectomy cohort, suggesting a high incidence of aspirations. The locations of the conduit, rather than anastomosis site, seem to play a role in the development of these findings. Further research is needed to evaluate the clinical significance of these findings.

Nulla Per Os (NPO) guidelines: time to revisit?

PURPOSE OF REVIEW: Preoperative fasting guidelines are generalized to elective procedures and usually do not distinguish between the ambulatory and inpatient setting. Prevalence of aspiration is low while prolonged preoperative fasting is common clinical reality. Recently, changes in preoperative fasting guidelines have been widely discussed. RECENT FINDINGS: Rates of prolonged clear fluid fasting (>4 h) prior to surgery are reported in up to 80% of patients with mean fasting duration of up to 16 h and beyond. Prolonged fasting may result in adverse effects such as intraoperative hemodynamic instability, postoperative delirium, patient discomfort, and extended hospital length of stay. Liberal approaches allowing clear fluids up to 1 h prior to anesthesia or until premedication/call to the operating room have shown no increase in adverse events among children. Various anesthesia societies now encourage clear fluid intake up to 1 h prior to pediatric elective anesthesia. Similar reports in the adult cohort are scarce. SUMMARY: Allowing sips of water until call to the operating room may help reducing prolonged preoperative fasting and improving patient comfort while keeping a flexibility in operating room schedule. The feasibility and safety of a liberal clear fluid fasting regimen among adults undergoing elective anesthesia needs to be evaluated in future studies.

Aspiration in lethal drug abuse-a consequence of opioid intoxication.

AIMS: The primary objective of this study was to investigate whether the fatalities of opioid abuse are not only related to respiratory depression but also as a result of other side effects such as emesis, delayed gastric emptying, a reduction of the cough reflex, and impaired consciousness leading to the aspiration of gastric contents, a finding regularly observed in drug-related deaths. DESIGN: A retrospective exploratory study analyzing heroin/morphine/methadone-related deaths submitted to court-ordered autopsy. SETTING: Center for Forensic Medicine, Medical University of Vienna, Austria (2010-2015). PARTICIPANTS: Two hundred thirty-four autopsy cases were included in the study: morphine (n = 200), heroin (n = 11), and methadone (n = 23) intoxication. FINDINGS: Analyses revealed that 41.88% of all deceased showed aspiration of gastric contents with equal gender distribution (p = 0.59). Aspiration was more frequent in younger deceased (χ2 = 8.7936; p = 0.012) and in deceased with higher body mass index (BMI) (χ2 = 6.2441; p = 0.044). Blood opioid concentration was lower in deceased with signs of aspiration than in non-aspirators (p = 0.013). Toxicological evaluation revealed a high degree of concomitant substance abuse (91%)-benzodiazepines (61.6%) and/or alcohol (21.8%). CONCLUSIONS: There are lower opioid concentrations in deceased with signs of aspiration, a fact which strongly points to aspiration as alternative cause of death in opioid-related fatalities. Furthermore, this study highlights the common abuse of slow-release oral morphine in Vienna and discusses alternative medications in substitution programs (buprenorphine/naloxone or tamper-resistant slow-release oral morphine preparations), as they might reduce intravenous abuse and opioid-related deaths.

Práctica actual de la inducción de secuencia rápida en adultos: una encuesta nacional entre anestesiólogos en España / Current practice of rapid sequence induction in adults: a national survey among anesthesiologists in Spain

ANTECEDENTES: La inducción de secuencia rápida (ISR) en adultos ha experimentadcambios en los últimos años debido a los avances farmacológicos y tecnológicos. El objetivo de esta encuesta fue evaluar la práctica actual entre los anestesiólogos españoles. MÉTODOS: Se envió un cuestionario con 31 preguntas referentes a la práctica de la ISR a anestesiólogos de hospitales del Servicio Nacional de Salud de España. Las diferencias en las respuestas relacionadas con el tipo de hospital o experiencia se compararon para todos los datos utilizando el Chi-cuadrado y la prueba exacta de Fisher. RESULTADOS: Aproximadamente el 15,89% de los anestesiólogos españoles participaron en la encuesta (1.002 cuestionarios). Los resultados muestran una gran heterogeneidad en la mayoría de los aspectos de la ISR. El citrato sódico es administrado por menos del 20% de los participantes. El 64% de los encuestados coloca una sonda nasogástrica en pacientes con obstrucción intestinal. El residuo gástrico se evalúa con ultrasonidos en un 6%. Una cuarta parte de los encuestados controla la eficacia de la preoxigenación con la ETO2 y el 22% utiliza la insuflación nasal de oxígeno con gafas nasales o THRIVE. El 62% de los encuestados aplica presión cricoidea, pero solo se libera en un 50% cuando aparece dificultad en la intubación. Hasta el 40% de los anestesiólogos refirieron haber tenido algún caso de aspiración a pesar de aplicar presión cricoidea. El propofol fue el hipnótico más utilizado (97,6%), mientras que no hubo una diferencia clara en la preferencia del relajante neuromuscular (ratio suxametonio versus rocuronio de aproximadamente 1:1). Solo el 44% de los encuestados calcula la dosis de sugammadex necesaria para una reversión de emergencia del rocuronio. CONCLUSIONES: La encuesta demostró una variación significativa en la práctica de la ISR, similar a la de otros países. Se necesitan estudios prospectivos de calidad para estandarizar la práctica clínica

BACKGROUND: Rapid sequence induction (RSI) in adults has undergone changes in recent years due to pharmacological and technological advances. The objective of this survey was to evaluate current practice among Spanish anesthesiologists. METHODS: A 31-item questionnaire regarding RSI practice was sent to anesthesiologists working in Spanish public hospitals. Differences in responses according to the type of hospital or experience of the respondent were compared for all data using the chi-square and Fisher's exact test. RESULTS: Approximately 15.89% of Spanish anesthesiologists participated in the survey (1002 questionnaires). The results show considerable heterogeneity in most aspects of RSI. Less than 20% of respondents administer sodium citrate. Sixty-four percent place a nasogastric tube in patients with intestinal obstruction. Gastric residue is assessed by ultrasound in 6% of cases. Only 25% of respondents measure ETO2 to check the effectiveness of preoxygenation, and 22% use nasal oxygen insufflation with nasal prongs or THRIVE. Sixty two percent of respondents apply cricoid pressure, but only 50% release the pressure when encountering intubation difficulty. Up to 40% of respondents reported cases of aspiration despite applying cricoid pressure. Propofol was the most commonly used hypnotic (97.6%), but there was no clear preference in the choice of neuromuscular relaxant (suxamethonium versus rocuronium ratio of approximately 1:1). Only 44% of respondents calculated the dose of sugammadex that would be required for emergency reversal of rocuronium. CONCLUSIONS: The survey showed significant variation in RSI practice, similar to that of other countries. Quality prospective studies are needed to standardize clinical practice

Proximal reflux: biochemical mediators, markers, therapeutic targets, and clinical correlations.

Airway reflux is implicated in the pathophysiology of a wide range of adult and pediatric upper and lower airway diseases. However, the diagnosis of proximal reflux-associated disease remains challenging due to evolving clinical criteria and institutional and regional variances in diagnostic practices. Evidence suggests that nonacidic contents of reflux may serve as both pathologic mediators of and biomarkers for reflux in the upper airway. Furthermore, they offer potential pharmaceutical and surgical intervention targets and are the focus of novel clinical diagnostic tools currently under investigation.

The profibrotic effects of chronic microaspiration of bile acids on lungs of rats at different stages.

This study aimed to explore the profibrotic effects of chronic microaspiration of two major bile acids, including chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA), on lungs of rats at different stages, as well as the underlying mechanisms in vivo. A rat model was induced by weekly intratracheal instillation of DCA and CDCA. Our results showed that chronic microaspiration of bile acids resulted in alveolar structure disorder, and inflammatory cells infiltration in the pulmonary interstitium at the early stage. Subsequently, numerous fibroblasts were proliferated, and collagen deposition was profoundly increased over the interstitium of the airways and vessels. Compared with control group, the expression of α-smooth muscle actin, type I collagen, hydroxyproline, transforming growth factor-ß1 (TGF-ß1), and matrix metalloproteinase-9 in the lung tissues were remarkably elevated at the 2nd week, reached the highest level at the 6th week, and maintained high at the 8th week in both DCA- and CDCA-treated groups (P < 0.05). Furthermore, chronic microaspiration of bile acids led to higher levels of glutathione and malondialdehyde, while lower level of superoxide dismutase in lung tissues compared with controls (P < 0.05), thereby resulting in the oxidant/antioxidant enzyme imbalance in the formation of fibrosis. In addition, we also found a consistent growth in the expression of farnesoid X receptor (FXR) in both DCA- and CDCA-treated groups. Our findings suggested that chronic microaspiration of bile acids could initiate the process of pulmonary fibrosis from the early phase and promote its progression in a time-dependent manner, which likely involved the TGF-ß1, oxidative stress, and FXR-related pathways.

Predictive factors for gastrostomy at time of diagnosis and impact on survival in patients with amyotrophic lateral sclerosis.

BACKGROUND: Gastrostomy is recommended in patients with Amyotrophic Lateral Sclerosis (ALS) in the presence of weight loss over 10% as compared to usual weight, repeated aspirations or meal time duration longer than 45 min. Currently, the impact of gastrostomy on survival of ALS patients is not clear. AIMS: i) to describe diagnosis factors associated with the indication for gastrostomy ii) to evaluate survival of ALS patients with gastrostomy indication according to their acceptance of feeding tube placement. METHODS: Patients with ALS were included and followed in the ALS referral centre of Limoges's teaching hospital between 2006 and 2017. Neurological, nutritional and respiratory status was assessed prospectively from diagnosis to death. Statistical analysis was performed using Mann-Whitney test, Chi2 tests, Cox model and multivariate logistic regression. RESULTS: Two hundred and eighty-five patients were included. Among the 182 for whom gastrostomy was indicated, 63.7% accepted the placement. The median time was 7.3 months [IQR: 3.2-15.0] and 2.7 months [IQR: 0.9-5.8] respectively from diagnosis to indication and from indication to placement. Weight loss >5% significantly increased the risk of death by 17% (p < 0.0001). At time of diagnosis, bulbar onset, a loss of one point in the body mass index or on the bulbar functional scale were all positively associated with indication for gastrostomy (aOR = 10.0 [95%CI: 1.96-25.0]; p = 0.002, aOR = 1.17 [95%CI: 1.02-1.36]; p = 0.025 and aOR = 1.19 [95%CI: 1.06-1.32]; p = 0.002, respectively). However, gastrostomy placement did not have any impact on survival (aHR = 1.25 [95%CI: 0.88-1.79]; p = 0.22). CONCLUSION: Both neurological and nutritional criteria were associated with an indication for gastrostomy at diagnosis. Gastrostomy placement had no impact on survival. The study of earlier gastrostomy placement might be of interest in further prospective studies.

A Quality Improvement Initiative to Reduce Gastrostomy Tube Placement in Aspirating Patients.

OBJECTIVES: Oropharyngeal dysphagia and aspiration may occur in infants and children. Currently, there is wide practice variation regarding when to feed children orally or place more permanent gastrostomy tube placement. Through implementation of an evidence-based guideline (EBG), we aimed to standardize the approach to these patients and reduce the rates of gastrostomy tube placement. METHODS: Between January 2014 and December 2018, we designed and implemented a quality improvement intervention creating an EBG to be used by gastroenterologists evaluating patients ≤2 years of age with respiratory symptoms who were found to aspirate on videofluoroscopic swallow study (VFSS). Our primary aim was to encourage oral feeding and decrease the use of gastrostomy tube placement by 10% within 1 year of EBG initiation; balancing measures included total hospital readmissions or emergency department (ED) visits within 6 months of the abnormal VFSS. RESULTS: A total of 1668 patients (27.2%) were found to have aspiration or penetration noted on an initial VFSS during our initiative. Mean gastrostomy tube placement in these patients was 10.9% at the start of our EBG implementation and fell to 5.2% approximately 1 year after EBG initiation; this improvement was sustained throughout the next 3 years. Our balancing measures of ED visits and hospital readmissions also did not change during this time period. CONCLUSIONS: Through implementation of this EBG, we reduced gastrostomy tube placement by 50% in patients presenting with oropharyngeal dysphagia and aspiration, without increasing subsequent hospital admissions or ED visits.

An international multidisciplinary consensus statement on fasting before procedural sedation in adults and children.

The multidisciplinary International Committee for the Advancement of Procedural Sedation presents the first fasting and aspiration prevention recommendations specific to procedural sedation, based on an extensive review of the literature. These were developed using Delphi methodology and assessment of the robustness of the available evidence. The literature evidence is clear that fasting, as currently practiced, often substantially exceeds recommended time thresholds and has known adverse consequences, for example, irritability, dehydration and hypoglycaemia. Fasting does not guarantee an empty stomach, and there is no observed association between aspiration and compliance with common fasting guidelines. The probability of clinically important aspiration during procedural sedation is negligible. In the post-1984 literature there are no published reports of aspiration-associated mortality in children, no reports of death in healthy adults (ASA physical status 1 or 2) and just nine reported deaths in adults of ASA physical status 3 or above. Current concerns about aspiration are out of proportion to the actual risk. Given the lower observed frequency of aspiration and mortality than during general anaesthesia, and the theoretical basis for assuming a lesser risk, fasting strategies in procedural sedation can reasonably be less restrictive. We present a consensus-derived algorithm in which each patient is first risk-stratified during their pre-sedation assessment, using evidence-based factors relating to patient characteristics, comorbidities, the nature of the procedure and the nature of the anticipated sedation technique. Graded fasting precautions for liquids and solids are then recommended for elective procedures based upon this categorisation of negligible, mild or moderate aspiration risk. This consensus statement can serve as a resource to practitioners and policymakers who perform and oversee procedural sedation in patients of all ages, worldwide.

An international survey about rapid sequence intubation of 10,003 anaesthetists and 16 airway experts.

Pulmonary aspiration of gastric content is a significant cause of anaesthesia-related morbidity and mortality. High-quality prospective randomised evidence to support prevention strategies, such as rapid sequence intubation, is difficult to generate due to well-described practical, ethical and methodological barriers. We aimed to generate an understanding of worldwide practice through surveying clinically practicing anaesthetists and airway experts. Our survey was designed to assess the influence of: departmental standards; patient factors; socio-economic factors; training; and supervision. We surveyed 10,003 anaesthetists who responded to an invitation to participate on LinkedIn. We then surveyed 16 international airway experts on the same content. When asked about a hypothetical patient with intestinal obstruction, respondents expressed preferences for [OR (95%CI)]: the head-up or -down position 4.26 (3.98-4.55), p < 0.001; nasogastric tube insertion 29.5 (26.9-32.3), p < 0.001; and the use of cricoid force 2.80 (2.62-3.00), p < 0.001, as compared with a hypothetical patient without intestinal obstruction also requiring rapid sequence intubation. Respondents from lower income countries were more likely to prefer [OR (95%CI]: the supine position 2.33 (2.00-2.63), p < 0.001; nasogastric tube insertion 1.29 (1.09-1.51), p = 0.002; and cricoid force application 2.54 (2.09-3.09), p < 0.001 as compared with respondents from higher income countries for a hypothetical patient with intestinal obstruction. This survey, which we believe is the largest of its kind, demonstrates that preferences for positioning, nasogastric tube use and cricoid force application during rapid sequence intubation vary substantially. Achieving agreed consensus may yield better training in the principles of rapid sequence intubation.

Reliability of gastric suctioning compared with ultrasound assessment of residual gastric volume: a prospective multicentre cohort study.

We aimed to compare the reliability of aspiration via a nasogastric tube with ultrasound for assessment of residual gastric volume. Sixty-one adult patients who were mechanically ventilated and received continuous enteral feeding through a nasogastric tube for > 48 h were included. A first qualitative and quantitative ultrasound examination of the gastric antrum was followed by gastric suctioning, performed by an operator blinded to the result of the ultrasound examination. A second ultrasound examination was performed thereafter, followed by re-injection of the aspirated gastric contents (≤ 250 ml) into the stomach. A third ultrasound assessment was then immediately performed. If the suctioned volume was ≥ 250 ml, 250 mg erythromycin was infused over 30 min. A fourth ultrasound was performed 90 min after the third. Sixty (98%) patients had a qualitatively assessed full stomach at first ultrasound examination vs. 52 (85%) after gastric suctioning (p = 0.016). The calculated gastric volume significantly decreased after gastric suctioning, without a significant decrease in the number of patients with volume ≥ 250 ml. Four of the nine patients with calculated gastric volume ≥ 250 ml had vomiting within the last 24 h (p = 0.013). The antral cross-sectional area significantly decreased between the third and the fourth ultrasound examination (p = 0.015). Erythromycin infusion did not make a significant difference to gastric volume (n = 10). Our results demonstrate that gastric suctioning is not a reliable tool for monitoring residual gastric volume. Gastric ultrasound is a feasible and promising tool for gastric volume monitoring in clinical practice.