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Changes in end tidal CO2 vs thoracic impedance for detecting restoration of spontaneous circulation
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Abstracts / Resuscitation 96S (2015) 5–42
This patient was neurologically normal (Cerebral Perfusion Category 1). The one patient who survived had a number of factors that were as likely to have produced a good outcome (age 38, female, witnessed arrest, shockable rhythm, bystander CPR, ROSC prior to HEMS arrival). The cause of the arrest was not of coronary origin (it was arrhythmia secondary to mitral stenosis) so the thrombolysis is highly unlikely to have affected the outcome. Conclusion: The data presented do not support the use of thrombolysis in the treatment of medical cardiac arrest patients in this cohort. Further work is required to produce an evidence-based guideline to assist with decision-making with regard to administration of thrombolysis on scene. http://dx.doi.org/10.1016/j.resuscitation.2015.09.014 AS003 Changes in end tidal CO2 vs thoracic impedance for detecting restoration of spontaneous circulation Beatriz Chicote 1,∗ , Elisabete Aramendi 1 , Erik Alonso 1 , Unai Irusta 1 , James K. Russell 3 , Mohamud Daya 2 1 University of the Basque Country (UPV/EHU), Bilbao, Spain 2 Oregon Health & Science University, Portland, USA 3 Russell Consulting, Seattle, USA
Purpose: Human studies have shown that restoration of spontaneous circulation (ROSC) is associated with a significant increase in end tidal CO2 (EtCO2 ). However the optimal threshold for ROSC recognition is unknown. ROSC may also be detected by identifying fluctuations in the Thoracic Impedance (TI) associated to pulsegenerating heartbeats. The purpose of this study was to compare these two methods for detecting ROSC with regards to accuracy and timing. Materials and methods: We analyzed continuous CPR data files and prehospital care reports from 27 out-of-hospital patients with annotation of sustained ROSC by the treated EMS provider. Data were obtained from a cardiac arrest registry maintained by Tualatin Valley Fire & Rescue (Tigard, Oregon, USA). Continuous capnogram, TI and ECG signals were available before and after ROSC-onset. Three segments were selected per patient, one pre-ROSC and two post-ROSC. Segments were selected during pauses in chest compressions and with artifact-free TI. The capnogram was processed to compute the EtCO2 value for each segment. TI was adaptively processed to extract the signal component associated with pulse, and a TI-pulse detector classified every segment as pulsed/pulseless based on 2 ECG and 4 TI features. Results: EtCO2 was significantly higher in the two post-ROSC than in the pre-ROSC segment (60 ± 22 mmHg and 66 ± 19 mmHg vs 25 ± 11 mmHg, P < 0.001). A 30 mmHg threshold provided a 77.8% specificity, and sensitivities and median delays in ROSConset detection of 92.6/100% and 15/110 s for the first and second post-ROSC segments, respectively. TI pulse detection provided 100% specificity, and sensitivities and median ROSC-onset detection delays of 92.6/95.8% and 13/107 s, respectively. Conclusion: Both EtCO2 and TI can assist the recognition and confirmation of ROSC (sensitivities >92%) in a two-minute interval since pulse was suspected. An automatic procedure should be tested along complete episodes before and after ROSC for further conclusions. http://dx.doi.org/10.1016/j.resuscitation.2015.09.015
AS004 Hyperoxygenation during ECLS – Pitfalls of a novel therapy for refractory cardiac arrest Florian Ettl 1,∗ , Ingrid Anna Maria Magnet 1 , Alexandra-Maria Warenits 1 , Andreas Schober 1 , Christoph Testori 1 , Wolfgang Weihs 1 , Daniel Grassmann 1 , Michael Wagner 1 , Ursula Teubenbacher 2 , Sandra Högler 2 , Fritz Sterz 1 , Andreas Janata 3 1
Medical University of Vienna, Vienna, Austria University of Veterinary Medicine, Vienna, Austria 3 Hanusch Hospital, Vienna, Austria 2
Background: Extracorporeal life support (ECLS) after prolonged cardiac arrest gives control over reperfusion conditions, such as reperfusate composition, temperature, blood and gas flow. Still optimal settings during and after ECLS resuscitation are unknown. In this study we assessed trends in arterial blood gas analyses comparing conventional cardiopulmonary resuscitation (CPR) and ECLS resuscitation after 10 min of ventricular fibrillation cardiac arrest (VFCA) in rats, helping to improve this promising therapy. Methods: Sixteen rats (Sprague-Dawley, male, 480 g) were randomized into CPR (n = 8) or ECLS resuscitation (n = 8) following 10 min of VFCA and were examined for differences in arterial blood gases. As reperfusate a balanced crystalloid solution was used. Samples were taken before the induction of CA, 5 and 15 min after return of spontaneous circulation (ROSC). Data are presented as mean ± standard deviation. Group comparisons were made with a t-test. Results: Detailed results are listed in Fig. 1 below (significant differences marked). In the baseline blood gas (BL) lactate levels were slightly higher in CPR rats (p = 0.020). During the first five minutes after ROSC ECLS animals had notably higher pO2 levels (p = 0.001) while electrolyte levels changed significantly from BL and differed between groups. Glucose was higher in ECLS, while lactate did not differ after ROSC. Fifteen minutes after ROSC most parameters had evened between groups, though pO2 and calcium levels remained markedly lower in CPR animals. The changes in electrolyte and glucose levels between the time points differed significantly between the groups.
Fig. 1.
Conclusion: Arterial blood gas values differed significantly between the resuscitation method at 5 and 10 min after ROSC. Electrolyte levels seem to be susceptible to the resuscitation method. Possibly harmful hyperoxygenation by ECLS was a problem observed in the early reperfusion period. http://dx.doi.org/10.1016/j.resuscitation.2015.09.016
Abstracts / Resuscitation 96S (2015) 5–42
This patient was neurologically normal (Cerebral Perfusion Category 1). The one patient who survived had a number of factors that were as likely to have produced a good outcome (age 38, female, witnessed arrest, shockable rhythm, bystander CPR, ROSC prior to HEMS arrival). The cause of the arrest was not of coronary origin (it was arrhythmia secondary to mitral stenosis) so the thrombolysis is highly unlikely to have affected the outcome. Conclusion: The data presented do not support the use of thrombolysis in the treatment of medical cardiac arrest patients in this cohort. Further work is required to produce an evidence-based guideline to assist with decision-making with regard to administration of thrombolysis on scene. http://dx.doi.org/10.1016/j.resuscitation.2015.09.014 AS003 Changes in end tidal CO2 vs thoracic impedance for detecting restoration of spontaneous circulation Beatriz Chicote 1,∗ , Elisabete Aramendi 1 , Erik Alonso 1 , Unai Irusta 1 , James K. Russell 3 , Mohamud Daya 2 1 University of the Basque Country (UPV/EHU), Bilbao, Spain 2 Oregon Health & Science University, Portland, USA 3 Russell Consulting, Seattle, USA
Purpose: Human studies have shown that restoration of spontaneous circulation (ROSC) is associated with a significant increase in end tidal CO2 (EtCO2 ). However the optimal threshold for ROSC recognition is unknown. ROSC may also be detected by identifying fluctuations in the Thoracic Impedance (TI) associated to pulsegenerating heartbeats. The purpose of this study was to compare these two methods for detecting ROSC with regards to accuracy and timing. Materials and methods: We analyzed continuous CPR data files and prehospital care reports from 27 out-of-hospital patients with annotation of sustained ROSC by the treated EMS provider. Data were obtained from a cardiac arrest registry maintained by Tualatin Valley Fire & Rescue (Tigard, Oregon, USA). Continuous capnogram, TI and ECG signals were available before and after ROSC-onset. Three segments were selected per patient, one pre-ROSC and two post-ROSC. Segments were selected during pauses in chest compressions and with artifact-free TI. The capnogram was processed to compute the EtCO2 value for each segment. TI was adaptively processed to extract the signal component associated with pulse, and a TI-pulse detector classified every segment as pulsed/pulseless based on 2 ECG and 4 TI features. Results: EtCO2 was significantly higher in the two post-ROSC than in the pre-ROSC segment (60 ± 22 mmHg and 66 ± 19 mmHg vs 25 ± 11 mmHg, P < 0.001). A 30 mmHg threshold provided a 77.8% specificity, and sensitivities and median delays in ROSConset detection of 92.6/100% and 15/110 s for the first and second post-ROSC segments, respectively. TI pulse detection provided 100% specificity, and sensitivities and median ROSC-onset detection delays of 92.6/95.8% and 13/107 s, respectively. Conclusion: Both EtCO2 and TI can assist the recognition and confirmation of ROSC (sensitivities >92%) in a two-minute interval since pulse was suspected. An automatic procedure should be tested along complete episodes before and after ROSC for further conclusions. http://dx.doi.org/10.1016/j.resuscitation.2015.09.015
AS004 Hyperoxygenation during ECLS – Pitfalls of a novel therapy for refractory cardiac arrest Florian Ettl 1,∗ , Ingrid Anna Maria Magnet 1 , Alexandra-Maria Warenits 1 , Andreas Schober 1 , Christoph Testori 1 , Wolfgang Weihs 1 , Daniel Grassmann 1 , Michael Wagner 1 , Ursula Teubenbacher 2 , Sandra Högler 2 , Fritz Sterz 1 , Andreas Janata 3 1
Medical University of Vienna, Vienna, Austria University of Veterinary Medicine, Vienna, Austria 3 Hanusch Hospital, Vienna, Austria 2
Background: Extracorporeal life support (ECLS) after prolonged cardiac arrest gives control over reperfusion conditions, such as reperfusate composition, temperature, blood and gas flow. Still optimal settings during and after ECLS resuscitation are unknown. In this study we assessed trends in arterial blood gas analyses comparing conventional cardiopulmonary resuscitation (CPR) and ECLS resuscitation after 10 min of ventricular fibrillation cardiac arrest (VFCA) in rats, helping to improve this promising therapy. Methods: Sixteen rats (Sprague-Dawley, male, 480 g) were randomized into CPR (n = 8) or ECLS resuscitation (n = 8) following 10 min of VFCA and were examined for differences in arterial blood gases. As reperfusate a balanced crystalloid solution was used. Samples were taken before the induction of CA, 5 and 15 min after return of spontaneous circulation (ROSC). Data are presented as mean ± standard deviation. Group comparisons were made with a t-test. Results: Detailed results are listed in Fig. 1 below (significant differences marked). In the baseline blood gas (BL) lactate levels were slightly higher in CPR rats (p = 0.020). During the first five minutes after ROSC ECLS animals had notably higher pO2 levels (p = 0.001) while electrolyte levels changed significantly from BL and differed between groups. Glucose was higher in ECLS, while lactate did not differ after ROSC. Fifteen minutes after ROSC most parameters had evened between groups, though pO2 and calcium levels remained markedly lower in CPR animals. The changes in electrolyte and glucose levels between the time points differed significantly between the groups.
Fig. 1.
Conclusion: Arterial blood gas values differed significantly between the resuscitation method at 5 and 10 min after ROSC. Electrolyte levels seem to be susceptible to the resuscitation method. Possibly harmful hyperoxygenation by ECLS was a problem observed in the early reperfusion period. http://dx.doi.org/10.1016/j.resuscitation.2015.09.016