The incidence and outcome of perioperative pulmonary aspiration in a university hospital: a 4-year retrospective analysis

Preoperative Nil Per Os Duration Predicts Mortality and Ambulation Following Below-Knee Amputation

BACKGROUND

Routine use of nil per os (NPO) prior to procedures has been associated with dehydration and malnutrition leading to patient discomfort. We aim to examine how duration of NPO status affects postoperative outcomes in patients undergoing elective below-knee amputation (BKA).

METHODS

We performed a retrospective chart review of 92 patients who underwent elective BKA between 2014-2022 for noninfectious indications. We performed statistical analysis using Chi-square tests, t-tests, and linear/logistic regression with odds ratio using P < .05 as our significance level.

RESULTS

The mean age was 48.0 ± 16.7 years, and there were 64 (70%) male patients and 41 (45%) Black patients. Mean NPO duration was 12.9 ± 4.7 hours. Patients with longer NPO duration were associated with increased rates of postoperative stroke (P = .03). Patients with shorter NPO duration had significantly lower mean BUN on postoperative day (POD) 1 (14.5, P < .001) and POD 3 (14.1, P < .001) compared to preoperative mean BUN (16.8), however this normalized by POD 7 (19.2, P = .26). There were no changes in postoperative renal function based on baseline kidney disease status or associated with longer NPO duration. Shorter NPO duration was a predictor of increased likelihood of 1-year follow-up (OR: 2.9 [1.24-6.79], P = .01), independent ambulation (OR: 2.7 [1.03-7.34], P = .04), and decreased mortality (OR: .11 [.013-.91], P = .04).

CONCLUSION

While NPO duration does not appear to result in postoperative renal dysfunction, prolonged NPO duration predicts worse rates of follow-up, ambulation, and survival and is associated with increased stroke rates.

Liberal Preoperative Fasting in Adults Undergoing Elective Surgery: A Scoping Review Protocol

Background

Prolonged fasting before surgery has negative effects on the physiology and psychology of patients. Preoperative liberal fasting proposes that patients can drink clear liquids before entering the operating theater, challenging the guideline strategy of a two-hour preoperative liquid fast for adults. In recent years, there have been an increasing number of studies on liberal preoperative fasting in adults. However, currently there is no consensus on the safe amount of fluid consumed, adverse effects, or benefits of this new policy.

Objective

This scoping review protocol will map the existing evidence of liberal preoperative fasting in adults undergoing elective surgery for clinical practice, to summarize more scientific evidence to healthcare professionals when providing perioperative care. Methods and Analysis. The methodology will follow the six steps of the Arksey and O'Malley methodological framework and be guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review. A comprehensive search of six databases will be performed from their inception to 31 May 2023 to identify suitable English studies. Two trained investigators will independently screen and extract the data, and any disagreements will be judged by a third investigator. The results of the study will be presented as graphs or tables. Ethics and Dissemination. This scoping review only examines literature in the database, without reference to human or animal studies, and therefore does not require ethical approval. The findings of this scoping review will be published in peer-reviewed journals or presented at conferences. The Registration Number. This scoping review has been registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/PMW7C).

Perioperative management of long-acting glucagon-like peptide-1 (GLP-1) receptor agonists: concerns for delayed gastric emptying and pulmonary aspiration

Prescriptions and use of glucagon-like peptide-1 (GLP-1) receptor agonists are increasing dramatically, as indications are expanding from the treatment of diabetes mellitus to weight loss for people with obesity. As GLP-1 receptor agonists delay gastric emptying, perioperative healthcare practitioners could be concerned about an increased risk for pulmonary aspiration during general anaesthesia. We summarise relevant medical literature and provide evidence-based recommendations for perioperative care for people taking GLP-1 receptor agonists. GLP-1 receptor agonists delay gastric emptying; however, ongoing treatment attenuates this effect. The risk of aspiration during general anaesthesia is unknown. However, we advise caution in patients who recently commenced on GLP-1 receptor agonists. After over 12 weeks of treatment, standard fasting times likely suffice to manage the risk of pulmonary aspiration for most otherwise low-risk patients.

Gastric point-of-care ultrasonography in patients undergoing radical gastrointestinal surgery before anesthetic induction: an observational cohort study

BACKGROUND

Pulmonary aspiration of gastric contents is a serious perioperative complication. Patients with gastric cancer may experience delayed gastric emptying. However, the role of qualitative and quantitative gastric ultrasound assessments in this patient population before anesthesia induction has not yet been determined.

METHODS

Adult patients with gastrointestinal cancer were recruited and examined using gastric point-of-care ultrasound (POCUS) before anesthetic induction from March 2023 to August 2023 in a tertiary cancer center. Three hundred patients with gastric cancer were conducted with POCUS prior to induction, and three hundred patients with colorectal cancer were included as controls. The cross-sectional area (CSA) of the gastric antrum and gastric volumes (GV) were measured and calculated. We determined the nature of the gastric contents and classified the antrum using a 3-point grading system. A ratio of GV to body weight > 1.5mL/Kg was defined as a high risk of aspiration.

RESULTS

In patients with gastric cancer, 70 patients were classified as grade 2 (23%, including 6 patients with solid gastric contents) and 63 patients (21%) were identified as having a high risk of aspiration. Whereas in patients with colorectal cancer, only 11 patients were classified as grade 2 (3.7%), and 27 patients (9.7%) were identified as having a high risk of aspiration. A larger tumor size (OR:1.169, 95% CI 1.045-1.307, P = 0.006), tumor located in antrum (OR:2.304, 95% CI 1.169-4.539,P = 0.016), gastrointestinal obstruction (OR:21.633, 95% CI 4.199-111.443, P < 0.0001) and more lymph node metastasis (OR:2.261, 95% CI 1.062-4.812, P = 0.034) were found to be positively while tumor site at cardia (OR:0.096, 95% CI 0.019-0.464, P = 0.004) was negatively associated with high aspiration risk in patients with gastric cancer.

CONCLUSION

The Gastric POCUS prior to induction provides an assessment of the status of gastric emptying and can identify the patients at high risk of aspiration, especially those with gastric cancer.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( www.chictr.org.cn ) identifier: ChiCTR2300069242; registered 10 March 2023.

Effect of left paratracheal pressure on left carotid blood flow

INTRODUCTION

Gautier et al. demonstrated that a compression in the left paratracheal region (left paratracheal pressure, LPP) can be used to seal the oesophagus. However, at this level, the left common carotid artery is very close to the carotid that could be affected during the manipulation. This study aimed to assess the hemodynamic effects of LPP on the carotid blood flow.

METHODS

We prospectively included 47 healthy adult volunteers. We excluded pregnant women and people with anomalies of the carotid arteries. The common and internal carotid arteries were preliminarily studied with ultrasounds to exclude atheromatous plaques or vascular malformation. A planimetry of the common and internal carotid arteries was performed. Doppler echography served to measure the peak systolic (PSV) and end-diastolic velocities (EDV) in the common and internal carotid arteries. All measurements were repeated while applying LPP.

RESULTS

Forty-seven participants were enrolled (32 women; mean [SD] age: 42 [13] years). The mean PSV difference [95% CI] in the left common carotid artery before and after LPP at the group level was -15.30 [-31.09 to 0.48] cm s-1 (p = .14). The mean surface difference [95% CI] in the left common carotid artery before and after LPP was 24.52 [6.11-42.92] mm2 (p = .11). Similarly, the same surface at the level of the left internal carotid artery changed by -18.89 [-51.59 to 13.80] mm2 after LPP (p = .58).

CONCLUSIONS

Our results suggest that LPP does not have a significant effect on carotid blood flow in individuals without a carotid pathology. However, the safety of the manoeuvre should be evaluated in patients at risk of carotid anomalies.

The effect of a 'Sip til Send' policy on patient satisfaction: a quality improvement project

Patients often are nil by mouth for prolonged periods pre-operatively, which is associated with adverse effects including discomfort, anxiety, thirst and nausea. As a result, several hospitals have introduced a more liberal regimen of pre-operative drinking, with patients encouraged to sip small volumes of water until transfer to the operating theatre ('Sip til Send'). The impact of 'Sip til Send' on patient satisfaction is still to be determined. We hypothesised that the introduction of a 'Sip til Send' policy would increase patient's satisfaction with their pre-operative fluid management regimen. We conducted a staged implementation of a 'Sip til Send' quality improvement initiative in two campuses of a large tertiary teaching hospital. This involved a targeted education and implementation programme that was refined and delivered through 'plan, do, study and act' cycles. Patient satisfaction with their pre-operative fluid management was measured by rating the statement "I am happy with the management of pre-operative drinking", against a five-point Likert scale (0, strongly disagree; 1, disagree; 2, neutral; 3, agree; and 4, strongly agree). Patient satisfaction with pre-operative fluid management was high at baseline, with pooled data for both campuses showing a median (IQR [range]) satisfaction score of 4 (3-4 [1-4]). After the implementation of 'Sip til Send', this improved to a median (IQR [range]) satisfaction score of 4 (4-4 [2-4]) (p < 0.001). The introduction of a 'Sip til Send' policy resulted in an increase in patient satisfaction. Key factors in successful implementation included the provision of a clear explanation of the underlying rationale to patients, nursing and anaesthetic staff, and establishing the policy as the default position for all elective patients.

Pre-operative gastric ultrasound in patients at risk of pulmonary aspiration: a prospective observational cohort study

Point-of-care gastric sonography offers an objective approach to assessing individual pulmonary aspiration risk before induction of general anaesthesia. We aimed to evaluate the potential impact of routine pre-operative gastric ultrasound on peri-operative management in a cohort of adult patients undergoing elective or emergency surgery at a single centre. According to pre-operative gastric ultrasound results, patients were classified as low risk (empty, gastric fluid volume ≤ 1.5 ml.kg-1 body weight) or high risk (solid, mixed or gastric fluid volume > 1.5 ml.kg-1 body weight) of aspiration. After sonography, examiners were asked to indicate changes in aspiration risk management (none; more conservative; more liberal) to their pre-defined anaesthetic plan and to adapt it if patient safety was at risk. We included 2003 patients, 1246 (62%) of which underwent elective and 757 (38%) emergency surgery. Among patients who underwent elective surgery, 1046/1246 (84%) had a low-risk and 178/1246 (14%) a high-risk stomach, with this being 587/757 (78%) vs. 158/757 (21%) among patients undergoing emergency surgery, respectively. Routine pre-operative gastric sonography enabled changes in anaesthetic management in 379/2003 (19%) of patients, with these being a more liberal approach in 303/2003 (15%). In patients undergoing elective surgery, pre-operative gastric sonography would have allowed a more liberal approach in 170/1246 (14%) and made a more conservative approach indicated in 52/1246 (4%), whereas in patients undergoing emergency surgery, 133/757 (18%) would have been managed more liberally and 24/757 (3%) more conservatively. We showed that pre-operative gastric ultrasound helps to identify high- and low-risk situations in patients at risk of aspiration and adds useful information to peri-operative management. Our data suggest that routine use of pre-operative gastric ultrasound may improve individualised care and potentially impact patient safety.

Preprocedural fasting policies for patients receiving tube feeding: A national survey

BACKGROUND

Patients who are critically ill frequently accrue substantial nutrition deficits due to multiple episodes of prolonged fasting prior to procedures. Existing literature suggests that, for most patients receiving tube feeding, the aspiration risk is low. Yet, national and international guidelines do not address fasting times for tube feeding, promoting uncertainty regarding optimal preprocedural fasting practice. We aimed to characterize current institutional fasting practices in the United States for patients with and without a secure airway, with variable types of enteral access, for representative surgical procedures.

METHODS

The survey was distributed to a purposive sample of academic institutions in the United States. Reponses were reported as restrictive (6-8 h preprocedurally) or permissive (<6 h or continued intraprocedurally) feeding policies. Differences between level 1 trauma centers and others, and between burn centers and others, were evaluated.

RESULTS

The response rate was 40.3% (56 of 139 institutions). Responses revealed a wide variability with respect to current practices, with more permissive policies reported in patients with secure airways. In patients with a secure airway, Level 1 trauma centers were significantly more likely to have permissive fasting policies for patients undergoing an extremity incision and drainage for each type of feeding tube surveyed.

CONCLUSIONS

Current hospital policies for preprocedural fasting in patients receiving tube feeds are conflicting and are frequently more permissive than guidelines for healthy patients receiving oral nutrition. Prospective research is needed to establish the safety and clinical effects of various fasting practices in tube-fed patients.

Point of care gastric ultrasound to predict aspiration in patients undergoing urgent endotracheal intubation in the emergency medicine department

BACKGROUND

One significant cause of morbidity and mortality in patients undergoing endotracheal intubation is the aspiration of gastric contents. Its prevalence is more in the emergency than in elective settings. Point-of-care gastric ultrasound (GUS) is a non-invasive bedside ultrasonogram that provides both qualitative and quantitative information about the stomach contents. The diagnostic accuracy of GUS in terms of gastric parameters (measured antral diameters, antral cross-sectional area, and calculated gastric volume) to predict aspiration is yet unknown. We aim to determine this in the patients undergoing urgent emergency intubation (UEI) in the emergency department.

METHODOLOGY

A prospective observational study was conducted at the emergency department of a tertiary healthcare center in India. Patients requiring UEI were identified and a bedside gastric ultrasound was done in the right lateral decubitus position using low frequency curved array probe. The qualitative data and the antral diameters (anteroposterior and craniocaudal) were assessed. The patient's clinical parameters and history regarding the last meal were noted. The cross-sectional area of gastric antrum was calculated using CSA = (AP × CC) π/4. The gastric volume is estimated using Perla's formula: GV = 27.0 + 14.6(RLD CSA) -1.28(age).

RESULTS

A hundred patients requiring urgent endotracheal intubation were enrolled in the study. Visible aspiration was more in participants with a distended gastric status (χ2 = 16.880, p =  < 0.001). The median gastric volume in the patients who aspirated was 146.37 mL, and it ranged from 111.59 mL-201.01 mL. Using ROC analysis, a cut-off of CC diameter ≥ 2.35 cm (sensitivity 88%, specificity 91%) and AP diameter ≥ 5.15 cm (sensitivity 88%, specificity 87%) predicts aspiration. A calculated USG CSA cut-off ≥ 9.27cm2 (sensitivity 100%, specificity 87%) and an USG gastric volume ≥ 111.594 mL (sensitivity 100%, a specificity 92%) predicts aspiration.

CONCLUSION

Point-of-care gastric ultrasound is an useful non-invasive bedside tool for risk stratification for aspiration in busy emergency rooms. We present threshold gastric antral parameters that can be used to predict aspiration along with its diagnostic accuracy. This can help the treating ED physician take adequate precautions, decide on intubation techniques and treatment modifications to aid in better patient management.

Ultrasonographic Assessment of Gastric Volume in Fasted Patients Undergoing Gastrointestinal Endoscopy Under Sedation

Purpose

In this prospective observational study, an ultrasonographic measurement of antral cross-sectional area (ACSA) was conducted to evaluate the gastric content and volume as well as to identify high-risk stomach in non-pregnant adult surgical patients adhering to preanesthetic fasting guidelines.

Patients and Methods

Fasted patients undergoing gastrointestinal endoscopy under sedation were included. Ultrasonographic measurements of ACSA were conducted in both semi-recumbent and right lateral decubitus positions before endoscopic procedures. Gastroscopy was employed to guide the measurement of suctioned gastric volume (GV). Ultrasonography was performed to assess gastric contents and identify patients with high-risk stomach. The relationship between ACSA and suctioned GV was also evaluated.

Results

ACSA was evaluated in 736 out of 782 patients. A significant positive correlation was discovered between ACSA in the right lateral decubitus position and suctioned GV, which was more reliable than in the semi-recumbent position. To analyze high-risk stomach with a GV > 100 mL, the cutoff value of ACSA in the right lateral decubitus was found to be 7.5 cm2, with the AUC, sensitivity and specificity of 0.80 (95% CI, 0.76-0.82; P<0.001), 82.4% and 67.3%, respectively. A novel mathematical model based on ACSA to estimate GV in non-pregnant fasted adults was presented.

Conclusion

Ultrasonographic measurement of ACSA can assist anesthesiologists in estimating the risk of pulmonary aspiration of gastric contents during general anesthesia and sedation.

Evolving Use of Regional versus General Anesthesia for the Surgical Repair of Open Globe Injuries

PURPOSE

The purpose of the current study is to report outcomes with the evolving use of regional anesthesia with monitored anesthesia care (RA-MAC) vs general anesthesia (GA) in the repair of open globe injuries.

DESIGN

Retrospective, consecutive, comparative, nonrandomized clinical study.

METHODS

The study includes 507 eyes of 507 patients with open globe injuries treated with either RA-MAC or GA at a tertiary referral center between 2015 and 2020. There was no predetermined protocol for selection of anesthesia method. However, based on experience and findings of prior research by this group, regional anesthesia with monitored anesthesia care was typically selected initially and changed to general anesthesia if warranted after evaluation of the patient and discussion with the surgeon. The main outcome measure was visual acuity at last follow-up. Results were compared to previously published study groups between 1995 and 2014.

RESULTS

Primary closure of open globe injury was performed under RA-MAC anesthesia in 462 patients (91%) and under GA in 45 patients (9%). Zone 1, 2, and 3 injuries were recorded in 251, 170, and 86 patients, respectively. Zone 1 (96%, 240 of 251 patients) or zone 2 (92%, 156 of 170 patients) (P < .001) were more likely to be repaired under RA-MAC vs zone 3 injuries (76%, 65 of 86 patients). The improvement from presenting visual acuity was similar for the 2 anesthesia groups, 0.52 logMAR and 0.46 logMAR for RA-MAC and GA, respectively (P = .68, CI -0.3 to 0.2). The use of RA-MAC anesthesia for open globe injuries has increased at our institution from 64% in 1995-1999 to 91% in the present study, 2015-2020 (P < .00001).

CONCLUSION

The current study demonstrates that with anesthesiologists experienced in ophthalmic regional anesthesia techniques, and appropriate case selection, RA-MAC can be safely used as an alternative to general anesthesia for open globe repair. Considerations when employing RA-MAC include a patient's ability to cooperate, position, and communicate for the duration of the globe repair.

Differences in preoperative gastric ultrasound findings in elderly compared to the mid-aged surgical patients: A retrospective observational study

This study aimed to compare gastric ultrasound assessments between young and elderly patients, to determine whether the cross-section area (CSA) cutoff values for elderly and young patients should be different, and to suggest CSA cutoff values for elderly patients. This study evaluated the data of 120 patients who underwent elective surgery under general anesthesia between July 2019 and August 2020. Demographic and gastric ultrasound assessment data were retrieved. Patients were divided into the elderly group (n = 58, age: ≥65 years) and young group (n = 62, age: <65 years). The CSAs in the supine and right lateral decubitus positions (RLDP), semiquantitative 3-point Perlas grade (grades 0, 1, and 2), and gastric volume (GV) were determined. CSAs according to different Perlas grades were compared between the 2 groups. To compare normally and non-normally distributed continuous data, Student t test and the Mann-Whitney U test were used, respectively. Categorical data were compared using the chi-square test or Fisher exact test, as appropriate. The receiver operating characteristic (ROC) curves were built for the CSAs to predict pulmonary aspiration. The CSA cutoff values for predicting a high risk of pulmonary aspiration in both the groups were determined. Among patients with Perlas grade 0, the CSAsupine (P = .002) and CSARLDP (P = .002) were greater in the elderly group than in the young group. The specificity, positive predictive value, and accuracy of the CSA decreased when the CSA cutoff value for the young group was applied to the elderly group. The CSA cutoff values for the elderly group were: CSAsupine, 6.92 cm2 and CSARLDP, 10.65 cm2. The CSA of the empty stomach was greater in elderly patients than in young patients. We suggest that the following CSA cutoff values should be used for predicting pulmonary aspiration risk in elderly patients: CSAsupine, 6.92 cm2 and CSARLDP, 10.65 cm2.

Association of a Liberal Fasting Policy of Clear Fluids Before Surgery With Fasting Duration and Patient Well-being and Safety

Importance

Current fasting guidelines for procedures under anesthesia are poorly implemented, leading to negative metabolic sequelae. Recent studies in children showed support of liberal clear fluid intake; adult physiology can support clear fluid intake, but implementation studies are lacking.

Objective

To evaluate the successfulness of implementation of a liberal clear fluid policy with regard to fasting duration, well-being, and safety in adults scheduled for anesthesia.

Design, Setting, and Participants

This was a quality improvement study conducted from January 2016 to July 2021 at a tertiary referral hospital in the Netherlands. Adults scheduled for nonemergency procedures under anesthesia were included in the study. Patients undergoing obstetrics procedures or those who were intubated preoperatively were excluded.

Interventions

Stepwise introduction of a liberal fluid fasting policy, allowing for ingestion of clear fluids until arrival at the operating room.

Main Outcomes and Measures

The primary outcome was change in fasting duration. Secondary outcomes were patient well-being, measured as preoperative thirst, amount of fluid ingested, postoperative nausea and vomiting (PONV), and administration of antiemetics. Safety was measured as incidence of regurgitation and aspiration (pneumonia).

Results

Of the 76 451 patients (mean [SD] age, 56 [17] years; 39 530 male individuals [52%] 36 921) included in the study, 59 036 (78%) followed the standard policy, and 16 815 (22%) followed the liberal policy. Time series analysis showed an estimated fasting duration decrease of 3:07 hours (IQR, 1:36-7:22; P < .001) after implementation of the liberal policy. Postimplementation median (IQR) fasting duration was 1:20 (0:48-2:24) hours. The incidence of regurgitation changed from 18 (95% CI, 14-21) to 24 (95% CI, 17-32) in 10 000 patients, and the incidence of aspiration changed from 1.7 (95% CI, 0.6-2.7) to 2.4 (95% CI, 0.5-4.7) in 10 000 patients. In the liberal policy, thirst feelings decreased (37% [4982 of 8615] vs 46% [3373 of 7362]; P < .001). PONV incidence decreased from 10.6% (6339 of 59 636) to 9.4% (1587 of 16 815; P < .001) and antiemetic administration decreased from 11.0% (6538 of 59 636) to 9.5% (1592 of 16 815; P < .001).

Conclusions and Relevance

Results of this quality improvement study suggest that a liberal fasting policy was associated with a clinically relevant reduction in fasting duration and improved patient well-being with regard to preoperative thirst and PONV. Although a slightly higher incidence of regurgitation could not be ruled out, wider implementation of such a policy may be advocated as results are still within the clinically accepted risks margins. Results suggest that surgical procedures in patients who drink clear fluids within 2 hours before anticipated anesthesia should not be postponed or canceled.

2023 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting: Carbohydrate-containing Clear Liquids with or without Protein, Chewing Gum, and Pediatric Fasting Duration-A Modular Update of the 2017 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting

These practice guidelines are a modular update of the "Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: Application to healthy patients undergoing elective procedures." The guidance focuses on topics not addressed in the previous guideline: ingestion of carbohydrate-containing clear liquids with or without protein, chewing gum, and pediatric fasting duration.

Retained Food During Esophagogastroduodenoscopy Is a Risk Factor for Gastric-to-Pulmonary Aspiration

BACKGROUND

Residual food (RF) during esophagogastroduodenoscopy (EGD) is thought, but not proven, to be a risk factor for gastric-to-pulmonary aspiration.

AIMS

The aims of this study were to determine the prevalence of RF during EGD, to investigate whether RF was associated with an increased risk of aspiration, especially when monitored anesthesia care (MAC) or general anesthesia (GA) were administered, and to determine whether aspiration associated with RF led to a more severe clinical outcome.

METHODS

Patients undergoing EGD between October 2012 and September 2018 were identified. Patient age, sex, aspiration events, RF, sedation type, structural foregut abnormalities, and diagnoses associated with impaired esophageal or gastric motility were noted. The clinical course after an aspiration event was evaluated.

RESULTS

RF was identified during 4% of 81,367 EGDs. Aspiration events occurred during 41 (5/10,000) procedures. Aspiration was more likely to occur in patients with RF (odds ratio [OR] 15.1) or those receiving MAC or GA (OR 9.6 and 16.8 relative to conscious sedation, respectively). RF and MAC/GA were synergistically associated with increased odds of aspiration. In a multivariate nominal logistic regression model, older age (OR 2.6), MAC (OR 3.8), GA (OR 4.4), vagotomy (OR 5.2), achalasia (OR 3.8), and RF (OR 10.0) were risk factors for aspiration. Aspiration events in the presence or absence of RF led to similar clinical outcomes.

CONCLUSIONS

While aspiration events are rare in patients undergoing EGD, RF and the use of MAC or GA were associated with substantially increased odds of aspiration.

A randomized trial of non-fasting vs. fasting for cardiac implantable electronic device procedures (Fast-CIED Study)

AIMS

Data on safety and efficacy of a non-fasting strategy in minimal invasive cardiac procedures are lacking. We assessed a non-fasting strategy compared with a fasting strategy regarding patient's well-being and safety in elective cardiac implantable electronic device (CIED) procedures.

METHODS AND RESULTS

In this randomized, single-blinded clinical trial, 201 patients (non-fasting = 100, fasting = 101) with a mean age of 72.0 ± 11.6 years (66.7% male) were assigned to a non-fasting strategy (solids/fluids allowed up to 1 h) or a fasting strategy (at least 6 h no solids and 2 h no fluids) before the procedure and analysed on an intention-to-treat basis. The co-primary outcomes were patients' well-being scores (based on numeric rating scale, 0-10) and incidence of intra-procedural food-related adverse events, including vomiting, perioperative pulmonary aspiration, and emergency intubation. Renal, haematological, and metabolic blood parameters and 30-day follow-up data were gathered. The summed pre-procedural patients' well-being score was significantly lower in the non-fasting group [non-fasting: 13.1 ± 9.6 vs. fasting: 16.5 ± 11.4, 95% confidence interval (CI) of mean difference (MD) -6.35 to -0.46, P = 0.029], which was mainly driven by significantly lower scores for hunger and tiredness in the non-fasting group (non-fasting vs. fasting; hunger: 0.9 ± 1.9 vs. 3.1 ± 3.2, 95% CI of MD -2.86 to -1.42, P < 0.001; tiredness: 1.6 ± 2.3 vs. 2.6 ± 2.7, 95% CI of MD -1.68 to -0.29, P = 0.023). No intra-procedural food-related adverse events were observed. Relevant blood parameters and 30-day follow-up did not show significant differences.

CONCLUSION

These results showed that a non-fasting strategy is beneficial to a fasting one regarding patient's well-being and comparable in terms of safety for CIED procedures (NCT04389697).

Ultrasound-Determined Residual Gastric Volume after Clear-Fluid Ingestion in the Paediatric Population: Still a Debatable Issue

Background: Current fasting guidelines are often exceeded in clinical practice, resulting in stressful events during anaesthesia in children. This prospective study compares residual gastric volume after 1 versus 2 h of clear fluid ingestion in fasted children. METHODS: A total of 106 patients were enrolled in the study. Ultrasonography (USG) of gastric antrum (GA) was performed in the supine and right lateral decubitus (RLD) positions. All children fasted from solid food for 6 h. Blackcurrant flavoured drink (3 mL/kg) was given following the measurement of baseline (T0) USG of GA, with follow-ups after 1 (T1) and 2 (T2) hours post-ingestion. Residual gastric volume (RGV) was calculated from the cross-sectional area of GA using a standard formula. Parental satisfaction with their children’s behaviour concerning fasting time was recorded. Results: RGV was significantly higher at T1 compared to T2 (p < 0.001). No significant difference was seen between T0 and T2 (p = 0.30). Parental satisfaction was similar at T1 and T2 (p = 0.158). Conclusions: The RGV in paediatric patients after 1 h of clear fluid ingestion was significantly higher than after 2 h of ingestion. There was no difference observed in parental satisfaction concerning the two intervals of fluid fasting. RLD and supine positions can be used reliably to measure the RGV in children.

Preprocedural fasting for contrast-enhanced CT: when experience meets evidence

Traditional preparatory fasting policy prior to iodinated contrast media (ICM) assisted contrast-enhanced CT (CECT) examinations lacks methodologically acceptable evidence. Considering the possible negative effects of preprocedural fasting, the latest European Society of Urogenital Radiology guidelines V10.0 and American Committee of Radiology 2021 guidelines clearly state that preprocedural fasting is not recommended prior to routine intravenous ICM administration. This comprehensive and detailed Review presents the current global dietary preparation policies, potential harm of excessive fasting, and a systematical and well-bedded description of practice advancements of dietary preparation. The evidences revealed that there has been no single instance of vomiting-associated aspiration pneumonia due to the undemanding implementation of preparatory fasting prior to CECT yet. Non-fasting would not increase the incidence of emetic symptoms and the risk of aspiration pneumonia. Not every patient should undergo all CECT examinations without preparatory fasting. There is still much more refinement to be done on the preparatory fasting policy. Changes in traditional preparatory fasting policy will make positive and significant implications on clinical practice. This Review aims to provide operational guidance and suggestions for practitioners and policymakers, motivate efficient, reasonable, safe and normative ICM usage, and achieve optimal patient clinical benefits and high-quality radiological care practices.

Pre-induction Ultrasonographic Evaluation of Gastric Residual Volume in Elective Gastrointestinal Cancer Surgeries

Pulmonary aspiration of gastric contents during elective surgery remains a major cause of airway-related mortality and morbidity. The preoperative fasting times for solids and liquids have been standardized across various anesthesia society guidelines. Enhanced Recovery After Surgery (ERAS) guidelines now advocate liberal clear fluid intake with carbohydrate loading up to 2 h preoperatively. The aim of the study was to assess whether practicing both ASA fasting guidelines and ERAS protocol makes the patients prone to a full stomach. The supine position standard curvilinear ultrasound probe (2-5 MHz) with Sonosite M-Turbo ©system was used to obtain the images. Gastric residual volume (GRV) was derived from the cross-sectional area (CSA) using the Perlas and colleagues model. A total of 102 patients were recruited and analyzed. The mean age and BMI were 50.65 years ± 13.35 years and 22.23 kg/m² ± 3.7 kg/m², respectively. A total of four patients (3.92%) had gastric volume > 1.5 ml/kg; out of these four patients, three were female and one was male. We did not observe any case of pulmonary aspiration in any of our patients. In conclusion, even though for elective surgeries, the current fasting guidelines are adequate, these findings cannot be extrapolated to patients with risk factors for high gastric residual volume where further studies need to be performed.

Quality-improvement project to reduce actual fasting times for fluids and solids before induction of anaesthesia

Background

Despite well-defined recommendations, prolonged fasting times for clear fluids and solids are still common before elective surgery in adults. Extended fasting times may lead to discomfort, thirst, hunger and physiological dysfunctions. Previous studies have shown that prolonged fasting times are frequently caused by patients being misinformed as well as inadequate implementation of the current guidelines by medical staff.

This study aimed to explore how long elective surgery patients fast in a German secondary care hospital before and after the introduction of an educational note for patients and re-training for the medical staff.

Methods

A total of 1002 patients were enrolled in this prospective, non-randomised interventional study. According to the power calculation, in the first part of the study actual fasting times for clear fluids and solids were documented in 502 consecutive patients, verbally instructed as usual regarding the recommended fasting times for clear fluids (2 h) and solids (6 h). Subsequently, we implemented additionally to the verbal instruction a written educational note for the patients, including the recommended fasting times. Furthermore, the medical staff was re-trained regarding the fasting times using emails, newsletters and employee meetings. Thereafter, another 500 patients were included in the study.

We hypothesised, that after these quality improvement procedures, actual fasting times for clear fluids and solids would be more accurate on time.

Results

Actual fasting times for clear fluids were in the median 11.3 (interquartile range 6.8–14.3; range 1.5–25.5) h pre-intervention, and were significantly reduced to 5.0 (3.0–7.2; 1.5–19.8) h after the intervention (median difference (95%CI) − 5.5 (− 6.0 to − 5.0) h). The actual fasting times for solids also decreased significantly, but only from 14.5 (12.1–17.2; 5.4–48.0) h to 14.0 (12.0–16.3; 5.4–32.0) h after the interventions (median difference (95%CI) − 0.52 (− 1.0 to − 0.07) h).

Conclusions

The study showed considerably extended actual fasting times in elective adult surgical patients, which were significantly reduced by simple educational/training interventions. However, the actual fasting times still remained considerably longer than defined in recommended guidelines, meaning further process optimisations like obligatory fluid intake in the early morning are necessary to improve patient comfort and safety in future.

Trial registration

German registry of clinical studies (DRKS-ID: DRKS 00020530, retrospectively registered).

Pulmonary Aspiration of Gastric Contents: A Closed Claims Analysis

BACKGROUND

Perioperative pulmonary aspiration of gastric contents has been associated with severe morbidity and death. The primary aim of this study was to identify outcomes and patient and process of care risk factors associated with gastric aspiration claims in the Anesthesia Closed Claims Project. The secondary aim was to assess these claims for appropriateness of care. The hypothesis was that these data could suggest opportunities to reduce either the risk or severity of perioperative pulmonary aspiration.

METHODS

Inclusion criteria were anesthesia malpractice claims in the American Society of Anesthesiologists Closed Claims Project that were associated with surgical, procedural, or obstetric anesthesia care with the year of the aspiration event 2000 to 2014. Claims involving pulmonary aspiration were identified and assessed for patient and process factors that may have contributed to the aspiration event and outcome. The standard of care was assessed for each claim.

RESULTS

Aspiration of gastric contents accounted for 115 of the 2,496 (5%) claims in the American Society of Anesthesiologists Closed Claims Project that met inclusion criteria. Death directly related to pulmonary aspiration occurred in 66 of the 115 (57%) aspiration claims. Another 16 of the 115 (14%) claims documented permanent severe injury. Seventy of the 115 (61%) patients who aspirated had either gastrointestinal obstruction or another acute intraabdominal process. Anesthetic management was judged to be substandard in 62 of the 115 (59%) claims.

CONCLUSIONS

Death and permanent severe injury were common outcomes of perioperative pulmonary aspiration of gastric contents in this series of closed anesthesia malpractice claims. The majority of the patients who aspirated had either gastrointestinal obstruction or acute intraabdominal processes. Anesthesia care was frequently judged to be substandard. These findings suggest that clinical practice modifications to preoperative assessment and anesthetic management of patients at risk for pulmonary aspiration may lead to improvement of their perioperative outcomes.

EDITOR’S PERSPECTIVE

Swallowing ability and intra-oral water-retaining ability during moderate propofol sedation in healthy human volunteers: A prospective observational study

BACKGROUND

The cough reflex or aspiration under monitored anaesthesia care might be associated with sedative-induced changes in swallowing and intra-oral water-retaining abilities.

OBJECTIVES

To investigate the effects of moderate propofol sedation on swallowing and intra-oral water-retaining ability.

DESIGN

Prospective observational study.

SETTING

Single tertiary care centre during 2017.

PARTICIPANTS

A total of 13 healthy adult volunteers.

INTERVENTION

Volunteers in the supine position were asked to retain 10 ml of orally injected water for 5 min. After 5 minutes or when the water was spontaneously swallowed, the retention time and residual intra-oral water volume were measured. Subjects then voluntarily swallowed a further 10 ml of injected water and the residual water volume was measured. This whole process was repeated under sedation with propofol at effect-site concentrations of 0.5, 1.0 and 1.5 μg ml-1.

MAIN OUTCOME MEASURES

The primary outcome was the estimated volume swallowed (swallowing volume); the secondary outcome was water retention time.

RESULTS

Median water retention time decreased from 300 to 11 s (P < 0.001), and greater spontaneous swallowing was induced with increased propofol effect-site concentrations measuring up to 1.5 μg ml-1 (P < 0.001). The median of the estimated swallowing volumes with voluntary swallowing while awake and with all three concentrations of propofol were 9.5, 9.6, 9.6 and 9.4 ml, respectively (P = 0.805); more water remained after spontaneous swallowing than after voluntary swallowing at all concentrations. Differences in mean estimated swallowing volumes between voluntary and spontaneous swallowing were 3.4 ml (95% CI, 0.9 to 6.0, P = 0.016) for 0.5 μg ml-1, 4.1 ml (95% CI, 1.8 to 6.3, P = 0.002) for 1.0 μg ml-1 and 5.1 ml (95% CI, 3.4 to 6.8, P < 0.001) for 1.5 μg ml-1.

CONCLUSIONS

Moderate propofol sedation decreases water-retaining ability but has no effect on voluntary swallowing. Ensuring that patients can respond under sedation may effectively prevent the unexpected cough reflex and aspiration by enabling occasional voluntary swallowing.

TRIAL REGISTRATION

UMIN Clinical Trials Registry identifier: UMIN000027517.

Assessment of remifentanil for rapid sequence induction and intubation in patients at risk of pulmonary aspiration of gastric contents compared to rapid-onset paralytic agents: study protocol for a non-inferiority simple blind randomized controlled trial (the REMICRUSH study)

Background

Rapid-onset paralytic agents are recommended to achieve muscle relaxation and facilitate tracheal intubation during rapid sequence induction in patients at risk of pulmonary aspiration of gastric contents. However, opioids are frequently used in this setting. The study’s objective is to demonstrate the non-inferiority of remifentanil compared to rapid-onset paralytic agents, in association with an hypnotic drug, for tracheal intubation in patients undergoing  procedure under general anesthesia and at risk of pulmonary aspiration of gastric contents.

Methods

The REMICRUSH (Remifentanil for Rapid Sequence Induction of Anaesthesia) study is a multicenter, single-blinded, non-inferiority randomized controlled trial comparing remifentanil (3 to 4 μg/kg) with rapid-onset paralytic agents (succinylcholine or rocuronium 1 mg/kg) for rapid sequence induction in 1150 adult surgical patients requiring tracheal intubation during general anesthesia. Enrolment started in October 2019 in 15 French anesthesia units. The expected date of the final follow-up is October 2021. The primary outcome is the proportion of successful tracheal intubation without major complications. A non-inferiority margin of 7% was chosen. Analyses of the intent-to-treat and per-protocol populations are planned.

Discussion

The REMICRUSH trial protocol has been approved by the ethics committee of The Comité de Protection des Personnes Sud-Ouest et Outre-Mer II and will be carried out according to the principles of the Declaration of Helsinki and the Good Clinical Practice guidelines. The results of this study will be disseminated through presentations at scientific conferences and publications in peer-reviewed journals. The REMICRUSH trial is the first randomized controlled trial powered to investigate whether remifentanil with hypnotics is non-inferior to rapid-onset paralytic agents with hypnotic in rapid sequence induction of anesthesia for full stomach patients considering successful tracheal intubation without major complication.

Trial registration

ClinicalTrials.gov NCT03960801. Registered on May 23, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05192-x.

[Intraoperative Aspiration]

术中误吸是外科手术中常见的肺部并发症，麻醉和体位是导致术中误吸的主要因素。近年来，围手术期肺保护已受到外科和麻醉医师的广泛关注，如何加速术后康复进程，减少相关并发症发生，显著改善患者预后已成为当前外科治疗的主要目标。本文将以术中误吸为重点，从解剖、病理生理、表现、诊断、处理和预防等方面展开综述。

Real-Time Ultrasound Detection of Left Paratracheal Esophagus on Air Entry into the Gastric Antrum in the Induction Period of General Anesthesia: A Prospective, Randomized Study

Background

Positive-pressure ventilation (PPV) delivered via a facemask during anesthesia induction can result in gastric content being inhaled into the lungs. We hypothesized that the real-time ultrasound left paratracheal esophagus monitoring could more effectively reduce air entry into the stomach than real-time ultrasound monitoring of the gastric antrum (GA).

Methods

Patients were divided into two groups: study (S; n=30) and control (C; n=30) groups. During the induction of general anesthesia, mask ventilation adopts a pressure control mode. The initial ventilation pressure of both groups was 15 cmH₂O. Before anesthesia induction, an ultrasonic probe was used to monitor the cross-sectional area (CSA) of the GA and the presence of gas in the stomach. During and after anesthesia induction, group S used a high-frequency ultrasound probe to observe the entry of air from the left paratracheal esophagus into the GA. The ventilation pressure was gradually reduced over time until no esophageal air was found. In group C, the ventilatory pressure was set maintained at 15 cmH₂O and the CSA of the GA and air intake were monitored using an ultrasonic probe.

Results

Before and after PPV, the CSA of the GA in group S decreased (P<0.001), whereas the CSA in group C increased (P=0.002). The GA CSA in group C after PPV was larger than in group S after PPV (P=0.002). The proportion of patients who experienced intragastric air intake in group S (23.3%) was significantly lower than that in group C (66.7) (P=0.001).

Conclusion

Compared with ultrasound monitoring of the GA, real-time ultrasound detection of LPEOAE into the GA during anesthesia induction was more effective, more sensitive, significantly reduced the prevalence of intragastric air intake, and provided sufficient tidal volume and oxygen for patients.

The Obese Patient: Facts, Fables, and Best Practices

The prevalence of obesity continues to rise worldwide, and anesthesiologists must be aware of current best practices in the perioperative management of the patient with obesity. Obesity alters anatomy and physiology, which complicates the evaluation and management of obese patients in the perioperative setting. Gastric point-of-care ultrasound (PoCUS) is a noninvasive tool that can be used to assess aspiration risk in the obese patient by evaluating the quantity and quality of gastric contents. An important perioperative goal is adequate end-organ perfusion. Standard noninvasive blood pressure (NIBP) is our best available routine surrogate measurement, but is vulnerable to greater inaccuracy in patients with obesity compared to the nonobese population. Current NIBP methodologies are discussed. Obese patients are at risk for wound and surgical site infections, but few studies conclusively guide the exact dosing of intraoperative prophylactic antibiotics for them. We review evidence for low-molecular-weight heparins and weight-based versus nonweight-based administration of vasoactive medications. Finally, intubation and extubation of the patient with obesity can be complicated, and evidence-based strategies are discussed to mitigate danger during intubation and extubation.

Aspiration pneumonia during general anesthesia induction after esophagectomy: A case report

BACKGROUND

Esophageal cancer is a common malignant tumor of the digestive system. At present, surgery is the most important treatment strategy. After esophagectomy and gastric esophagoplasty, the patients are prone to regurgitation. However, these patients currently do not receive much attention, especially from anesthesiologists.

CASE SUMMARY

A 55-year-old woman was scheduled for right lower lung lobectomy. The patient had undergone radical surgery for esophageal cancer under general anesthesia 6 mo prior. Although the patient had fasted for > 17 h, unexpected aspiration still occurred during induction of general anesthesia. Throughout the operation, oxygen saturation was 98%-100%, but the airway pressure was high (35 cmH₂O at double lung ventilation). The patient was sent to the intensive care unit after surgery. Bedside chest radiography was performed, which showed exudative lesions in both lungs compared with the preoperative image. After surgery, antibiotics were given to prevent lung infection. On day 2 in the intensive care unit, the patient was extubated and discharged on postoperative day 7 without complications related to aspiration pneumonia.

CONCLUSION

After esophagectomy, patients are prone to regurgitation. We recommend nasogastric tube placement followed by rapid sequence induction or conscious intubation.

Perioperative Point-of-Care Ultrasound in Children

Anesthesiologists and other acute care physicians perform and interpret portable ultrasonography-point-of-care ultrasound (POCUS)-at a child's bedside, in the perioperative period. In addition to the established procedural use for central line and nerve block placement, POCUS is being used to guide critical clinical decisions in real-time. Diagnostic point-of-care applications most relevant to the pediatric anesthesiologist include lung ultrasound for assessment of endotracheal tube size and position, pneumothorax, pleural effusion, pneumonia, and atelectasis; cardiac ultrasound for global cardiac function and hydration status, and gastric ultrasound for aspiration risk stratification. This article reviews and discusses select literature regarding the use of various applications of point-of-care ultrasonography in the perioperative period.

Point-of-care ultrasound for the pediatric regional anesthesiologist and pain specialist: a technique review

Point-of-care ultrasound (PoCUS) has been well described for adult perioperative patients; however, the literature on children remains limited. Regional anesthesiologists have gained interest in expanding their clinical repertoire of PoCUS from regional anesthesia to increasing numbers of applications. This manuscript reviews and highlights emerging PoCUS applications that may improve the quality and safety of pediatric care.

In infants and children, lung and airway PoCUS can be used to identify esophageal intubation, size airway devices such as endotracheal tubes, and rule in or out a pulmonary etiology for clinical decompensation. Gastric ultrasound can be used to stratify aspiration risk when nil-per-os compliance and gastric emptying are uncertain. Cardiac PoCUS imaging is useful to triage causes of undifferentiated hypotension or tachycardia and to determine reversible causes of cardiac arrest. Cardiac PoCUS can assess for pericardial effusion, gross ventricular systolic function, cardiac volume and filling, and gross valvular pathology. When PoCUS is used, a more rapid institution of problem-specific therapy with improved patient outcomes is demonstrated in the pediatric emergency medicine and critical care literature.

Overall, PoCUS saves time, expedites the differential diagnosis, and helps direct therapy when used in infants and children. PoCUS is low risk and should be readily accessible to pediatric anesthesiologists in the operating room.

Investigation of fluctuations in blood glucose level due to dietary restrictions during impacted mandibular third molar extraction under intravenous sedation: effect of perioperative glucose administration

Objective

We aimed to investigate the usefulness of glucose administration for maintaining perioperative glycemic control in patients with dietary restrictions during 4 h prior to impacted mandibular third molar extraction under intravenous sedation.

Methods

Fifty-four individuals scheduled to undergo extraction of impacted mandibular third molars under intravenous sedation, with preoperative blood glucose levels (GL) of 70–110 mg/dL, were evaluated and divided into 3 groups (n = 18 each): control group receiving glucose-free sodium lactate Ringer’s solution, perioperative GL group receiving 100 mL of 5% glucose solution immediately after local anesthesia, and postoperative GL group receiving 100 mL of 5% glucose solution immediately after surgery completion. Blood glucose levels, systolic blood pressure, diastolic blood pressure, and heart rate were measured.

Results

Glucose levels of those in the control and perioperative GL groups decreased within the standard range 90 min after surgery, compared with the preoperative blood glucose level. However, in the postoperative GL group, glucose levels were similar to the preoperative levels. Systolic and diastolic blood pressure and heart rate were not affected by glucose administration, and sedation could be maintained without an invasive procedure.

Conclusions

Following a restriction on eating and drinking 4 h prior to surgery, the blood glucose level gradually decreased in the perioperative period but remained within the reference range until 90 min following surgery. The administration of 100 mL 5% glucose solution immediately after surgery was sufficient for the prevention of postoperative hypoglycemia. This approach may be useful for perioperative glycemic control during third molar extraction.

Ultrasound to guide the individual medical decision by evaluating the gastric contents and risk of aspiration: A literature review

Pulmonary aspiration of gastric contents is one of the most terrible complications following general anesthesia. It is important for patients to prevent this complication by obeying the preoperative fasting protocol strictly. At present, it has been reported by many studies that bedside ultrasound, as a non-invasive and convenient method, could be used to evaluate gastric contents qualitatively and quantitatively. With the advantages of reliability, accuracy and repeatability, it can greatly reduce the risk of aspiration and ensure patients' life security. But most of the data were acquired from the healthy volunteers. For the gastrointestinal disorder, the pregnant women, obesity, children, the elderly and diabetes patients, the accuracy and reliability of ultrasound to predict the risk of aspiration remains to be identified by more further studies. For these patients with increasing risk of aspiration, I-AIM (Indication, Acquisition, Interpretation, Medical decision-making) framework plays an important role in ensuring the safety of patients. It is crucial to make appropriate clinical decisions by evaluating the gastric contents with ultrasound.

Evaluating the Safety and Efficacy of Intraoperative Enteral Nutrition in Critically Ill Burn Patients: A Systematic Review and Meta-analysis

Major burn injuries incite a hypermetabolic response, and the initiation of early enteral nutrition is the standard of care in patients with large burns and contributes to improved outcomes. Perioperative fasting is a common cause of caloric deficits in burn patients and can be obviated with intraoperative enteral nutrition. However, the risks and benefits of this practice are unknown, and there is a concern for aspiration. We conducted a systematic review and meta-analysis to evaluate the safety and efficacy of intraoperative enteral nutrition. We performed a systematic literature search using PubMed, Scopus, and OvidSP MEDLINE databases. We identified studies that evaluated the effects of intraoperative enteral nutrition in adult burn patients compared to those undergoing routine perioperative fasting. We performed a meta-analysis on the incidence of mortality, pneumonia, wound infections, and aspiration in burn patients receiving intraoperative enteral nutrition. We identified seven articles for qualitative review and four for quantitative review (N = 83 patients). There were no statistically significant increases in the risk of mortality (odds ratio [OR] = 1.28, 95% confidence interval [CI]: 0.49, 3.31), wound infections (OR = 0.71, 95% CI: 0.16, 3.24), pneumonia (OR = 2.1, 95% CI: 0.7, 6.1), and aspiration (OR = 1.14, 95% CI: 0.07, 18.75) in patients receiving intraoperative enteral nutrition. Within individual studies, intraoperative enteral nutrition patients received significantly more calories than standard fasting patients. Intraoperative enteral nutrition may increase nutritional intake in burn patients without an increase in complications; however, this is based on limited studies. Randomized controlled trials are needed before recommendations on intraoperative enteral nutrition practice can be made.

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.

Evaluation of Gastric Emptying Time of a Rice-Based Meal Using Serial Sonography

The aim of this prospective study was to evaluate the gastric emptying time of a rice-based meal by serial ultrasonography of the stomach. After baseline ultrasonographic assessment of ten fasted healthy volunteers, volunteers ingested standardized 420 g, 536 kcal rice-based meal (bibimbap), and serial evaluations were performed every hour until the stomach became empty. At baseline, all the participants had an empty stomach. The average time of complete gastric emptying of the rice-based meal was 5.8 ± 0.8 h (95% confidence interval (CI), 5.0 h to 6.5 h). Since the first postintake cross-sectional area (CSA) measurement, a decrease was observed, and CSA was maintained until postprandial 3–4 h (P > 0.05). It declined rapidly 4 h after meal intake (P=0.031), reaching the nadir at approximately 6 h after meal intake. The gastric CSA and hunger score showed a positive correlation (correlation r = 0.616, P < 0). The rice-based meal is emptied after 5.8 ± 0.8 h on average in healthy volunteers. Based on our results, 6.5 h (upper limit of CI) of fasting after the ingestion of a rice-based meal would be a safe preoperative fasting time, and this is in accordance with the current guidelines for preoperative fasting.

Gentle facemask ventilation during induction of anesthesia

BACKGROUND

To determine the level of inspiratory pressure minimizing the risk of gastric insufflation while providing adequate pulmonary ventilation.

METHODS

In this prospective, randomized, double-blind study, patients were allocated to one of the two groups (P10, P15) defined by the inspiratory pressure applied during controlled-pressure ventilation: 10 and 15 cm H₂O. Anesthesia was induced using propofol and sufentanil; no neuromuscular-blocking agent was administered. Once loss of eyelash reflex occurred, facemask ventilation was started for a 2-min period. The cross-sectional antral area was measured using ultrasonography before and after facemask ventilation. Respiratory parameters were recorded.

RESULTS

Forty patients were analyzed. Mean tidal volume was about 7 ml/kg in group P10, and was >11 ml/kg in group P15 in the same period. As indicated by ultrasonography test, the antral area in P15 group was markedly incresed compared with P10 group.

CONCLUSION

Inspiratory pressure of 10 cm H₂O allowed for reduced occurrence of gastric insufflation with proper lung ventilation during induction of anesthesia with sufentanil and propofol in nonparalyzed and nonobese patients.

Impact of Nutrition on Enhanced Recovery After Surgery (ERAS) in Gynecologic Oncology

Enhanced recovery after surgery (ERAS) pathways aim to improve surgical outcomes by applying evidence-based practices before, during, and after surgery. Patients undergoing surgery for gynecologic malignancies are at high risk of complications due to population, patient, disease, and surgical factors. The nutritional status of the patient provides the foundation for recovery after surgery, and opportunities to optimize outcomes exist from the first patient assessment to the early days after surgery. This review highlights the importance of nutritional assessment and intervention during the pre-operative and post-operative periods in the context of ERAS in gynecologic oncology surgery. The emerging role of immunonutrition, carbohydrate loading, and the importance of individualized care are explored. Evidence from studies in gynecologic oncology is presented, where available, and extrapolated from colorectal and other cancer surgery trials when applicable.

Endoscopic control of gastric emptying after administration of intravenous erythromycin in an awake patient scheduled for urgent rigid bronchoscopy

Certain interventional pulmonology procedures such as the placement of a tracheal stent or resection of stenosing tracheal tumours require rigid bronchoscopy under general anaesthesia. Unlike an endotracheal tube with a cuff, the rigid bronchoscope only partially protects the airway from bronchoaspiration. For this reason, this procedure is performed on an elective basis in fasted patients. We describe the case of a 60-year-old man with acute respiratory distress requiring emergent rigid bronchoscopy following distal migration of a tracheal stent. One hour before the procedure, the patient had eaten a full meal. Gastric emptying was accelerated by perfusion of intravenous erythromycin and verified by endoscopy with a small diameter gastric endoscope under local anaesthesia. This 1 min procedure was very well tolerated by the patient and allowed to verify with certainty that the stomach was empty. The urgent rigid bronchoscopy for stent retrieval could then be performed safely without any risk of bronchoaspiration.

Chewing gum for 1 h does not change gastric volume in healthy fasting subjects. A prospective observational study

STUDY OBJECTIVE

Perioperative fasting guidelines differ in their approaches to chewing gum in the preoperative period. Current recommendations range from canceling the surgery to proceeding with it. Given this lack of consensus, we performed gastric ultrasound assessments in healthy volunteers before and after a standardized period of chewing gum. The objective of our study was to determine if chewing gum for 1 h change the gastric volume.

DESIGN

Observational prospective analytical study.

SETTING

Bedside gastric ultrasound.

PATIENTS

Following institutional Review Board approval, 55 healthy (American Society of Anesthesiologists class I to II) fasted (non-surgical research) volunteers provided written informed consent to participate in the study. Morbid obesity, renal failure, diabetes mellitus, pregnancy and previous upper abdominal surgery were exclusion criteria.

INTERVENTIONS

Volunteers chewed gum for 1 h between the first and second assessment.

MEASUREMENTS

Four gastric ultrasound assessments were performed, the first one at baseline and then hourly thereafter.

MAIN RESULTS

Fifty-five healthy volunteers were studied. The proportion of subjects who presented a completely empty stomach (Grade 0 antrum) was similar at baseline and after 1 h of gum-chewing [81% vs. 84%, p = 0.19, CI 95% (-12%, 16%)]. Among those subjects who had visible fluid at baseline, the volume remained unchanged throughout the study period.

CONCLUSIONS

One hour of gum-chewing had no significant effect on the gastric fluid volume of healthy volunteers, suggesting that it may be safe for healthy subjects to chew gum prior to elective surgery.

Pulmonary aspiration during procedural sedation: a comprehensive systematic review

Background

Although pulmonary aspiration complicating operative general anaesthesia has been extensively studied, little is known regarding aspiration during procedural sedation.

Methods

We performed a comprehensive, systematic review to identify and catalogue published instances of aspiration involving procedural sedation in patients of all ages. We sought to report descriptively the circumstances, nature, and outcomes of these events.

Results

Of 1249 records identified by our search, we found 35 articles describing one or more occurrences of pulmonary aspiration during procedural sedation. Of the 292 occurrences during gastrointestinal endoscopy, there were eight deaths. Of the 34 unique occurrences for procedures other than endoscopy, there was a single death in a moribund patient, full recovery in 31, and unknown recovery status in two. We found no occurrences of aspiration in non-fasted patients receiving procedures other than endoscopy.

Conclusions

This first systematic review of pulmonary aspiration during procedural sedation identified few occurrences outside of gastrointestinal endoscopy, with full recovery typical. Although diligent caution remains warranted, our data indicate that aspiration during procedural sedation appears rare, idiosyncratic, and typically benign.

When fasted is not empty: a retrospective cohort study of gastric content in fasted surgical patients†

Background

Perioperative aspiration leads to significant morbidity and mortality. Point-of-care gastric ultrasound is an emerging tool to assess gastric content at the bedside.

Methods

We performed a retrospective cohort study of baseline gastric content on fasted elective surgical patients. The primary outcome was the incidence of full stomach (solid content or >1.5 ml kg−1 of clear fluid). Secondary outcomes included: gastric volume distribution (entire cohort, each antral grade); the association between gastric fullness, fasting intervals, and co-morbidities; anaesthetic management changes and incidence of aspiration.

Results

We identified 538 patients. Thirty-two patients (6.2%) presented with a full stomach. Nine of these (1.7%) had solid content and 23 (4.5%) had clear fluid >1.5 ml kg−1. An empty stomach was documented in 480 (89.8%) patients. The examination was inconclusive in the remaining 20 patients (5.0%). As expected, increasing antral grade was correlated with larger antral cross-sectional area and higher gastric volume (P<0.001). Of the 32 patients with a full stomach, only six had a documented risk factor for prolonged gastric emptying. The anaesthetic management was changed in all nine patients with solid content. No aspiration was reported.

Conclusions

This retrospective cohort study suggests that a small proportion of elective surgical patients may present with a full stomach despite the recommended duration of fasting. Further research is needed to establish the clinical implications of these findings in the elective setting. At present, the clinical role of gastric ultrasound continues to be for the evaluation of gastric contents to guide management when the risk of aspiration is uncertain or unknown.

Preoperative Assessment of Ultrasonographic Measurement of Antral Area for Gastric Content

BACKGROUND Pulmonary aspiration of the gastric contents is a serious perioperative complication. The aim of this study was to evaluate the efficacy of portable ultrasonography in the preoperative evaluation of the gastric contents of patients. The secondary aim was to examine the relationship between gastric antrum cross-sectional area and age and body mass index (BMI). MATERIAL AND METHODS This single-center, prospective, cross-sectional study included 120 patients who underwent surgery. Measurements the gastric antral cross-sectional areas and quantitative and qualitative measurements of the stomach were taken by ultrasonography guidance in all patients. RESULTS With the patient in a supine position, the mean gastric antrum cross-sectional area was found to be 3.4±2.43 cm² (range, 0.79-17.3 cm²). As the number of hours of fasting increased, the gastric antral cross-sectional area statistically significantly decreased (P<0.05). Increased age and BMI values were determined to increase the gastric antrum cross-sectional area in a linear correlation; r=0.209, P<0.05 and r=0.252, P=0.05, respectively. It was determined that 20.8% of the patients exceeded the high-risk stomach antral cutoff cross-sectional area that was defined as 340 mm2 in patients fasting for at least 8 hours. CONCLUSIONS It was determined that bedside ultrasonography is a useful, non-invasive tool in the determination of gastric content and volume. A significant proportion of surgical patients may not present with an empty stomach despite the recommended fasting protocols.

Pulmonary aspiration during intubation in a high-risk patient: A video clip and clinical implications

We report a case of pulmonary aspiration during induction of general anesthesia in a patient who was status post esophagectomy. Sudden, unexpected aspiration occurred even though the patient had fasted adequately (over 13 hours) and received rapid sequence anesthesia induction. Since during esophagectomy, the lower esophageal sphincter is excised, stomach vagal innervation is lost, and the stomach is flaccid, draining only by gravity, the patient becomes vulnerable to aspiration. As the incidence of perioperative pulmonary aspiration is relatively low, precautions to prevent aspiration tend to be overlooked. We present a video clip showing pulmonary aspiration and discuss the literature concerning the risk of aspiration and its preventive strategies.

Identification of perioperative pulmonary aspiration in children using quality assurance and hospital administrative billing data

BACKGROUND

Perioperative aspiration is a rare but potentially devastating complication, occurring in 1-10 per 10 000 anesthetics based on studies of quality assurance databases. Quality assurance reporting is known to underestimate the incidence of adverse outcomes, but few large studies use supplementary data sources. This study aims to identify the incidence of and risk factors for perioperative aspiration in children using quality assurance data supplemented by administrative billing records, and to examine the utility of billing data as a supplementary data source.

METHODS

Aspiration events for children receiving anesthesia at a tertiary care pediatric hospital between 2008 and 2014 were identified using (i) a perioperative quality assurance database and (ii) hospital administrative billing records with International Classification of Diseases, Ninth Revision Clinical Modification coded diagnoses of aspiration. Records were subject to review by pediatric anesthesiologists. Following identification of all aspiration events, the incidence of perioperative aspiration was calculated and risk factors were assessed.

RESULTS

47 272 anesthetic cases were evaluated over 7 years. The quality assurance database identified 20 cases of perioperative aspiration occurring in surgical inpatients, same-day admissions, and outpatients. Using hospital administrative data (which excludes outpatients with shorter than a 24-hour stay), 9 cases of perioperative aspiration were identified of which 6 had not been found through quality assurance data. Overall, International Classification of Diseases, Ninth Revision coding demonstrated a positive predictive value of 94.5% for any aspiration event; however, positive predictive value was <4% for perioperative aspiration. A total incidence of 5.5 perioperative aspirations per 10 000 (95% CI: 3.7-8.0 per 10 000) anesthetics was found.

CONCLUSION

Quality assurance data offer an efficient way to measure the incidence of rare events, but may underestimate perioperative complications. International Classification of Diseases, Ninth Revision codes for aspiration used as a secondary data source were nonspecific for perioperative aspiration, but when combined with record review yielded a 30% increase in identified cases of aspiration over quality assurance data alone. The use of administrative data therefore holds potential for supplementing quality assurance studies of rare complications.