Diagnostic performance of ultrasound in the assessment of gastric contents: a meta-analysis and systematic review.

OBJECTIVE: To systematically analyze the accuracy of ultrasonic techniques in assessing the nature of gastric contents and their volume. METHODS: English-language articles that used ultrasonic techniques to assess the nature of gastric contents and their volume in patients were selected. In eligible studies, data were recalculated and analyzed for forest plots and subject summary curves of operating characteristics (SROC). Study quality was assessed using the diagnostic accuracy study quality assessment tool QUADAS-2. Publication bias was tested using funnel plots. RESULTS: Nine articles with a total of 523 study subjects were identified for this review. All studies were feasibility studies. The sensitivity of ultrasound assessment of gastric contents ranged from 53 to 100% and the specificity from 48 to 99%. The combined analysis yielded an area under the working characteristic curve for subjects of 97% (95% confidence interval (CI), 95-98%), a sensitivity of 95% (95% CI, 84-99%), and a specificity of 88% (95% CI, 72-95%). There was a high degree of heterogeneity among the studies due to inter-operator differences and small sample sizes. CONCLUSION: Ultrasound techniques have high diagnostic accuracy in assessing the nature of gastric contents and their volume in patients. However, most of the studies were feasibility studies with small sample sizes, lacked standardization, and had high risk of bias. More studies are needed in the future to investigate the diagnostic performance of gastric ultrasound assessment techniques. CRITICAL RELEVANCE STATEMENT: Ultrasonography can be used to assess gastric contents, but standardized data integration and reporting are needed to account for the diagnostic capabilities of this technology. KEY POINTS: • Ultrasound is a safe and feasible tool for assessing gastric contents. • Ultrasound has good diagnostic performance for gastric contents. • There is still a certain heterogeneity within our analysis process; more research is needed in the future to improve our results.

Prevalence and factors associated with high-risk gastric contents in women admitted to the maternity unit for childbirth: a prospective multicentre cohort study.

BACKGROUND: This multicentre prospective observational study sought to determine the prevalence and the factors associated with high-risk gastric contents in women admitted to the maternity unit for childbirth, and to identify the clinical situations in which ultrasound assessment of gastric contents would be most helpful (i.e. when the prevalence of high-risk gastric contents is close to 50%). METHODS: Ultrasound assessments of gastric contents were performed within the first hour after admission to the maternity unit. The prevalence of high-risk gastric contents was calculated and variables associated with high-risk gastric contents were identified using logistic regression analyses. RESULTS: A total of 1003 parturients were analysed. The prevalence of high-risk gastric contents was 70% (379/544; 95% confidence interval: 66-74%) in women admitted in spontaneous labour and 65% (646/1003; 95% confidence interval: 61-67%) in the whole cohort. Lower gestational age, increased fasting duration for solids, and elective Caesarean delivery were independently associated with reduced likelihood of high-risk gastric contents. In women admitted in spontaneous labour and in the whole cohort, the prevalence of high-risk gastric contents ranged from 85% to 86% for fasting duration for solids <6 h, 63%-68% for fasting 6-8 h, 54%-55% for fasting 8-12 h, and 47%-51% for fasting ≥12 h. CONCLUSIONS: Around two-thirds of parturients had high-risk gastric contents within the first hour after admission to the maternity unit. Our results suggest that gastric emptying for solids continues in labouring women, and that gastric ultrasound would be most helpful when fasting duration is ≥8 h.

A fatal case of aspiration due to consumption of the hallucinogenic tryptamine derivative dipropyltryptamine (DPT).

BACKGROUND AND AIM: This case involves a 20-year-old man with prior hallucinogen-use experience, who sniffed an unknown amount of dipropyltryptamine in an apartment. Dipropyltryptamine, a hallucinogenic compound belonging to the tryptamine class is recognized for inducing effects similar to dimethyltryptamine (DMT) but with a longer duration. Ten to fifteen minutes later he experienced visual hallucinations, followed by increasing apathy. Two hours post consumption he developed abdominal pain, leading to collapse, seizure, and vomiting. Despite emergency medical resuscitation on site, transport to hospital 2.5 hours post consumption and extracorporeal life support he died 21 hours later. Relevant toxicological and morphological findings are presented. METHODS: A serum sample was collected four hours post consumption. Autopsy was performed six days after death. Antemortem serum, as well as postmortem cardiac blood and urine were analyzed for alcohol and psychoactive drugs by systematic toxicological analyses employing gas chromatography-mass spectrometry (Maurer/Pfleger/Weber library among others), liquid chromatography-ion trap mass spectrometry (LC-MSn, Toxtyper™), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Dipropyltryptamine was quantified by LC-MS/MS after solid-phase extraction. RESULTS: Autopsy revealed a state after deep aspiration of gastric contents with consecutive brain edema due to oxygen deprivation. Dipropyltryptamine concentrations were approximately 210 ng/ml, 110 ng/ml and 180 ng/ml in antemortem serum, postmortem cardiac blood and urine, respectively. To the best of our knowledge, these are the first reported concentrations of dipropyltryptamine in a fatal case. CONCLUSION: Unlike typical tryptamine overdose reports, this case did not present with agitation, hyperthermia, or tachycardia. Despite the individual's prior experience with tryptamines and the generally low toxicity associated with this class of hallucinogens, death in this case was an indirect consequence of the nasal consumption of a high dose of dipropyltryptamine.

Diagnostic accuracy of a simple qualitative ultrasound assessment for the diagnosis of high-risk gastric contents in the parturient. A prospective observational cohort study.

STUDY OBJECTIVE: Interpretation of gastric ultrasound relies on the use of a clinical algorithm that combines qualitative analysis of the gastric antrum contents with the calculation of the volume of fluid contents. This reference method may be difficult to apply in the parturient. We therefore aimed to assess the diagnostic accuracy of a simple qualitative assessment in the supine position for the diagnosis of high-risk gastric contents in the parturient. We also assessed the diagnostic accuracy of a composite scale and another clinical algorithm based on a mathematical model different to that used in the reference method. DESIGN: Prospective observational cohort study. SETTING: University hospital, Lyon, France. PATIENTS: Adult women admitted to the delivery room. INTERVENTIONS: Qualitative and quantitative gastric ultrasound examination within the first hour following admission. MEASUREMENTS: With respect to the reference method, the diagnostic accuracy of a simple qualitative assessment for the diagnosis of high-risk gastric contents was assessed. The diagnostic accuracy of a composite scale and another clinical algorithm, and the agreement between each approach were also assessed. MAIN RESULTS: A total of 235 parturients were included and analyzed. The simple qualitative assessment led to conclusive ultrasound assessment in 233 (99%) women, while the reference method led to conclusive assessment in 213 (91%) women (P < 0.05). The sensitivity and the specificity of the simple qualitative assessment were 97% (95%CI: 93 to 99%) and 96% (95%CI: 90 to 99%), respectively. These were not significantly different from those of the composite scale and the clinical algorithm. The four approaches showed almost perfect agreement with each other. CONCLUSIONS: These results suggest that simple qualitative assessment may be useful in clinical practice to help the anesthesiologist in the assessment of gastric contents status and risk of aspiration.

Development and validation of a novel nomogram model to assess the risk of gastric contents in outpatients undergoing elective sedative gastrointestinal endoscopy procedures.

BACKGROUND: Gastric contents may contribute to patients' aspiration during anesthesia. Ultrasound can accurately assess the risk of gastric contents in patients undergoing sedative gastrointestinal endoscopy (GIE) procedures, but its efficiency is limited. Therefore, developing an accurate and efficient model to predict gastric contents in outpatients undergoing elective sedative GIE procedures is greatly desirable. METHODS: This study retrospectively analyzed 1501 patients undergoing sedative GIE procedures. Gastric contents were observed under direct gastroscopic vision and suctioned through the endoscope. High-risk gastric contents were defined as having solid content or liquid volume > 25 ml and pH < 2.5; otherwise, they were considered low-risk gastric contents. Univariate analysis and multivariate analysis were used to select the independent risk factors to predict high-risk gastric contents. Based on the selected independent risk factors, we assigned values to each independent risk factor and established a novel nomogram. The performance of the nomogram was verified in the testing cohort by the metrics of discrimination, calibration, and clinical usefulness. In addition, an online accessible web calculator was constructed. RESULTS: We found BMI, cerebral infarction, cirrhosis, male, age, diabetes, and gastroesophageal reflux disease were risk factors for gastric contents. The AUROCs were 0.911 and 0.864 in the development and testing cohort, respectively. Moreover, the nomogram showed good calibration ability. Decision curve analysis and Clinical impact curve demonstrated that the predictive nomogram was clinically useful. The website of the nomogram was https://medication.shinyapps.io/dynnomapp/. CONCLUSIONS: This study demonstrates that clinical variables can be combined with algorithmic techniques to predict gastric contents in outpatients. Nomogram was constructed from routine variables, and the web calculator had excellent clinical applicability to assess the risk of gastric contents accurately and efficiently in outpatients, assist anesthesiologists in assessment and identify the most appropriate patients for ultrasound.

A way forward in pulmonary aspiration incidence reduction: ultrasound, mathematics, and worldwide data collection

Abstract Aspiration of gastric contents during induction of general anesthesia remains a significant cause of mortality and morbidity in anesthesia. Recent data show that pulmonary aspiration still accounts for many cases with implications on mortality despite technical and technological evolution. Practical, ethical, and methodological issues prevent high-quality research in the setting of aspiration and rapid sequence induction/intubation, and significant controversy is ongoing. Patients' position, drugs choice, dosing and timing, use of cricoid force, and a reliable risk assessment are widely debated with significant questions still unanswered. We focus our discussion on three approaches to promote a better understanding of rapid sequence induction/intubation and airway management decision-making. Firstly, we review how we can use qualitative and quantitative assessment of fasting status and gastric content with the point-of-care ultrasound as an integral part of preoperative evaluation and planning. Secondly, we propose using imaging-based mathematical models to study different patient positions and aspiration mechanisms, including identifying aspiration triggers. Thirdly, we promote the development of a global data collection system aiming to obtain precise epidemiological data. Therefore, we fill the gap between evidence-based medicine and experts' opinion through easily accessible and diffused computer-based databases. A better understanding of aspiration epidemiology obtained through focused global data gathering systems, the widespread use of ultrasound-based prandial status evaluation, and development of advanced mathematical models might potentially guide safer airway management decision making in the 21st century.

Comparison of Intubation Conditions Between Airtraq, McGrath Video Laryngoscopes, and Macintosh Under Conditions of Simulated Trauma Airway and Rapid Sequence Induction Intubation.

BACKGROUND: Patients arriving at the emergency department with a potential cervical spine injury and immobilized in a rigid cervical collar often require emergency airway management and rapid sequence induction intubation (RSII). There have been several advances in airway management with the advent of channeled (AirtraqⓇ; Prodol Meditec) and nonchanneled (McGrathⓇ; Meditronics) video laryngoscopes, which enable intubation without the removal of the cervical collar, but their efficacy and superiority over conventional laryngoscopy (Macintosh) in the presence of a rigid cervical collar and cricoid pressure have not been evaluated. OBJECTIVE: Our aim was to compare the channeled (Airtraq [group A]) and nonchanneled (McGrath [Group M]) video laryngoscopes with a conventional laryngoscope (Macintosh [Group C]) in a simulated trauma airway. METHODS: A prospective randomized controlled study was conducted in a tertiary care center. Participants were 300 patients requiring general anesthesia (American Society of Anesthesiologists class I or II), of both sexes, and aged 18-60 years. Airway management was simulated without removal of a rigid cervical collar and using cricoid pressure during intubation. After RSI, patients were intubated with one of the study techniques according to randomization. Intubation time and intubation difficulty scale (IDS) score were noted. RESULTS: Mean intubation time was 42.2 s in group C, 35.7 s in group M, and 21.8 s in group A (p = 0.001). Intubation was easy in group M and group A (median IDS score of 0; interquartile range [IQR] 0-1 for group M and median IDS score of 1; IQR 0-2 for group A and group C; p < 0.001). A higher proportion (95.1%) of patients had an IDS score of < 1 in group A. CONCLUSIONS: The performance of RSII with cricoid pressure in the presence of a cervical collar was easier and more rapid with channeled video laryngoscope than with other techniques.

A way forward in pulmonary aspiration incidence reduction: ultrasound, mathematics, and worldwide data collection.

Aspiration of gastric contents during induction of general anesthesia remains a significant cause of mortality and morbidity in anesthesia. Recent data show that pulmonary aspiration still accounts for many cases with implications on mortality despite technical and technological evolution. Practical, ethical, and methodological issues prevent high-quality research in the setting of aspiration and rapid sequence induction/intubation, and significant controversy is ongoing. Patients' position, drugs choice, dosing and timing, use of cricoid force, and a reliable risk assessment are widely debated with significant questions still unanswered. We focus our discussion on three approaches to promote a better understanding of rapid sequence induction/intubation and airway management decision-making. Firstly, we review how we can use qualitative and quantitative assessment of fasting status and gastric content with the point-of-care ultrasound as an integral part of preoperative evaluation and planning. Secondly, we propose using imaging-based mathematical models to study different patient positions and aspiration mechanisms, including identifying aspiration triggers. Thirdly, we promote the development of a global data collection system aiming to obtain precise epidemiological data. Therefore, we fill the gap between evidence-based medicine and experts' opinion through easily accessible and diffused computer-based databases. A better understanding of aspiration epidemiology obtained through focused global data gathering systems, the widespread use of ultrasound-based prandial status evaluation, and development of advanced mathematical models might potentially guide safer airway management decision making in the 21st century.

Ultrasound assessment of residual gastric volume in older adults undergoing staged-bilateral total knee arthroplasty after consuming carbohydrate-containing fluids: a prospective observational study.

BACKGROUND: We compared preoperative residual gastric volume (GV) between the first and second stages of total knee arthroplasty (TKA) in older adults after drinking carbohydrate-containing fluid 2 h prior to surgery. METHODS: In this study, 36 patients, aged > 65 years, scheduled for staged bilateral TKA with one-week interval, were enrolled. The patients consumed 400 ml of carbohydrate-containing fluid 2 h prior to surgery. Before the induction of spinal anesthesia, the gastric antral cross-sectional area was measured at the first and second TKA using ultrasound, and the residual GV was calculated. The primary outcome was the residual GV. Qualitative GV (grades 0, 1, and 2) and analgesic consumption after the first TKA were assessed as secondary outcomes. RESULTS: The GV (median [Q1, Q3]) was greater in the second-stage TKA (41.1 [22.5, 62.8] ml) than in the first-stage TKA (10.3 [0.0, 27.1] ml) (P < 0.001). In the qualitative assessment, the distribution was not different between the two stages of TKA (P = 0.219) and only one patient showed grade 2 gastric content in the second TKA. When opioid consumption was converted to an equivalent dose of morphine, an average of 53.9 mg of morphine was required after the first TKA. CONCLUSIONS: Residual GV after drinking carbohydrate-containing fluid differed according to the stage of TKA, showing a larger residual GV in the second TKA than in the first one. In older adults scheduled to undergo bilateral staged TKA, caution is required in preoperative fasting practice, especially in second-stage surgery.

Preoperative fasting for the infusion of "yerba mate": a randomized clinical trial with ultrasound evaluation of gastric contents

Abstract Background The traditional infusion of "yerba mate" is widely consumed in South America and exported to countries around the world. Although generally considered a "clear fluid", there is no data to date on the gastric emptying time of yerba mate and safe preoperative fasting intervals. The objective of this study was to evaluate the gastric emptying time of a standardized infusion of yerba mate using bedside ultrasound and compare it with the time confirm of hot and cold tea. Methods This was a prospective, randomized crossover experimental study. Thirty healthy volunteers were evaluated after 8 hours of fasting for both fluids and solids. Gastric antral area and gastric volume were evaluated at baseline and every 20 minutes after drinking 300 mL of randomly assigned infusion of "yerba mate", hot tea, or cold tea. Results The mean gastric emptying time was: 69.7 ± 22.1 min, 63.1 ± 14.5 min, and 64.3 ± 23.5 min for the mate, hot tea, and cold tea respectively. No significant differences were found in emptying time among the infusion groups (p-value = 0.043). When same time measures were compared, the only significant difference detected was between hot teas and mate infusion at 20 minutes (p-value = 0.012) Conclusion Yerba mate infusion has a similar gastric emptying time to that of tea. All subject's gastric volume returned to baseline values by 100 minutes. It is reasonable to recommend a similar fasting period of 2 hours for mate infusion prior to elective surgery.

Preoperative fasting for the infusion of "yerba mate": a randomized clinical trial with ultrasound evaluation of gastric contents.

BACKGROUND: The traditional infusion of "yerba mate" is widely consumed in South America and exported to countries around the world. Although generally considered a "clear fluid", there is no data to date on the gastric emptying time of yerba mate and safe preoperative fasting intervals. The objective of this study was to evaluate the gastric emptying time of a standardized infusion of yerba mate using bedside ultrasound and compare it with the time confirm of hot and cold tea. METHODS: This was a prospective, randomized crossover experimental study. Thirty healthy volunteers were evaluated after 8 hours of fasting for both fluids and solids. Gastric antral area and gastric volume were evaluated at baseline and every 20 minutes after drinking 300 mL of randomly assigned infusion of "yerba mate", hot tea, or cold tea. RESULTS: The mean gastric emptying time was: 69.7 ± 22.1 min, 63.1 ± 14.5 min, and 64.3 ± 23.5 min for the mate, hot tea, and cold tea respectively. No significant differences were found in emptying time among the infusion groups (p-value = 0.043). When same time measures were compared, the only significant difference detected was between hot teas and mate infusion at 20 minutes (p-value = 0.012) CONCLUSION: Yerba mate infusion has a similar gastric emptying time to that of tea. All subject's gastric volume returned to baseline values by 100 minutes. It is reasonable to recommend a similar fasting period of 2 hours for mate infusion prior to elective surgery.

Ultrasound assessment of gastric contents prior to placental delivery: A prospective multicentre cohort study.

BACKGROUND: There is ongoing debate regarding the optimal general anaesthetic technique for manual removal of the placenta after vaginal delivery. Using ultrasound examination of the gastric antrum, this study aimed to assess the change in gastric contents during vaginal delivery and to determine the prevalence of stomach at risk for pulmonary aspiration in the immediate postpartum period before placental delivery. METHODS: In this prospective multicentre cohort study, antral ultrasonography was performed at full cervical dilatation within the thirty minutes preceding the beginning of expulsive efforts and after vaginal birth, before placental delivery. High-risk gastric content was defined as the visualisation of any solid content in the antrum or antral cross-sectional area in the semi-recumbent position (SR-CSA) > 608 mm². RESULTS: Twenty-six women were included and analysed. There was a significant decrease in both the proportion of patients with solid gastric content and the SR-CSA between the two-ultrasound examinations. Twenty-one patients (80.8%) exhibited a decrease in the SR-CSA during vaginal delivery. The prevalence of stomach at risk for pulmonary aspiration was significantly lower after vaginal delivery than before vaginal delivery (23.1% vs. 57.7%, P = 0.0004). CONCLUSION: Our results suggest that gastric emptying is at least partially preserved during vaginal birth. Nevertheless, almost a quarter of women did have high-risk gastric content in the immediate postpartum period. Point-of-care antral ultrasonography may be of interest for the fast assessment of the gastric content status when a general anaesthesia is required for manual removal of retained placenta.

Fatores predisponentes do volume residual gástrico após preparo expresso com manitol / Gastric residual volume factors after bowel preparation with mannitol express

ABSTRACT BACKGROUND: Bowel preparation with mannitol is a well-established method in Brazil. However, factors that interfere with the gastric emptying time period are yet to be known. Knowing these factors may favor the examination scheduling logistics and the individualized orientation for each patient. OBJECTIVE: Know the factors that can contribute to the gastric emptying time after intestinal preparation with express mannitol. METHODS: This is a prospective observational study to know factors that may contribute on the gastric emptying timing: predominant type of diet, comorbidities, medication usage, previous surgeries, number of evacuation per week, bearer of bowel obstipation, fecal type, diet type, number of evacuations after the home usage of bisacodyl before the ingestion of mannitol and number of evacuations after the ingestion of mannitol until reaching a proper bowel preparation. Before starting the colonoscopy exam, an upper digestive endoscopy exam was made to aspirate the gastric content. RESULTS: Sample was composed of 103 patients, 55 (53.4%) women, medium age 61 (±12.1) years, medium weight 75.3 (±14.1) kg, medium height 1.7 (±10) m and medium BMI of 26.6 (±3.9) kg/m2. Average gastric residual volume was 120.9 (0-900) mL. Gastric residual volume (GRV) below 100 mL (GRV ≤100 mL) occurred in 45 (43.6%) patients, 24 (53.3%) women, medium age of 61.0 years and medium BMI of 26.7 kg/m2. Gastric residual volume above 100 mL (GRV >100 mL) occurred on 58 (56.3%) patients, 29 (50%) women, medium age of 61.0 years and medium BMI of 26.2 kg/m2. Comparing both groups, average fasting time period after the ingestion of mannitol was significantly higher on the group with GRV ≤100 mL than group with GRV >100 mL, 123.1 (60-246) vs 95.3 (55-195) minutes, respectively. There was also statistical significance concerning the usage of ezetimibe 6 (13.7%) in the group with GRV ≤100 mL and statistical significance in the group with GRV >100 mL concerning the usage of paroxetine 3 (6.7%) and tadalafil 3 (6.7%) and surgical history of prostatectomy 3 (6.7%) and bridle withdrawal 3 (6.7%). CONCLUSION: We may conclude in this study that the usage of ezetimibe and fasting above 2 hours after the ingestion of mannitol decrease significantly the incidence of a GRV >100 mL. The usage of paroxetine, tadalafil and surgical history of prostatectomy or bridle withdrawal may contribute to increase de incidence of a GRV >100 mL.

RESUMO CONTEXTO: O preparo intestinal com manitol é um método bem estabelecido no Brasil. No entanto, os fatores que interferem no tempo de esvaziamento gástrico ainda não são conhecidos. O conhecimento desses fatores pode favorecer a logística de agendamento do exame e a orientação individualizada para cada paciente. OBJETIVO: Estudar os fatores que podem contribuir para o tempo de esvaziamento gástrico após o preparo intestinal com manitol expresso. MÉTODOS: Trata-se de um estudo observacional prospectivo com o objetivo de conhecer os seguintes fatores que podem contribuir no tempo de esvaziamento gástrico: tipo de dieta predominante, comorbidades, uso de medicamentos, cirurgias anteriores, número de evacuações por semana, portador de obstipação intestinal, tipo fecal, tipo de dieta, número de evacuações após o uso domiciliar de bisacodil antes da ingestão de manitol e número de evacuações após a ingestão de manitol até atingir o preparo intestinal adequado. Antes de iniciar o preparo intestinal, os pacientes responderam a um questionário clínico. O endoscópio foi introduzido para aspirar o conteúdo gástrico, antes de iniciar a colonoscopia. RESULTADOS: A amostra foi composta por 103 pacientes, sendo 55 mulheres, com média de idade de 61 anos, peso médio de 75,3 kg, altura média de 1,7 m e IMC médio de 26,6 kg/m2. O volume residual gástrico médio medido foi 120,9 (0-900) mL. Volume residual gástrico inferior a 100 mL (VRG ≤100 mL) foi encontrado em 45 (43,6%) pacientes, sendo 24 (53,3%) mulheres, com média de idade de 61,0 anos e IMC médio de 26,7 kg/m2. Volume residual gástrico acima de 100 mL (VRG >100 mL) ocorreu em 58 (56,3%) pacientes, sendo 29 (50%) mulheres, com idade média de 61,0 anos e IMC médio de 26,2 kg/m2. Comparando os dois grupos, notou-se que o tempo médio de jejum após a ingestão de manitol foi significativamente maior no grupo com VRG ≤100 mL do que no grupo com VRG> 100 mL, 123,1 (60-246) vs 95,3 (55-195) minutos, respectivamente. Também houve significância estatística em relação ao uso de ezetimiba 6 (13,7%), sendo maior no grupo com VRG ≤100 mL. Além disso, houve significância estatística no grupo com VRG >100 mL quanto ao uso de paroxetina 3 (6,7%) e tadalafil 3 (6,7%) e história cirúrgica de prostatectomia 3 (6,7%) e retirada de bridas 3 (6,7%). CONCLUSÃO: Podemos concluir neste estudo que o uso de ezetimiba e o jejum acima de 2 horas após a ingestão de manitol diminuem significativamente a incidência de um VRG> 100 mL. O uso de paroxetina, tadalafil e história cirúrgica de prostatectomia ou retirada de bridas podem contribuir para o aumento da incidência de um VRG >100 mL.

Type 2 Diabetes Mellitus: Relationships Between Preoperative Physiologic Stress, Gastric Content Volume and Quality, and Risk of Pulmonary Aspiration.

Pulmonary aspiration is a potentially fatal anesthetic complication occurring when gastric contents enter the respiratory system. Fasting guidelines aim to decrease the risk of pulmonary aspiration by recommending a timeframe in which patients abstain from food and drink before surgery. Fasting guidelines recommended for healthy individuals fail to account for patients with type 2 diabetes mellitus (T2DM). Gastroparesis, a common condition associated with T2DM, is exacerbated during stress such as an impending surgery. This study sought to determine whether a relationship exists between stress levels and gastric contents in fasting patients with T2DM presenting for an elective surgical or diagnostic procedure. The quality and quantity of gastric contents and preoperative stress were evaluated using gastric ultrasonography and salivary α-amylase levels. No relationship existed between preoperative stress and gastric contents; however, glycated hemoglobin levels of 7% or greater were associated with increased gastric fluid, which was the most significant finding in this study. In addition, there was a significant difference between the mean gastric volume in healthy individuals and patients with T2DM. Performance of gastric ultrasonography preoperatively provides objective data that could influence the anesthetic plan and decrease the risk of pulmonary aspiration in patients with T2DM.

A clinical study comparing ultrasound-measured pyloric antrum cross-sectional area to computed tomography-measured gastric content volume to detect high-risk stomach in supine patients undergoing emergency abdominal surgery.

The main aim of this study was to assess whether the ultrasound examination and measurement of the pyloric antral cross-sectional area (antral-CSA) in the supine position could be useful to diagnose a full stomach using a computed tomography (CT) as a comparator in emergency patients. Immediately before general anesthesia induction in patients undergoing emergency abdominal surgery, antral-CSA was measured and the volume of the gastric contents was evaluated via ultrasound in the supine position. Gastric content volume was also calculated from a CT image taken prior to the operation. The primary outcome of this study was to determine the antral-CSA threshold of the "high-risk stomach" defined as the presence of solid/thick fluid and/or gastric content volume > 1.5 mL/kg. The secondary outcome was to evaluate the correlation between gastric content volume calculated by CT and antral-CSA. Thirty-nine patients provided consent and were included. Ten patients had gastric contents over 1.5 mL/kg, and 18 patients showed solid contents/thick fluids. The median [IQR] antral-CSA and gastric content volume were 3.82 [2.74-5.07] cm2 and 0.32 [0.09-2.08] mL/kg, respectively. The antral-CSA cutoff value of "high-risk stomach" was 3.01 cm2. This value had a sensitivity of 85%, a negative predictive value of 53%, and AUC of the ROC of 0.670 (p = 0.03). The Spearman rank-order correlation between both measures was 0.420 (p = 0.01). The correlation was improved, particularly in stomachs with solid contents/thick fluids. Antral-CSA measured in the supine position may help to assess the high-risk stomach patients undergoing emergency surgery.Trial registration: www.umin.ac.jp (UMIN 000013416). Registered 14 March 2014.

Impact of nutrition route on microaspiration in critically ill patients with shock: a planned ancillary study of the NUTRIREA-2 trial.

BACKGROUND: Microaspiration of gastric and oropharyngeal secretions is the main mechanism of entry of bacteria into the lower respiratory tract in intubated critically ill patients. The aim of this study is to determine the impact of enteral nutrition, as compared with parenteral nutrition, on abundant microaspiration of gastric contents and oropharyngeal secretions. METHODS: Planned ancillary study of the randomized controlled multicenter NUTRIREA2 trial. Patients with shock receiving invasive mechanical ventilation were randomized to receive early enteral or parenteral nutrition. All tracheal aspirates were collected during the 48 h following randomization. Abundant microaspiration of gastric contents and oropharyngeal secretions was defined as the presence of significant levels of pepsin (> 200 ng/ml) and salivary amylase (> 1685 UI/ml) in > 30% of tracheal aspirates. RESULTS: A total of 151 patients were included (78 and 73 patients in enteral and parenteral nutrition groups, respectively), and 1074 tracheal aspirates were quantitatively analyzed for pepsin and amylase. Although vomiting rate was significantly higher (31% vs 15%, p = 0.016), constipation rate was significantly lower (6% vs 21%, p = 0.010) in patients with enteral than in patients with parenteral nutrition. No significant difference was found regarding other patient characteristics. The percentage of patients with abundant microaspiration of gastric contents was significantly lower in enteral than in parenteral nutrition groups (14% vs 36%, p = 0.004; unadjusted OR 0.80 (95% CI 0.69, 0.93), adjusted OR 0.79 (0.76, 0.94)). The percentage of patients with abundant microaspiration of oropharyngeal secretions was significantly higher in enteral than in parenteral nutrition groups (74% vs 54%, p = 0.026; unadjusted OR 1.21 (95% CI 1.03, 1.44), adjusted OR 1.23 (1.01, 1.48)). No significant difference was found in percentage of patients with ventilator-associated pneumonia between enteral (8%) and parenteral (10%) nutrition groups (HR 0.78 (0.26, 2.28)). CONCLUSIONS: Our results suggest that enteral and parenteral nutrition are associated with high rates of microaspiration, although oropharyngeal microaspiration was more common with enteral nutrition and gastric microaspiration was more common with parenteral nutrition. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03411447 . Registered 18 July 2017. Retrospectively registered.

Effect of body position on qualitative and quantitative ultrasound assessment of gastric fluid contents.

We assessed the impact of raising the upper section of the bed, and patient positioning, on ultrasound assessment of gastric fluid contents. We performed ultrasound examinations in 25 subjects lying on their back, left and right sides at bed angles of 0°, 30°, 45° and 90°; this was carried out while the subjects were fasted, and repeated 10 min after drinking ≥ 50 ml water. After drinking, gastric contents were detected more frequently in the 45° semirecumbent position compared with the supine and 30° positions. The diagnostic performance of the Perlas qualitative grading scale to detect gastric fluid volume > 1.5 ml.kg-1 was improved at 45°, compared with 0° and 30° angles. The use of a composite ultrasound grading scale at a 45° angle was associated with the best performance, with a sensitivity and specificity of 82%. Antral cross-sectional area was significantly increased when measured in the right lateral position, but there was no effect of raising the bed. In conclusion, raising the upper section of the bed significantly affected qualitative assessment of gastric fluid contents. Further studies are required to determine the most appropriate composite ultrasound grading scale and bed angle for fast and reliable qualitative ultrasound detection of fluid volumes > 1.5 ml.kg-1 .

Fatal pulmonary aspiration during balanced sedation with dexmedetomidine and midazolam: A case report

Recently, balanced sedation has commonly been used during procedural sedation. Dexmedetomidine is known for its relative safety to cause “conscious sedation” with little respiratory depression but has some limitations such as frequent awakening and hemodynamic instability during surgery. To facilitate sedation, a small dose of midazolam can be co-administered rather than escalating the dose of dexmedetomidine, especially in elderly patient. Despite the respiratory safety profile of dexmedetomidine, the overall safety of co-administration has not been clarified. We describe the first case of fatal pulmonary aspiration that developed in an elderly patient during balanced sedation with spinal anesthesia for elective femur fracture surgery.