Acute Intraoperative Pulmonary Aspiration

A case series of incidents reported to webAIRS relating to glucagon-like peptide 1 agonist use

The increasing prescription of glucagon-like peptide 1 (GLP-1) agonists presents a peri-operative challenge for anaesthetists. These drugs delay gastric emptying, potentially increasing pulmonary aspiration risk. Despite recent recommendations from the Australian and New Zealand College of Anaesthetists, Australian Society of Anaesthetists, and American Society of Anesthesiologists, there remain no formalised guidelines regarding preoperative optimisation for patients taking GLP-1 agonists. Given the current lack of evidence, we present a case series of incidents involving patients treated with GLP-1 agonists reported to webAIRS, a web-based anaesthetic incident reporting system in Australia and New Zealand. Among 11,700 reports from July 2009 to April 2024, 13 incidents related to GLP-1 agonist use were identified, including seven cases concerning aspiration. Patient factors potentially contributing to increased aspiration risks in these incidents included a higher body mass index, type 2 diabetes mellitus, gastro-oesophageal reflux disease, emergency case, and time from GLP-1 agonist cessation. Most incidents involved a rapid sequence induction for general anaesthesia with no cases utilising gastric ultrasound, preoperative nasogastric tube insertion, or intravenous erythromycin use. This case series highlights the potential concerns relating to GLP-1 treatment in the perioperative setting. Interdisciplinary collaboration and communication between anaesthetists, surgeons, general practitioners and endocrinologists are required to further investigate and establish preoperative guidelines for safe GLP-1 agonist use. Specifically, consideration in determining actual gastric contents of each patient despite generic fasting guidelines is needed. Early preoperative risk stratification should also improve patient safety and outcomes.

Glucagon-like peptide-1 receptor agonists increase the risk of residual gastric content and pulmonary aspiration on upper endoscopy: A meta-analysis

BACKGROUND AND AIMS

Glucagon-like peptide-1 receptor agonists (GLP1-RA) are associated with increased residual gastric content (RGC); however, there is debate about their impact on RGC-related clinical outcomes, particularly aspiration.

METHODS

PubMed, Embase, Web of Science and Cochrane Library databases were systematically searched for studies published up to January 4, 2025, comparing GLP1-RA with control groups (non-GLP1-RA) in patients undergoing endoscopy. The outcomes of interest included the risk of RGC, pulmonary aspiration, interrupted and repeated endoscopic procedures, and delays in gastric transit time during capsule endoscopy. For the meta-analysis, a random-effects model was used to calculate the pooled odds ratio (OR) and mean difference (MD) with 95 % confidence intervals (CIs).

RESULTS

Thirty-nine studies composed of a total of 1,253,498 subjects, were included. The pooled analysis demonstrated that the GLP1-RA group had a significantly increased risk of RGC (OR 4.86, 95 % CI 3.85-6.14; adjusted OR 5.24, 95 % CI 3.49-7.87), pulmonary aspiration (OR 2.29, 95 % CI 1.36-3.87), interrupted endoscopic procedures (OR 3.22, 95 % CI 1.65-6.29), repeated endoscopy (OR 2.16, 95 % CI 1.14-4.11), and delays in gastric transit time during capsule endoscopy (MD 45.51, 95 % CI 1.33-89.68).

CONCLUSIONS

GLP1-RA use increased the risk of RGC, pulmonary aspiration, interrupted and repeated endoscopy and gastric transit time, reducing the safety and completion of upper endoscopy.

Glucagon-like peptide-1 receptor agonists in peri-operative care: Dispelling myths and unveiling insights with essential considerations for anaesthesiologists

With the growing use of glucagon-like-peptide-1 (GLP-1) receptor (GLP-1R) agonists as anti-obesity medication it is becoming increasingly important to examine its consequences in the peri-operative period. GLP-1R agonists are known for their effects of glucose-lowering and gastroparesis the latter causing some safety concerns regarding induction of anaesthesia, more specifically the risk of pulmonary aspiration. This article gathers the available evidence on this subject in addition to the already established guidelines. Current evidence makes us assume there is indeed an increased level of gastroparesis, but there are no studies to date with evidential confirmation of a presumed elevated risk of pulmonary aspiration. Future perspectives should focus on the actual risk of pulmonary aspiration and the possible implementation of ultrasound in the preoperative assessment.

Aspiration after Critical Illness: Role of Endotracheal Tube, Tracheostomy, and Swallowing Disorders

Swallowing is a complex process that involves over 50 muscles and nerves and has two critical roles: passing food from the oral cavity through the pharynx and into the esophagus and preventing contents from entering the airway. If a patient's swallowing physiology or airway protective mechanisms are disturbed, the airways and the lungs have innate defense systems to protect against injury and infection. However, critically ill patients are more likely to develop dysphagia, which is an impairment or malfunction in any aspect of the swallowing mechanism, due to the numerous interventions they undergo. When airway reflexes fail, commonly in the presence of dysphagia, aspiration can occur, which is the entry of a fluid or solid below the level of the true vocal cords. If left unmanaged, dysphagia has been associated with aspiration pneumonia, pneumonitis, airway obstruction, delayed enteral nutrition, prolonged length of intensive care unit (ICU) and hospital stay, reduced quality of life, and even death; in some cases, dysphagia is an independent risk factor for mortality. It is important to routinely assess dysphagia in all critically ill patients using a multimodal approach, including systematic assessments, scoring indices, trained specialists, and ICU nurses. Several interventions are crucial for preventing and managing dysphagia and its associated problems. Further research is necessary to help determine the best ways to prevent and manage pulmonary aspiration in critically ill patients. Several interventions are essential in preventing and managing dysphagia and the sequelae of swallowing dysfunction. Further research is needed to help elucidate the best way to avoid and manage pulmonary aspiration in critically ill patients.

Aspiration after Anesthesia: Chemical versus Bacterial, Differential Diagnosis, Management, and Prevention

Aspiration following anesthesia is a major patient issue and a difficulty for anesthesiologists. Aspiration syndromes are more common than anticipated, and the condition is frequently undetected. Clinical signs are often dictated by the characteristics of aspiration, such as the infectivity of the material, its volume, and the severity of the underlying clinical condition. Pulmonary aspiration can cause an acute or persistent inflammatory response in the lungs and upper airways that can be complicated by tracheobronchitis, aspiration pneumonia, aspiration pneumonitis, acute respiratory distress syndrome, and subsequent bacterial infection due to particle, acid, and bacteria-related processes. Aspiration during anesthesia, while relatively rare, poses significant risks for patient morbidity and mortality. Chemical and bacterial aspiration provide distinct diagnostic and management issues. Preventive strategies such as a complete preoperative risk assessment, adherence to fasting rules, proper patient positioning, and the use of protective airway devices are critical in reducing aspiration risk. In addition, drugs such as proton pump inhibitors can help lower stomach acidity and volume. Innovations in monitoring techniques, better training, and awareness activities are critical to enhancing aspiration event management. Given the importance of this entity, this narrative review sought to make an updated overview of the management of aspiration after anesthesia: chemical versus bacterial, differential diagnosis, management, and prevention.

Mitigating Aspiration Risk With Awake Intubation: A Case of Intrathoracic Stomach

Hiatal hernias are common in the elderly and in most cases asymptomatic and no intervention is needed. Hiatal hernias can range from asymptomatic to an intrathoracic stomach, a rare but potentially life-threatening condition, characterized by the migration of the stomach into the thoracic cavity. Its need for urgent intervention presents a major concern for the anesthesiologist because it is associated with a high risk of aspiration. This case report discusses the clinical presentation and anesthetic management of an intrathoracic full stomach proposed for urgent surgery. By presenting this case, we hope to enhance the understanding of preoperative management in patients with intrathoracic full stomach and the role of awake fiberoptic guided intubation as a valuable technique in emergency surgical settings. This case reinforces the importance of existing healthcare professionals with practice in managing similar clinical scenarios effectively.

Perioperative Management of Patients with Diabetes and Cancer: Challenges and Opportunities

BACKGROUND

Both diabetes and cancer are major global health issues that are among the leading causes of morbidity and mortality. There is a high prevalence of diabetes among cancer patients, many of whom require a surgical procedure. This review focuses on the operative complications in patients with diabetes and cancer, and the perioperative management of diabetes in cancer patients.

METHODOLOGY

A literature search of articles in English-published between January 2010 and May 2024-was carried out using the databases PubMed, MEDLINE, Google Scholar, and the Cochrane Database of Systematic Reviews. The search primarily focused on the operative complications in patients with diabetes and cancer, and perioperative management strategies.

RESULTS

The relationship between cancer and diabetes is complex; cancer patients have a high risk of developing diabetes, while diabetes is a risk factor for certain cancers. In addition, various cancer therapies can induce or worsen diabetes in susceptible patients. Many individuals with cancer and diabetes require surgery, and due to underlying diabetes, they may have elevated risks for operative complications. Optimal perioperative management for these patients includes managing perioperative glycemia and other comorbid illnesses, adjusting diabetic and cancer treatments, optimizing nutrition, minimizing the duration of fasting, supporting early mobilization, and providing patient education to enable self-management.

CONCLUSIONS

While evidence is limited, optimal perioperative management for patients with both diabetes and cancer is necessary in order to reduce surgical complications. Future studies are needed to develop evidence-informed perioperative strategies and improve outcomes for these patients.

General Anesthesia for Patients With Cyclic Vomiting Syndrome and Obesity: A Case Report

Cyclic vomiting syndrome (CVS) is a chronic digestive disorder characterized by recurrent episodes of severe nausea and vomiting. The perioperative management of patients with CVS undergoing general anesthesia is challenging, especially when combined with obesity. This case report describes the successful management of a patient with CVS and obesity who underwent dental surgery under general anesthesia. A 21-year-old woman with CVS, obesity (body mass index, 35), and intellectual disability was scheduled for tooth extraction and composite resin restoration under general anesthesia. The patient was diagnosed with CVS at the age of 20 years with frequent vomiting attacks requiring hospitalization. Surgery was scheduled during the CVS remission to reduce the risk of perioperative vomiting. Preoperative laboratory test results were normal, including serum adrenocorticotropic hormone (ACTH), anti-diuretic hormone (ADH), and cortisol levels. General anesthesia was induced using remifentanil and propofol. Nasal endotracheal intubation was performed after rocuronium administration. Local anesthesia (2% lidocaine with 1:80,000 epinephrine) was used for all dental procedures. Postoperatively, midazolam was administered to control agitation. No postoperative vomiting occurred. Serum ACTH, ADH, and cortisol levels showed no significant changes before and after anesthesia, suggesting that hypothalamic-pituitary-adrenal (HPA) axis activation due to surgical stress did not occur. This case highlights the importance of careful perioperative planning and monitoring stress-related hormone levels in patients with CVS or obesity. An anesthetic approach using midazolam may effectively suppress HPA axis activation and prevent postoperative vomiting.

Regional anesthesia in a patient with primary ciliary dyskinesia: A case report

BACKGROUND

Primary ciliary dyskinesia (PCD) is an inherited autosomal-recessive disorder of impaired mucociliary clearance characterized by chronic respiratory diseases, otolaryngological diseases, central nervous system abnormalities, reproductive system abnormalities, and cardiac function abnormalities. General anesthesia in these patients is associated with a higher incidence of respiratory complications than in patients without the disease.

CASE SUMMARY

A 16-year-old male patient was referred to the emergency room complaining of right ankle pain due to distal tibiofibular fracture. Three years prior, he had been diagnosed with PCD. At that time, he had experienced several episodes of pneumonia, sinusitis, and chronic middle ear infections, for which he underwent surgical interventions. At the current admission, he presented with cough and sputum but no other respiratory symptoms. A chest computed tomography scan revealed centrilobular ground-glass opacities in both lower lobes and a calcified nodule in the left lower lobe. For the surgical procedure and postoperative pain management, combined spinal-epidural anesthesia was employed. The patient's postoperative pain score was measured by the numerical rating scale (NRS). On the day of surgery, his NRS was 5 points. By the second postoperative day, the NRS score had decreased to 2-3 points. The epidural catheter was removed on the fourth day following the operation. The patient was subsequently discharged no respiratory complications.

CONCLUSION

We performed combined spinal-epidural anesthesia in a patient with PCD. The patient experienced no additional respiratory complications and was discharged with a low NRS score for pain.

Glucagon-Like Peptide-1 Receptor Agonists Increase Solid Gastric Residue Rates on Upper Endoscopy Especially in Patients With Complicated Diabetes: A Case-Control Study

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) prescribed for weight loss and type 2 diabetes mellitus (T2DM) can delay gastric emptying, but risk factors and impact on procedure outcomes remain unclear.

METHODS

We compared frequency of gastric residue on upper endoscopy in patients on a GLP-1RA and propensity score-matched controls in this retrospective case-control study of consecutive patients undergoing endoscopic procedures over a 3.5-year period. GLP-1RAs were not held before endoscopy. The gastric residue presence was assessed by reviewing endoscopy reports and images. Predictors and consequences of gastric residue with GLP-1RA were determined.

RESULTS

In 306 GLP-1RA users compared with matched controls, rates of gastric residue were significantly higher with GLP-1RA use (14% vs 4%, P < 0.01), especially in patients with T2DM (14% vs 4%, P < 0.01), with insulin dependence (17% vs 5%, P < 0.01) and T2DM complications (15% vs 2%, P < 0.01). Lower gastric residue rates were noted after prolonged fasting and clear liquids for concurrent colonoscopy (2% vs 11%, P < 0.01) and in patients with afternoon procedures (4% vs 11%, P < 0.01). While 22% with gastric residue required intubation and 25% had early procedure termination, no procedural complications or aspiration were recorded.

DISCUSSION

GLP-1RA use is associated with increased gastric residue on upper endoscopy, particularly in patients with T2DM, surpassing the impact of opiates alone. Risk is highest in the presence of T2DM complications while prolonged fasting and a clear-liquid diet are protective. This increased risk of gastric residue does not appear to translate to an increased risk of procedural complications.

Preoperative ultrasound assessment of gastric content in patients with diabetes: A meta-analysis based on a systematic review of the current literature

STUDY OBJECTIVE

To conduct a systematic literature review of the current evidence on the effect of diabetes mellitus on gastric volume observed during a preoperative ultrasound examination. Using the results of this systematic literature review, a meta-analysis was performed to investigate whether there was an association between diabetes mellitus and an increased risk of presenting with a high-risk stomach (gastric volume associated with an increased risk of pulmonary aspiration).

DESIGN

Review article and meta-analysis.

SETTING

Review of published literature.

PATIENTS

A total of 3366 patients underwent surgery.

INTERVENTION

Gastric ultrasound examination.

MEASUREMENTS

Data for the meta-analysis and literature review were collected from the PubMed/Medline, Embase, Web of Science, and Google Scholar databases of the National Library of Medicine from the date of inception to January 2023. All included studies measured the gastric antral cross-sectional area and/or gastric residual volume in patients with diabetes and those without diabetes. The data utilized in the meta-analysis included all studies that evaluated the incidence of high-risk stomachs based on ultrasonographic measurements of the gastric antral cross-sectional area or gastric residual volume.

MAIN RESULTS

Most collated studies revealed that diabetes mellitus was associated with increased antral cross-sectional area and gastric residual volume. A meta-analysis of published reports indicated that patients with diabetes have an increased rate of high-risk stomachs.

CONCLUSIONS

Diabetes mellitus is associated with an increased rate of high-risk stomachs. The authors recommend large prospective trials to ascertain the safety of the current fasting guidelines for patients with diabetes undergoing surgery.

Point-of-Care Ultrasound Aids in the Management of Patient Taking Semaglutide Before Surgery: A Case Report

Semaglutide, a glucagon-like peptide-1 (GLP-1) analog, has various effects on the gastrointestinal tract. In patients undergoing anesthesia delayed gastric emptying time can have sequelae if not identified preoperatively. Modalities include thorough history regarding the last dose administration of a GLP-1 analog and ultrasound of gastric contents before induction of anesthesia. We present a case in which gastric ultrasound identified a patient at increased risk for aspiration on induction and allowed for appropriate alterations in the anesthetic plan.

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.

Effect of total fasting hours on the overall quality of recovery after surgery: An observational study

Context

Preoperative fasting is one of the pre-requisite for patients undergoing a surgery. Despite clear instructions, patients frequently fast for extended periods before elective surgeries. Longer periods of fasting may cause discomfort, thirst, hunger, and other physiological problems.

Aims

To assess the quality of postoperative recovery among adult patients having different preoperative fasting hours by using the postoperative Quality of Recovery40 (QoR40) score.

Settings and Design

This was an observational study that was conducted for adult patients undergoing elective surgery during four weeks between 19th September and 13th October 2022 at Security Forces Hospital Riyadh, Kingdom of Saudi Arabia.

Methods and Material

We excluded pediatric patients, patients undergoing spine or neurosurgery, emergency cases, or local anesthesia cases. Non-probability convenient sampling technique was used in this study. The postoperative quality of recovery-40 (QoR-40) questionnaire was distributed among 200 patients.

Statistical Analysis Used

All analyses were performed with Statistical Package for the Social Sciences software (SPSS) v25. Descriptive statistics (frequency, percentage, median, and IQR) were used for the questionnaire's variables. The difference between the variables was analyzed using Kruskal-Wallis, and a P value <0.05 was considered statistically significant.

Results

Out of 200 patients, 172 patients responded but 16 responses were excluded. A total of 156 adult patients' responses were included in this study. The majority were female (53%), 31% were older than 45 years. More than 50% of patients reported fasting for more than 6 hours for drinking and more than 8 hours for eating. On the positive scale, the comfort score was significantly affected by the fasting hours for drinking (P value = 0.045). On the negative scale of the questionnaire, the emotions were significantly affected by fasting hours for both drinking (P value = 0.027) and eating (P value = 0.043).

Conclusions

The study results showed better comfort for patients with lesser fasting hours for drinking. Moreover, the results strongly suggest the need of following the fasting guidelines without prolonging the fasting duration. However, further studies with larger sample sizes are recommended.

Carbohydrate Loading and Aspiration Risk in Bariatric Patients: Safety in Preoperative Enhanced Recovery Protocols

BACKGROUND

Enhanced recovery protocols have been developed to improve perioperative outcomes; however, there is ongoing concern for aspiration with recent oral intake in patients with obesity, who may be predisposed to impaired gastrointestinal motility and greater gastric volumes. We aim to study the safety of a 300-mL preoperative carbohydrate-loading drink preceding bariatric surgery.

STUDY DESIGN

Data were collected prospectively from patients undergoing primary bariatric surgery. All bariatric patients at our institution are prescribed a proton pump inhibitor for 4 weeks before surgery and undergo a screening preoperative esophagogastroduodenoscopy (EGD) before surgery with a traditional 8-hour fast (NOCARB), followed by an intraoperative day-of-operation EGD with carbohydrate loading (CARB) 2 to 4 hours before incision. Gastric volumes and pH are measured after being endoscopically suctioned via direct visualization during both settings.

RESULTS

We identified 203 patients: 94 patients (46.3%) in the CARB group and 109 patients (53.7%) in the NOCARB group. The patients were 82.3% female with a mean age of 42.8 years and average BMI of 41.7 kg/m 2 . There was no difference in gastric volume between NOCARB and CARB (17.0 vs 16.1 mL, p = 0.59). The NOCARB group had lower pH values than the CARB group (2.8 vs 3.8, p = 0.001). Subset analysis of 23 patients who had measurements on both screening and intraoperative EGD revealed lower gastric volumes in CARB patients (13.3 vs 18.3, p < 0.0001).

CONCLUSIONS

When included in an enhanced recovery protocol, proton pump inhibitor use and preoperative carbohydrate loading 2 to 4 hours before bariatric surgery does not increase aspiration risk based on gastric volumes and pH and should be strongly considered in all eligible bariatric patients.

Relationship between perioperative semaglutide use and residual gastric content: A retrospective analysis of patients undergoing elective upper endoscopy

STUDY OBJECTIVE

Semaglutide is a long-acting glucagon-like peptide-1 receptor agonist used for management of type 2 diabetes and/or obesity. To test the hypothesis that perioperative semaglutide use is associated with delayed gastric emptying and increased residual gastric content (RGC) despite adequate preoperative fasting, we compared the RGC of patients who had and had not taken semaglutide prior to elective esophagogastroduodenoscopy. The primary outcome was the presence of increased RGC.

DESIGN

Single-center retrospective electronic chart review.

SETTING

Tertiary hospital.

PATIENTS

Patients undergoing esophagogastroduodenoscopy under deep sedation/general anesthesia between July/2021-March/2022.

INTERVENTIONS

Patients were divided into two (SG = semaglutide, NSG = non-semaglutide) groups, according to whether they had received semaglutide within 30 days prior to the esophagogastroduodenoscopy.

MEASUREMENTS

Increased RGC was defined as any amount of solid content, or > 0.8 mL/Kg (measured from the aspiration/suction canister) of fluid content.

MAIN RESULTS

Of the 886 esophagogastroduodenoscopies performed, 404 (33 in the SG and 371 in the NSG) were included in the final analysis. Increased RGC was observed in 27 (6.7%) patients, being 8 (24.2%) in the SG and 19 (5.1%) in the NSG (p < 0.001). Semaglutide use [5.15 (95%CI 1.92-12.92)] and the presence of preoperative digestive symptoms (nausea/vomiting, dyspepsia, abdominal distension) [3.56 (95%CI 2.2-5.78)] were associated with increased RGC in the propensity weighted analysis. Conversely, a protective [0.25 (95%CI 0.16-0.39)] effect against increased RGC was observed in patients undergoing esophagogastroduodenoscopy combined with colonoscopy. In the SG, the mean time of preoperative semaglutide interruption in patients with and without increased RGC was 10.5 ± 5.5 and 10.2 ± 5.6 days, respectively (p = 0.54). There was no relationship between semaglutide use and the amount/volume of RGC found on esophagogastroduodenoscopy (p = 0.99). Only one case (in the SG) of pulmonary aspiration was reported.

CONCLUSIONS

Semaglutide was associated with increased RGC in patients undergoing elective esophagogastroduodenoscopy. Digestive symptoms prior to esophagogastroduodenoscopy were also predictive of increased RGC.

Complications of catheter ablation for ventricular tachycardia

With the increasing literature demonstrating benefits of catheter ablation for ventricular tachycardia (VT), the number of patients undergoing VT ablation has increased dramatically. As VT ablation is being performed more routinely, operators must be aware of potential complications of VT ablation. This review delves deeper into the practice of VT ablation with a focus on periprocedural complications.

Advantages of ketamine in pediatric anesthesia

Although ketamine is primarily used for induction and maintenance of general anesthesia, it also presents sedative, amnestic, anesthetics, analgesic, antihyperalgesia, neuroprotective, anti-inflammatory, immunomodulant, and antidepressant effects. Its unique pharmacodynamics and pharmacokinetic properties allow the use of ketamine in various clinical settings including sedation, ambulatory anesthesia, and intensive care practices. It has also adopted to manage acute and chronic pain management. Clinically, ketamine produces dissociative sedation, analgesia, and amnesia while maintaining laryngeal reflexes, with respiratory and cardiovascular stability. Notably, it does not cause respiratory depression, maintaining both the hypercapnic reflex and the residual functional capacity with a moderate bronchodilation effect. In the pediatric population, ketamine can be administered through practically all routes, making it an advantageous drug for the sedation required setting such as placement of difficult vascular access and in uncooperative and oppositional children. Consequently, ketamine is indicated in prehospital induction of anesthesia, induction of anesthesia in potentially hemodynamic unstable patients, and in patients at risk of bronchospasm. Even more, ketamine does not increase intracranial pressure, and it can be safely used also in patients with traumatic brain injuries. This article is aimed to provide a brief and practical summary of the role of ketamine in the pediatric field.

Bile acids-induced lung injury: update of reverse translational biology

The presence of bile acids in lung tissue is associated with some clinical features observed in various medical specialties, but it took time to understand that these are due to a "bile acid-induced lung injury" since specific translational studies and cross-disciplinary awareness were lacking. We used a reverse translational approach to update and summarize the current knowledge about the mechanisms of bile acid-induced lung injury. This has been done in a cross-disciplinary fashion since these conditions may occur in patients of various age and in different medical fields. We here define these clinical conditions, then we review the physiopathology of these conditions and the animal models used to mimic them and, finally, their pathobiology. Mechanisms of bile acid-induced lung injury have been partially clarified overtime and are represented by: 1) the interaction with secretory phospholipase A2 pathway, 2) the effect on surfactant function and structure, 3) the biological effects on inflammation and local immunity, 4) the direct cellular toxicity. These mechanisms are schematically illustrated and histological comparisons between ARDS induced by bile acids and other triggers are also provided. Based on these mechanisms we propose possible direct therapeutic applications and, finally, we discuss further research steps to improve the understanding of processes that generate pathological clinical conditions.

Management of pulmonary aspiration due to undiagnosed achalasia during induction of general anesthesia: a case report with literature review - A case report -

Background

Intraoperative pulmonary aspiration is a rare but potentially fatal complication associated with various risk factors. Preoperative recognition of these risk factors can prevent aspiration events during general anesthesia or facilitate prompt corrective measures in patients experiencing this complication.

Case

A 70-year-old female patient with hypertension underwent bilateral total knee arthroplasty under general anesthesia. Despite using a midnight nothing-per-oral (NPO) protocol, an unpredictable intraoperative aspiration event occurred during anesthesia induction. A detailed evaluation of the patient’s medical history and subsequent diagnostic imaging examinations indicated achalasia. She was treated for aspiration pneumonia for 2 weeks. After 2 months, rescheduled total knee arthroplasty was performed under spinal anesthesia without any complications.

Conclusions

Obtaining the patient’s medical history and assessing the risk factors are important to prevent unpredictable intraoperative pulmonary aspiration. High-risk patients should undergo adequate preoperative fasting and regional anesthesia or rapid-sequence intubation should be considered for safe induction of general anesthesia.

Aspiration syndromes and associated lung injury: incidence, pathophysiology and management

Aspiration is a common condition affecting healthy or sick patients which could create an acute or chronic inflammatory reaction in the lungs. Aspiration syndromes could be categorized according to a content entering the respiratory system into bacterial aspiration pneumonia with the gastric or oropharyngeal bacteria entering, aspiration chemical pneumonitis with bacteria-freegastric acid aspiration, or aspiration of a foreign body which causes an acute pulmonary emergency. There are differences in the clinical presentation of volume-dependent aspirations (microaspiration and macroaspiration): the higher is the volume of aspiration, the greater is the injury to the patient and more serious are the health consequences (with 70 % mortality rate for hospitalized patients). Aspiration syndromes can affect both the airways and pulmonary parenchyma, leading to acute lung injury, increased hospitalization rate and worse outcomes in critically ill patients. Impaired alveolar-capillary permeability, oedema formation, neutrophilic inflammatory response and pulmonary surfactant inactivation lead to reduced lung compliance and loss of aerated lung tissue and give rise to hypoxemia and respiratory failure. This review discusses the effect of aspiration events on the pulmonary tissue. The main focus is to distinguish the differences between bacterial and chemical pneumonia, their clinical presentation and symptoms, risk factors of developing the changes, possibilities of diagnostics and management as well as prevention of aspirations. Because of a risk of serious lung damage after the aspiration, pathophysiology and processes leading to lung tissue injury are discussed in detail. Data sources represent a systematic literature search using relevant medical subject headings.

Gastric content and perioperative pulmonary aspiration in patients with diabetes mellitus: a scoping review

BACKGROUND

Gastric emptying may be delayed in patients with diabetes mellitus (DM). However, the incidence of full stomach in fasting patients with DM and their risk of pulmonary aspiration under anaesthesia is not well understood.

METHODS

A scoping review was undertaken to map the literature on aspiration risk in DM. A search was conducted in seven bibliographic databases, including MEDLINE and Embase, for original articles that studied aspiration risk, gastric emptying, or gastric content and volume. Selection and characterisation were performed by two independent reviewers using a predefined protocol registered externally.

RESULTS

The search identified 5063 unique records, and 16 studies (totalling 775 patients with DM) were selected: nine studied gastric emptying and seven studied gastric content or volume. There were no studies reporting the incidence of aspiration in subjects with DM. All nine studies reported delayed emptying in patients with DM compared with healthy controls. Amongst the seven studies that compared gastric residual content/volume (GRV) in the perioperative period, five reported clinically negligible GRV in both patients with DM and controls, whereas two observed a higher incidence of 'full' stomach in patients with DM.

CONCLUSIONS

The evidence concerning the aspiration risk for surgical patients with DM is based on a limited number of studies, mostly unblinded, reporting physiological data on gastric emptying and gastric volume as surrogate markers of aspiration risk. Data on fasting gastric content and volume in patients with DM are limited and contradictory; hence, the true risk of aspiration in fasting patients with DM is unknown.

Reinforcing the valuable role of gastric ultrasound for volume and content assessment: an observational study

BACKGROUND

Pulmonary aspiration is one of the most important complications in anesthesiology. Assessment of gastric content by ultrasound is a good method to quantify gastric volume and to determine the risk of intraoperative pulmonary aspiration. The aim of this study is to determine the accuracy of the gastric ultrasonography in the qualitative analysis of gastric content, mainly in the analysis of small amounts of liquid content.

METHODS

Gastric ultrasound was performed to 36 patients before upper gastrointestinal endoscopy (UGI), making two longitudinal scans at the epigastric level, one in supine position and the other in right lateral decubitus position, measuring two diameters and the area of the gastric antrum and assessing the content characteristics determining whether it was an empty stomach or contained fluid or solid content. Subsequently, the ultrasound findings were compared with UGI findings.

RESULTS

Gastric areas were analyzed by the trace and the lengths of the craniocaudal and anteroposterior axes concluding that there are no significant differences between the two methods. No statistically significant difference was found between UGI and US assessment technics. No statistically significant difference was found between the estimated volume by UGI and US.

CONCLUSIONS

Though our study has some limitations, qualitative analysis of gastric content using ultrasound followed by endoscopy enabled the conclusion that there are no differences in the qualitative assessment regarding these two techniques, supporting the important role of point-of-care gastric ultrasound (POCGUS) in the assessment of pulmonary aspiration risk by the anesthesiologist in the perioperative period.

The effects of diabetes mellitus on gastric emptying: A prospective observational cohort study

STUDY OBJECTIVE

Our goal was to evaluate the effect of diabetic severity and duration on preoperative residual gastric volume. Secondarily we compared ultrasonic estimates of residual gastric volume with actual volume determined by aspiration during endoscopy.

DESIGN

This was a prospective, observational cohort study that included adults with a history of diabetes mellitus and/or opioid use scheduled for gastrointestinal endoscopic procedures.

SETTING

Endoscopy unit at Cleveland Clinic Main Campus from 2017 to 2019.

PARTICIPANT

Adults scheduled for upper endoscopy with or without colonoscopy.

INTERVENTION AND MEASUREMENTS

Residual gastric volumes were primarily determined by aspiration during endoscopy, and secondarily estimated with ultrasound. We evaluated the relationship between gastric residual volume and preoperative HBA1C concentration and duration of diabetes. Secondarily, we conducted an agreement analysis between the two gastric volume measurement techniques.

MAIN RESULTS

Among 145 enrolled patients, 131 were diabetic and 17 were chronic opioid users. Among 131 diabetic patients, the mean ± SD HbA1c was 7.2 ± 1.5% and the median (Q1, Q3) duration of diabetes was 8.5 (3, 15) years. Neither HbA1c nor duration of diabetes was associated with residual gastric volume. The adjusted mean ratio of residual gastric volume was 1.07 (98.3% CI: 0.89, 1.28; P = 0.38) for 1% increase in HbA1c concentration, and 0.84 (98.3% CI: 0.63, 1.14; P = 0.17) for each 10-year increase induration of diabetes. The median [Q1-Q3] absolute difference between gastric ultrasound measurement and endoscopic measurement was 25 [15, 65] ml.

CONCLUSIONS

In this prospective observational cohort study, neither the duration nor severity of diabetes influenced preoperative residual gastric volume. Gastric ultrasound can help identify patients who have excessive residual volumes despite overnight fasting.

A protocol implementation to determine aspiration risk in patients with multiple risk factors for gastroparesis

Patients with risk factors for gastroparesis are at increased risk for aspiration into the tracheobronchial tree. Current American Society of Anesthesiologists fasting guidelines use subjective measures to determine aspiration risk. A gastric ultrasound protocol can identify patients with risk factors for gastroparesis and determine the need to perform a point-of-care gastric ultrasound to objectively assess gastric antral contents. This enables the anaesthesia provider to assess patients at increased risk for aspiration. Additionally, many patients who present for surgery with risk factors for gastroparesis have an empty gastric antrum. Thus, the gastric ultrasound protocol checklist saves time and manpower requirements of anaesthesia staff without impacting patient safety or perioperative efficiency. A convenience sample of 40 patients consented for surgery was assessed using a screening tool to identify those at risk for gastroparesis and possible aspiration. Patients deemed at risk received a gastric ultrasound examination to evaluate for the presence of gastric contents. Over 12% of these patients had solid food gastric contents on exam. All patients with solid food gastric contents had an American Society of Anesthesiologists Physical Status Classification of 3 or higher, and two or more risk factors for gastroparesis.

[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。

Pulmonary Aspiration During Induction of General Anesthesia

Perioperative pulmonary aspiration of gastric contents can induce complications of varying severity, including aspiration pneumonitis or pneumonia, which may be lethal. A 34-year-old man with no significant medical history presented to Okayama University Hospital for extraction of the third molars and incisive canal cystectomy under general anesthesia. He experienced pulmonary aspiration of clear stomach fluid during mask ventilation after induction. After aspiration occurred, the patient was immediately intubated, and suctioning was performed through the endotracheal tube (ETT). An anteroposterior (AP) chest radiograph was obtained that demonstrated atelectasis in the left lower lobe, in addition to increased peak airway pressures being noted, although SpO2 remained at 96% to 99% at an FiO2 of 1.0. The decision was made to proceed, and the scheduled procedures were completed in approximately 2 hours. A repeat AP chest radiograph obtained at the end of the operation revealed improvement of the atelectasis, and no residual atelectasis was observed on the next day. Although the patient reported following standard preoperative fasting instructions (no fluids for 2 hours preoperatively), more than 50 mL of clear fluid remained in his stomach. Because vomiting can occur despite following NPO guidelines, the need for continued vigilance by anesthesia providers and proper timely management is reinforced.

The Effects of Preoperative Fasting on Patients Undergoing Thoracic Surgery

PURPOSE

The purpose of this study was to determine the effects of fasting before surgery on patients undergoing thoracic surgery.

DESIGN

This descriptive cross-sectional study was conducted from January 1 to June 30, 2017.

METHODS

The study was carried out with 85 patients who underwent thoracotomy, mediastinoscopy, or rib resection in the thoracic surgery department of a university hospital. All patients started fasting midnight before day of surgery. Data were collected using a questionnaire, Visual Analog Patient Satisfaction Scale, and preoperative laboratory findings form.

FINDINGS

The mean fasting hours of solids and clear fluids were 8 and 16, respectively, and the mean duration of preoperative fasting (POF) was 10.16 (SD = 1.67), total fasting time average was 28.09 (SD = 7.11). Total protein and albumin levels decreased, and glucose level increased after surgery. The difference between total protein, albumin, and glucose levels preoperatively and postoperatively was significant (P < .05). The difference between patient satisfaction and thirst was found to be statistically significant (P < .05). A positive correlation was found between POF and thirst (r = 0.450; P = .000), hunger (r = 0.402; P = .000), total protein (r = 0.508; P = .000), albumin (r = 0.537; P = .000), and glucose levels (r = 0.371; P = .000).

CONCLUSIONS

POF had an adverse effect on thirst, hunger, and total protein as well as albumin and glucose levels.

Development and Validation of a Questionnaire Assessing Patient Distress from Preoperative Fasting in Cataract Surgery

Purpose: To develop and psychometrically validate a questionnaire to measure patient distress with preoperative fasting related to cataract surgery.Methods: In this single-centered cross-sectional study, consecutive sampling of cataract patients was undertaken immediately preoperatively from February to December 2019. A questionnaire evaluating patient distress with fasting was designed and administered. Questionnaire development occurred in an iterative process and was conducted with consultation from expert investigators and patients. Validation and psychometric evaluation of the questionnaire were performed with Rasch analysis.Results: A preliminary version of the questionnaire was developed by 10 study investigators. Across five iterations of development, the questionnaire was administered to 186 cataract patients. Psychometric evaluation of the 13-item questionnaire demonstrated ordered thresholds, acceptable item calibration and fit, adequate internal consistency, ability to discriminate between three levels of distress from preoperative fasting and no notable differential item functioning. However, issues with mistargeting, clustering of items on the person-item map and multidimensionality remained. Given these concerns, 13 separate re-analyses were conducted via removal of certain items. A 6-item subset was determined to be well targeted, unidimensional, did not display item clustering and was able to discriminate between patients with high and low distress from preoperative fasting.Conclusion: A 6-item questionnaire is a valid, psychometrically robust and reliable measure for the assessment of patient distress with preoperative fasting in cataract surgery. Items include hunger, thirst, hoarseness, weakness, anxiety and nausea. Future studies should seek to validate this questionnaire across a variety of sociodemographic contexts, languages and specialties.

Dysphagia Screening for Pneumonia Prevention in a Cancer Hospital: Results of a Quality/Safety Initiative

OBJECTIVE

Hospital-acquired aspiration pneumonia remains a rare but potentially devastating problem. The best means by which to prevent aspiration in a cancer hospital population has not been evaluated. The aim of this study was to evaluate the impact of dysphagia screening on aspiration pneumonia rates in an acute care oncology hospital.

METHODS

A prospective single-institution quality improvement dysphagia screening protocol at a comprehensive cancer center. Effect of dysphagia screening implemented in 2016 on hospital-acquired aspiration pneumonia rates coded "aspiration pneumonitis due to food/vomitus" was compared with rates from 2014 to 2015 prior to implementation. Screening compliance, screening outcomes, patient demographics, and medical data were reviewed as part of a post hoc analysis.

RESULTS

Of 12,392 admissions in 2014 to 2016, 97 patients developed aspiration pneumonia during their hospitalization. No significant change in aspiration pneumonia rate was seen during the dysphagia screening year when compared to prior years (baseline, 7.36; screening year, 8.78 per 1000 discharges; P = .33). Sixty-eight of the cases (66%) were associated with emesis/gastrointestinal obstruction or perioperative aspiration and only 15 (15%) with oropharyngeal dysphagia. Multivariate analysis found that patients admitted to gastrointestinal surgery had an aspiration risk equivalent to patients admitted to head and neck, thoracic, and pulmonary services (odds ratio, 0.65; P = .2).

DISCUSSION

Nursing-initiated dysphagia screening did not decrease aspiration pneumonia rates. The causes of aspiration-associated pneumonia were heterogeneous. Aspiration of intestinal contents is a more common source of hospital-acquired pneumonia than oropharyngeal dysphagia.

Pneumonia due to aspiration of povidine iodine after preoperative disinfection of the oral cavity

INTRODUCTION

Povidone-iodine (PI) is thought to be an effective disinfectant and safe for many surgeons. Aspiration pneumonia is usually caused by gastric contents, but if PI solution will be aspirated, pneumonia or other complications may occur.

CASE REPORT

We present a case of pneumonia to aspiration of PI solution in a 91-year-old man patient who underwent oral-maxillofacial surgery. When surgeons used PI solution for disinfection into the oral cavity, the solution seems to be sinking gradually. The patient showed severe respiratory distress and developed hypoxia. There were much frothy fluids into a tracheal tube. We suctioned through the endotracheal tube and performed bronchoscopy, that revealed a redness which appeared associated to a chemical injury on the left trachea and bronchus. His condition was complicated by ARDS and DIC. Periodical bronchial suction and guideline-based treatments of ARDS were carried in ICU. He recovered without severe complication.

CONCLUSION

Although PI solution for an oral disinfection is used routinely, all operators need to be aware of the risk for PI aspiration.

Periprocedural pulmonary aspiration: An analysis of medical malpractice cases and alleged causative factors

RATIONALE AIMS AND OBJECTIVES

Pulmonary aspiration is a feared complication of anaesthesia that is associated with significant morbidity and mortality. Within the small existing body of literature on medical malpractice claims related to periprocedural aspiration, very little information is available regarding the case-specific factors that were alleged to contribute to each aspiration event.

METHODS

This study searched an extensive nationwide database of medical malpractice claims and identified 43 relating to periprocedural pulmonary aspiration.

RESULTS

The most common mechanism of causation cited in these claims (37%) was the failure to secure the airway with an endotracheal tube (ETT) when an elevated aspiration risk existed, most commonly because endotracheal intubation was not originally selected as part of the anaesthetic plan. The second most common alleged category of causation (33%) was the failure to perform a proper rapid-sequence induction and/or place a nasogastric tube (NGT) for decompression prior to induction. An equal amount of cases resulted in defendant versus plaintiff verdicts (44.2% each), while a settlement was reached in the remaining 11.6% of cases.

CONCLUSION

These findings are generalizable to clinical practice improvement on a broader scale. They demonstrate the need to develop reliable, high-sensitivity tests for detecting elevated risk before clinicians can be expected to take special steps to protect susceptible patients, and they also show that medical malpractice can be alleged because of failure to uphold currently accepted standards of care even when the published evidence for those standards is weak. This study demonstrates that careful review of medical malpractice litigation can elucidate common contributory factors and facilitate improvements in clinical practice and decision-making.

The association of preoperative delirium with postoperative outcomes following hip surgery in the elderly

STUDY OBJECTIVE

To determine the association of preoperative delirium with postoperative outcomes following hip surgery in the elderly.

DESIGN

Retrospective cohort study.

SETTING

Postoperative recovery.

PATIENTS

8466 patients all of whom were 65 years of age or older undergoing surgical repair of a femoral fracture. Of the total population studied, 1075 had preoperative delirium. Of those with preoperative delirium, 746 were ASA class 3 or below and 327 were ASA class 4 or above. Of the 7391 patients without preoperative delirium, 5773 were ASA class 3 or below and 1605 were ASA class 4 or above. The remainder in each group was of unknown ASA class.

INTERVENTIONS

We used multivariable logistic regression to explore the association of preoperative delirium with 30-day postoperative outcomes. The odds ratio (OR) with associated 95% confidence interval (CI) was reported for each covariate.

MEASUREMENTS

Data was collected regarding the incidence of postoperative outcomes including: delirium, pulmonary complications, extended hospital stay, infection, renal complications, vascular complications, cardiac complications, transfusion necessity, readmission, and mortality.

MAIN RESULTS

After adjusting for potential confounders, the odds of postoperative delirium (OR 9.38, 95% CI 7.94-11.14), pulmonary complications (OR 1.83, 95% CI 1.4-2.36), extended hospital stay (OR 1.47, 95% CI 1.26-1.72), readmission (OR 1.27, 95% CI 1.01-1.59) and mortality (OR 1.92, 95% CI 1.54-2.39) were all significantly higher in patients with preoperative delirium compared to those without.

CONCLUSIONS

After controlling for potential confounding variables, we showed that preoperative delirium was associated with postoperative delirium, pulmonary complications, extended hospital stay, hospital readmission, and mortality. Given the lack of studies on preoperative delirium and its postoperative outcomes, our data provides a strong starting point for further investigations as well as the development and implementation of targeted risk-reduction programs.

Effectiveness and safety of perioperative enteral feeding in patients with burn injuries: a systematic review protocol

OBJECTIVE

The objective of this review is to determine whether perioperative enteral feeding improves outcomes in patients with burns.

INTRODUCTION

Literature has identified many positive benefits of nutrition support for patients with burn injuries, including preservation of lean body mass, improved wound healing, reduced gastrointestinal permeability and enhanced immunity. Fasting for surgery can undermine the nutritional care of these patients by causing nutrient deficits. It may also negatively affect patient well-being and insulin resistance. Perioperative fasting is intended to protect patients from regurgitation and pulmonary aspiration. This research aims to investigate whether perioperative feeding impacts outcomes in patients with burn injuries.

INCLUSION CRITERIA

This systematic review will consider studies whose participants have a burn injury. The intervention is perioperative enteral feeding (either intragastric or post-pyloric). Patients who received perioperative feeding will be compared with patients who had enteral nutrition withheld during the perioperative period. A number of outcome measures will be investigated, including mortality, length of stay, wound infection, wound healing rate and aspiration pneumonia.

METHODS

The key databases searched will be PubMed, CINAHL, Embase, Web of Science and Cochrane Central Register of Controlled Trials and Scopus. Only studies published in English will be considered. There will be no date limits. Full texts of selected studies will be retrieved and assessed against inclusion criteria. Studies that do not meet the inclusion criteria will be excluded, with reasons provided. Data synthesis will be pooled in a statistical meta-analysis. Subgroup analysis will be conducted where possible. Where statistical pooling is not possible, the findings will be presented in narrative form.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42018119034.

A Case Report of an Inadvertent Placement of Tracheostomy Tube Into the Pharynx After Emergency Tracheostomy: Management of a Failed Surgical Airway

Inadvertent placement of a tracheostomy tube through the stoma with the distal tip cephalad in the pharynx is an unusual but potentially devastating complication. Previously reported only once in the literature, its occurrence is not well known. There are several causes of ineffective ventilation after an emergency surgical airway, and an incorrectly placed tracheostomy tube is a differential diagnosis to consider. Prompt identification of this rare complication is essential because the consequences can be fatal. We present a case describing the inadvertent insertion of a tracheostomy tube into the pharynx during emergency tracheostomy and its subsequent management.

Application via mechanical dropper alleviates sufentanil-induced cough: a prospective, randomized, single-blinded trial

Background

It was reported that prolonging the injection time or diluting administration can reduce the incidence of opioid-induced cough. However, the incidence of sufentanil-induced cough (SIC) via a standardized infusion rate is unclear. A mechanical dropper is an infusion filtering device commonly used for intravenous degassing; it can also be used to administer special drugs due to its temporary storage and dilution effect. This study assesses the effectiveness of administration via mechanical dropper on SIC.

Methods

Two hundred patients undergoing general anesthesia were enrolled. Patients received sufentanil at a strength of 0.3 μg·kg^− 1 either via T-connector (group C) or by mechanical dropper (group M) at 1 ml·s^− 1. Cough severity was graded as none (0), mild (1–2), moderate (3–5), or severe (> 5), and the incidence of SIC was evaluated for 5 min after the start of sufentanil injection. Other adverse reactions such as hypotension, hypertension, bradycardia, tachycardia, hypoxemia, vomiting, and aspiration during the induction period of general anesthesia were also observed. The primary outcome was the incidence of SIC. The secondary outcomes were the severity of SIC and other adverse reactions.

Results

The incidence of SIC in group M was significantly lower than that in group C (2% versus 21%, P = 0.000), and the prevalence of moderately severe coughing was also statistically different (none in group M versus 11% in group C, P = 0.001). However, there were no statistical differences in the incidence of other adverse reactions between two groups (P > 0.05).

Conclusion

Sufentanil application via mechanical dropper can significantly alleviate the occurrence of SIC during the induction phase of total intravenous general anesthesia. This method is simple, safe, and reliable, and has wide prospective application for clinical use.

Trial registration

Chinese Clinical Trial Register, ChiCTR-IOR-17011561. Registered on 3 June 2017.

The influence of different patient positions during rapid induction with severe regurgitation on the volume of aspirate and time to intubation: a prospective randomised manikin simulation study

BACKGROUND

Aspiration is a main contributor to morbidity and mortality in anaesthesia. The ideal patient positioning for rapid sequence induction remains controversial. A head-down tilt and full cervical spine extension (Sellick) might prevent aspiration but at the same time compromise airway management. We aimed to determine the influence of three different positions during induction of general anaesthesia on the volume of aspirate and on participants' airway management.

METHODS

Eighty-four anaesthetic trainees and consultants participated in a prospective randomised simulation study. Anaesthesia was induced in reverse Trendelenburg position (+ 15°) in a manikin capable of dynamic fluid regurgitation. Participants were randomised to change to Trendelenburg position (- 15°) a) as soon as regurgitation was noticed, b) as soon as 'patient' had been anaesthetised, and c) as soon as 'patient' had been anaesthetised and with full cervical spine extension (Sellick). Primary endpoints were the aspirated volume and the time to intubation. Secondary endpoints were ratings of the laryngoscopic view and the intubation situation (0-100 mm).

RESULTS

Combining head-down tilt with Sellick position significantly reduced aspiration (p < 0.005). Median time to intubate was longer in Sellick position (15 s [8-30]) as compared with the head in sniffing position (10 s [8-12.5]; p < 0.05). Participants found laryngoscopy more difficult in Sellick position (39.3 ± 27.9 mm) as compared with the sniffing position (23.1 ± 22.1 mm; p < 0.05). Both head-down tilt intubation situations were considered equally difficult: 34.8 ± 24.6 mm (Sniffing) vs. 44.2 ± 23.1 mm (Sellick; p = n.s).

CONCLUSIONS

In a simulated setting, using a manikin-based simulator capable of fluid regurgitation, a - 15° head-down tilt with Sellick position reduced the amount of aspirated fluid but increased the difficulty in visualising the vocal cords and prolonged the time taken to intubate. Assessing the airway management in the identical position in healthy patients without risk of aspiration might be a promising next step to take.

Low-dose combined spinal-epidural anesthesia for a patient with a giant hiatal hernia who underwent urological surgery

A hiatal hernia refers to herniation of the abdominal organs through the esophageal hiatus of the diaphragm. A giant hiatal hernia affects digestive and cardiopulmonary function by compressing the organs. We report a patient who had low-dose combined spinal and epidural anesthesia (CSEA) for safe and effective anesthesia for conservative treatment of a giant hiatal hernia. An 84-year-old woman who had a giant hiatal hernia was scheduled for ureteroscopic removal of a ureteral stone. CSEA was performed at the L4 to L5 lumbar interspace and an epidural catheter tip was placed 5 cm cephalad from the inserted level. The T12 block was checked after 10 minutes of intrathecal injection of 6 mg of 0.5% bupivacaine. The T10 block was checked after additional injection of 80 mg of 2% lidocaine through the epidural catheter. During anesthesia and surgery, the patient's vital signs remained stable and the operation was completed within 1 hour without any problems. In conclusion, low-dose CSEA may be safely used without any cardiopulmonary and gastrointestinal problems in patients with a giant hiatal hernia undergoing urological surgery.

Preoperative fasting for ambulatory cataract surgery: asystematic review

Given the lack of policy standardization in Canada, this systematic review investigates the optimal duration of preoperative fasting in cataract surgery. A literature search was conducted on Ovid MEDLINE, with potential articles screened by 2 independent authors. The primary endpoint was the incidence of aspiration. Overall, 231 articles were screened, of which 6 were eligible. Two studies found no cases of aspiration in over 35 000 patients who underwent cataract surgery without preoperative fasting, some with intravenous sedation (50% in 1 series, less than 1% in the second). A survey of the British Ophthalmic Anaesthesia Society found that over 50% of centres did not require fasting before cataract surgery. Only 1 included report discussed a case of aspiration pneumonitis following cataract surgery with general anaesthesia and 14hours of preoperative fasting. In closing, further evidence is needed to delineate the risk of pulmonary aspiration based on fasting time in cataract surgery.

Perianesthetic Implications and Considerations for Myasthenia Gravis

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease in which antibodies against the post-nicotinic acetylcholine receptor at the neuromuscular junction develop. Although the exact cause of MG remains unknown, the thymus is a common factor in many cases. Patients with underlying junctional disease, such as MG, have greater anesthesia-related risks because of their known predisposition toward prolonged muscle weakness. Medications given in the perioperative period, such as anesthetic agents, antibiotics, cardiovascular drugs, and corticosteroids, affect neuromuscular transmission that contributes to muscle weakness. Judicious use of neuromuscular blocking agents for patients with MG must be considered. This patient population is at high risk for respiratory failure, and therefore must be carefully assessed throughout the perioperative period to ensure that a regular spontaneous respiratory pattern is sufficient to provide adequate oxygenation. Perianesthesia providers must consider anesthetic, ventilatory, and pharmacologic implications when proposing, providing, and recovering anesthesia for the patient with MG.

Endotracheal tube obstruction with a blood clot following aspiration of rumen contents in a reindeer

Summary

An apparently otherwise healthy female reindeer was anaesthetised for open reduction and fixation of a hip luxation. The animal developed ruminal bloat which was treated with passage of an orogastric tube that was left indwelling during the procedure. A fluid inspiratory noise was audible two hours after decompression, and clear fluid was suctioned from the airway. It showed no other signs of regurgitation and aspiration of rumen contents intraoperatively, and did not develop obvious respiratory compromise while mechanically ventilated. In recovery, the deer became apnoeic and cyanotic and died suddenly within minutes of being positioned in the recovery box. Just before dying, it coughed a large blood clot out of the endotracheal tube (ETT) . Additional clots were found partially obstructing the ETT lumen once extubated postmortem. Evidence of aspiration was detected at postmortem examination, which also identified pulmonary haemorrhage.