Patient and surgery factors associated with the incidence of failed and difficult intubation

Difficult airway management in 25 hospitals across China: A multicenter cross-sectional study

STUDY OBJECTIVE

Difficult airway management is a significant challenge in clinical anesthesia, critical care, and emergency medicine. Inadequate management can lead to severe complications including organ damage and death. This study assessed the variability in difficult airway management across China and focused on how patient and operator factors influenced outcomes in operating rooms.

DESIGN

A multicenter observational cross-sectional study.

SETTING

This study was conducted from November 2022 to November 2023 and included 25 secondary and tertiary hospitals across various regions in China.

PATIENTS

In the total of 181,399 general anesthesia patients, 384 (0.21 %) were identified as having difficult airways.

INTERVENTIONS

Data were gathered from a specialized questionnaire comprising four sections with 27 questions and analyzed using logistic regression in SPSS to identify key factors that influenced effective management of difficult airways.

MEASUREMENTS

This study focused on preoperative assessment, anesthesia selection, intubation attempts, and contingency planning for difficult airway management practices among anesthesiologists.

MAIN RESULTS

In anticipated difficult airways, rapid sequence induction was used in 51.7 % of the cases, maintaining spontaneous breathing under general anesthesia in 11.1 %, and awake intubation in 36 %. For unanticipated difficult airways, 95.9 % of the anesthesiologists opted for rapid sequence induction. Limited mouth opening was the most common cause of difficult airways and obesity and ankylosing spondylitis were identified as significant factors. The logistic regression analysis identified the type of difficult airway, anesthesiologist experience, and assessment methods as key factors influencing the first attempt intubation success.

CONCLUSIONS

The accuracy of difficult airway assessment and first attempt intubation success is influenced by both patient-related factors and the anesthesiologist's expertise. Regional and institutional variability in decision-making and tool selection underscores the critical need for standardized guidelines and comprehensive training to enhance airway management outcomes across diverse clinical settings in China.

CT based 3D radiomic and clinical airway examination model for evaluating mask ventilation in oral and maxillofacial surgery patients

The objective of this study is to develop a model that incorporates clinical measurements with 3D radiomic signatures extracted from CT images of oral and maxillofacial surgery patients to evaluate mask ventilation. A prospective cohort trial was conducted to enroll patients scheduled for oral and maxillofacial surgery. After obtaining informed consent, clinical measurements and head and neck CT images were collected. The anesthesiologist who managed the airway graded the mask ventilation. Difficult mask ventilation was defined as mask ventilation that required assistance or the use of an oral airway or other adjuvant by the anesthesiologist. For radiomics analysis, 3D airway segmentation was extracted and calculated 3D radiomic signatures and corresponding radiological features. Subsequently, features in the clinical measurements model and radiomic signatures model were determined using the least absolute shrinkage and selection operator (LASSO) classifier. A mixed model was developed that incorporated both radiomic signature features and clinical measurement features. A total of 716 patients were enrolled in the study. The mixed model combined the five 3D radiomic signatures and six clinical measurements, and was found to have the highest predictive accuracy. In the validation group, the mixed group had an area under the curve (AUC) of 0.851, which was higher than the AUC of 0.812 in the clinical measurements model and 0.827 in the radiomic signatures model. This study developed a mixed model that combines 3D radiomic signatures and clinical measurements. Its application in clinical practice can assist in identifying patients at risk of experiencing difficult mask ventilation during oral and maxillofacial surgeries.

The Evaluation and Modification of Standard Airway Assessment Tests for Virtual Anaesthetic Assessments: A Pilot Study

Background/Objectives: Virtual preoperative anaesthetic assessments can significantly reduce healthcare costs and improve patient convenience. The challenge with virtual consults is often the airway assessments, which screen for potentially difficult airways (PDAs). The objective of this pilot study was to determine the reliability of standard airway screening tests for detecting PDAs when conducted virtually. Methods: An observational longitudinal study was conducted between July 2021 and April 2022 at a tertiary hospital in Singapore. We compared the Mallampati score (MS), upper lip bite test (ULBT), thyromental distance, mouth opening test, and neck movements in 94 patients, first during virtual assessments before surgery and subsequently at face-to-face preoperative assessments (gold standard) on the day of surgery by the same team of anaesthesiology trainees. Goodman and Kruskal's gamma coefficient measured concordance between virtual and face-to-face assessment results. Logistic regression (LR) identified virtual predictors of PDAs in clinical practice. AUROC values informed tool performance. Results: LR showed that elevated virtual MS, virtual ULBT, and body mass index (BMI) were potential predictors of clinical PDAs. Termed the "MBBS", this collective score showed good performance with a sensitivity of 95% and an AUROC of 0.79. Importantly, all screening tests performed poorly in virtual assessments when applied individually (sensitivity < 50%). Conclusions: In this pilot study, BMI combined with MS and ULBT could reliably detect PDAs during virtual airway assessments. The data herein support further large multi-centre studies to validate the MBBS for clinical use.

Tracheostomy before and during COVID-19 pandemic

BACKGROUND

The aim of the study was to provide insight into the influence of the COVID-19 on the frequency and characteristics of urgent and emergent tracheostomies (TS), comparing data collected both before and during the pandemic. Our two hypotheses were that during COVID-19, more TS were performed in the emergent setting and that during COVID-19 more TS were performed under general anaesthesia.

PATIENTS AND METHODS

The research was retrospective. The study period included the two years before and after the COVID-19 outbreak in Slovenia. Forty-one patients in each period met the inclusion criteria. Their medical charts were reviewed. The anamnestic, clinical, surgical and anaesthesiological data were collected. The two groups of patients from corresponding time periods were statistically compared.

RESULTS

Predominantly men required the surgical resolution of acute upper airway obstruction (76% of patients). The causes for acute respiratory distress included head and neck cancer (62%), infections (20%), vocal cord paralysis (16%), and stenosis (2%). There were no statistically significant differences either in the (emergent/urgent) setting of TS or in the type of anaesthesia used. Both hypotheses were rejected. A statistically significant rise in use of the C-MAC laryngoscope during COVID-19 (from 3% to 15%) was reported.

CONCLUSIONS

The outbreak of COVID-19 did not have a statistically significant effect on the frequency of performing emergent and urgent tracheostomies nor on the use of general or local anaesthesia. It did, however, require a change of intubation technique. Consequently, a significant rise in the use of the C-MAC laryngoscope was noted.

Radiotherapy Effects on Airway Management in Patients with Nasopharyngeal Cancer

Background: At present, there is a paucity of data in the literature pertaining to the impact of radiotherapy (RT) on the success of tracheal intubation in patients with nasopharyngeal cancer (NPC). The aim of this study is to investigate the frequency of difficult tracheal intubation in patients with NPC following RT. Methods: Patients with NPC who underwent RT followed by surgery between 2012 and April 2024 at the University Hospital Heidelberg were retrospectively analyzed. Results: Twenty-three patients, predominantly males (73.9%) with a mean age of 52.9 years, were enrolled. Overall, 65.2% of the patients had an American Society of Anesthesiologists (ASA) class of III. The mean total laryngeal dose was 53.5 Gy for the main and boost plan, and the maximum total laryngeal dose was 66.61 Gy. Direct laryngoscopy was performed in 69.6% of cases, followed by 26.1% videolaryngoscopy, and 4.2% required fiberoptic intubation. In total, 47.8% of the patients had a Cormack/Lehane grade of I, followed by 43.5% with grade II and 8.7% with grade III. Overall, 87% of patients were successfully intubated on the first attempt. Conclusions: It has been demonstrated by previous studies that RT has the potential to enhance complications and difficulties encountered during airway management. While the results must be interpreted with caution, our study provides no evidence of severe impairment in advanced airway management in patients with nasopharyngeal cancer who have undergone radiotherapy.

A holistic perspective of the comorbidities in childhood obesity

Childhood obesity is associated with comorbidities that affect almost all body systems, including, among others, the endocrine, gastrointestinal, pulmonary, cardiovascular and musculoskeletal systems, as well as medical and surgical procedures that may be required due to different clinical situations. The objective of this article is to describe the classic and emerging comorbidities associated with obesity and the complications of procedures that involve invasive manoeuvres. Although some of the problems associated with obesity during childhood are widely known, such as musculoskeletal and cutaneous disorders or apnoea-hypopnoea syndrome, others, such as changes in kidney function, non-alcoholic fatty liver and cardiometabolic risk, have received less attention due to their insidious development, as they may not manifest until adulthood. In contrast, there is another group of comorbidities that may have a greater impact due to their frequency and consequences, which are psychosocial problems. Finally, in the context of invasive medico-surgical interventions, obesity can complicate airway management. The recognition of these pathologies in association with childhood obesity is of vital importance not only in childhood but also due to their ramifications in adulthood.

Assessing the efficacy of difficult airway alerts in electronic medical records: a quality improvement study

STUDY DESIGN

Retrospective analysis of difficult airway alerts in a major tertiary centre.

OBJECTIVE

To investigate the completeness, utility and efficacy of difficult airway alerts and their impact on future airway management episodes.

DESIGN, DATA SOURCES AND METHODS

Patients who had a "difficult airway" entry on electronic medical records (EMR) from 2011 to 2021 were included. Each alert was analyzed by a team of anesthetists with expertise in difficult airway management for its quality, appropriateness, and impact on future airway management episodes. Alert quality was defined as to whether the content of the alert contained pertinent information for emergent airway management. Alert appropriateness was defined as to whether the experts would be unhappy to perform a rapid sequence induction and intubation, if required, following review of all available documentation.

RESULTS

141 patients were included for this study, with a mean age of 58.6 +/- 15.3 years. Ninety-three (66%) alerts were created by medical staff, of which 52 were recorded by consultant anesthetists. 117 alerts (83%) were deemed to be appropriate by the airway expert team, but only 40 alerts (28%) were found to have sufficient quality to be helpful in emergent airway management. Sixty-five patients (47%) had at least one subsequent airway management episode, of which 35 patients (56%) underwent a change of management following alert creation. We proceeded to modify 103 alerts (73%) to improve their quality to aid future encounters.

CONCLUSION

Difficult Airway encounters are an uncommon event in anesthesia, but clear, comprehensive and effectively communicated documentation is required to minimize the risk in future encounters. In our institution, while most difficult airway alerts were appropriate, we found significant heterogeneity in the quality of this documentation, which limits the clinical utility of the alert system. We have taken measures to improve local processes of difficult airway documentation and considered the implications of our project for the broader airway management community.

TRIAL REGISTRATION

Not applicable.

Predictors of paediatric difficult intubation according to the experience of a university hospital in a low- and middle-income country: A prospective observational study

BACKGROUND

Difficult airway management is one of the main challenges in paediatric anaesthesia, particularly in low- and middle-income countries.

AIMS

The aim of this study was to investigate the main predictors of difficult paediatric intubation.

METHODS

In this observational study, we included all children aged less than five years undergoing intra-abdominal surgery with endotracheal intubation. Patients were divided into two groups according to the incidence of difficult intubation. Then, we investigated predictors for difficult paediatric intubation.

RESULTS

We included 217 children, and difficult intubation was observed in 10% of them. Predictors were as follows: Mallampati III-IV class (adjusted odds ratio = 2.21; 95% confidence interval = 1.1-6.4), limited mouth opening (adjusted odds ratio = 2.4; 95% confidence interval = 1.8-3.5), facial dysmorphia (adjusted odds ratio = 2.6; 95% confidence interval = 1.32-7.4) and anaesthesia without muscle relaxant (adjusted odds ratio = 1.8; 95% confidence interval = 1.0-5.1) or without opioids during crash inductions (adjusted odds ratio = 1.7; 95% confidence interval = 1.01-4.8).

CONCLUSION

Facial dysmorphia and limited mouth opening were predictors of difficult intubation in children. Furthermore, it seems that Mallampati class and anaesthesia technique may also predict challenging intubation, which may guide us to change our perioperative practice.

Impact of Radiotherapy on Endotracheal Intubation Quality Metrics in Patients with Esophageal Cancer: A Challenge for Advanced Airway Management?

(1) Background: Currently, no data are available in the literature investigating the influence of radiotherapy (RT) on endotracheal intubation success in patients with esophageal cancer. This study aims to evaluate the impact of RT on endotracheal intubation quality metrics in patients with esophageal cancer. (2) Methods: Patients with esophageal cancer who underwent RT followed by surgery between 2012 and 2023 at the University Hospital Heidelberg, Germany, were retrospectively analyzed. (3) Results: Fifty-five patients, predominantly males 65.5% with a mean age of 64 years, were enrolled. Overall, 81.8% of the patients had an ASA class of III, followed by 27.2% ASA II. The mean prescribed cumulative total dose to the primary tumor and lymph node metastasis was 48.2 Gy with a mean single dose of 1.8 Gy. The mean laryngeal total dose was 40.0 Gy. Direct laryngoscopy was performed in 80.0% of cases, followed by 12.1% videolaryngoscopy, and 7.2% required fiberoptic intubation. Overall, 96.4% of patients were successfully intubated on the first attempt. (4) Conclusions: It has been demonstrated that post-RT effects can increase the risk of airway management difficulties and complications. The results of our study did not indicate any evidence of impaired advanced airway management in patients with esophageal cancer who had undergone RT.

Improving difficult direct laryngoscopy prediction using deep learning and minimal image analysis: a single-center prospective study

Accurate prediction of difficult direct laryngoscopy (DDL) is essential to ensure optimal airway management and patient safety. The present study proposed an AI model that would accurately predict DDL using a small number of bedside pictures of the patient's face and neck taken simply with a smartphone. In this prospective single-center study, adult patients scheduled for endotracheal intubation under general anesthesia were included. Patient pictures were obtained in frontal, lateral, frontal-neck extension, and open mouth views. DDL prediction was performed using a deep learning model based on the EfficientNet-B5 architecture, incorporating picture view information through multitask learning. We collected 18,163 pictures from 3053 patients. After under-sampling to achieve a 1:1 image ratio of DDL to non-DDL, the model was trained and validated with a dataset of 6616 pictures from 1283 patients. The deep learning model achieved a receiver operating characteristic area under the curve of 0.81-0.88 and an F1-score of 0.72-0.81 for DDL prediction. Including picture view information improved the model's performance. Gradient-weighted class activation mapping revealed that neck and chin characteristics in frontal and lateral views are important factors in DDL prediction. The deep learning model we developed effectively predicts DDL and requires only a small set of patient pictures taken with a smartphone. The method is practical and easy to implement.

Comparative Evaluation of Direct Laryngoscopy Versus GlideScope for the Purpose of Laryngoscopy Management and Intubation in Candidates of Cesarean Delivery with General Anesthesia

Background

The present study aimed at comparing the hemodynamic responses to laryngoscopy and initiation of intubation with either direct or video-assisted laryngoscopy.

Materials and Methods

This double-blind clinical trial was performed on 90 pregnant women candidates for cesarean section under general anesthesia. The participants were divided into two groups. In the first group, intubation was performed using direct Macintosh laryngoscope (MCL group). The second group underwent intubation using the GlideScope video laryngoscope (GSL group). Then, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), the percentage of the saturation of peripheral oxygen (SpO2), the time-to-intubation (TTI), and the number of intubation attempts were recorded.

Results

SBP, DBP, and MAP in the MCL group were significantly higher than GSL group 1, 3, and 5 min after laryngoscopy (P < 0.05). HR in the MCL group with the mean of 118.44 ± 15.53 bpm was significantly higher than that the GSL group with the mean of 110.11 ± 16.68 bpm only 3 min after laryngoscopy (P = 0.016). The TTI in the MCL group was significantly longer than that of the GSL group (12.80 ± 1.86 vs. 10.15 ± 2.61; P = 0.001). The frequency of the first intubation attempt in the GSL group with 91.1% was significantly higher than that the MCL group with 84.4% (P = 0.003).

Conclusion

It seems that the GSL technique is a better choice to conduct laryngoscopy with more success in intubation and a higher stability of the patients' hemodynamic status.

Difficult Tracheal Intubation and Airway Outcomes after Radiation for Nasopharyngeal Carcinoma

OBJECTIVE

The aim of the study was to characterize the incidence and management of difficult tracheal intubations (DTIs) in nasopharyngeal carcinoma (NPC) after primary radiation therapy (RT).

METHODS

The study was a retrospective review of airway assessment and outcomes in post-RT NPC patients. Primary analysis was performed on patients who underwent post-RT procedures, who were split into non-DTI and DTI groups. Patients were classified as DTI if they (i) required >1 attempt to intubate, (ii) failed to be intubated, or (iii) experienced complications attributed to airway management. Secondary analysis was performed between patients who underwent post-RT procedures (procedure group) and those who did not (control group).

RESULTS

One-hundred and fifty patients were included, and 71.3% underwent post-RT procedures, with no differences in characteristics between the procedure and control groups. One-hundred and fifty procedures were identified, and 28.0% were categorized as DTI. There was no difference in patient characteristics or airway assessment measures between DTI and non-DTI groups. Regression analysis revealed concurrent cervical mobility restriction, and trismus increased DTI incidence by 7.1-fold (p = 0.011). Being non-White was an independent predictor of DTI. The incidence of high-grade intraoperative laryngoscopic view was lower in the non-DTI compared to the DTI group (20.4% vs. 64.3%, p < 0.0001). Failure to intubate occurred in 2.0% of cases, and 6.0% cases had perioperative complications. Based on preoperative assessment, sensitivity of predicting DTI was 54.8% and specificity was 63.9%.

CONCLUSION

NPC patients frequently undergo post-RT procedures requiring complex airway management. Rates of DTI and failed intubation are significantly higher than those in the general surgical population, and the ability to predict DTI with standard preoperative airway measures is poor.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:120-126, 2024.

The impact of residency training level on early postoperative desaturation: A retrospective multicenter cohort study

OBJECTIVE

We studied the primary hypothesis that the training level of anesthesiology residents (first clinical anesthesia year, CA1 vs CA2/3 residents) is associated with early postoperative desaturation (oxygen saturation < 90%). We also analyzed the change in the rate (trajectory) of desaturation during the resident's development from CA1 to CA2/3 resident, and its effects on postoperative respiratory complications.

DESIGN

Retrospective hospital registry study.

SETTING

Two university-affiliated hospitals networks (MA and NY, USA).

PATIENTS

140,818 adults undergoing non-cardiac surgery under general anesthesia and extubation in the operating room by residents (n = 378) between 2005 and 2021.

MEASUREMENTS

Multivariate logistic and quantile regression were used in the analyses. The secondary outcome was major respiratory complication within 7 days after surgery.

MAIN RESULTS

In 6.5% and 1.6% of cases, early postoperative desaturation to < 90% and 80% occurred. Compared to CA2/3 residents, CA1 residents had higher odds of experiencing early postoperative desaturation to < 90% and 80% (adjusted odds ratio [ORadj], 1.07; 95%CI 1.03-1.12; p = 0.002, and ORadj 1.10; 95%CI 1.01-1.20; p = 0.037, respectively). The change in postoperative desaturation rate during the transition from CA1 to CA2/3 status varied substantially from ORadj 0.80 (decreased risk) to 1.33 (increased risk). Major respiratory complication did not differ between experience levels (p = 0.52). However, a strong decline in improvement regarding the rate of postoperative desaturation during the transition from CA1 to CA2/3, was paralleled by an increased odds of major respiratory complication for CA2/3 residents (ORadj 1.20; 95%CI 1.02-1.42; p = 0.026, p-for-interaction = 0.056).

CONCLUSION

Patients treated by CA1 residents have an increased risk of postoperative desaturation. Some residents show an improvement and others a decline in postoperative desaturation rate. Our secondary analysis suggests that there should be more focus on those residents who had a declining performance in postoperative desaturation despite becoming more experienced.

Machine Vision and Image Analysis in Anesthesia: Narrative Review and Future Prospects

Machine vision describes the use of artificial intelligence to interpret, analyze, and derive predictions from image or video data. Machine vision-based techniques are already in clinical use in radiology, ophthalmology, and dermatology, where some applications currently equal or exceed the performance of specialty physicians in areas of image interpretation. While machine vision in anesthesia has many potential applications, its development remains in its infancy in our specialty. Early research for machine vision in anesthesia has focused on automated recognition of anatomical structures during ultrasound-guided regional anesthesia or line insertion; recognition of the glottic opening and vocal cords during video laryngoscopy; prediction of the difficult airway using facial images; and clinical alerts for endobronchial intubation detected on chest radiograph. Current machine vision applications measuring the distance between endotracheal tube tip and carina have demonstrated noninferior performance compared to board-certified physicians. The performance and potential uses of machine vision for anesthesia will only grow with the advancement of underlying machine vision algorithm technical performance developed outside of medicine, such as convolutional neural networks and transfer learning. This article summarizes recently published works of interest, provides a brief overview of techniques used to create machine vision applications, explains frequently used terms, and discusses challenges the specialty will encounter as we embrace the advantages that this technology may bring to future clinical practice and patient care. As machine vision emerges onto the clinical stage, it is critically important that anesthesiologists are prepared to confidently assess which of these devices are safe, appropriate, and bring added value to patient care.

Emergency treatment of airway obstruction caused by a laryngeal neuroendocrine tumor: A case report

RATIONALE

Laryngeal obstruction is a life-threatening adverse event that requires urgent and appropriate management, particularly in patients with coexisting cardiopulmonary and brain comorbidities. However, laryngeal obstruction caused by laryngeal neuroendocrine tumors has rarely been reported.

PATIENT CONCERNS

Neuroendocrine tumors can cause pathological changes in the neuro-humoral system, and asphyxia caused by airway obstruction has a more adverse effect on patients with neuroendocrine tumors.

DIAGNOSES

We report the case of a 64-year-old man with clinical manifestations of dyspnea. Preoperative and intraoperative pathological examination indicated that the patient was diagnosed with life-threatening airway obstruction caused by a laryngeal neuroendocrine tumor, pneumonia, and scoliosis.

INTERVENTIONS

The patient underwent laryngeal tumor resection under general anesthesia. He was recovered well and was generally good without the necessity of undergoing radiotherapy and chemotherapy at the 6-months follow-up.

OUTCOMES

This case report has provided an emergency treatment strategy associated with awake intubation. We concluded that flexible establishment of an artificial airway, skilled anesthesia and surgical manipulation, and necessary postoperative intensive care are extremely important for improving the prognosis of patients with severely difficult airway. It is noteworthy that the timely adjust for endotracheal intubation strategy according to the patient's response is needed. It is important for the long-term prognosis of patients to avoid the establishment of a traumatic artificial airway and the occurrence of adverse complications.

LESSONS

1. Introduction; 2. Case presentation; 3. Discussion; 4. Conclusion.

Ramped versus sniffing position in the videolaryngoscopy-guided tracheal intubation of morbidly obese patients: a prospective randomized study

BACKGROUND

Ramped positioning is recommended for intubating obese patients undergoing direct laryngoscopy. However, whether the use of the ramped position can provide any benefit in videolaryngoscopy-guided intubation remains unclear. This study assessed intubation time using videolaryngoscopy in morbidly obese patients in the ramped versus sniffing positions.

METHODS

This is a prospective randomized study in patients with morbid obesity (n = 82; body mass index [BMI] ≥ 35 kg/m2). Patients were randomly allocated to either the ramped or the standard sniffing position groups. During the induction of general anesthesia, difficulty in mask ventilation was assessed using the Warters scale. Tracheal intubation was performed using a C-MAC® D-Blade videolaryngoscope, and intubation difficulty was assessed using the intubation difficulty scale (IDS). The primary endpoint was the total intubation time calculated as the sum of the laryngoscopy and tube insertion times.

RESULTS

The percentage of difficult mask ventilation (Warters scale ≥ 4) was significantly lower in the ramped (n = 40) than in the sniffing group (n = 41) (2.5% vs. 34.1%, P < 0.001). The percentage of easy intubation (IDS = 0) was significantly higher in the ramped than in the sniffing group (70.0% vs. 7.3%, P < 0.001). The total intubation time was significantly shorter in the ramped than in the sniffing group (22.5 ± 6.2 vs. 40.9 ± 9.0, P < 0.001).

CONCLUSIONS

Compared with the sniffing position, the ramped position reduced intubation time in morbidly obese patients and effectively facilitated both mask ventilation and tracheal intubation using videolaryngoscopy.

Practice of oxygen use in anesthesiology – a survey of the European Society of Anaesthesiology and Intensive Care

Background

Oxygen is one of the most commonly used drugs by anesthesiologists. The World Health Organization (WHO) gave recommendations regarding perioperative oxygen administration, but the practice of oxygen use in anesthesia, critical emergency, and intensive care medicine remains unclear.

Methods

We conducted an online survey among members of the European Society of Anaesthesiology and Intensive Care (ESAIC). The questionnaire consisted of 46 queries appraising the perioperative period, emergency medicine and in the intensive care, knowledge about current recommendations by the WHO, oxygen toxicity, and devices for supplemental oxygen therapy.

Results

Seven hundred ninety-eight ESAIC members (2.1% of all ESAIC members) completed the survey. Most respondents were board-certified and worked in hospitals with > 500 beds. The majority affirmed that they do not use specific protocols for oxygen administration. WHO recommendations are unknown to 42% of respondents, known but not followed by 14%, and known and followed by 24% of them. Respondents prefer inspiratory oxygen fraction (FiO₂) ≥80% during induction and emergence from anesthesia, but intraoperatively < 60% for maintenance, and higher FiO₂ in patients with diseased than non-diseased lungs. Postoperative oxygen therapy is prescribed more commonly according to peripheral oxygen saturation (SpO₂), but shortage of devices still limits monitoring. When monitoring is used, SpO₂ ≤ 95% is often targeted. In critical emergency medicine, oxygen is used frequently in patients aged ≥80 years, or presenting with respiratory distress, chronic obstructive pulmonary disease, myocardial infarction, and stroke. In the intensive care unit, oxygen is mostly targeted at 96%, especially in patients with pulmonary diseases.

Conclusions

The current practice of perioperative oxygen therapy among respondents does not follow WHO recommendations or current evidence, and access to postoperative monitoring devices impairs the individualization of oxygen therapy. Further research and additional teaching about use of oxygen are necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01884-2.

Management of difficult and failed intubation in the general surgical population: a historical cohort study in a tertiary care centre

PURPOSE

The objective of this study was to describe the incidence, management, and complications of difficult and failed endotracheal intubation in a general surgical population.

METHODS

This historical cohort study included all cases of difficult endotracheal intubation in general surgical patients at Mount Sinai Hospital (Toronto, ON, Canada) from 1 January 2011 to 31 December 2017. Patient charts and electronic records were reviewed to collect data on airway management and complications. Endotracheal intubation was graded as "difficult" if more than two attempts with direct laryngoscopy or if additional equipment for second or subsequent attempts was required, and "failed" if it could not be achieved despite the attempts. The primary outcome was the incidence of difficult and failed intubation. The secondary outcomes were complications, difficult airway parameters, mask ventilation, number of intubation attempts, and rescue devices including the eventually successful method.

RESULTS

We identified 111 cases of difficult intubation (0.26%) and 14 cases of failed intubation (0.03%) in 42,805 surgical cases requiring endotracheal intubation over the seven-year period. The incidence was highest in 2012 (0.36%) and lowest in 2017 (0.13%). Difficulty was anticipated in 84 (76%) patients. The median (range) number of intubation attempts was 2 (2-5). Videolaryngoscopy was the eventually successful method in those with unsuccessful first attempt direct laryngoscopy (n = 91) and videolaryngoscopy (n = 17) in 71% and 77% cases, respectively. Intubation failed in 14 patients, three of whom required a surgical airway because the lungs could not be ventilated. Poor visualization of the glottis (93%) and airway bleeding (36%) were the leading causes of failed intubation. Desaturation was seen in 8%, airway bleeding in 7%, and airway edema in 6% of cases of difficult intubation.

CONCLUSION

The incidences of difficult and failed intubations in our study were 2.6 and 0.3 per 1,000 surgeries requiring laryngoscopies, respectively, with a decrease over time. Videolaryngoscopy showed a high success rate as a rescue device.

The Association of Laryngeal Position on Videolaryngoscopy and Time Taken to Intubate Using Spatial Point Pattern Analysis of Prospectively Collected Quality Assurance Data

BACKGROUND

During videolaryngoscopy (VL), the larynx appears within the defined area of the video screen, and its location can be measured as a point within this space. Spatial statistics offer methods to explore the relationship between location data and associated variables of interest. The aims of this study were to use spatial point pattern analysis to explore if the position of the larynx on VL is associated with longer times to intubate, increased risk of a needing >1 intubation attempt, or percentage of glottic opening.

METHODS

Quality assurance data and clinical notes from all prehospital intubations using C-MAC Pocket Monitor with CMAC-4 blade (Karl Storz) from January 1, 2018, to July 31, 2020, were reviewed. We extracted 6 measurements corresponding to the time taken to obtain the initial and then best laryngeal view, time to manipulate a bougie, and time to place the endotracheal tube, as well a percentage of glottic opening and a number of intubation attempts. Larynx location was the middle of the base of glottis, in cm from the left and bottom on the C-MAC screen. Two plots were produced to summarize the base of glottis location and time to perform each time component of intubation. Next, a cross mark function and a maximum absolute deviation hypothesis test were performed to assess the null hypotheses that the spatial distributions were random. The association between glottis location and >1 intubation attempt was assessed by a spatial relative risk plot.

RESULTS

Of 619 eligible intubations, 385 had a video for analysis. The following time variables had a nonrandom spatial distribution with a tendency for longer times when the larynx was off-center to the top or right of the screen: laryngoscope passing from teeth to glottis, glottis first view to best view of the larynx, time from bougie appearing to being placed in the cords, and overall time from teeth to endotracheal tube passing through cords. There was no increased relative risk for >1 intubation attempt.

CONCLUSIONS

Spatial point pattern analysis identified a relationship between the position of the larynx during VL and prolonged intubation times. We did not find a relationship between larynx location and >1 attempt. Whether the location of the larynx on the screen is a marker for difficult VL or if optimizing the larynx position to the center of the screen improves intubation times would require further prospective studies.

Upper lip bite test compared to modified Mallampati test in predicting difficult airway in obstetrics: A prospective observational study

Difficult airway and intubation can have dangerous sequela for patients if not managed promptly. This issue is even more challenging among obstetric patients. Several studies have aimed to determine whether the test to predict a difficult airway or difficult intubation, is higher in accuracy. This study aims to compare the upper lip bite test with the modified Mallampati test in predicting difficult airway among obstetric patients. During this prospective observational study, 184 adult pregnant women, with ASA physical status of II, were enrolled. Difficult intubations of Cormack-Lehane grade III and IV were defined as difficult airways and difficult intubation in this study. Upper lip bite test, modified Mallampati test, thyromental distance and sternomental distance were noted for all patients. Modified Mallampati test, upper lip bite test and sternomental distance had highest specificity. Based on regression analysis, body mass index and Cormack-Lehane grade have a significant association. Modified Mallampati test was the most accurate test for predicting difficult airway. The best cut-off points of thyromental distance and sternomental distance in our study were 5cm and 15cm, respectively, by receiver operating characteristic curve analysis. Based on the results of the present study, it can be concluded that in the obstetric population, modified Mallampati test is practically the best test for predicting difficult airway. However, combining this test with upper lip bite test, thyromental distance and sternomental distance might result in better diagnostic accuracy.

Advanced endoscopic gastrointestinal techniques for the bariatric patient: implications for the anesthesia provider

PURPOSE OF REVIEW

The incidence of obesity and the use of endoscopy have risen concurrently throughout the 21st century. Bariatric patients may present to the endoscopy suite for primary treatments as well as preoperatively and postoperatively from bariatric surgery. However, over the past 10 years, endoscopic bariatric and metabolic therapies (EBMTs) have emerged as viable alternatives to more invasive surgical approaches for weight loss.

RECENT FINDINGS

The United States Food and Drug Administration (FDA) has approved several different gastric EBMTs including aspiration therapy, intragastric balloons, and endoscopic suturing. Other small intestine EBMTs including duodenal mucosal resurfacing, endoluminal magnetic partial jejunal diversion, and Duodenal-Jejunal Bypass Liner are not yet FDA approved, but are actively being investigated.

SUMMARY

Obesity causes anatomic and physiologic changes to every aspect of the human body. All EBMTs have specific nuances with important implications for the anesthesiologist. By considering both patient and procedural factors, the anesthesiologist will be able to perform a safe and effective anesthetic.

[Cardiac arrest under special circumstances]

These guidelines of the European Resuscitation Council (ERC) Cardiac Arrest under Special Circumstances are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required for basic and advanced life support for the prevention and treatment of cardiac arrest under special circumstances; in particular, specific causes (hypoxia, trauma, anaphylaxis, sepsis, hypo-/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), specific settings (operating room, cardiac surgery, cardiac catheterization laboratory, dialysis unit, dental clinics, transportation [in-flight, cruise ships], sport, drowning, mass casualty incidents), and specific patient groups (asthma and chronic obstructive pulmonary disease, neurological disease, morbid obesity, pregnancy).

Factors and Economic Outcomes Associated with Documented Difficult Intubation in the United States

Purpose

Establishing good mechanical ventilation is a critical component and prerequisite to a wide range of surgical and medical interventions. Yet difficulties in intubating patients, and a variety of associated complications, are well documented. The economic burden resulting from difficult intubation (DI), however, is not well understood. The current study examines the economic burden of documented DI during inpatient surgical admissions and explores factors that are associated with DI.

Patients and Methods

Using data from the Premier Healthcare Database, adult patients with inpatient surgical admissions between January 1, 2016 and December 31, 2018 were selected. International Classification of Diseases, Tenth Edition, Clinical Modification (ICD-10-CM) diagnosis codes were used to classify the patients into matched cohorts of DI and non-DI patients.

Results

Patients in the DI group have mean inpatient costs and intensive care unit (ICU) costs that are substantially higher than patients without difficult intubations ($14,468 and $4,029 higher, respectively). Mean hospital length of stay and ICU length of stay were 3.8 days and 2.0 days longer, respectively (all p<0.0001, except ICU cost p=0.0001) in the DI group. Obesity, other chronic conditions, and larger hospital size were significantly associated with DI.

Conclusion

DI is associated with higher average cost and longer average length of stay.

European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances

These European Resuscitation Council (ERC) Cardiac Arrest in Special Circumstances guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required to basic and advanced life support for the prevention and treatment of cardiac arrest in special circumstances; specifically special causes (hypoxia, trauma, anaphylaxis, sepsis, hypo/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), special settings (operating room, cardiac surgery, catheter laboratory, dialysis unit, dental clinics, transportation (in-flight, cruise ships), sport, drowning, mass casualty incidents), and special patient groups (asthma and COPD, neurological disease, obesity, pregnancy).

The evaluation of maximum condyle-tragus distance can predict difficult airway management without exposing upper respiratory tract; a prospective observational study

Background

Routine preoperative methods to assess airway such as the interincisor distance (IID), Mallampati classification, and upper lip bite test (ULBT) have a certain risk of upper respiratory tract exposure and virus spread. Condyle-tragus maximal distance(C-TMD) can be used to assess the airway, and does not require the patient to expose the upper respiratory tract, but its value in predicting difficult laryngoscopy compared to other indicators (Mallampati classification, IID, and ULBT) remains unknown. The purpose of this study was to observe the value of C-TMD to predict difficult laryngoscopy and the influence on intubation time and intubation attempts, and provide a new idea for preoperative airway assessment during epidemic.

Methods

Adult patients undergoing general anesthesia and tracheal intubation were enrolled. IID, Mallampati classification, ULBT, and C-TMD of each patient were evaluated before the initiation of anesthesia. The primary outcome was intubation time. The secondary outcomes were difficult laryngoscopy defined as the Cormack-Lehane Level > grade 2 and the number of intubation attempts.

Results

Three hundred four patients were successfully enrolled and completed the study, 39 patients were identified as difficult laryngoscopy. The intubation time was shorter with the C-TMD>1 finger group 46.8 ± 7.3 s, compared with the C-TMD<1 finger group 50.8 ± 8.6 s (p<0.01). First attempt success rate was higher in the C-TMD>1 finger group 98.9% than in the C-TMD<1 finger group 87.1% (P<0.01). The correlation between the C-TMD and Cormack-Lehane Level was 0.317 (Spearman correlation coefficient, P<0.001), and the area under the ROC curve was 0.699 (P<0.01). The C-TMD < 1 finger width was the most consistent with difficult laryngoscopy (κ = 0.485;95%CI:0.286–0.612) and its OR value was 10.09 (95%CI: 4.19–24.28), sensitivity was 0.469 (95%CI: 0.325–0.617), specificity was 0.929 (95%CI: 0.877–0.964), positive predictive value was 0.676 (95%CI: 0.484–0.745), negative predictive value was 0.847 (95%CI: 0.825–0.865).

Conclusion

Compared with the IID, Mallampati classification and ULBT, C-TMD has higher value in predicting difficult laryngoscopy and does not require the exposure of upper respiratory tract.

Trial registration

The study was registered on October 21, 2019 in the Chinese Clinical Trial Registry (ChiCTR1900026775).

Long-term intubation and high rate of tracheostomy in COVID-19 patients might determine an unprecedented increase of airway stenoses: a call to action from the European Laryngological Society

INTRODUCTION

The novel Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2, may need intensive care unit (ICU) admission in up to 12% of all positive cases for massive interstitial pneumonia, with possible long-term endotracheal intubation for mechanical ventilation and subsequent tracheostomy. The most common airway-related complications of such ICU maneuvers are laryngotracheal granulomas, webs, stenosis, malacia and, less commonly, tracheal necrosis with tracheo-esophageal or tracheo-arterial fistulae.

MATERIALS AND METHODS

This paper gathers the opinions of experts of the Laryngotracheal Stenosis Committee of the European Laryngological Society, with the aim of alerting the medical community about the possible rise in number of COVID-19-related laryngotracheal stenosis (LTS), and the aspiration of paving the way to a more rationale concentration of these cases within referral specialist airway centers.

RESULTS

A range of prevention strategies, diagnostic work-up, and therapeutic approaches are reported and framed within the COVID-19 pandemic context.

CONCLUSIONS

One of the most important roles of otolaryngologists when encountering airway-related signs and symptoms in patients with previous ICU hospitalization for COVID-19 is to maintain a high level of suspicion for LTS development, and share it with colleagues and other health care professionals. Such a condition requires specific expertise and should be comprehensively managed in tertiary referral centers.