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.

Ultrasonography for airway management

Ultrasonography (USG) allows a new approach to the airway in anaesthesia and intensive care. USG visualises the airway from the mouth to the lungs. By exploring the entire airway, USG proposes new criteria (1) to assess the risk of difficult laryngoscopy, (2) to anticipate the management of a difficult airway, (3) to confirm the position of the endotracheal tube (ETT), and (4) to confirm that the lungs are effectively ventilated. Intraoperatively, USG may also help to resolve acute ventilatory problems such as pneumothorax, delayed selective bronchial intubation after patient positioning (Trendelenburg, prone or lateral position) or acute pulmonary oedema.

Point-of-Care Ultrasound for Pediatric Endotracheal Tube Placement Confirmation by Advanced Practice Transport Nurses

OBJECTIVE

This study aimed to identify which point-of-care ultrasound (POCUS) techniques and sonographic signs were reliably acquired and interpreted by transport nurses for the confirmation of endotracheal tube placement in children.

METHODS

We developed and assessed a multimodal POCUS training curriculum for transport nurses that evaluated 5 sonographic signs using 3 scanning techniques.

RESULTS

Twenty-one transport nurses were enrolled in the curriculum. The mean scores (95% confidence interval [CI]) of the knowledge test were 82% (95% CI, 63%-93%), 88% (95% CI, 68%-95%), and 74% (95% CI, 53%-87%) for tracheal, lung, and hemidiaphragmatic scans, respectively. For the simulation image evaluation, 94% (95% CI, 77%-99%) of tracheal scan images, 97% (95% CI, 81%-99%) of lung scan images, and 88% (95% CI, 69%-96%) of hemidiaphragmatic scan images were determined clinically useful. For the pediatric intensive care unit image evaluation, 100% (95% CI, 86%-100%) of tracheal scan images, 100% (95% CI, 86%-100%) of lung scan images, and 79% (95% CI, 59%-91%) of hemidiaphragmatic scan images were determined clinically useful. A tracheal dilation sign was rarely captured by POCUS.

CONCLUSION

Transport nurses can acquire POCUS skills to confirm endotracheal tube placement in children. A combination of a double trachea sign, a lung sliding sign, and a lung pulse sign could be a feasible POCUS approach.

Ultrasound-guided percutaneous dilatational tracheostomy using a saline-filled endotracheal tube cuff as an ultrasonographic puncture target: A feasibility study

PURPOSE

The saline-filled endotracheal tube (ETT) cuff can be easily identified under cervical ultrasound and can serve as an ideal puncture target during percutaneous dilatational tracheostomy (PDT). The authors present their initial experience with this novel technique.

MATERIALS AND METHODS

The records of 38 consecutive critically ill patients who underwent saline-filled cuff puncture PDT between October 2016 and December 2017 were retrospectively reviewed. The saline-filled ETT cuff was easily identified using ultrasound. Ultrasound-guided puncture into the cuff, followed by an inward-push of the ETT through the tube exchanger, facilitated accurate passage of the guidewire through the needle tip into the tracheal lumen.

RESULTS

Of 38 consecutive procedures, 37 (97.4%) were performed successfully, with only one converted to surgical tracheostomy due to guidewire displacement. The median procedure time was 8 min. There were no complications, such as accidental extubation, major bleeding, or posterior tracheal wall laceration or pneumothorax, and no procedure-related mortalities.

CONCLUSIONS

PDT performed using a saline-filled cuff as the ultrasound-guided puncture target and an endotracheal tube exchanger is feasible, and appeared to be easier to perform than standard PDT. Larger studies are required to confirm the safety and benefits of this technique.

[Ultrasound guided airway access]

Ultrasound has increasingly growing applications in anesthesia. This procedure has proven to be a novel, non-invasive and simple technique for the upper airway management, proving to be a useful tool, not only in the operating room but also in the intensive care unit and emergency department. Indeed, over the years mounting evidence has showed an increasing role of ultrasound in airway management. In this review, the authors will discuss the importance of ultrasound in the airway preoperative assessment as a way of detecting signs of difficult intubation or to define the type and/or size of the endotracheal tube as well as to help airway procedures such as endotracheal intubation, cricothyrotomy, percutaneous tracheal intubation, retrograde intubation as well as the criteria for extubation.

Auscultation versus Point-of-care Ultrasound to Determine Endotracheal versus Bronchial Intubation

Background

Unrecognized malposition of the endotracheal tube (ETT) can lead to severe complications in patients under general anesthesia. The focus of this double-blinded randomized study was to assess the accuracy of point-of-care ultrasound in verifying the correct position of the ETT and to compare it with the accuracy of auscultation.

Methods

Forty-two adult patients requiring general anesthesia with ETT were consented. Patients were randomized to right main bronchus, left main bronchus, or tracheal intubation. After randomization, the ETT was placed via fiber-optic visualization. Next, the location of the ETT was assessed using auscultation by a separate blinded anesthesiologist, followed by an ultrasound performed by a third blinded anesthesiologist. Ultrasound examination included assessment of tracheal dilation via cuff inflation with air and evaluation of pleural lung sliding. Statistical analysis included sensitivity, specificity, positive predictive value, negative predictive value, and interobserver agreement for the ultrasound examination (95% CI).

Results

In differentiating tracheal versus bronchial intubations, auscultation showed a sensitivity of 66% (0.39 to 0.87) and a specificity of 59% (0.39 to 0.77), whereas ultrasound showed a sensitivity of 93% (0.66 to 0.99) and specificity of 96% (0.79 to 1). Identification of tracheal versus bronchial intubation was 62% (26 of 42) in the auscultation group and 95% (40 of 42) in the ultrasound group (P = 0.0005) (CI for difference, 0.15 to 0.52), and the McNemar comparison showed statistically significant improvement with ultrasound (P < 0.0001). Interobserver agreement of ultrasound findings was 100%.

Conclusion

Assessment of trachea and pleura via point-of-care ultrasound is superior to auscultation in determining the location of ETT.