Predictive Value of Tracheal Rapid Ultrasound Exam Performed in the Emergency Department for Verification of Tracheal Intubation

Confirmatory methods for endotracheal tube placement in out-of-hospital settings: A systematic review of the literature

Background

Confirming proper placement of an endotracheal tube (ETT) is important, as accidental misplacements may occur and lead to critical injuries, potentially leading to adverse outcomes. Multiple methods are available for determining the correct ETT placement in prehospital care.

Objective

To assess the accuracy and reliability of the different methods used to confirm endotracheal intubation in prehospital settings.

Methods

A comprehensive literature search was performed in the MEDLINE, EMBASE, Scopus, and Web of Science databases for studies that were published between 1-June-1992 and 12-June-2022 using a combination of predetermined search terms. Studies that met the inclusion criteria were included and assessed for risk of bias using "Risk of Bias in Non-randomized Studies of Intervention" tool.

Results

Of the 1016 identified studies, nine met the inclusion criteria. Capnography and point-of-care ultrasound showed high sensitivity and specificity rates when applied to confirm ETT placement in prehospital care. Other methods including capnometry, colorimetric detectors, ODDs, and auscultation showed varied sensitivity and specificity. Patient comorbidities and device failure contributed to decreased accuracy rates in prehospital care. Capnography was less reliable in distinguishing between endotracheal intubation and right main stem intubation, which is known as a complication in out-of-hospital endotracheal intubation. Point-of-care ultrasound was more accurate and reliable in detecting oesophageal and endobronchial misplacements. ETCO2 monitors, i.e., capnometry and colorimetric detectors, were less reliable in patients with low perfusion states.

Conclusion

This systematic review showed that there is no single method with 100% accuracy in confirming the correct ETT placement and detecting the occurrence of accidental oesophageal or endobronchial misplacements in prehospital care. Further studies with a larger sample size are needed to assess the accuracy of multiple confirmatory methods in prehospital settings.

Point-of-Care Ultrasound in Airway Evaluation and Management: A Comprehensive Review

Airway management is a common and critical procedure in acute settings, such as the Emergency Department (ED) or Intensive Care Unit (ICU) of hospitals. Many of the traditional physical examination methods have limitations in airway assessment. Point-of-care ultrasound (POCUS) has emerged as a promising tool for airway management due to its familiarity, accessibility, safety, and non-invasive nature. It can assist physicians in identifying relevant anatomy of the upper airway with objective measurements of airway parameters, and it can guide airway interventions with dynamic real-time images. To date, ultrasound has been considered highly accurate for assessment of the difficult airway, confirmation of proper endotracheal intubation, prediction of post-extubation laryngeal edema, and preparation for cricothyrotomy by identifying the cricothyroid membrane. This review aims to provide a comprehensive overview of the key evidence on the use of ultrasound in airway management. Databases including PubMed and Embase were systematically searched. A search strategy using a combination of the term "ultrasound" combined with several search terms, i.e., "probe", "anatomy", "difficult airway", "endotracheal intubation", "laryngeal edema", and "cricothyrotomy" was performed. In conclusion, POCUS is a valuable tool with multiple applications ranging from pre- and post-intubation management. Clinicians should consider using POCUS in conjunction with traditional exam techniques to manage the airway more efficiently in the acute setting.

The diagnostic accuracy of an inclusive three-window ultrasonography assessment for the rapid authentication of endotracheal tube position in RICU

Background

Assurance of proper endotracheal tube (ETT) location is crucial immediately after intubation as undiagnosed esophageal intubation can be catastrophic. The primary purpose for this study is to determine the diagnostic accuracy of to evaluate the accuracy of an inclusive three-window ultrasonography assessment for the rapid authentication of endotracheal tube position in the intensive care unit (RICU) with reference to Co2 monitors (capnography) (the gold standard technique), The study included 100 patients who needed emergency intubation in the ICU of Aswan university hospital. Upon entrance to ICU, intubations was done by the residents and collective bedside three-windows ultra-sonography (tracheal, lung, diaphragmatic ultra-sonography) was carried out instantly after intubation Subsequently, the correct position of the endotracheal tube was established by the resident investigator via the use a capnometer.

Results

Waveform capnography revealed endotracheal intubation in 80 cases (80%) and esophageal intubation in 20 cases (20%). However, trans-tracheal ultra-sonography (TUS) was able to detect endotracheal intubation in 78 cases (78%) and esophageal intubation in 22 cases (22%) patients. SLS detected only 17 esophageal intubations from 20 cases detected by CO2 detectors. DUS was able to detect proper endotracheal intubation in 77 cases (77%) and esophageal intubation in 23 cases (23%). However, it detected only 17 esophageal intubations from 20 cases detected by Co2 detectors.

Conclusions

Ultra-sonography, as recently introduced practice for validation of correct endotracheal tube location has both high accuracy and safety profile and can be used as a primary authentication technique.

Trial registration

NCT05747248

Comparison of Upper Airway Ultrasonography With End-Tidal Capnography for the Confirmation of Endotracheal Tube Placement in Patients Requiring General Anesthesia

Introduction End-tidal capnography (EtCO₂) has been the gold standard method for confirmation of endotracheal intubation. Upper airway ultrasonography (USG) is a new promising method for confirming endotracheal tube (ETT) placement and has the potential to become the first-line non-invasive airway assessment tool in the future thanks to widespread POCUS knowledge, greater technology improvements, portability, and availability of ultrasound in the majority of essential areas. Hence our study aimed to compare upper airway USG and EtCO₂ for the confirmation of ETT placement in patients undergoing general anesthesia. Aim To compare the upper airway USG with EtCO₂ for confirmation of ETT placement in patients requiring general anesthesia for elective surgical procedures. The objectives of the study were to compare the time taken for confirmation, and the number of correct identification of tracheal and esophageal intubation by both upper airway USG and EtCO₂. Materials and methods After obtaining institutional ethical committee (IEC) approval, a prospective randomized comparative study involving 150 patients under American Society of Anesthesiologists (ASA) grade I and II requiring endotracheal intubation for elective surgeries under general anesthesia was randomized into two groups, Group U-upper airway USG and Group E-EtCO₂ with 75 patients in each group. ETT placement confirmation was done by upper airway USG in Group U and by EtCO₂ in Group E and the time taken for confirmation of ETT placement and correct identification of esophageal and tracheal intubation by USG and EtCO₂ was noted. Results The demographic details among both groups were statistically insignificant. Upper airway USG had a faster average confirmation time of 16.41 seconds when compared to EtCO₂ which took an average confirmation time of 23.56 seconds. In our study, upper airway USG was able to identify esophageal intubation with 100% specificity. Conclusion Upper airway USG can be a reliable method and can be employed as a standard method for confirmation of ETT location in patients undergoing elective surgeries under general anesthesia when compared to EtCO₂.

Screening Performance Characteristics of Ultrasonography in Confirmation of Endotracheal Intubation; a Systematic Review and Meta-analysis

Introduction:

Recent studies have suggested that point-of-care ultrasonography can be used for confirming the placement of endotracheal tube. This systematic review and meta-analysis aimed to investigate the sensitivity and specificity of ultrasonography for confirming endotracheal tube placement.

Methods:

In this meta-analysis, systematic search of the previous published papers investigating the diagnostic accuracy of ultrasonography for confirmation of endotracheal tube placement was performed. Seven electronic databases, including PubMed, Scopus, Google Scholar, EBSCO, EMBASE, Web of Science, and Cochrane Database were searched up to July 2021, for all relevant articles published in English on this topic. Meta-DiSc version 1.4 software was used for statistical analysis.

Results:

The estimated pooled sensitivity and specificity of ultrasonography for confirmation of endotracheal tube location were 0.98 (95% CI: 0.98–0.99) and 0.94 (95% CI 0.91–0.96), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 5.94 (95% CI 4.41–7.98) and 0.03 (95% CI: 0.02-0.04), respectively. The diagnostic odds ratio of ultrasonography was 281.47 and the area under hierarchical summary receiver operating characteristic (HSROC) revealed an appropriate accuracy of 0.98.

Conclusion:

Ultrasonography has high diagnostic accuracy and can be used as a promising tool for confirmation of endotracheal tube placement, especially in critically ill patients or when capnography is not available, or its result is equivocal.

Comparative study of the reliability of ultrasound to confirm the position of endotracheal tube with cuff inflated with saline versus air

Aim: To compare the reliability of transtracheal ultrasound to confirm the endotracheal tube position with saline versus air inflated cuff. Methods: This was a prospective randomized cadaveric study. Four techniques were randomized: endotracheal tube in the trachea with air or saline inflated cuff, and endotracheal tube in the esophagus with air or saline inflated cuff. The investigator used the Mcgrath to randomly place the endotracheal tube in the trachea or in the esophagus with saline or air inflated cuff. During the first series of measurements, nine residents performed transtracheal ultrasound with linear transducer placed transversely at the suprasternal notch. They were recorded with a cut off fixed to 30 seconds, and a questionnaire was completed by the residents after each transtracheal ultrasound in order to report where the endotracheal tube is positioned according to them. The second series followed the same protocol and included three residents who had participated in the first series. The primary outcome was the success rate in determining the position of the endotracheal tube. Results: In the first series, the success rate was 46.5%. In the second series, the success rate was 72.9%. There was no significant difference between cuff inflated with saline and air (p = 1.00). The overall mean time required was 20.6 s (95% CI 13.0–28.2 s). Based on an empirical data set, transtracheal ultrasound had a sensitivity of 62.2%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 26.08%. Conclusion: This investigation shows that regardless of the contents of the endotracheal tube cuff, the use of transtracheal ultrasound to confirm the position of endotracheal tube reports disappointing results.

Ultrasound for Intubation Confirmation: A Randomized Controlled Study among Emergency Medicine Residents

Confirmation of endotracheal tube (ETT) placement during intubation is a critical skill for emergency medicine (EM) residents; airway ultrasonography has been suggested as an accessible and accurate method of ETT confirmation. Here, we investigated the accuracy with which EM residents could identify ETT location in cadavers using different ultrasound modes. EM attendings intubated either the trachea or the esophagus of a cadaver, and blinded residents identified ETT position using either B-mode or B-mode plus color Doppler. Residents correctly identified ETT location in 1075 of 1203 trials (89.4%); performance improved with post-graduate year (residents in post-graduate year 3 had 97.8% accurate identifications). There were 556 (91.7%) correct identifications made with B-mode and 519 (86.9%) with B-mode plus color Doppler (p value = 0.007); thus, accuracy did not improve with addition of color Doppler to B-mode. Further research is needed on the efficacy of different ultrasound modes in confirming ETT placement in live intubations.