- Email: [email protected]
Hands-on defibrillation: How well would medical examination gloves protect rescuers from defibrillation voltages?
Abstracts / Resuscitation 81S (2010) S1–S114 References 1. Berger RD, Palazzolo J, Halperin H. Rhythm discrimination during uninterrupted CPR using motion artefact reduction system. Resuscitation 2007;75:145–52. 2. Wik L, Kramer-Johansen J, Myklebust H, et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. JAMA 2005;293:299–304. 3. Worksheetfor Evidence-Based Review of Science for Emergency Cardiac Care BLS-039. http://www.americanheart.org/presenter.jhtml?identifier=3070881.
S15
the primary analysis group. Based on the AED randomization, 262/540 patients were given two minutes of CPR prior to defibrillation and 278/540 patients were treated with a shockfirst protocol. The initial VF score was highly predictive (p < 0.001) for survival to hospital discharge overall. For subjects below threshold, no significant differences were identified between the shock-first and CPR-first protocols for ROSC (27% vs. 29%, p = 0.57), sustained ROSC (20% vs. 22%, p = 0.75), and survival to admission (23% vs. 22%, p = 1.00) or discharge (7% vs. 7%, p = 1.00). Conclusions: Initial VF score is highly predictive for subsequent survival to hospital discharge. However, its use to guide initial CPR treatment for patients with low quality VF did not alter survival.
doi:10.1016/j.resuscitation.2010.09.070 doi:10.1016/j.resuscitation.2010.09.072 AS055 AS057 Hands-on defibrillation: How well would medical examination gloves protect rescuers from defibrillation voltages? Sullivan J.L., Chapman F.W.
Takahashi H. 1 , Tanaka H. 1 , Takyu H. 2 , Kaneko H. 3
Physio-Control, Redmond, WA, USA Purpose: Hands-on defibrillation can reduce pauses in chest compressions during CPR, but how safe is it? Common biphasic defibrillation shocks range from 1400 to 2800 V; monophasic defibrillators can go to 5000 V. Safety of a rescuer contacting the patient during these shocks is determined by (1) the fraction of the shock voltage presented to the rescuer, and (2) the breakdown voltage of the rescuer’s gloves. Neither has been adequately investigated. We determined the electrical breakdown voltage for medical examination gloves. Methods: We used a dielectric analyzer to apply an increasing voltage ramp to each glove until an electrical arc occurred, current flow exceeded a pre-defined limit, or 5000 V was reached. Four glove polymers were tested in single-layer and double-layer configurations with current limits of 0.1 mA (based on existing leakage current standards) or 10 mA (threshold for glove breakdown and significant injury potential) for a total of 320 measurements. Results: Glove breakdown voltages minimum, median, n Polymer Latex Chloroprene Nitrile Vinyl
Single layer 0.1mA 3000 V, 5000 V, 40 2250 V, 2986 V, 40 811 V, 1575 V, 40 604 V, 972 V, 40
Biphasic AED or mono-phasic AED? Which is effective on OHCA patients outcome: An nationwide population-based, observational study
Double layer 10mA 2502 V, 4252 V, 20 2998 V, 3321 V, 20 1745 V, 3221 V, 20 1873 V, 3995 V, 20
0.1 mA – – 2092 V, 2453 V, 40 789 V, 965 V, 40
Of the single gloves tested, 0% latex, 29% chloroprene, 100% nitrile and 100% vinyl gloves exceeded leakage current standards at or below 2800 V. In addition, 10% latex, 0% chloroprene, 8% nitrile, and 8% vinyl gloves permitted current levels that could allow significant rescuer injury. Conclusions: The voltages at which leakage current standards were exceeded or electrical breakdown occurred varied considerably between glove types. The other factor affecting safety, the fraction of shock voltage presented to the rescuer, may be difficult to assess. Until this fraction is firmly established it may be prudent to use gloves designed to withstand the maximum defibrillator output voltage.
1 Graduate
school of Emergency Medical System, Kokushikan University, Tama, Japan Department of Rehabilitation, Chubu Gakuin University, Seki, Japan 3 Nagoya City Fire Department, Nagoya, Japan 2
Background: Biphasic automated external defibrillator (AED) has been reported to be better defibrillation waveform than mono-phasic AED. However, those two AEDs are still equally used for out-of-hospital cardiac arrest (OHCA) patients in Japan. Thus, it remains unclear whether biphasic AED improves outcomes or not. Objective: To compare the effectiveness of a biphasic AED with a mono-phasic AED on witnessed OHCA due to ventricular fibrillation. Materials and methods: From January 1, 2007 through December 31, 2008, a total of 14,950 OHCA patients were extracted from nationwide Utstein style database. Exclusion criteria: Patients younger than 18 and older than 120 of age. Endpoint: The primary outcome measure was 1-month survival with good neurologic outcome (CPC 1 or 2) and secondary outcome was return of spontaneous circulation (ROSC) before arriving at hospital. Statistical analysis: Propensity score and conditional logistic regression modeling technique were used to calculate the relative risk (RR) of biphasic waveform over monophasic waveform, adjusting for potential confounders including witness status of the arrest, bystander cardiopulmonary resuscitation, initial ECG rhythm, and call-response interval. Results: 14,950 VF OHCA patients extracted from over all data. Termination of VF with first shock in 2246/6022 patients (37.3%) in the biphasic AED and 469/1251 patients (37.5%) in the mono-phasic AED. The propensity score matching yielded 682 matched pairs. A RR (95%CI) of biphasic waveform for the CPC score at 1-month post-arrest was 1.22 (0.91–1.63) and a RR (95%CI) of biphasic waveform for the ROSC was 1.25 (0.98–1.59). Discussion: There were no statistically significant differences between biphasic and mono-phasic AED waveform defibrillation on the patients neurologic outcome and ROSC. Conclusion: Our results suggest that, regardless waveform type of the AED, It is important to increase the number of AED installed and increase number of bystander CPR. doi:10.1016/j.resuscitation.2010.09.073
doi:10.1016/j.resuscitation.2010.09.071 AS056 Can waveform analysis-guided treatment (shock-first versus CPR first) improve survival among patients with low quality VF? Results of an international prospective double-blinded randomised controlled trial Freese J.P. 1,2 , Jorgenson D.B. 3 , Liu P. 4 , Innes J. 5 , Matallana L. 1 , Nammi K. 3 , Donohoe R.T. 5 , Whitbread M. 5 , Silverman R.A. 1,6 , Kaufman B.J. 1,6 , Isaacs D.A. 1,6 , Prezant D.J. 1 1 Office
of Medical Affairs, Fire Department of New York (FDNY), New York, NY USA Department of Emergency Medicine, Emergency Medical Associates LLC / Hudson Valley Hospital, Cortlandt Manor, NY USA 3 Philips Healthcare, Seattle, WA USA 4 Fred Hutchinson Cancer Research Center, Seattle, WA USA 5 London Ambulance Service, London, England UK 6 Department of Emergency Medicine, North Shore – Long Island Jewish Medical Center, New Hyde Park, NY USA 2
Purpose: The 2005 American Heart Association Guidelines noted the potential use of ventricular fibrillation (VF) waveform analysis to “include prediction of success of cardioversion. . . and optimization of timing of defibrillation relative to CPR and medication delivery.”1 This prospective double-blinded randomized controlled trial was designed to assess the use of a VF waveform analysis algorithm to improve survival. Methods: Out-of-hospital cardiac arrest (OOHCA) patients from two large metropolitan EMS systems were treated with automated external defibrillators (AEDs) randomized to a universal shock-first or VF waveform analysis protocol. Study inclusion was limited to presenting VF of primary cardiac aetiology. VF waveform characteristics were used to calculate a novel score representing VF quality. Patients whose score was below a predefined threshold received either immediate defibrillation or a 2-min period of CPR prior to defibrillation based on AED randomization. The primary outcome was survival to hospital discharge. Results: Between May 5, 2006 and June 30, 2009, a total of 6738 OOHCA patients were enrolled. 5751 patients were excluded, the majority (85%) due to a non-VF presenting rhythm. Of the 987 included cases, 540 (54.7%) presented below threshold and comprised
S15
the primary analysis group. Based on the AED randomization, 262/540 patients were given two minutes of CPR prior to defibrillation and 278/540 patients were treated with a shockfirst protocol. The initial VF score was highly predictive (p < 0.001) for survival to hospital discharge overall. For subjects below threshold, no significant differences were identified between the shock-first and CPR-first protocols for ROSC (27% vs. 29%, p = 0.57), sustained ROSC (20% vs. 22%, p = 0.75), and survival to admission (23% vs. 22%, p = 1.00) or discharge (7% vs. 7%, p = 1.00). Conclusions: Initial VF score is highly predictive for subsequent survival to hospital discharge. However, its use to guide initial CPR treatment for patients with low quality VF did not alter survival.
doi:10.1016/j.resuscitation.2010.09.070 doi:10.1016/j.resuscitation.2010.09.072 AS055 AS057 Hands-on defibrillation: How well would medical examination gloves protect rescuers from defibrillation voltages? Sullivan J.L., Chapman F.W.
Takahashi H. 1 , Tanaka H. 1 , Takyu H. 2 , Kaneko H. 3
Physio-Control, Redmond, WA, USA Purpose: Hands-on defibrillation can reduce pauses in chest compressions during CPR, but how safe is it? Common biphasic defibrillation shocks range from 1400 to 2800 V; monophasic defibrillators can go to 5000 V. Safety of a rescuer contacting the patient during these shocks is determined by (1) the fraction of the shock voltage presented to the rescuer, and (2) the breakdown voltage of the rescuer’s gloves. Neither has been adequately investigated. We determined the electrical breakdown voltage for medical examination gloves. Methods: We used a dielectric analyzer to apply an increasing voltage ramp to each glove until an electrical arc occurred, current flow exceeded a pre-defined limit, or 5000 V was reached. Four glove polymers were tested in single-layer and double-layer configurations with current limits of 0.1 mA (based on existing leakage current standards) or 10 mA (threshold for glove breakdown and significant injury potential) for a total of 320 measurements. Results: Glove breakdown voltages minimum, median, n Polymer Latex Chloroprene Nitrile Vinyl
Single layer 0.1mA 3000 V, 5000 V, 40 2250 V, 2986 V, 40 811 V, 1575 V, 40 604 V, 972 V, 40
Biphasic AED or mono-phasic AED? Which is effective on OHCA patients outcome: An nationwide population-based, observational study
Double layer 10mA 2502 V, 4252 V, 20 2998 V, 3321 V, 20 1745 V, 3221 V, 20 1873 V, 3995 V, 20
0.1 mA – – 2092 V, 2453 V, 40 789 V, 965 V, 40
Of the single gloves tested, 0% latex, 29% chloroprene, 100% nitrile and 100% vinyl gloves exceeded leakage current standards at or below 2800 V. In addition, 10% latex, 0% chloroprene, 8% nitrile, and 8% vinyl gloves permitted current levels that could allow significant rescuer injury. Conclusions: The voltages at which leakage current standards were exceeded or electrical breakdown occurred varied considerably between glove types. The other factor affecting safety, the fraction of shock voltage presented to the rescuer, may be difficult to assess. Until this fraction is firmly established it may be prudent to use gloves designed to withstand the maximum defibrillator output voltage.
1 Graduate
school of Emergency Medical System, Kokushikan University, Tama, Japan Department of Rehabilitation, Chubu Gakuin University, Seki, Japan 3 Nagoya City Fire Department, Nagoya, Japan 2
Background: Biphasic automated external defibrillator (AED) has been reported to be better defibrillation waveform than mono-phasic AED. However, those two AEDs are still equally used for out-of-hospital cardiac arrest (OHCA) patients in Japan. Thus, it remains unclear whether biphasic AED improves outcomes or not. Objective: To compare the effectiveness of a biphasic AED with a mono-phasic AED on witnessed OHCA due to ventricular fibrillation. Materials and methods: From January 1, 2007 through December 31, 2008, a total of 14,950 OHCA patients were extracted from nationwide Utstein style database. Exclusion criteria: Patients younger than 18 and older than 120 of age. Endpoint: The primary outcome measure was 1-month survival with good neurologic outcome (CPC 1 or 2) and secondary outcome was return of spontaneous circulation (ROSC) before arriving at hospital. Statistical analysis: Propensity score and conditional logistic regression modeling technique were used to calculate the relative risk (RR) of biphasic waveform over monophasic waveform, adjusting for potential confounders including witness status of the arrest, bystander cardiopulmonary resuscitation, initial ECG rhythm, and call-response interval. Results: 14,950 VF OHCA patients extracted from over all data. Termination of VF with first shock in 2246/6022 patients (37.3%) in the biphasic AED and 469/1251 patients (37.5%) in the mono-phasic AED. The propensity score matching yielded 682 matched pairs. A RR (95%CI) of biphasic waveform for the CPC score at 1-month post-arrest was 1.22 (0.91–1.63) and a RR (95%CI) of biphasic waveform for the ROSC was 1.25 (0.98–1.59). Discussion: There were no statistically significant differences between biphasic and mono-phasic AED waveform defibrillation on the patients neurologic outcome and ROSC. Conclusion: Our results suggest that, regardless waveform type of the AED, It is important to increase the number of AED installed and increase number of bystander CPR. doi:10.1016/j.resuscitation.2010.09.073
doi:10.1016/j.resuscitation.2010.09.071 AS056 Can waveform analysis-guided treatment (shock-first versus CPR first) improve survival among patients with low quality VF? Results of an international prospective double-blinded randomised controlled trial Freese J.P. 1,2 , Jorgenson D.B. 3 , Liu P. 4 , Innes J. 5 , Matallana L. 1 , Nammi K. 3 , Donohoe R.T. 5 , Whitbread M. 5 , Silverman R.A. 1,6 , Kaufman B.J. 1,6 , Isaacs D.A. 1,6 , Prezant D.J. 1 1 Office
of Medical Affairs, Fire Department of New York (FDNY), New York, NY USA Department of Emergency Medicine, Emergency Medical Associates LLC / Hudson Valley Hospital, Cortlandt Manor, NY USA 3 Philips Healthcare, Seattle, WA USA 4 Fred Hutchinson Cancer Research Center, Seattle, WA USA 5 London Ambulance Service, London, England UK 6 Department of Emergency Medicine, North Shore – Long Island Jewish Medical Center, New Hyde Park, NY USA 2
Purpose: The 2005 American Heart Association Guidelines noted the potential use of ventricular fibrillation (VF) waveform analysis to “include prediction of success of cardioversion. . . and optimization of timing of defibrillation relative to CPR and medication delivery.”1 This prospective double-blinded randomized controlled trial was designed to assess the use of a VF waveform analysis algorithm to improve survival. Methods: Out-of-hospital cardiac arrest (OOHCA) patients from two large metropolitan EMS systems were treated with automated external defibrillators (AEDs) randomized to a universal shock-first or VF waveform analysis protocol. Study inclusion was limited to presenting VF of primary cardiac aetiology. VF waveform characteristics were used to calculate a novel score representing VF quality. Patients whose score was below a predefined threshold received either immediate defibrillation or a 2-min period of CPR prior to defibrillation based on AED randomization. The primary outcome was survival to hospital discharge. Results: Between May 5, 2006 and June 30, 2009, a total of 6738 OOHCA patients were enrolled. 5751 patients were excluded, the majority (85%) due to a non-VF presenting rhythm. Of the 987 included cases, 540 (54.7%) presented below threshold and comprised