Wen-Chu Chiang

Comparison of Both Clinical Features and Mortality Risk Associated with Bacteremia due to Community-Acquired Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus

BACKGROUND The majority of research about community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection has focused on skin and soft-tissue infections. No literature has been published on the clinical features and outcomes of adult patients with CA-MRSA bacteremia in comparison with patients with community-acquired methicillin-susceptible S. aureus (CA-MSSA) bacteremia. METHODS From 1 January 2001 through 31 December 2006, the demographic data and outcome of 215 consecutive adult patients admitted to a tertiary care center in Taiwan with S. aureus bacteremia (age, >16 years) who fulfilled the criteria for community-acquired S. aureus bacteremia were collected for analysis. RESULTS The mean age (+/-SD) was 56.8+/-20.5 years. There were 30 patients (14%) with CA-MRSA bacteremia and 185 (86%) patients with CA-MSSA bacteremia. Cutaneous abscess (odds ratio, 5.46; 95% confidence interval, 1.66-17.94) and necrotizing pneumonia (odds ratio, 24.81; 95% confidence interval, 2.63-234.03) were the independent predictors of CA-MRSA bacteremia; endovascular infection was the only independent predictor of CA-MSSA bacteremia. After Cox regression analysis, the independent significant risk factors for 30-day mortality included increased age, shock, and thrombocytopenia (<100,000 cells/microL). After adjustment, the day 30 mortality of patients with CA-MRSA bacteremia was not significantly higher than that of patients with CA-MSSA bacteremia (adjusted hazard ratio, 1.01; 95% confidence interval, 0.30-3.39; P = .986). Most (92%) of 25 available CA-MRSA isolates were multilocus sequence typing 59. CONCLUSIONS The number of adult patients with CA-MRSA bacteremia increased with time, and the disease was associated with more necrotizing pneumonia and cutaneous abscess but less endovascular infection than was CA-MSSA bacteremia. Patients with CA-MRSA bacteremia did not have higher mortality than did patients with CA-MSSA, even though most of the patients with CA-MRSA bacteremia did not receive empirical glycopeptide therapy.

A systematic review of retention of adult advanced life support knowledge and skills in healthcare providers

OBJECTIVE Advanced life support (ALS) guidelines are widely adopted for healthcare provider training with recommendations for retraining every two years or longer. This systematic review studies the retention of adult ALS knowledge and skills following completion of an ALS course in healthcare providers. METHODS We retrieved original articles using Medline, CINAHL, Cochrane Library, and PubMed, and reviewed reference citations to identify additional studies. We extracted data from included articles using a structured approach and organized outcomes by evaluation method, and knowledge and skills retention. RESULTS Among 336 articles retrieved, 11 papers were included. Most studies used multiple-choice questionnaires to evaluate knowledge retention and cardiac arrest simulation or other skills tests to evaluate skills retention. All studies reported variable rates of knowledge or skills deterioration over time, from 6 weeks to 2 years after training. Two studies noted retention of knowledge at 18 months and up to 2 years, and one reported skills retention at 3 months. Clinical experience, either prior to or after the courses, has a positive impact on retention of knowledge and skills. CONCLUSION There is a lack of large well-designed studies examining the retention of adult ALS knowledge and skills in healthcare providers. The available evidence suggests that ALS knowledge and skills decay by 6 months to 1 year after training and that skills decay faster than knowledge. Additional studies are needed to help provide evidence-based recommendations for assessment of current knowledge and skills and need for refresher training to maximize maintenance of ALS competency.

Effect of different resuscitation fluids on cytokine response in a rat model of hemorrhagic shock

This study was designed to determine the effects of different resuscitation fluids on the production of proinflammatory and anti-inflammatory cytokines in an animal model of hemorrhagic shock. Wistar male rats (n = 24; 8/group) were subjected to a volume-controlled hemorrhagic shock for 30 minutes and resuscitated as follows: (1) sham group without resuscitation, (2) lactated Ringer solution (LR), 3:1; (3) 4% hydroxyethyl starch (HES) solution, 1:1; and (4) 4% modified fluid gelatin (GEL), 1:1. Hemodynamic parameters were recorded, and blood samples were collected at 0 min and 30, 90, 150, 210, 270, and 330 min after hemorrhage for plasma levels of IL-6, IL-10, and TNFα. The circulating concentrations of IL-6 at 90, 150, 210, 270, and 330 min and TNFα levels at 150, 210, and 270 min after hemorrhage were significantly elevated in animals resuscitated with GEL compared with HES or LR (P < 0.05). At 210, 270, and 330 min, IL-10 concentration was decreased significantly in GEL-resuscitated rats compared with rats resuscitated with LR or HES (P < 0.05). Mean blood pressure and serum levels of lactate after resuscitation were not different among three kinds of fluids. LR, HES, and GEL are comparable in volume efficacy for resuscitation of hemorrhagic shock but are associated with different postresuscitation immune responses. Resuscitation with GEL may be associated with cytokine production favoring a proinflammatory response. The marked elevation of IL-6 observed in the GEL-treated animals may play a role in the relatively high frequency of anaphylactoid reaction in clinical use of GEL.

Detection of SARS-associated Coronavirus in Throat Wash and Saliva in Early Diagnosis

Early detection of SARS-CoV in throat wash and saliva suggests that these specimens are ideal for SARS diagnosis.

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.

Methicillin-Resistant Staphylococcus aureus (MRSA) Staphylococcal Cassette Chromosome mec Genotype Effects Outcomes of Patients With Healthcare-Associated MRSA Bacteremia Independently of Vancomycin Minimum Inhibitory Concentration

BACKGROUND Recent evidence has shown that community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is less virulent than traditional hospital-associated MRSA. We explored whether the antimicrobial susceptibilities of the different strains account for their disparity in clinical virulence. METHODS This 10-year retrospective cohort study enrolled 291 patients with community-onset, healthcare-associated MRSA bacteremia. The vancomycin minimum inhibitory concentration (MIC) and staphylococcal cassette chromosome mec (SCCmec) type were determined for all isolates. CA-MRSA was defined as an isolate possessing the SCCmec type IV or V genes, and hospital-associated MRSA (HA-MRSA) was defined as an isolate possessing SCCmec type I, II, or III genes. Low and high vancomycin MICs were defined as MICs of ≤1 and ≥2 μg/mL, respectively. Patients with bacteremia due to CA-MRSA with a low vancomycin MIC (n = 111), due to HA-MRSA with a low vancomycin MIC (n = 127), or due to HA-MRSA with a high vancomycin MIC (n = 47) entered the outcome analysis. The outcomes of the 2 HA-MRSA bacteremia groups were compared to those of the CA-MRSA bacteremia group. RESULTS Treatment failure was observed in 35 (31.5%), 59 (46.5%), and 27 (57.4%) of patients with low-vancomycin-MIC CA-MRSA, low-vancomycin-MIC HA-MRSA, and high-vancomycin-MIC HA-MRSA bacteremia, respectively. After adjustment for potential confounding factors, the risk of treatment failure was significantly higher among patients with low-vancomycin-MIC HA-MRSA (adjusted odds ratio [aOR], 1.853; 95% confidence interval [CI], 1.006-3.413) and high-vancomycin-MIC HA-MRSA (aOR, 2.393; 95% CI, 1.079-5.309), compared with patients with low-vancomycin-MIC CA-MRSA. CONCLUSIONS The higher risk for treatment failure among patients with traditional hospital-associated MRSA infections, compared with patients with CA-MRSA infections, is independent of the vancomycin MIC, suggesting a potential intrinsic strain-specific virulence effect.

Application of Tele-Ultrasound in Emergency Medical Services

In emergency medical services, portable ultrasound scanners have the potential to become new-age stethoscopes for emergency physicians. For trauma cases in particular, portable ultrasound scanners can scan the chest and abdomen of emergency patients both rapidly and conveniently. This study describes the development of tele-ultrasound for pre-diagnosis in a medical emergency setting as a part of the updated Mobile Hospital Emergency Medical System (MHEMS). An emergency medical technician can provide an emergency physician with a patients ultrasound images and medical information during the patients pre-hospitalization and transportation period using a combination of the MHEMS, the portable ultrasound scanner, and the onboard 3G communication capabilities. The MHEMS includes a Dispatch and Mission Control Center that facilitates the communication between the Emergency Department of a specified hospital, the systems aboard the ambulance. Early receipt of information relevant to the patient will enhance pre-diagnosis options for on-duty emergency physicians and allow for a hospitals emergency department to promptly prepare necessary surgical instruments or beds. Furthermore, emergency medical technicians can also obtain instructions from on-duty physicians to enhance damage and disaster control ability in critical moments.