Transtracheal ultrasonographic confirmation of endotracheal intubation using I-gel and an endotracheal tube introducer

BackgroundThis study aimed to investigate the efficacy of transtracheal ultrasonography in confirming the placement of an endotracheal tube introducer during endotracheal intubation using the I-gel supraglottic airway as a guide.MethodsIn this prospective study, endotracheal intubation using an endotracheal tube introducer through the I-gel was performed in patients with return of spontaneous circulation after I-gel insertion for out-of-hospital cardiac arrest. The introducer placement was assessed by the occurrence of hyperechoic artifacts within the trachea or esophagus in transtracheal ultrasonography. Results of ultrasonography were confirmed by waveform capnography in the case of tracheal artifacts and direct visualization by laryngoscopy in the case of esophageal artifacts.ResultsOne hundred and six patients were enrolled in this study. In transtracheal ultrasonography, artifacts of introducer in the trachea and esophagus were observed in 80 (75.5%) and 26 (24.5%) patients, respectively. Transtracheal ultrasonography in identifying the placement of introducers revealed a sensitivity of 100% (95% CI 95.4 to 100), specificity of 96.3% (95% CI 81.0 to 99.9), a PPV of 98.7% (95% CI 92.0 to 99.8), and a NPV of 100% (95% CI 94.8 to 99.9).ConclusionTranstracheal ultrasonography is an accurate method for identifying introducer placement during endotracheal intubation using an endotracheal tube introducer through the I-gel.     

Ultrasound confirmation of endotracheal tube placement

Real-time B-mode ultrasound imaging was performed in 24 intubated patients in order to confirm the correct placement of endotracheal tubes. The large acoustic impedance mismatch between the air within the endotracheal tube cuff and the tracheal wall could be bypassed by (1) use of a foam-cuffed Bivona endotracheal tube, or by (2) cuff inflation with saline instead of air. Optimal repositioning of the endotracheal tube could be done under direct visualization. Imaging of the foam-filled and saline-filled cuffs was easier in the longitudinal (sagittal) than in the transverse view, was enhanced by a slight longitudinal to-and-fro motion of the tube, and was often improved with the use of a stand-off pad. Cases of esophageal intubation were not considered. Use of a noninvasive imaging modality such as ultrasound will spare selected patients from the radiation exposure associated with a chest x-ray. This is of value in pregnant patients and in those requiring frequent chest radiographs for the sole purpose of confirming correct endotracheal tube placement. Limitations of the techniques are discussed.     

Real-time tracheal ultrasonography for confirmation of endotracheal tube placement during cardiopulmonary resuscitation

ObjectiveThis study aimed to evaluate the accuracy of tracheal ultrasonography for assessing endotracheal tube position during cardiopulmonary resuscitation (CPR).MethodsWe performed a prospective observational study of patients undergoing emergency intubation during CPR. Real-time tracheal ultrasonography was performed during the intubation with the transducer placed transversely just above the suprasternal notch, to assess for endotracheal tube positioning and exclude esophageal intubation. The position of trachea was identified by a hyperechoic air–mucosa (A–M) interface with posterior reverberation artifact (comet-tail artifact). The endotracheal tube position was defined as endotracheal if single A–M interface with comet-tail artifact was observed. Endotracheal tube position was defined as intraesophageal if a second A–M interface appeared, suggesting a false second airway (double tract sign). The gold standard of correct endotracheal intubation was the combination of clinical auscultation and quantitative waveform capnography. The main outcome was the accuracy of tracheal ultrasonography in assessing endotracheal tube position during CPR.ResultsAmong the 89 patients enrolled, 7 (7.8%) had esophageal intubations. The sensitivity, specificity, positive predictive value, and negative predictive value of tracheal ultrasonography were 100% (95% confidence interval [CI]: 94.4–100%), 85.7% (95% CI: 42.0–99.2%), 98.8% (95% CI: 92.5–99.0%) and 100% (95% CI: 54.7–100%), respectively. Positive and negative likelihood ratios were 7.0 (95% CI: 1.1–43.0) and 0.0, respectively.ConclusionsReal-time tracheal ultrasonography is an accurate method for identifying endotracheal tube position during CPR without the need for interruption of chest compression. Tracheal ultrasonography in resuscitation management may serve as a powerful adjunct in trained hands.     

Diagnostic utilities of tracheal ultrasound and USB-endoscope for the confirmation of endotracheal tube placement: A cadaver study

Objectives

Confirmation of the endotracheal tube placement (CoETP) has the utmost importance in the management of an airway. Visualization of tracheal rings or carina with a fiber-optical bronchoscope (FOB) has considered to be a reliable method for the CoETP. However, FOB is expensive, time-consuming, and not always practical. Inexpensive endoscopic USB-cameras were shown to aid intubation successfully and reliably. On the other hand, there have been no studies investigating their use for the CoETP. Tracheal ultrasonography (TUS) is also a new, inexpensive and widely available alternative. A cadaver study has planned to evaluate the diagnostic utility of TUS and a USB-camera.

Dead-space reduction and tracheal pressure measurements using a coaxial inner tube in an endotracheal tube

OBJECTIVE: To evaluate the effects on CO(2) washout of the coaxial double lumen tube (DLT) as compared to a standard endotracheal tube (ETT) and tracheal gas insufflation (TGI). Precision of tracheal pressure monitoring through the DLT and safety issues, including intrinsic PEEP (PEEPi) formation during DLT ventilation, were also evaluated. DESIGN: Lung model study. SETTING: University research laboratory. MEASUREMENTS AND RESULTS: CO(2) washout was analysed in a lung model by measuring single alveolar CO(2) concentration during DLT ventilation as compared to standard ETT ventilation, at different minute ventilation (6-14 l/min) and different CO(2)-output levels (180 ml/min, 240 ml/min, and 300 ml/min). At a CO(2) output level of 240 ml/min the CO(2) washout was also compared to tidal volume-adjusted continuous TGI and expiratory synchronised TGI. Precision of tracheal pressure monitoring and PEEPi formation during DLT ventilation was evaluated by comparing pressure in each limb above the tube to reference tracheal pressure, varying I:E ratios (1:2, 1:1, and 2:1), tidal volumes (300-700 ml), breathing frequencies (15-25), and compliance (20-50 ml/cmH(2)O). DLT ventilation had the same efficacy in removing CO(2) as continuous and expiratory synchronised TGI, reducing single alveolar CO(2) concentration by 9-21% compared to normal ventilation. Tracheal pressure could be measured through the DLT with high precision. There was only marginal formation of PEEPi at tidal volumes 相似文献   

A novel airway device with tactile sensing capabilities for verifying correct endotracheal tube placement

We present a new device for verifying endotracheal tube (ETT) position that uses specialized sensors intended to distinguish anatomical features of the trachea and esophagus. This device has the potential to increase the safety of resuscitation, surgery, and mechanical ventilation and decrease the morbidity, mortality, and health care costs associated with esophageal intubation and unintended extubation by potentially improving the process and maintenance of endotracheal intubation. The device consists of a tactile sensor connected to the airway occlusion cuff of an ETT. It is intended to detect the presence or absence of tracheal rings immediately upon inflation of the airway occlusion cuff. The initial study detailed here verifies that a prototype device can detect contours similar to tracheal rings in a tracheal model.     

The assessment of three methods to verify tracheal tube placement in the emergency setting

We studied prospectively the reliability of clinical methods, end-tidal carbon dioxide (ETCO(2)) detection, and the esophageal detector device (EDD) for verifying tracheal intubation in 137 adult patients in the emergency department. Immediately after intubation, the tracheal tube position was tested by the EDD and ETCO(2) monitor, followed by auscultation of the chest. The views obtained at laryngoscopy were classified according to the Cormack grade. Of the 13 esophageal intubations that occurred, one false-positive result occurred in the EDD test and auscultation. In the non-cardiac arrest patients (n=56), auscultation, the ETCO(2), and EDD test correctly identified 89.3, 98.2*, and 94.6%* of tracheal intubations, respectively (*, P<0.05 vs. the cardiac arrest patients). In the cardiac arrest patients (n=81), auscultation, the ETCO(2), and the EDD tests correctly identified 92.6**, 67.9, and 75.3% of tracheal intubations, respectively (**, P<0.05 vs. EDD and ETCO(2)). The frequencies of Cormack grade 1 or 2 were 83.9% in the non-cardiac arrest, and 95.1% in the cardiac arrest patients. In conclusion, the ETCO(2) monitor is the most reliable method for verifying tracheal intubation in non-cardiac arrest patients. During cardiac arrest and cardiopulmonary resuscitation, however, negative results by the ETCO(2) or the EDD are not uncommon, and clinical methods are superior to the use of these devices.