A Cluster-Randomized Control Study Comparing a New Cue "Two Compressions per Second" with "100-120 Compressions per Minute" in Training of Bystander Cardiopulmonary Resuscitation.

BACKGROUND: Chest compression at a rate of 100-120 compressions per minute (cpm) during cardiopulmonary resuscitation (CPR) is associated with the highest survival rates. Performing compressions at a faster rate may exhaust the rescuers. OBJECTIVES: To compare a new cue of 'two compressions per second' to the traditional cue of '100-120 compressions per minute' on compression rate in CPR training. METHODS: In this cluster-randomized study, students from two senior high schools were assigned into two groups. For the experimental group, the cue for the compression rate was 'two compressions per second'. For the control group, the cue was '100-120 cpm'. Except the different cues, all participants underwent the same standardized CPR training program. Verbal compression rate-related feedback was not obtained during practice. Quality indicators of chest compressions were recorded by a sensorized manikin. The primary outcome measure was mean compression rate at course conclusion. The secondary outcome measures were individual compression quality indicators at course conclusion and 3 months after training. RESULTS: We included 164 participants (85 participants, experimental group; 79 participants, control group). Both groups had similar characteristics. The experimental group had a significantly lower mean compression rate at course conclusion (144.3 ± 16.17 vs. 152.7 ± 18.38 cpm, p = 0.003) and at 3 months after training (p = 0.09). The two groups had similar mean percentage of adequate compression rate (≥ 100 cpm), mean compression depth, and mean percentage of complete recoil at course conclusion and 3 months after training. CONCLUSION: The new cue of 'two compressions per second' resulted in participants having a lower compression rate, although it still exceeded 120 cpm.

Sub-ppb level HCN photoacoustic sensor employing dual-tube resonator enhanced clamp-type tuning fork and U-net neural network noise filter.

Hydrogen cyanide (HCN) is a toxic industrial chemical, necessitating low-level detection capabilities for safety and environmental monitoring. This study introduces a novel approach for detecting hydrogen cyanide (HCN) using a clamp-type custom quartz tuning fork (QTF) integrated with a dual-tube acoustic micro-resonator (AmR) for enhanced photoacoustic gas sensing. The design and optimization of the AmR geometry were guided by theoretical simulation and experimental validation, resulting in a robust on-beam QEPAS (Quartz-Enhanced Photoacoustic Spectroscopy) configuration. To boost the QEPAS sensitivity, an Erbium-Doped Fiber Amplifier (EDFA) was incorporated, amplifying the laser power by approximately 286 times. Additionally, a transformer-based U-shaped neural network, a machine learning filter, was employed to refine the photoacoustic signal and reduce background noise effectively. This combination yielded a significantly low detection limit for HCN at 0.89 parts per billion (ppb) with a rapid response time of 1 second, marking a substantial advancement in optical gas sensing technologies. Key modifications to the QTF and innovative use of AmR lengths were validated under various experimental conditions, affirming the system's capabilities for real-time, high-sensitivity environmental monitoring and industrial safety applications. This work not only demonstrates significant enhancements in QEPAS but also highlights the potential for further technological advancements in portable gas detection systems.

Intraosseous versus intravenous vascular access in upper extremity among adults with out-of-hospital cardiac arrest: cluster randomised clinical trial (VICTOR trial).

OBJECTIVE: To compare the effectiveness of intraosseous versus intravenous vascular access in the treatment of adult patients with out-of-hospital cardiac arrest. DESIGN: Cluster randomised controlled trial. SETTING: The VICTOR (Venous Injection Compared To intraOsseous injection during resuscitation of patients with out-of-hospital cardiac arrest) trial involved emergency medical service agencies with all four advanced life support ambulance teams in Taipei City, Taiwan. The enrolment period spanned 6 July 2020 to 30 June 2023 and was temporarily suspended between 20 May 2021 and 31 July 2021 owing to the covid-19 pandemic. PARTICIPANTS: Adult (age 20-80 years) patients with non-traumatic out-of-hospital cardiac arrest. INTERVENTIONS: Biweekly randomised clusters of four participating advanced life support ambulance teams were assigned to insert either intravenous or intraosseous access. MAIN OUTCOME MEASURES: The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation, sustained return of spontaneous circulation (≥2 hours), and survival with favourable neurological outcomes (cerebral performance category score ≤2) at hospital discharge. RESULTS: Among 1771 enrolled patients, 1732 (741 in the intraosseous group and 991 in the intravenous group) were included in the primary analysis (median age 65.0 years; 1234 (71.2%) men). In the intraosseous group, 79 (10.7%) patients were discharged alive, compared with 102 (10.3%) patients in the intravenous group (odds ratio 1.04, 95% confidence interval 0.76 to 1.42; P=0.81). The odds ratio of intraosseous versus intravenous access was 1.23 (0.89 to 1.69; P=0.21) for pre-hospital return of spontaneous circulation, 0.92 (0.75 to 1.13; P=0.44) for sustained return of spontaneous circulation, and 1.17 (0.82 to 1.66; P=0.39) for survival with favourable neurological outcomes. CONCLUSIONS: Among adults with non-traumatic out-of-hospital cardiac arrest, initial attempts to establish vascular access through the intraosseous route did not result in different outcomes compared with intravenous access in terms of the proportion of patients surviving to hospital discharge, pre-hospital return of spontaneous circulation, sustained return of spontaneous circulation, and favourable neurological outcomes. TRIAL REGISTRATION: NCT04135547ClinicalTrials.gov NCT04135547.

Off-plane quartz-enhanced photoacoustic spectroscopy.

In this work, we developed off-plane quartz-enhanced photoacoustic spectroscopy (OP-QEPAS). In the OP-QEPAS the light beam went neither through the prong spacing of the quartz tuning fork (QTF) nor in the QTF plane. The light beam is in parallel with the QTF with an optimal distance, resulting in low background noise. A radial-cavity (RC) resonator was coupled with the QTF to enhance the photoacoustic signal by the radial resonance mode. By offsetting both the QTF and the laser position from the central axis, we enhance the effect of the acoustic radial resonance and prevent the noise generated by direct laser irradiation of the QTF. Compared to IP-QEPAS based on a bare QTF, the developed OP-QEPAS with a RC resonator showed a >10× signal-to-noise ratio (SNR) enhancement. The OP-QEPAS system has great advantages in the use of light emitting devices (LEDs), long-wavelength laser sources such as mid-infrared quantum cascade lasers, and terahertz sources. When employing a LED as the excitation source, the noise level was suppressed by ∼2 orders of magnitude. Furthermore, the radial and longitudinal resonance modes can be combined to further improve the sensor performance.

Development of a prediction model for emergency medical service witnessed traumatic out-of-hospital cardiac arrest: A multicenter cohort study.

BACKGROUND/PURPOSE: To develop a prediction model for emergency medical technicians (EMTs) to identify trauma patients at high risk of deterioration to emergency medical service (EMS)-witnessed traumatic cardiac arrest (TCA) on the scene or en route. METHODS: We developed a prediction model using the classical cross-validation method from the Pan-Asia Trauma Outcomes Study (PATOS) database from 1 January 2015 to 31 December 2020. Eligible patients aged ≥18 years were transported to the hospital by the EMS. The primary outcome (EMS-witnessed TCA) was defined based on changes in vital signs measured on the scene or en route. We included variables that were immediately measurable as potential predictors when EMTs arrived. An integer point value system was built using multivariable logistic regression. The area under the receiver operating characteristic (AUROC) curve and Hosmer-Lemeshow (HL) test were used to examine discrimination and calibration in the derivation and validation cohorts. RESULTS: In total, 74,844 patients were eligible for database review. The model comprised five prehospital predictors: age <40 years, systolic blood pressure <100 mmHg, respiration rate >20/minute, pulse oximetry <94%, and levels of consciousness to pain or unresponsiveness. The AUROC in the derivation and validation cohorts was 0.767 and 0.782, respectively. The HL test revealed good calibration of the model (p = 0.906). CONCLUSION: We established a prediction model using variables from the PATOS database and measured them immediately after EMS personnel arrived to predict EMS-witnessed TCA. The model allows prehospital medical personnel to focus on high-risk patients and promptly administer optimal treatment.

Modified physiologic criteria for the field triage scheme: Efficacy of major trauma recognition in different age groups in Asia.

BACKGROUND: Major trauma is a leading cause of unexpected death globally, with increasing age-adjusted death rates for unintentional injuries. Field triage schemes (FTSs) assist emergency medical technicians in identifying appropriate medical care facilities for patients. While full FTSs may improve sensitivity, step-by-step field triage is time-consuming. A simplified FTS (sFTS) that uses only physiological and anatomical criteria may offer a more rapid decision-making process. However, evidence for this approach is limited, and its performance in identifying all age groups requiring trauma center resources in Asia remains unclear. METHODS: We conducted a multinational retrospective cohort study involving adult trauma patients admitted to emergency departments in the included countries from 2016 to 2020. Prehospital and hospital data were reviewed from the Pan-Asia Trauma Outcomes Study database. Patients aged ≥18 years transported by emergency medical services were included. Patients lacking data regarding age, sex, physiological criteria, or injury severity scores were excluded. We examined the performance of sFTS in all age groups and fine-tuned physiological criteria to improve sFTS performance in identifying high-risk trauma patients in different age groups. RESULTS: The sensitivity and specificity of the physiological and anatomical criteria for identifying major trauma (injury severity score ≥ 16) were 80.6% and 58.8%, respectively. The modified sFTS showed increased sensitivity and decreased specificity, with more pronounced changes in the young age group. Adding the shock index further increased sensitivity in both age groups. CONCLUSIONS: sFTS using only physiological and anatomical criteria is suboptimal for Asian adult patients with trauma of all age groups. Adjusting the physiological criteria and adding a shock index as a triage tool can improve the sensitivity of severely injured patients, particularly in young age groups. A swift field triage process can maintain acceptable sensitivity and specificity in severely injured patients.

Comparing the effects of blended learning and traditional instruction on basic life support for laypersons: A randomized controlled trial.

BACKGROUND/PURPOSE: Blended learning offers the advantages of both instructor-led and self-instruction methods in basic life support (BLS). Our study aims to compare the effects of blended learning with those of traditional instructor-led methods on the performance of laypersons taking BLS courses. METHODS: A total of 108 participants were randomly assigned to three groups: traditional instruction (group A, n = 36), blended learning with two rounds of practice (group B, n = 36), and blended learning with three rounds of practice (group C, n = 36). Group A received a 90-min lecture and a 30-min hands-on practice session using a manikin and a metronome. Participants in groups B and C received 18-min standardized online video lessons and performed hands-on practice twice and thrice, respectively. The primary outcome was chest compression at a correct speed (100-120 compressions per min) after the training course. Secondary outcomes included knowledge test scores, attitudes and confidence, and individual skill performance after training. RESULTS: Patient characteristics were similar between the groups. Blended learning with practicing thrice resulted in the highest compressions at a correct speed (group A vs. B vs. C, 68.09 vs 80.03 vs 89.42, p = 0.015) and the shortest average hands-off time (group A vs. B vs. C, 1.12 vs 0.86 vs 0.17 s, p = 0.015). Both blended groups performed better in confirming environmental safety (p < 0.001). No differences in scores of the knowledge test, attitude, or confidence were noted among the three groups. CONCLUSION: Blended learning with three rounds of hands-on practice may be considered an alternative teaching method.

Ppbv-level mid-infrared photoacoustic sensor for mouth alcohol test after consuming lychee fruits.

A ppbv-level mid-infrared photoacoustic spectroscopy sensor was developed for mouth alcohol tests. A compact CO2 laser with a sealed waveguide and integrated radio frequency (RF) power supply was used. The emission wavelength is ∼9.3 µm with a power of 10 W. A detection limit of ∼18 ppbv (1σ) for ethanol gas with an integration of 1 s was achieved. The sensor performed a linear dynamic range with an R square value of ∼0.999. A breath measurement experiment after consuming lychees was conducted. The photoacoustic signal amplitude decreased with the quality of lychee consumed, confirming the existence of residual alcohol in the mouth. During continuous measurement, the photoacoustic signal decreased in < 10 min when consuming 30 g lychee fruits, proving that the alcohol detected in exhaled breath originated from the oral cavity rather than the bloodstream. This work provided valuable information on the distinction of alcoholism and crime.

Emergency Medical Services in Taiwan: Past, Present, and Future.

This review assessed the development of Taiwan's emergency medical services (EMS) and focused on the optimizing initiatives of the EMS systems, the current state of Taiwan's EMS system, EMS benchmarks in different regions of Taiwan, EMS response during the coronavirus disease 2019 (COVID-19) pandemic, and future design. In the past decade, there has been a noticeable increase in prehospital services, numerous optimizing initiatives to improve patient prognosis, and the medical oversight model. Taiwan's current EMS system, including the dispatch system, out-of-hospital cardiac arrest (OHCA) patient management, time-sensitive critical illness in prehospital settings, and disaster response, has undergone significant improvements. These improvements have been demonstrated to have a measurable impact on patient outcomes, as supported by medical literature. Each region in Taiwan has developed a unique EMS system with local characteristics, such as the implementation of the Global Resuscitation Alliance 10 steps for OHCA-related quality control, hearing automated external defibrillator program, a five-level prehospital triage system, an island-hopping strategy for patients with major trauma, dispatcher-assisted teamwork for OHCA resuscitation, and optimized prehospital care for acute coronary syndrome patients. In response to the COVID-19 pandemic from 2019 to 2023, Taiwan's EMS implemented measures to combat the outbreak such as interagency collaboration to obtain patient's personal information, to optimize prehospital management initiatives, and to provide financial compensation and personal insurance for emergency medical technicians. The areas that need focus include integrating prehospital and in-hospital information to build a national-level database (One-Stop Emergency Management), increasing public awareness of first responders and emergency casualty care, and evolving the EMS system by incorporating private EMS system, initiating school-based education of paramedicine, and legally recognizing paramedics as medical and health care personnel. By improving these areas, we can better prepare for the future and ensure that Taiwan's EMS system continues to provide high-quality care to those in need.

Helmholtz-resonator quartz-enhanced photoacoustic spectroscopy.

In this work, Helmholtz-resonator quartz-enhanced photoacoustic spectroscopy (HR-QEPAS) was developed for trace gas sensing. A pair of Helmholtz resonators with high-order resonance frequency was designed and coupled with a quartz tuning fork (QTF). Detailed theoretical analysis and experimental research were carried out to optimize the HR-QEPAS performance. As a proof-of-concept experiment, the water vapor in the ambient air was detected using a 1.39 µm near-infrared laser diode. Benefiting from the acoustic filtering of the Helmholtz resonance, the noise level of QEPAS was reduced by >30%, making the QEPAS sensor immune to environmental noise. In addition, the photoacoustic signal amplitude was improved significantly by >1 order of magnitude. As a result, the detection signal-to-noise ratio was enhanced by >20 times, compared with a bare QTF.

Quartz-Enhanced Photoacoustic Spectroscopy-Conductance Spectroscopy for Gas Mixture Analysis.

A novel spectroscopic method, named quartz-enhanced photoacoustic spectroscopy-conductance spectroscopy (QEPAS-CS), was first developed for gas mixture analysis. In QEPAS-CS, the advantage of photoacoustic detection and conductance analysis was realized by a quartz tuning fork (QTF). Two-component gas analysis was done by photoacoustic detection and conductance detection. For an explicit application, natural spider silk was used as a water vapor transducer to modify the QTF, making a conductance sensing channel. A 2004 nm laser diode was used as an excitation source for a photoacoustic sensing channel. Such a QEPAS-CS sensor was used for H2O/CO2 gas mixture analysis in a cell incubator. This provides a solution to calibrate an infrared photoacoustic spectroscopy gas sensor. This example effectively confirms the capacity of multigas analysis by the QEPAS-CS sensor.

Epidemiology and Prehospital Care of Pediatric Unintentional Injuries Among Countries with Different Economic Status in Asia: A Cross-National, Multi-Center Observational Study.

OBJECTIVE: Injury is a major cause of morbidity and mortality in children. However, the epidemiology and prehospital care for pediatric unintentional injuries in Asia are still unclear. METHODS: A total of 9,737 pediatric patients aged <18 years with unintentional injuries cared for at participating centers of the Pan-Asian Trauma Outcome Study (PATOS) from October 2015 to December 2020 were reviewed retrospectively. Patients were divided into two groups: those <8 and those ≥8 years of age. Variables such as patient demographics, injury epidemiology, Injury Severity Score (ISS), and prehospital care were collected. Injury severity and administered prehospital care stratified by gross national income were also analyzed. RESULTS: Pediatric unintentional injuries accounted for 9.4% of EMS-transported trauma cases in the participating Asian centers, and the mortality rate was 0.88%. The leading cause of injury was traffic injuries in older children aged ≥8 years (56.5%), while falls at home were common among young children aged <8 years (43.9%). Compared with younger children, older children with similar ISS tended to receive more prehospital interventions. Uneven disease severity was found in that older children in lower-middle and upper-middle-income countries had higher ISS compared with those in high-income countries. The performance of prehospital interventions also differed among countries with different gross national incomes. Immobilizations were the most performed prehospital intervention followed by oxygen administration, airway management, and pain control; only one patient received prehospital thoracentesis. Procedures were performed more frequently in high-income countries than in upper-middle-income and lower-middle-income countries. CONCLUSIONS: The major cause of injury was road traffic injuries in older children, while falls at home were common among young children. Prehospital care in pediatric unintentional injuries in Asian countries was not standardized and might be insufficient, and the economic status of countries may affect the implementation of prehospital care.

Resuscitative Endovascular Balloon Occlusion of the Aorta for Traumatic Cardiopulmonary Arrest in the Emergency Department: The First Case With Successful Return of Spontaneous Circulation in Taiwan.

Exsanguinating torso hemorrhage is a leading cause of death in trauma patients. Bleeding leads to hypothermia, acidosis, and coagulopathy, the so-called "lethal triad," and creates a vicious cycle. Therefore, bleeding control tops the priority list in the management of trauma patients. Placement of resuscitative endovascular balloon occlusion of the aorta (REBOA) in patients with traumatic non-compressible torso hemorrhage is a developing technique in the emergency departments (EDs) in Taiwan, and it is a possible solution for abdominal and pelvic trauma patients with hemodynamic instability. It not only temporarily controls bleeding below the inflation site but also increases cerebral and coronary circulation. It can create a bridge for definitive care such as an operation or an embolization, possibly preventing death. Compared to thoracotomy followed by an aortic cross clamp, REBOA is a less invasive and possibly, a more efficient way to control the hemorrhage and may lead to better overall survival. The use of REBOA has been proven to be associated with improved survival-to-discharge in severely injured trauma patients. We report a case of out-of-hospital cardiac arrest caused by penetrating injury wherein return of spontaneous circulation was successfully achieved after 39-minute cardiopulmonary resuscitation and REBOA placement in the ED. The REBOA balloon was deflated after bleeding was stopped during the laparotomy operation. The patient was then transferred to the intensive care unit for postoperative care. Unfortunately, the patient passed away approximately 12 hours after the surgery.

Using a telemedicine-assisted airway model to improve the communication and teamwork of tracheal intubation during the coronavirus disease 2019 pandemic.

INTRODUCTION: Isolated spaces impair communication and teamwork during tracheal intubation (TI) in suspected coronavirus disease 2019 patients. We thus aimed to evaluate the telemedicine-assisted airway model (TAM) to improve communication and teamwork during the pandemic. METHODS: This two-stage prospective study included adult patients intubated in the emergency department of the National Taiwan University Hospital between 1 August 2020 and 31 July 2021. First, we randomised patients receiving TI in the standard setting into the conventional group (Con-G) and the isolation area into the isolation group (Iso-G). We evaluated the obstacles to communication and teamwork in an isolation scenario. Second, we developed the TAM to facilitate communication and teamwork between staff in separate spaces during TI and assigned patients to the TAM group (TAM-G). Communication and teamwork were evaluated using the Team Emergency Assessment Measure (TEAM). Subjective evaluations were conducted using a questionnaire administered to medical staff. RESULTS: Eighty-nine patients were enrolled: 17, 34, and 38 in the Con-G, Iso-G, and TAM-G, respectively. The communication frequency (CF) of the Con-G and Iso-G was the highest and lowest, respectively. The CF of the TAM-G increased and approached that of the Con-G. The overall TEAM score was the highest in the Con-G and the lowest in the Iso-G, while the overall score in the TAM-G was comparable to that of the Con-G. DISCUSSION: The TAM may improve communication and teamwork for TIs without compromising efficacy during the pandemic. This study was registered at ClinicalTrials.gov; registration numbers: NCT04479332 and NCT04591873.

Spider Silk-Improved Quartz-Enhanced Conductance Spectroscopy for Medical Mask Humidity Sensing.

Spider silk is one of the hottest biomaterials researched currently, due to its excellent mechanical properties. This work reports a novel humidity sensing platform based on a spider silk-modified quartz tuning fork (SSM-QTF). Since spider silk is a kind of natural moisture-sensitive material, it does not demand additional sensitization. Quartz-enhanced conductance spectroscopy (QECS) was combined with the SSM-QTF to access humidity sensing sensitively. The results indicate that the resonance frequency of the SSM-QTF decreased monotonously with the ambient humidity. The detection sensitivity of the proposed SSM-QTF sensor was 12.7 ppm at 1 min. The SSM-QTF sensor showed good linearity of ~0.99. Using this sensor, we successfully measured the humidity of disposable medical masks for different periods of wearing time. The results showed that even a 20 min wearing time can lead to a >70% humidity in the mask enclosed space. It is suggested that a disposable medical mask should be changed <2 h.

Influence of advanced life support response time on out-of-hospital cardiac arrest patient outcomes in Taipei.

BACKGROUND: The association between out-of-hospital cardiac arrest patient survival and advanced life support response time remained controversial. We aimed to test the hypothesis that for adult, non-traumatic, out-of-hospital cardiac arrest patients, a shorter advanced life support response time is associated with a better chance of survival. We analyzed Utstein-based registry data on adult, non-traumatic, out-of-hospital cardiac arrest patients in Taipei from 2011 to 2015. METHODS: Patients without complete data, witnessed by emergency medical technicians, or with response times of ≥ 15 minutes, were excluded. We used logistic regression with an exposure of advanced life support response time. Primary and secondary outcomes were survival to hospital discharge and favorable neurological outcomes (cerebral performance category ≤ 2), respectively. Subgroup analyses were based on presenting rhythms of out-of-hospital cardiac arrest, bystander cardiopulmonary resuscitation, and witness status. RESULTS: A total of 4,278 cases were included in the final analysis. The median advanced life support response time was 9 minutes. For every minute delayed in advanced life support response time, the chance of survival to hospital discharge would reduce by 7% and chance of favorable neurological outcome by 9%. Subgroup analysis showed that a longer advanced life support response time was negatively associated with the chance of survival to hospital discharge among out-of-hospital cardiac arrest patients with shockable rhythm and pulse electrical activity groups. CONCLUSIONS: In non-traumatic, adult, out-of-hospital cardiac arrest patients in Taipei, a longer advanced life support response time was associated with declining odds of survival to hospital discharge and favorable neurologic outcomes, especially in patients presenting with shockable rhythm and pulse electrical activity.

Integrated near-infrared QEPAS sensor based on a 28 kHz quartz tuning fork for online monitoring of CO2 in the greenhouse.

In this paper, a highly sensitive and integrated near-infrared CO2 sensor was developed based on quartz-enhanced photoacoustic spectroscopy (QEPAS). Unlike traditional QEPAS, a novel pilot line manufactured quartz tuning fork (QTF) with a resonance frequency f 0 of 28 kHz was employed as an acoustic wave transducer. A near-infrared DFB laser diode emitting at 2004 nm was employed as the excitation light source for CO2 detection. An integrated near-infrared QEPAS module was designed and manufactured. The QTF, acoustic micro resonator (AmR), gas cell, and laser fiber are integrated, resulting in a super compact acoustic detection module (ADM). Compared to a traditional 32 kHz QTF, the QEPAS signal amplitude increased by > 2 times by the integrated QEPAS module based on a 28 kHz QTF. At atmospheric pressure, a 5.4 ppm detection limit at a CO2 absorption line of 4991.25 cm-1 was achieved with an integration time of 1 s. The long-term performance and stability of the CO2 sensor system were investigated using Allan variance analysis. Finally, the minimum detection limit (MDL) was improved to 0.7 ppm when the integration time was 125 s. A portable CO2 sensor system based on QEPAS was developed for 24 h continuous monitoring of CO2 in the greenhouse located in Guangzhou city. The CO2 concentration variations were clearly observed during day and night. Photosynthesis and respiration plants can be further researched by the portable CO2 sensor system.

Effect of Placement of a Supraglottic Airway Device vs Endotracheal Intubation on Return of Spontaneous Circulation in Adults With Out-of-Hospital Cardiac Arrest in Taipei, Taiwan: A Cluster Randomized Clinical Trial.

Importance: Prehospital advanced airway management with either initial endotracheal intubation (ETI) or initial supraglottic airway (SGA) insertion in patients with out-of-hospital cardiac arrest (OHCA) remains controversial. Objective: To compare the effectiveness of ETI and SGA in patients with nontraumatic OHCA. Design, Setting, and Participants: The Supraglottic Airway Device vs Endotracheal intubation (SAVE) trial was a multicenter cluster randomized clinical trial conducted in Taipei City, Taiwan. Individuals aged 20 years or older who experienced nontraumatic OHCA requiring advanced airway management and were treated by participating emergency medical service agencies were enrolled from November 11, 2016, to December 31, 2019. The final day of follow-up was February 19, 2020. Interventions: Four advanced life support ambulance teams were divided into 2 randomization clusters, with each cluster assigned to either ETI or SGA in a biweekly period. Main Outcomes and Measures: The primary outcome of the SAVE trial was sustained return of spontaneous circulation (ROSC) (≥2 hours) after resuscitation. Secondary outcomes included prehospital ROSC, survival to hospital discharge, and favorable neurologic outcome, defined as a cerebral performance category score less than or equal to 2. Prespecified subgroups and the association between time to advanced airways were explored. Per protocol and intention-to-treat analysis were performed. Results: A total of 936 patients (517 in the ETI group and 419 in the SGA group) were included in the primary analysis (median age, 77 [IQR, 62-85] years; 569 men [60.8%]). The first-attempt airway success rates were 77% with ETI (n = 413) and 83% with SGA (n = 360). Sustained ROSC was 26.9% (n = 139) in the ETI group vs 25.8% (n = 108) in the SGA group. The odds ratio of sustained ROSC was 1.02 (95% CI, 0.98-1.06) in the ETI group vs SGA group. The odds ratio of ETA vs SGA was 1.04 (95% CI, 1.02-1.07) for prehospital ROSC, 1.00 (95% CI, 0.94-1.06) for survival to hospital discharge, and 0.99 (95% CI, 0.94-1.03) for cerebral performance category scores less than or equal to 2. Conclusions and Relevance: In this randomized clinical trial, among patients with OHCA, initial airway management with ETI did not result in a favorable outcome of sustained ROSC compared with SGA device insertion. Trial Registration: ClinicalTrials.gov Identifier: NCT02967952.

High-power near-infrared QEPAS sensor for ppb-level acetylene detection using a 28 kHz quartz tuning fork and 10 W EDFA.

A high-power near-infrared (NIR) quartz enhanced photoacoustic spectroscopy (QEPAS) sensor for part per billion (ppb) level acetylene (C2H2) detection was reported. A 1536 nm distributed feedback (DFB) diode laser was used as the excitation light source. Cooperated with the laser, a C-band 10 W erbium-doped fiber amplifier (EDFA) was employed to boost the optical excitation power to improve QEPAS detection sensitivity. A pilot line manufactured quartz tuning fork (QTF) with a resonance frequency of 28 kHz was used as the photoacoustic transducer. In the case of high excitation power, gas flow effect and temperature effect were found and studied. Benefitting from the low QTF resonance frequency, high excitation power, and vibrational-translational (V-T) relaxation promoter, a detection limit of ∼7 ppb was achieved for C2H2 detection, corresponding to a normalized noise equivalent absorption coefficient of 4.4×10-8cm-1 · W · Hz-1/2.

Ppb-level gas detection using on-beam quartz-enhanced photoacoustic spectroscopy based on a 28 kHz tuning fork.

In this paper, an on-beam quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on a custom quartz tuning fork (QTF) acting as a photoacoustic transducer, was realized and tested. The QTF is characterized by a resonance frequency of 28 kHz, ~15% lower than that of a commercially available 32.7 kHz standard QTF. One-dimensional acoustic micro resonator (AmR) was designed and optimized by using stainless-steel capillaries. The 28 kHz QTF and AmRs are assembled in on-beam QEPAS configuration. The AmR geometrical parameters have been optimized in terms of length and internal diameter. The laser beam focus position and the AmR coupling distance were also adjusted to maximize the coupling efficiency. For comparison, QEPAS on-beam configurations based on a standard QTF and on the 28 kHz QTF were compared in terms of H2O and CO2 detection sensitivity. In order to better characterize the performance of the system, H2O, C2H2 and CO2 were detected for a long time and the long-term stability was analyzed by an Allan variance analysis. With the integration time of 1 s, the detection limits for H2O, C2H2 and CO2 are 1.2 ppm, 28.8 ppb and 2.4 ppm, respectively. The detection limits for H2O, C2H2 and CO2 can be further improved to 325 ppb, 10.3 ppb and 318 ppb by increasing the integration time to 521 s, 183 s and 116 s.