No evidence for decreased incidence of aspiration after rapid sequence induction

Preoperative fasting and the risk of pulmonary aspiration-a narrative review of historical concepts, physiological effects, and new perspectives

In the early days of anaesthesia, the fasting period for liquids was kept short. By the mid-20th century 'nil by mouth after midnight' had become routine as the principles of the management of 'full stomach' emergencies were extended to include elective healthy patients. Back then, no distinction was made between the withholding of liquids and solids. Towards the end of the last century, recommendations of professional anaesthesiology bodies began to reduce the fasting time of clear liquids to 2 h. This reduction in fasting time was based on the understanding that gastric emptying of clear liquids is rapid, exponential, and proportional to the current filling state of the stomach. Furthermore, there was no evidence of a link between drinking clear liquids and the risk of aspiration. Indeed, most instances of aspiration are caused by failure to identify aspiration risk factors and adjust the anaesthetic technique accordingly. In contrast, long periods of liquid withdrawal cause discomfort and may also lead to serious postoperative complications. Despite this, more than two decades after the introduction of the 2 h limit, patients still fast for a median of up to 12 h before anaesthesia, mainly because of organisational issues. Therefore, some hospitals have decided to allow patients to drink clear liquids within 2 h of induction of anaesthesia. Well-designed clinical trials should investigate whether these concepts are safe in patients scheduled for anaesthesia or procedural sedation, focusing on both aspiration risk and complications of prolonged fasting.

Glucagon-Like Peptide-1 Receptor Agonist Use and Residual Gastric Content Before Anesthesia

Importance

Glucagon-like peptide-1 receptor agonist (GLP-1 RA) use is rapidly increasing in the US, driven by its expanded approval for weight management in addition to hyperglycemia management in patients with type 2 diabetes. The perioperative safety of these medications, particularly with aspiration risk under anesthesia, is uncertain.

Objective

To assess the association between GLP-1 RA use and prevalence of increased residual gastric content (RGC), a major risk factor for aspiration under anesthesia, using gastric ultrasonography.

Design, Setting, and Participants

This cross-sectional study prospectively enrolled patients from a large, tertiary, university-affiliated hospital from June 6 through July 12, 2023. Participants followed preprocedural fasting guidelines before an elective procedure under anesthesia. Patients with altered gastric anatomy (eg, from previous gastric surgery), pregnancy, recent trauma (<1 month), or an inability to lie in the right lateral decubitus position for gastric ultrasonography were excluded.

Exposure

Use of a once-weekly GLP-1 RA.

Main Outcomes and Measures

The primary outcome was the presence of increased RGC, defined by the presence of solids, thick liquids, or more than 1.5 mL/kg of clear liquids on gastric ultrasonography. Analysis was adjusted for confounders using augmented inverse probability of treatment weighting, a propensity score-based technique. Secondarily, the association between the duration of drug interruption and the prevalence of increased RGC was explored.

Results

Among the 124 participants (median age, 56 years [IQR, 46-65 years]; 75 [60%] female), the prevalence of increased RGC was 56% (35 of 62) in patients with GLP-1 RA use (exposure group) compared with 19% (12 of 62) in patients who were not taking a GLP-1 RA drug (control group). After adjustment for confounding, GLP-1 RA use was associated with a 30.5% (95% CI, 9.9%-51.2%) higher prevalence of increased RGC (adjusted prevalence ratio, 2.48; 95% CI, 1.23-4.97). There was no association between the duration of GLP-1 RA interruption and the prevalence of increased RGC (adjusted odds ratio, 0.86; 95% CI, 0.65-1.14).

Conclusions and Relevance

Use of a GLP-1 RA was independently associated with increased RGC on preprocedural gastric ultrasonography. The findings suggest that the preprocedural fasting duration suggested by current guidelines may be inadequate in this group of patients at increased risk of aspiration under anesthesia.

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.

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.

Anesthetic management of a patient with achalasia, a disease with a considerable risk for aspiration under anesthesia

BACKGROUND

Achalasia is a rare condition characterized by dysfunction of esophageal motility and impaired relaxation of the lower esophageal sphincter. Anesthetic management of these patients is challenging due to the elevated risk of regurgitation and aspiration.

CASE PRESENTATION

A 53-year-old man diagnosed with achalasia was scheduled for renal cancer surgery before esophageal myotomy. Since his severe dysphagia suggested the possibility of vomiting and aspiration under anesthesia, a stomach tube was inserted before induction of general anesthesia. After preoxygenation, rapid sequence induction was performed and an antiemetic was administered to prevent postoperative vomiting. Although anesthetic management was uneventful, the inserted stomach tube coiled up in the dilated esophagus and substantial residue was aspirated via the tube even after a prolonged fasting period.

CONCLUSION

Anesthesiologists should be familiar with achalasia even though it is an uncommon disease, since affected patients are at risk of regurgitation and aspiration under anesthesia.

Prophylactic ligation of the opacified thoracic duct in minimally invasive esophagectomy - feasibility and safety

BACKGROUND

Chyle leak is a rare but morbid complication of esophagectomy. We assessed the feasibility of visualization and prophylactic ligation of the opacified thoracic duct (TD) after administration of 50 ml of olive oil.

METHODS

This prospective single center study considered all patients with carcinoma of the middle and lower thirds of the thoracic esophagus including the gastroesophageal junction (GEJ), managed from January 2018 to December 2019, for inclusion. All patients underwent McKeown minimally invasive esophagectomy. After anesthesia and endotracheal intubation, 50 ml of olive oil was administered through a nasogastric (NG) tube. During thoracoscopic esophageal mobilization, the opacified thoracic duct was identified and ligated using Weck Hem-o-lok clips immediately above the diaphragmatic hiatus. Postoperatively, the nature, volume, and triglyceride levels of the fluid from the chest drain were recorded.

RESULTS

Forty-three patients with carcinoma of the esophagus were assessed for inclusion and eventually, 33 were enrolled. The median age of the study population was 55 years, and there were 20 males. The tumor site was the lower esophagus in 24 (72.7%) patients. The most common histolopathological finding was squamous cell carcinoma (97%). The opacified thoracic duct could be identified and ligated in 31 (93.9%) patients. The median duration from the administration of olive oil to the ligation of the thoracic duct was 100 min. The median chest drain output and triglyceride levels on postoperative day (POD) one were 250 ml and 48 mg% respectively. No patient developed postoperative chylothorax.

CONCLUSION

Opacification and visualization of the thoracic duct during thoracoscopy can be aided by administering olive oil. Ligation of this opacified duct is feasible and safe.

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

Rapid sequence induction: An international survey

BACKGROUND

Rapid sequence induction (RSI) is a standard procedure, which should be implemented in all patients with a risk of aspiration/regurgitation during anaesthesia induction.

OBJECTIVE

The primary aim was to evaluate clinical practice in RSI, both in adult and paediatric populations.

DESIGN

Online survey.

SETTINGS

A total of 56 countries.

PARTICIPANTS

Members of the European Society of Anaesthesiology.

MAIN OUTCOME MEASURES

The aim was to identify and describe the actual clinical practice of RSI related to general anaesthesia.

RESULTS

From the 1921 respondents, 76.5% (n=1469) were qualified anaesthesiologists. When anaesthetising adults, the majority (61.7%, n=1081) of the respondents preoxygenated patients with 100% O₂ for 3 min and 65.9% (n=1155) administered opioids during RSI. The Sellick manoeuvre was used by 38.5% (n=675) and was not used by 37.4% (n=656) of respondents. First-line medications for a haemodynamically stable adult patient were propofol (90.6%, n=1571) and suxamethonium (56.0%, n=932). Manual ventilation (inspiratory pressure <12 cmH₂O) was used in 35.5% (n=622) of respondents. In the majority of paediatric patients, 3 min of preoxygenation (56.6%, n=817) and opioids (54.9%, n=797) were administered. The Sellick manoeuvre and manual ventilation (inspiratory pressure <12 cmH₂O) in children were used by 23.5% (n=340) and 35.9% (n=517) of respondents, respectively. First-line induction drugs for a haemodynamically stable child were propofol (82.8%, n=1153) and rocuronium (54.7%, n=741).

CONCLUSION

We found significant heterogeneity in the daily clinical practice of RSI. For patient safety, our findings emphasise the need for international RSI guidelines.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03694860

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.

[New aspects of rapid sequence induction including treatment of pulmonary aspiration]

Pulmonary aspiration of solid components leads to displacement of the tracheobronchial tree, the aspiration of acidic gastric juices to chemical pneumonitis (Mendelson's syndrome) and the aspiration of oropharyngeal secretions or gastrointestinal pathogens to aspiration pneumonia. Principally, pulmonary aspiration can occur at any stage of anesthesia. In the clinical routine the aim must therefore be to identify those patients who have an increased risk of aspiration. When this is successful, measures can be taken to reduce the risk; these can be regional anaesthesia or the performance of general anaesthesia as rapid sequence induction (RSI). If severe pulmonary aspiration occurs despite all preventive measures, mostly during induction of anaesthesia, extensive experience and rapid action are necessary. This can only be achieved if the induction to RSI is performed by three persons with supervision of the trainee anaesthetist by a consultant anaesthetist.

Ultrasound guided paralaryngeal pressure versus cricoid pressure on the occlusion of esophagus: a crossover study

The primary objective of this study is to compare the effectiveness of cricoid pressure (CP) and paralaryngeal pressure (PLP) on occlusion of eccentric esophagus in patients under general anesthesia (GA). Secondary objectives include the prevalence of patients with central or eccentric esophagus both before and after GA, and the success rate of CP in occluding centrally located esophagus in patients post GA. Fifty-one ASA physical status I and II patients, undergoing GA for elective surgery were enrolled in this study. Ultrasonography imaging were performed to determine the position of the esophagus relative to the trachea: (i) before induction of GA, (ii) after GA before external CP maneuver, (iii) after GA with CP, and (iv) after GA with PLP. CP was applied to all patients whilst PLP via fingertip technique was only applied to patients with an eccentric esophagus. Among a total of 51 patients, 28 of them (55%) had eccentric esophagus pre GA, while this number increase to 33 (65%) after induction of GA. CP success rate was 100% in 18 patients with central esophagus post GA versus 27% in 33 patients with eccentric esophagus post GA (P<0.00001). Overall success rate for CP was 53%. In 33 patients with eccentric esophagus anatomy post GA, PLP success rate was 30% compared with 27% with CP (P=1.000). Ultrasound guided PLP fingertips technique was not effective in patients with an eccentrically located esophagus post GA. Ultrasound guided CP achieved 100% success rate in patients with a centrally located esophagus post GA.

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.

Use of Handheld Point-of-Care Ultrasound in Emergency Airway Management

Emergency airway management (EAM) is associated with a high rate of complications, morbidity, and mortality. Handheld point-of-care ultrasound shows promise as an emerging technology to facilitate rapid screening for difficult laryngoscopy, identify the cricothyroid membrane for potential cricothyroidotomy, and assess for increased aspiration risk, as well as provide confirmation of proper endotracheal tube positioning. This review summarizes the available evidence for the use of point-of-care ultrasound in EAM, provides an algorithm to facilitate its incorporation into existing EAM practice to improve patient safety, and serves as a framework for future validation studies.

Current practice of rapid sequence induction in adults: A national survey among anesthesiologists in Spain

BACKGROUND

Rapid sequence induction (RSI) in adults has undergone changes in recent years due to pharmacological and technological advances. The objective of this survey was to evaluate current practice among Spanish anesthesiologists.

METHODS

A 31-item questionnaire regarding RSI practice was sent to anesthesiologists working in Spanish public hospitals. Differences in responses according to the type of hospital or experience of the respondent were compared for all data using the chi-square and Fisher's exact test.

RESULTS

Approximately 15.89% of Spanish anesthesiologists participated in the survey (1002 questionnaires). The results show considerable heterogeneity in most aspects of RSI. Less than 20% of respondents administer sodium citrate. Sixty-four percent place a nasogastric tube in patients with intestinal obstruction. Gastric residue is assessed by ultrasound in 6% of cases. Only 25% of respondents measure ETO₂ to check the effectiveness of preoxygenation, and 22% use nasal oxygen insufflation with nasal prongs or THRIVE. Sixty two percent of respondents apply cricoid pressure, but only 50% release the pressure when encountering intubation difficulty. Up to 40% of respondents reported cases of aspiration despite applying cricoid pressure. Propofol was the most commonly used hypnotic (97.6%), but there was no clear preference in the choice of neuromuscular relaxant (suxamethonium versus rocuronium ratio of approximately 1:1). Only 44% of respondents calculated the dose of sugammadex that would be required for emergency reversal of rocuronium.

CONCLUSIONS

The survey showed significant variation in RSI practice, similar to that of other countries. Quality prospective studies are needed to standardize clinical practice.

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.

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.

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.

Ultrasound assessment of the gastric contents for the guidance of the anaesthetic strategy in infants with hypertrophic pyloric stenosis: a prospective cohort study

BACKGROUND

Evacuation of gastric content through a nasogastric tube, followed by rapid sequence induction, is usually recommended in infants undergoing pyloromyotomy. However, rapid sequence induction may be challenging, and is therefore controversial. Some anaesthetists regularly perform classical non-rapid induction technique, after blind aspiration of the gastric contents, although this aspiration may have been incomplete. This prospective observational study aimed to assess whether the ultrasound monitoring of the aspiration of the stomach contents, may be useful to appropriately guide the choice of the anaesthetic induction technique, in infants undergoing pyloromyotomy.

METHODS

Infants undergoing pyloromyotomy were consecutively included. Ultrasound assessment of the antrum was performed before and after the aspiration of the gastric contents through a 10 French gastric tube. The stomach was defined as empty when no content was seen in both supine and right lateral positions. The correlation between antral area and the aspirated gastric volume was also tested.

RESULTS

We analysed 34 infants. Ultrasound examination of the antrum failed in three infants. The stomach was empty in 30/34 infants (nine before aspiration, 21 after aspiration), allowing to perform a non-rapid induction technique in 88.2% of the infants. There was a significant correlation between antral area measured in right lateral decubitus and the aspirated gastric volume.

CONCLUSIONS

Our results suggest that the qualitative ultrasound assessment of the antral content may be a simple and useful point-of-care tool, for the choice of the most appropriate anaesthetic technique for pyloromyotomy according to the estimated risk of pulmonary aspiration of gastric contents.

A survey of practice of rapid sequence induction for caesarean section in England

BACKGROUND

In view of newer techniques of preoxygenation and laryngoscopy and recent obstetric guidelines concerning the management of difficult intubation, we aimed to evaluate the current practice of rapid sequence induction for caesarean section in England.

METHODS

In 2017, 316 questionnaire surveys were posted to all 158 hospitals with caesarean section capabilities in England. At each hospital, one questionnaire was to be completed by the obstetric anaesthetic consultant lead and one by an anaesthetic trainee. Differences in responses between consultants and trainees, regardless of their place of work, were compared for all data using the chi-square and the Fisher's exact tests.

RESULTS

One-hundred-and-eighty complete questionnaires were returned, with an overall response rate of 57%, 98 (54%) from obstetric anaesthetic consultant leads and 82 (45.6%) from trainees). Both head up (57%) and ramped (56%) were the preferred positions for preoxygenation. Less than half of respondents (43%) preoxygenated until the surgeon was scrubbed. Cricoid pressure was used by almost all respondents (98%). Thiopentone (67%) was the most commonly chosen anaesthetic induction agent and most respondents (82%) supported a change to the use of propofol. Suxamethonium (92%) was the neuromuscular blocker of choice but more than half the respondents (52%) supported a change to rocuronium. In the event of a failed intubation, the rescue supraglottic airway device of choice was the i-gel® (65%).

CONCLUSIONS

Our survey demonstrated the significant variation in the practice of rapid sequence induction for caesarean section in obstetrics in the United Kingdom.

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.

A Systematic Review of the High-flow Nasal Cannula for Adult Patients

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2018. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Laparoscopy during pregnancy: Case report and key points to improve laparoscopic management

CASE REPORT

A 34-year-old woman in her 19th week of gestation was admitted to the Emergency Department of our hospital for acute abdominal pain. The patient was diagnosed with haemoperitoneum. Laparoscopy was performed and revealed acute bleeding from a crumbly superficial uterine vascular network. Haemostasis was achieved and both mother and foetus recovered well after surgery. A caesarean section was performed at 38 weeks, delivering a healthy newborn and revealing that the pregnancy had developed in a rudimentary hemiuterus. Laparoscopy during pregnancy is safe and feasible and can be performed in any trimestre of pregnancy with no differences in perinatal outcomes but, as intervention complexity increases with gestational age, laparoscopy during pregnancy should be performed by experienced surgeons To minimise surgical risk several recommendations should be taken into account: gravid patients should be positioned in a left-tilted supine position, trocar placement should be adjusted to uterine size and gas insuflattion of 10-15mmHg can be used.

Cricoid Pressure Controversies

Since cricoid pressure was introduced into clinical practice, controversial issues have arisen, including necessity, effectiveness in preventing aspiration, quantifying the cricoid force, and its reliability in certain clinical entities and in the presence of gastric tubes. Cricoid pressure–associated complications have also been alleged, such as airway obstruction leading to interference with manual ventilation, laryngeal visualization, tracheal intubation, placement of supraglottic devices, and relaxation of the lower esophageal sphincter. This review synthesizes available information to identify, address, and attempt to resolve the controversies related to cricoid pressure. The effective use of cricoid pressure requires that the applied force is sufficient to occlude the esophageal entrance while avoiding airway-related complications. Most of these complications are caused by excessive or inadequate force or by misapplication of cricoid pressure. Because a simple-to-use and reliable cricoid pressure device is not commercially available, regular training of personnel, using technology-enhanced cricoid pressure simulation, is required. The current status of cricoid pressure and objectives for future cricoid pressure–related research are also discussed.

General Anesthesia for a Patient With Pelizaeus-Merzbacher Disease

We report the successful management of general anesthesia for a patient with Pelizaeus-Merzbacher disease (PMD). PMD is one of a group of progressive, degenerative disorders of the cerebral white matter. The typical clinical manifestations of PMD include psychomotor retardation, nystagmus, abnormal muscle tone, seizures, and cognitive impairment. General anesthesia for a patient with PMD may be difficult mainly because of seizures and airway complications related to poor pharyngeal muscle control. In addition, the possibility of exacerbation of spasticity should be considered. A 20-year-old man with PMD required removal of impacted wisdom teeth under general anesthesia. General anesthesia was induced with thiamylal, fentanyl, and desflurane. Anesthesia was maintained with desflurane and continuous intravenous remifentanil under bispectral index and train-of-4 monitoring. Anesthesia lasted 1 hour 20 minutes and was completed uneventfully. Airway complications, seizures, and exacerbation of spasticity did not occur postoperatively. Preoperatively, our patient had no history of epilepsy attacks or aspiration pneumonia, and no clinical symptoms of gastroesophageal reflux disease. Therefore, exacerbation of spasticity was one of the most likely potential complications. Identification of these associated conditions and evaluation of risk factors during preoperative examination is important for performing safe anesthesia in these patients.

Pulmonary aspiration under GA: a 13-year audit in a tertiary pediatric unit

INTRODUCTION

Pulmonary aspiration is a known risk of general anesthesia. We aim to find out the incidence, risk factors, and outcome of pulmonary aspiration in our pediatric population.

METHODS

Since 2000, all critical incidents are reported on a standardized audit form. All cases with pulmonary aspiration being reported as a critical incident were identified and their case notes traced to look at the perioperative details.

RESULTS

From 2000 to 2013, a total of 102 425 pediatric cases were done in our hospital. Twenty-two cases were reported to have aspirated during anesthesia giving an incidence of 0.02% (1 in 4655). Majority (59.0%) of the children were between the ages of 3-12 and of ASA 1 (54.5%). None of them had any history of pulmonary aspiration. Of the 22 cases, 12 occurred during induction, three during maintenance, three during emergence, three during recovery, and one occurred preinduction. Twelve cases had intravenous induction while the rest received inhalational induction. The type of induction does not appear to affect the incidence of aspiration (OR 1.139 95% CI: 0.457-2.818 P = 0.76). Two cases were found to have a difficult airway during induction and 45.5% were emergency operations. Emergency surgeries put the patient at a higher risk of aspiration (OR 4.321 95% CI: 1.735-10.687 P = 0.001). No mortality was reported. Surgery was canceled for one patient, two had unplanned admissions, seven were admitted to high dependency unit or intensive care unit with two requiring postoperative ventilation.

CONCLUSION

The incidence of aspiration under general anesthesia in our hospital is comparable to published reports. Our audit highlights the fact that pulmonary aspiration although rare mostly occur in healthy ASA 1 and 2 children with no prior history. Emergency surgeries put the patient at a higher risk of aspiration. They occurred usually during induction, a process which tends to be variable (in technique and duration) for pediatric patients.

Acute Intraoperative Pulmonary Aspiration

Acute intraoperative aspiration is a potentially fatal complication with significant associated morbidity. Patients undergoing thoracic surgery are at increased risk for anesthesia-related aspiration, largely due to the predisposing conditions associated with this complication. Awareness of the risk factors, predisposing conditions, maneuvers to decrease risk, and immediate management options by the thoracic surgeon and the anesthesia team is imperative to reducing risk and optimizing patient outcomes associated with acute intraoperative pulmonary aspiration. Based on the root-cause analyses that many of the aspiration events can be traced back to provider factors, having an experienced anesthesiologist present for high-risk cases is also critical.

The use of cricoid pressure during rapid sequence induction in trauma patients – UK and European practice compared

Introduction

There is ongoing debate and conflicting evidence surrounding the place of cricoid pressure (CP) as part of a rapid sequence induction (RSI) of anaesthesia. This study investigated the current use of CP during trauma RSI and compared reported practice in the UK with the rest of Europe.

Methods

An anonymised, web-based survey was sent to all clinicians registered as European Trauma Course instructors.

Results

CP use was reported by 83.1% of UK respondents and 39.4% from the rest of Europe, with an overall reported use of 49.8%. Anaesthetists use CP less commonly (35.6%) than clinicians from other specialties (63.6%). The most common reason given for not using CP (76.7%) was a perceived lack of evidence of effectiveness.

Conclusion

Generally the use of CP appears to be in decline with only half of all clinicians reporting to use it; however it remains much more commonly used in the UK than the rest of Europe.