Kah-Meng Chong

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

OBJECTIVE This study aimed to evaluate the accuracy of tracheal ultrasonography for assessing endotracheal tube position during cardiopulmonary resuscitation (CPR). METHODS We 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. RESULTS Among 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. CONCLUSIONS Real-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.

Ultrasonographic lung sliding sign in confirming proper endotracheal intubation during emergency intubation.

AIM OF STUDY Unrecognized one-lung intubations (also known as main-stem intubation) can lead to hypoventilation, atelectasis, barotrauma, and even patient death. Many traditional methods can be employed to detect one-lung intubation; however, each of these methods has limitations and is not consistently reliable in emergency settings. This study aimed to assess the accuracy and timeliness of ultrasound to confirm proper endotracheal intubation. METHODS This was a prospective, single-center, observational study conducted at the emergency department of a national university teaching hospital. Patients received emergency tracheal intubation because of respiratory failure or cardiac arrest. After intubation, bedside ultrasound was performed with a transducer placed on the chest bilaterally at the mid-axillary line, to identify lung sliding over the lungs bilaterally during ventilation. Chest radiography was used as the criterion standard for confirmation of endotracheal tube position. RESULTS One hundred and fifteen patients needing tracheal intubation were included, and nine (7.8%) had one-lung intubations. The overall accuracy of ultrasound to confirm proper endotracheal intubation was 88.7% (95% confidence interval (CI): 81.6-93.3%). The positive predictive value was 94.7% (95% CI: 87.1-97.9%) in the non-cardiac-arrest group and 100% (95% CI: 87.1-100.0%) in the cardiac-arrest group. The median operating time of ultrasound was 88 s (interquartile range [IQR]: 55.0, 193.0), and of chest radiography was 1349 s (IQR: 879.0, 2221.0) post intubation. CONCLUSIONS In this study, the positive predictive value of bilateral lung sliding in confirming proper endotracheal intubation was high, especially among patients with cardiac arrest. Considerable time advantage of ultrasound over chest radiography was demonstrated.

The Effect of Successful Intubation on Patient Outcomes After Out-of-Hospital Cardiac Arrest in Taipei

Study objective: The effect of out‐of‐hospital intubation in patients with out‐of‐hospital cardiac arrest remains controversial. The Taipei City paramedics are the earliest authorized to perform out‐of‐hospital intubation among Asian areas. This study evaluates the association between successful intubation and out‐of‐hospital cardiac arrest survival in Taipei. Methods: We analyzed 6 years of Utstein‐based registry data from nontrauma adult patients with out‐of‐hospital cardiac arrest who underwent out‐of‐hospital airway management including intubation, laryngeal mask airway, or bag‐valve‐mask ventilation. The primary analysis was intubation success on patient outcomes. The primary outcome was survival to discharge and the secondary outcomes included sustained return of spontaneous circulation and favorable neurologic survival. Sensitivity analysis was performed with intubation attempts rather than intubation success. Subgroup analysis of advanced life support–serviced districts was also performed. Results: A total of 10,853 cases from 2008 to 2013 were analyzed. Among out‐of‐hospital cardiac arrest patients receiving airway management, successful intubation, laryngeal mask airway, and bag‐valve‐mask ventilation was reported in 1,541, 3,099, and 6,213 cases, respectively. Compared with bag‐valve‐mask device use, successful out‐of‐hospital intubation was associated with improved chances of sustained return of spontaneous circulation (adjusted odds ratio [aOR] 1.91; 95% confidence interval [CI] 1.66 to 2.19), survival to discharge (aOR 1.98; 95% CI 1.57 to 2.49), and favorable neurologic outcome (aOR 1.44; 95% CI 1.03 to 2.03). The results were comparable in sensitivity and subgroup analyses. Conclusion: In nontrauma adult out‐of‐hospital cardiac arrest in Taipei, successful out‐of‐hospital intubation was associated with improved odds of sustained return of spontaneous circulation, survival to discharge, and favorable neurologic outcome.

Ultrasonography for proper endotracheal tube placement confirmation in out-of-hospital cardiac arrest patients: two-center experience

Among the 96 patients enrolled, 7 (7.3%) had esophageal intubations. The sensitivity, specificity, positive predictive value, and negative predictive value of tracheal ultrasonography were 98.9% (95% confidence interval [CI]: 94.0-99.8%), 100% (95% CI: 61-100.0%), 100% (95% CI: 95.9-100.0%) and 85.7% (95% CI: 48.7-97.4%), respectively. Positive and negative likelihood ratios were 7.0 (95% CI: 1.1-43.0) and 0.0, respectively.

US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation: Validation and potential impact

BACKGROUND We previously developed a US-CAB protocol for evaluation of circulatory-airway-breathing status during cardiopulmonary resuscitation (CPR). This study aimed at validating its application in real CPR scenarios and the potential impact on CPR outcomes. METHODS The US-CAB protocol was implemented at the emergency department of National Taiwan University Hospital since January 2016. The US images, initiation time and operation duration of each US-CAB procedure, and relevant CPR information were recorded for analysis. RESULTS From January 2016 to March 2017, 177 cardiac arrest patients receiving US-CAB were included. The durations of US-C-A-B procedure were 9.0 ± 1.4, 7.5 ± 1.5, and 16.0 ± 1.9 s, respectively. Cardiac activity was identified in 47 cases (26.6%), with higher rates of return of spontaneous circulation (ROSC) (95.7% vs. 21.5%, p < .0001) and survival to hospital discharge (25.5% vs. 10.0%, p < .01). Detection of cardiac activity after 10 min of CPR exhibited 100% sensitivity, specificity, positive and negative predictive value for ROSC. Cardiac tamponade was noted in eight patients. ROSC was achieved in two (25.0%) after pericardiocentesis, and aortic dissection was diagnosed in one (12.5%). Confirmation of correct intubation was significantly faster by US than by capnography (7.4 ± 1.4 vs. 38.3 ± 110.2 s, p < .001). US detected 21 (11.9%) esophageal intubations and 3 (1.7%) one-lung intubations. All were promptly corrected. CONCLUSION The US-CAB protocol is feasible in real CPR scenarios. It confers diagnostic value and prognostic implications which potentially impact the efficacy and outcomes of CPR. However, a future prospective multi-center study to validate its feasibility and indicate the need of structured training is mandated.

Public knowledge, attitudes and willingness regarding bystander cardiopulmonary resuscitation: A nationwide survey in Taiwan

BACKGROUND A low bystander cardiopulmonary resuscitation (CPR) rate is one of the factors associated with low cardiac arrest survival. This study aimed to assess knowledge, attitudes, and willingness towards performing CPR and the barriers for implementation of bystander-initiated CPR. METHODS Telephone interviews were conducted using an author-designed and validated structured questionnaire in Taiwan. After obtaining a stratified random sample from the census, the results were weighted to match population data. The factors affecting bystander-initiated CPR were analysed using logistic regression. RESULTS Of the 1073 respondents, half of them stated that they knew how to perform CPR correctly, although 86.7% indicated a willingness to perform CPR on strangers. The barriers to CPR performance reported by the respondents included fear of legal consequences (44%) and concern about harming patients (36.5%). Most participants expressed a willingness to attend only an hour-long CPR course. Respondents who were less likely to indicate a willingness to perform CPR were female, healthcare providers, those who had no cohabiting family members older than 65 years, those who had a history of a stroke, and those who expressed a negative attitude toward CPR. CONCLUSION The expressed willingness to perform bystander CPR was high if the respondents possessed the required skills. Attempts should be made to recruit potential bystanders for CPR courses or education, targeting those respondent subgroups less likely to express willingness to perform CPR. The reason for lower bystander CPR willingness among healthcare providers deserves further investigation.

Data on evaluation of proficiency for the US-CAB curriculum

Data presented in this article relates to the research article entitled “US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation: validation and potential impact” (Lien et al., in press). The article provides data regarding proficiency of the 10 emergency residents attending the US-CAB curriculum. Assessments included immediate evaluation at the end of training and re-evaluation 6 months later. A written test, and the ultrasound image acquisition were required in the immediate evaluation The re-evaluation included the written test and performance on the same healthy volunteer.