Patrick Chow-In Ko

A wireless PDA-based physiological monitoring system for patient transport

This paper proposes a mobile patient monitoring system, which integrates current personal digital assistant (PDA) technology and wireless local area network (WLAN) technology. At the patients location, a wireless PDA-based monitor is used to acquire continuously the patients vital signs, including heart rate, three-lead electrocardiography, and SpO/sub 2/. Through the WLAN, the patients biosignals can be transmitted in real-time to a remote central management unit, and authorized medical staffs can access the data and the case history of the patient, either by the central management unit or the wireless devices. A prototype of this system has been developed and implemented. The system has been evaluated by technical verification, clinical test, and user survey. The evaluation of performance yields a high degree of satisfaction (mean=4.64, standard deviation-SD=0.53 in a five-point Likert scale) of users who used the PDA-based system for intrahospital transport. The results also show that the wireless PDA model is superior to the currently used monitors both in mobility and in usability, and is, therefore, better suited to patient transport.

Outcomes for out-of-hospital cardiac arrests across 7 countries in Asia: The Pan Asian Resuscitation Outcomes Study (PAROS)

BACKGROUND The Pan Asian Resuscitation Outcomes Study (PAROS) Clinical Research Network (CRN) was established in collaboration with emergency medical services (EMS) agencies and academic centers in Japan, Singapore, South Korea, Malaysia, Taiwan, Thailand, and UAE-Dubai and aims to report out-of-hospital cardiac arrests (OHCA) and provide a better understanding of OHCA trends in Asia. METHODS AND RESULTS This is a prospective, international, multi-center cohort study of OHCA across the Asia-Pacific. Each participating country provided between 1.5 and 2.5 years of data from January 2009 to December 2012. All OHCA cases conveyed by EMS or presenting at emergency departments were captured. 66,780 OHCA cases were submitted to the PAROS CRN; 41,004 cases were presumed cardiac etiology. The mean age OHCA occurred varied from 49.7 to 71.7 years. The proportion of males ranged from 57.9% to 82.7%. Proportion of unwitnessed arrests ranged from 26.4% to 67.9%. Presenting shockable rhythm rates ranged from 4.1% to 19.8%. Bystander cardiopulmonary resuscitation (CPR) rates varied from 10.5% to 40.9%, however <1.0% of these arrests received bystander defibrillation. For arrests that were with cardiac etiology, witnessed arrest and VF, the survival rate to hospital discharge varied from no reported survivors to 31.2%. Overall survival to hospital discharge varied from 0.5% to 8.5%. Survival with good neurological function ranged from 1.6% to 3%. CONCLUSIONS Survival to hospital discharge for Asia varies widely and this may be related to patient and system differences. This implies that survival may be improved with interventions such as increasing bystander CPR, public access defibrillation and improving EMS.

Interactive video instruction improves the quality of dispatcher-assisted chest compression-only cardiopulmonary resuscitation in simulated cardiac arrests.

Objective:Bystander cardiopulmonary resuscitation (CPR) significantly improves survival of cardiac arrest victims. Dispatch assistance increases bystander CPR, but the quality of dispatcher-assisted CPR remains unsatisfactory. This study was conducted to assess the effect of adding interactive video communication to dispatch instruction on the quality of bystander chest compressions in simulated cardiac arrests. Design:A randomized controlled study with a scenario developed to simulate cardiac arrest in a public place. Setting:The victim was simulated by a mannequin and the cell phone for dispatch assistance was a video cell phone with both voice and video modes. Chest compression-only CPR instruction was used in the dispatch protocol. Subjects:Ninety-six adults without CPR training within 5 years were recruited. Interventions:The subjects were randomized to receive dispatch assistance on chest compression with either voice instruction alone (voice group, n = 53) or interactive voice and video demonstration and feedback (video group, n = 43) via a video cell phone. Measurements and Main Results:Performance of chest compression-only CPR throughout the scenario was videotaped. The quality of CPR was evaluated by reviewing the videos and mannequin reports. Chest compressions among the video group were faster (median rate 95.5 vs. 63.0 min−1, p < 0.01), deeper (median depth 36.0 vs. 25.0 mm, p < 0.01), and of more appropriate depth (20.0% vs. 0%, p < 0.01). The video group had more “hands-off” time (5.0 vs. 0 second, p < 0.01), longer time to first chest compression (145.0 vs. 116.0 seconds, p < 0.01) and total instruction time (150.0 vs. 121.0 seconds, p < 0.01). Conclusion:The addition of interactive video communication to dispatcher-assisted chest compression-only CPR initially delayed the commencement of chest compressions, but subsequently improved the depth and rate of compressions. The benefit was achieved mainly through real-time feedback.

Impact of Adding Video Communication to Dispatch Instructions on the Quality of Rescue Breathing in Simulated Cardiac Arrests- a Randomized Controlled Study

OBJECTIVE Both ventilations and compressions are important for victims of prolonged cardiopulmonary resuscitation (CPR) and asphyxial arrest. Dispatch assistance increases bystander CPR, but the quality of dispatcher-assisted CPR (DA-CPR), especially rescue breathing, remains unsatisfactory. This study was conducted to assess the impact of adding interactive video communication to dispatch instructions on the quality of rescue breathing in simulated cardiac arrests. METHODS In this simulation-based study, adults without CPR training within 5 years were recruited between April and July 2007 and randomized to receive dispatch assistance with either voice instruction alone (voice group, n=53) or interactive voice and video instruction (video group, n=43) via a video cell phone. The quality of rescue breathing was evaluated by reviewing the videos and mannequin reports. RESULTS Subjects in the video group were more likely to open the airway correctly (95.3% vs. 58.5%, P<0.01) and to lift the chin properly (95.3% vs. 62.3%, P<0.01), but had similar rates of head-tilt (95.3% vs. 84.9%, P=0.10). Volunteers in the video group had larger volume of ventilation (median volume 540 ml vs. 0 ml, P<0.01), greater possibility to sustain an open airway (88.4% vs. 60.4%, P<0.01) and a tendency towards better nose-pinch (97.7% vs. 86.8%, P=0.06). The video group spent longer time to open the airway (59 s vs. 56 s, P<0.05) and to give the first rescue breathing (139 s vs. 102 s, P<0.01). CONCLUSION Adding video communication to dispatch instructions improved the quality of bystander rescue breathing, including higher proportion of airway opened, and larger volume of ventilation delivered, in simulated cardiac arrests.

Detrended fluctuation analysis predicts successful defibrillation for out-of-hospital ventricular fibrillation cardiac arrest

AIMS Repeated failed shocks for ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OOHCA) can worsen the outcome. It is very important to rapidly distinguish between early and late VF. We hypothesised that VF waveform analysis based on detrended fluctuation analysis (DFA) can help predict successful defibrillation. METHODS Electrocardiogram (ECG) recordings of VF signals from automated external defibrillators (AEDs) were obtained for subjects with OOHCA in Taipei city. To examine the time effect on DFA, we also analysed VF signals in subjects who experienced sudden cardiac death during Holter study from PhysioNet, a publicly accessible database. Waveform parameters including root-mean-squared (RMS) amplitude, mean amplitude, amplitude spectrum analysis (AMSA), frequency analysis as well as fractal measurements including scaling exponent (SE) and DFA were calculated. A defibrillation was regarded as successful when VF was converted to an organised rhythm within 5s after each defibrillation. RESULTS A total of 155 OOHCA subjects (37 successful and 118 unsuccessful defibrillations) with VF were included for analysis. Among the VF waveform parameters, only AMSA (7.61+/-3.30 vs. 6.30+/-3.13, P=0.028) and DFAalpha2 (0.38+/-0.24 vs. 0.49+/-0.24, P=0.013) showed significant difference between subjects with successful and unsuccessful defibrillation. The area under the curves (AUCs) for AMSA and DFAalpha2 was 0.63 (95% confidence interval (CI)=0.52-0.73) and 0.65 (95% CI=0.54-0.75), respectively. Among the waveform parameters, only DFAalpha2, SE and dominant frequency showed significant time effect. CONCLUSIONS The VF waveform analysis based on DFA could help predict first-shock defibrillation success in patients with OOHCA. The clinical utility of the approach deserves further investigation.

EMS in Taiwan: Past, present, and future

Abstract Taiwan is a small island country located in East Asia. From around 1995 modern concepts of the EMS were imported and supported by legislation. Considerable progress has since been made towards the construction of an effective pre-hospital care system. This article introduces the current status of the EMS in Taiwan, including the systems, response configurations, funding, personnel, medical directorship, and outcome research. The features and problems of in-hospital emergency care are also discussed. Key areas for further development in the country vary depending on regional differences in available resource and population density. An analysis of the strength, weakness, opportunity, and threats of the evolving EMS in Taiwan could be an example for other countries where the EMS is undergoing a similar process of development and optimisation.

Predictive model of diagnosing probable cases of severe acute respiratory syndrome in febrile patients with exposure risk

Abstract Study objective Since the World Health Organization issued a global alert about severe acute respiratory syndrome (SARS) on March 12, 2003, the illness has become a major public health challenge worldwide. The objective of this study is to identify the clinical risk factors of SARS and to develop a scoring system for early diagnosis. Methods The detailed clinical data of all patients presenting to the emergency department (ED) with a temperature higher than 38.0°C (100.3°F), documented at home or at the ED, and risks of exposure to SARS within 14 days were assessed. The diagnosis of probable SARS was made according to the definition of the Centers for Disease Control and Prevention. Items with significant differences among symptoms, signs, and laboratory tests on presentation between SARS and non-SARS groups were determined and used to develop the scoring system. Results Seventy patients were enrolled and 8 were diagnosed as probably having SARS. None of the initially discharged patients or their relatives developed SARS. Compared with the non-SARS group, the SARS group was younger (33.9±15.9 years versus 44±9.8 years; P=.02), had a higher percentage of fever prolonged more than 5 days (87.5% versus 6.5%; P<.01), myalgia (75% versus 27.4%; P=.01), and diarrhea (50% versus 9.7%; P=.02); had less occurrence of cough before or during fever (0% versus 64.5%; P=.01); and had lower absolute lymphocyte (0.9±0.3×109/L versus 1.5±1.1×109/L; P<.01) and platelet counts (144.1±36.3×109/L versus 211.6±78.8×109/L; P=.02). A 4-item symptom score based on the presence of cough before or concomitant with fever, myalgia, diarrhea, and rhinorrhea or sore throat detects SARS with 100% sensitivity and 75.9% specificity; a 6-item clinical score based on lymphopenia (<1.0×109/L), thrombocytopenia (<150×109/L) and the 4 symptom items detects SARS with 100% sensitivity and 86.3% specificity. Conclusion Certain symptoms and laboratory tests indicate higher risk of febrile probable SARS. In nonendemic areas, the febrile patients with recent contact with SARS or travel history to endemic areas could be screened for the probability of SARS by the use of clinical and symptom scores.

Preventable deaths in patients admitted from emergency department.

Background: There is limited data about how appropriate medical care is in the emergency department (ED). Objectives: To investigate the rate and types of preventable deaths among patients with early mortality after emergency admission from the ED. Methods: We retrospectively reviewed charts of early mortality (defined as mortality which occurred within 24 hours after admission from the ED) over a 3 year period. Those patients with terminal cancer or out of hospital cardiac arrest (OHCA) at presentation were excluded. Two independent assessors reviewed each eligible chart and determined whether early mortality was preventable. Any disagreements were resolved through discussion between the investigators. A mortality event was considered preventable if actions or missed actions were identified that would have prevented the death. The types of preventability were categorised as misdiagnosis, delayed diagnosis, and inappropriate medical management. Interrater reliability in the initial determination was assessed using Cohen κ statistic. Results: Over a 3 year period, 210 early mortality cases were identified. Excluding patients with terminal cancer or OHCA, the rate of preventable deaths was 25.8% (32/124). The types of preventability were inappropriate medical management (17 patients), delayed diagnosis (eight), and misdiagnosis (seven). There was good agreement between assessors with a Cohen κ statistic of 0.81. Conclusions: Preventable deaths in emergency admitted patients with early mortality are not uncommon. Analysis and identification of preventability early mortality by using a chart based method may be used as a quality assurance index in emergency medical care.

Bystander-initiated CPR in an Asian metropolitan: Does the socioeconomic status matter?

OBJECTIVES To determine the association of neighborhood socioeconomic status (SES) with bystander-initiated cardiopulmonary resuscitation (CPR) and patient outcomes of out of hospital cardiac arrests (OHCAs) in an Asian metropolitan area. METHODS We performed a retrospective study in a prospectively collected cohort from the Utstein registry of adult non-traumatic OHCAs in Taipei, Taiwan. Average real estate value was assessed as the first proxy of SES. Twelve administrative districts in Taipei City were categorized into low versus high SES areas to test the association. The primary outcome was bystander-initiated CPR, and the secondary outcome was patient survival status. Factors associated with bystander-initiated CPR were adjusted for in multivariate analysis. The mean household income was assessed as the second proxy of SES to validate the association. RESULTS From January 1, 2008 to December 30, 2009, 3573 OHCAs received prehospital resuscitation in the community. Among these, 617 (17.3%) cases received bystander CPR. The proportion of bystander CPR in low-SES vs. high-SES areas was 14.5% vs. 19.6% (p<0.01). Odds ratio of receiving bystander-initiated CPR in low-SES areas was 0.72 (95% confidence interval: [0.60-0.88]) after adjusting for age, gender, witnessed status, public collapse, and OHCA unrecognized by the online dispatcher. Survival to discharge rate was significantly lower in low-SES areas vs. high-SES areas (4.3% vs. 6.8%; p<0.01). All results above remained consistent in the analyses by mean household income. CONCLUSIONS Patients who experienced an OHCA in low-SES areas were less likely to receive bystander-initiated CPR, and demonstrated worse survival outcomes.

Cost-effectiveness of Different Advanced Life Support Providers for Victims of Out-of-hospital Cardiac Arrests

BACKGROUND/PURPOSE The survival rate of out-of-hospital cardiac arrest (OHCA) is only about 1.4% in Taiwan. The best configuration to achieve optimal outcomes in OHCA is still uncertain for many communities. The purpose of this study was to investigate the cost-effectiveness of two models of providing advanced life support (ALS) services, emergency medical technicians (EMTs) vs. emergency physicians (EPs), in a two-tiered emergency medical services (EMS) system. METHODS This was a prospective, observational, multicenter study comparing ALS provided by EMTs vs. EPs for the management of victims of OHCA. The study population consisted of patients experiencing OHCA of non-traumatic origin in Taipei city, Taiwan, between November 1999 and December 2000, for whom ALS was activated. We performed a cost-effectiveness analysis to determine the economic attractiveness of these two ALS provider programs. The outcome measurements were aggregate costs, survival and incremental cost per life saved. Sensitivity analyses were performed on all variables. RESULTS The expected total cost per OHCA patient was 2,248.19 US