Learning curve of ultrasound measurement of subglottic diameter for endotracheal tube selection in pediatric patients

A Scoping Review of Ultrasonographic Techniques in the Evaluation of the Pediatric Airway

Point-of-care ultrasound is making rapid advancements in pediatrics, and ultrasonographic assessment of the airway is being employed in many specialties such as the pediatric, cardiac, and neonatal intensive care units, emergency department, pulmonary clinic, and the perioperative setting. This scoping review provides a technical description of image acquisition and interpretation, accompanying ultrasound images of the hallmark airway applications in pediatrics, and supporting evidence when available. We describe and illustrate ultrasound-determined endotracheal tube (ETT) sizing, ETT placement and depth confirmation, vocal fold assessment, prediction of post-extubation stridor, difficult laryngoscopy prediction, and cricothyrotomy guidance. This review aims to provide the descriptions and images necessary to learn and apply these skills at the point of care in the pediatric patient.

Endobronchial Intubation With the King Vision® and McGrath® Laryngoscopes in Simulated Easy and Difficult Airways by Novices (eKingMath)

Objective. The competency of using video laryngoscopes (VL) for double-lumen tube (DLT) endobronchial intubations can be improved with constant training as assessed by measuring the learning curves. We hypothesized that the time to DLT intubation would be reduced over the intubation attempts. Design. A crossover manikin study. Settings. University-affiliated hospital. Participants. Forty-two novice medical students unfamiliar with DLT intubation. Interventions. Participants were randomly allocated to two sequences, including DLT intubation, using King Vision and McGrath VLs. Each participant completed 100 DLT intubation attempts on both simulated easy and difficult airways on two different mannikins using the study devices (25 attempts for each). Measurements and Main Results. The primary outcome was the time to DLT intubation. The secondary outcomes included the best glottic view, optimizing maneuvers, and intubation first-pass success. The use of King Vision VL was associated with a significantly shorter time to DLT intubation (P < 0.044 and P < 0.05, respectively) and a higher percentage of glottic opening (POGO) compared to the McGrath VL (P < 0.011 and P < 0.002, respectively) in the simulated "easy" and "difficult" over most of the intubation attempts. In the simulated "easy" airway, the first-pass success ratio was higher when using the King Vision VL (median [Minimum-Maximum] 100% [100%-100%] and 100% [88%-100%], P = 0.012). Conclusion. Novice medical students developed skills over intubation attempts, meaning achievement of a faster DLT intubation, better laryngeal exposure, and higher success rate on simulated "easy" and "difficult" airways. A median of 9 DLT intubations was required to achieve a 92% or greater DLT intubation success rate.

Applications of Airway Ultrasound for Endotracheal Intubation in Pediatric Patients: A Systematic Review

Endotracheal intubation is a challenging procedure for pediatric patients. Airway ultrasound as a new technology is suitable for aiding this process, but its diagnostic value remains unclear. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the Chinese biomedical literature database to summarize specific applications of airway ultrasound in each step of endotracheal intubation in pediatric patients. Diagnostic accuracy and 95% confidence interval were used as outcomes. In total, 33 studies (6 randomized controlled trials and 27 diagnostic studies) with 1934 airway ultrasound examinations were included. Population included neonates, infants, and older children. Airway ultrasound could be used to determine the endotracheal tube size and confirm endotracheal intubation and intubation depth; the diagnostic accuracy for all these factors was 23.3-100%, 90.6-100%, and 66.7-100%, respectively. Furthermore, the accuracy of airway ultrasound in predicting endotracheal tube size was consistently higher than traditional methods, such as height formula, age formula, and the width of the little finger. In conclusion, airway ultrasound has unique advantages for confirming successful endotracheal intubation in pediatric patients, and it may become an effective auxiliary tool in this field. There is a need to develop a unified airway ultrasound protocol to conduct clinical trials and practice in the future.

A learning curve of a novel multimodal endotracheal intubation assistant device for novices in a simulated airway: a prospective manikin trial with cumulative sum method

BACKGROUND

Awake fiberoptic intubation is conventionally performed in anticipated difficult airways. However, obstruction by secretions and sputum makes it challenging for novices. A prototype of a novel multimodal endotracheal intubation assistant device (MEIAD) was developed for an indication of airway according to end-tidal carbon dioxide (ETCO₂) and image. At the tip, 4 sampling tubes collected ETCO₂ concentration. The airway direction is located according to an advanced algorithm based on 4 directions' concentrations. It assists awake intubation, especially with unclear view field. The objective was to analyze the learning curve of MEIAD for novices on a manikin by cumulative sum method (CUSUM) and evaluate the utility.

METHODS

A total of 16 novice residents with less than 2-year clinical experience were enrolled. After instruction, each individual exercised 40 insertions with MEIAD on a difficult airway simulation. Insertion success (defined as a visualization of the carina within 120 seconds), insertion time (the time from when the guiding scope entered the nasal cavity to the carina was visible), and self-confidence score (subjective score with a numerical rating scale from 0 to 10) were recorded. The acceptable and unacceptable failure rates of CUSUM were set as 15% and 30%, respectively. The exercises were divided into 2 phases (phase 1: 1-20, phase 2: 21-40) for further evaluation. All continuous data were expressed by median (IQR, interquartile ranges) and analyzed using Mann-Whitney test. All categorical variables were expressed as percentages and compared by the χ² test.

RESULTS

Among the 16 residents, 15 were able to cross the lower decision boundary in an average of 21.27±9.51 attempts using the novel device. The insertion time [24.0 (17.0-42.0) vs. 17.5 (14.0-28.0) seconds, P<0.001] and success rate (88.4% vs. 97.5%, P<0.001) were improved with increased experience. The confidence score was significantly improved from 2.5 (1.3-4.0) to 7.0 (7.0-8.0).

CONCLUSIONS

MEIAD showed a satisfactory learning curve and efficacy on the manikin for novices. However, as a small exploratory manikin trial, the results cannot be replicated in clinical practice. MEIAD is expected to be further improved and potential to be an alternative device for difficult airways.

Prediction of endotracheal tube size in pediatric patients: Development and validation of machine learning models

OBJECTIVE

We aimed to construct and validate machine learning models for endotracheal tube (ETT) size prediction in pediatric patients.

METHODS

Data of 990 pediatric patients underwent endotracheal intubation were retrospectively collected between November 2019 and October 2021, and separated into cuffed and uncuffed endotracheal tube subgroups. Six machine learning algorithms, including support vector regression (SVR), logistic regression (LR), random forest (RF), gradient boosting tree (GBR), decision tree (DTR) and extreme gradient boosting tree (XGBR), were selected to construct and validate models using ten-fold cross validation in training set. The optimal models were selected, and the performance were compared with traditional predictive formulas and clinicians. Furthermore, additional data of 71 pediatric patients were collected to perform external validation.

RESULTS

The optimal 7 uncuffed and 5 cuffed variables were screened out by feature selecting. The RF models had the best performance with minimizing prediction error for both uncuffed ETT size (MAE = 0.275 mm and RMSE = 0.349 mm) and cuffed ETT size (MAE = 0.243 mm and RMSE = 0.310 mm). The RF models were also superior in predicting power than formulas in both uncuffed and cuffed ETT size prediction. In addition, the RF models performed slightly better than senior clinicians, while they significantly outperformed junior clinicians. Based on SVR models, we proposed 3 novel linear formulas for uncuffed and cuffed ETT size respectively.

CONCLUSION

We have developed machine learning models with excellent performance in predicting optimal ETT size in both cuffed and uncuffed endotracheal intubation in pediatric patients, which provides powerful decision support for clinicians to select proper ETT size. Novel formulas proposed based on machine learning models also have relatively better predictive performance. These models and formulas can serve as important clinical references for clinicians, especially for performers with rare experience or in remote areas.

Prediction of endotracheal tube size in the pediatric age group by ultrasound: A systematic review and meta-analysis

Anatomical differences in the airway in pediatric patients, compared to adults pose many challenges during endotracheal intubation, such as selecting the proper sized endotracheal tube (ETT) during intubation. Our primary objective was to assess how accurate is ultrasound (US) co-relation in comparison to standard age-based formulas in pediatric patients. Meta-analysis was registered in PROSPERO 2020, CRD42020220041. Online literature available in PubMed, Cochrane, and Embase, Goggle scholar was searched from year 2000 till November 30, 2020, using relevant Mesh terms, ('airway US' OR (('airway'/exp OR airway) AND ('US'/exp OR US))) AND ('endotracheal intubation'/exp OR 'endotracheal intubation') AND ('pediatric'/exp OR pediatric)" to Predict endotracheal tube size/placement in pediatric age (neonate till 18 years) by the US. Bibliographic cross-references of selected publications were further manually screened. The full texts of each article were studied, once the abstract was found appropriate independently by two reviewers. A total of 48 papers published between 2010 and 2020 were identified as relevant and read in detail. Average numbers of patients were 86 and total numbers of patients were 1978. Most of the studies included pediatric patients posted for elective surgeries under general anesthesia and excluded emergency procedures, known laryngeal or tracheal pathology, high-risk patients, recent upper respiratory tract infections or allergy to ultrasound gel. A total of 18 independent correlations were analyzed. Final combined r value calculated from all the included articles was 0.824 (95% CI 0.677, 0.908) with a P < 0.00001 {strong co-relation (r > 0.80)}. Q statistic of 756.484, and I² statistics of 97.53% showed a large degree of heterogeneity in the effect size across the studies. Use of US for upper airway in pediatric patients is an effective modality and can effectively predict endotracheal tube size estimations in comparison to standard age-based or height-based formulae in the pediatric age group. US is a non-invasive, cost-effective, portable, and reproducible technique as compared to CT and MRI. It also takes less time with increasing expertise and experience.

Feasibility study of cumulative sum (CUSUM) analysis as a competency assessment tool for ultrasound-guided venous access procedures

PURPOSE

Typically, physician training programs use a self-reported case-log competency assessment that does not measure procedure success or objectively assess competency. Cumulative sum (CUSUM) analysis could provide objective assessments of competency and progress over the training period. Our study objective was to determine the feasibility of CUSUM analysis to assess competency of ultrasound-guided peripheral intravenous (USG-PIV) line placement in pediatric anesthesiology fellows.

METHODS

We applied a CUSUM analysis to assess competency in USG-PIV placement in three consecutive pediatric anesthesia fellowship classes. After a didactic and hands-on training session, fellows placed a USG-PIV line and self-reported the outcomes via a web-based application. Fellows were deemed competent if the CUSUM curve crossed two consecutive boundary lines from above.

RESULTS

Twenty-nine fellows reported 1,388 USG-PIV attempts, with 74% success. Most fellows (26/29; 90%) achieved competency by the end of the fellowship. Two fellows identified in the mid-year CUSUM as not progressing towards competency achieved competency after targeted interventions. Fellows achieving competency (11/29 vs 25/29; odds ratio, 15; 95% confidence interval [CI], 1.98 to 113.56; P = 0.01) and attempts needed to achieve competency (19 vs 11; mean difference, 8.5; 95% CI, 3.3 to 13.7; P = 0.002) were significantly lower in younger patients and significantly higher in older patients.

CONCLUSION

Our study showed that CUSUM can be used to assess competence in USG-PIV procedures performed by pediatric anesthesia fellows and to identify learners not progressing toward competency in procedural skills. Ultrasound-guided venous access required more attempts to achieve competency in younger patients.

Electromagnetic navigation-guided preoperative localization: the learning curve analysis

Background

The electromagnetic navigation bronchoscopy (ENB) was increasingly used to mark small pulmonary nodules (PNs) for video-assisted thoracic surgery (VATS) resection due to high effectiveness and low risk. However, no study reports the learning curve of ENB-guided preoperative localization. In the study, we aimed to describe the learning curve of ENB-guided preoperative PNs localization initially.

Methods

Consecutive PNs cases that underwent ENB localizations between October 2018 and October 2019 by the same surgeon in our center were included in the study. The cumulative sum (CUSUM) method was used to analyze the learning curve of ENB localization.

Results

A total of 89 ENB localization from 64 patients were included in this study. The learning curve was divided into 3 phases: Phase I (the initial 11 cases), Phase II (the 12th to the 47th cases), and Phase III (the 47th to the 89th cases). The success rate of ENB localization has increased with the accumulation of operational experience in 3 phases (72.73%, 91.67%, and 97.62%, P=0.049). The distance from the ENB guide wire tip to the center of the lesion in Phase I was significantly longer than those in Phase II and Phase III (2.46±1.76 vs. 1.36±0.94 and 1.47±0.97 cm, P=0.014 and 0.027, respectively). Sex, bronchus sign, and learning curve phase were independent risk factors influencing operative time (OT) (OR =8.187, 18.847, and 13.920, respectively).

Conclusions

The technical competency, which is indicated by higher success rate, localization accuracy, and shorter OT, for ENB-guided preoperative PNs localization was achieved at the 47th operation.

Pediatric airway: What is new in approaches and treatments?

Perioperative morbidity and mortality are high among patients in the extremes of life undergoing anesthesia. Complications in children occur mainly as a result of airway management-related events such as difficult approach, laryngospasm, bronchospasm and severe hypoxemia, which may result in cardiac arrest, neurological deficit or death. Reports and new considerations that have changed clinical practice in pediatric airway management have emerged in recent years. This narrative literature review seeks to summarize and detail the findings on the primary cause of morbidity and mortality in pediatric anesthesia and to highlight those things that anesthetists need to be aware of, according to the scientific reports that have been changing practice in pediatric anesthesia. This review focuses on the identification of “new” and specific practices that have emerged over the past 10 years and have helped reduce complications associated with pediatric airway management. At least 9 practices grouped into 4 groups are described: assessment, approach techniques, devices, and algorithms. The same devices used in adults are essentially all available for the management of the pediatric airway, and anesthesia-related morbidity and mortality can be reduced through improved quality of care in pediatrics.

Airway ultrasound: Point of care in children-The time is now

BACKGROUND

Point-of-care ultrasonography of the airway is becoming a first-line noninvasive adjunct assessment tool of the pediatric airway. It is defined as a focused and goal-directed portable ultrasonography brought to the patient and performed and interpreted on the spot by the provider. Successful use requires a thorough understanding of airway anatomy and ultrasound experience.

AIMS

To outline the many benefits, and some limitations, of airway ultrasonography in the clinical and perioperative setting.

MATERIALS AND METHODS

Expert review of the recent literature.

RESULTS

Ultrasound assessment of the airway may provide the clinician with valuable information that is specific to the individual airway static and dynamic anatomy of the patient. Ultrasound can help identify vocal cord dysfunction and pathology, assess airway size, predict the appropriate diameter of endotracheal and tracheostomy tubes, differentiate tracheal from esophageal intubation, localize the cricothyroid membrane for emergency airway access and identify tracheal rings for US-guided tracheostomy. Ultrasonography is also a great tool for the intraoperative diagnosis of a pneumothorax, the visualization of the movement of the diaphragms, and quantifying the amount of gastric content. Ultrasonography signs, tips, and pearls that allow these diagnoses are highlighted. The major disadvantage of ultrasonography remains interobserver variability, and operator dependence, as it requires specific training and experience.

CONCLUSION

Although it is not standard of care yet, there is significant potential for the integration of ultrasound technology into the routine care of the airway.