Abstract 371: Using Defibrillator Bioimpedance Waveforms to Measure Ventilation During Continuous Chest Compression CPR

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Teresa R Gordon ◽  
Enrique Rueda ◽  
Elisabete Aramendi ◽  
Unai Irusta ◽  
Pamela Owens ◽  
...  

Introduction: For patients with out of hospital cardiac arrest, prompt return of circulation and ventilation is vitally important for survival. Techniques and devices have been developed to ensure emergency responders are providing high quality chest compression, but there has been little progress in the area of ventilation. Until an advanced airway is placed, there has been no practical way to measure ventilation. The aim of this study is to develop a method to measure ventilation during continuous chest compressions cardiopulmonary resuscitation (CPR) that can be used to monitor and improve quality of ventilation during out of hospital CPR. Hypothesis: Defibrillator transthoracic bioimpedance can be used to identify ventilation waveforms prior to placement of an advanced airway during continuous chest compressions CPR. Methods: We examined 391 patients’ defibrillator files from four Resuscitation Outcomes Consortium sites for the presence of waveforms that met previously developed criteria and were manually annotated. Criteria for an acceptable ventilation waveform were: waveform amplitude ≥0.5 Ohm and waveform duration ≥1 sec. We recorded the number of ventilations, return of spontaneous circulation, initial heart rhythm, and ventilation rates. Following annotation, 333 of the 391 patients’ files had the necessary intubation time recorded and an automated program precisely measured the amplitude and duration of each ventilation. We determined mean (±SD) waveform amplitude and duration of inflation and deflation pre and post airway placement. Significance was determined using Wilcoxon ranked sum test. Results: Comparing the pre and post airway measurements did not result in any significant differences, except in duration of inflation, which was 1.06 ± 0.41 sec and 1.11 ± 0.52 sec, respectively, (p <0.001). Ventilation waveforms had significantly lower amplitude and shorter duration during chest compressions than during pauses in compressions. Conclusion: Defibrillator transthoracic bioimpedance can be used to identify and monitor ventilations during continuous chest compressions CPR. Ventilation waveforms have lower amplitudes and shorter durations during chest compressions than during pauses in compressions.

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Vishal Gupta ◽  
Robert Schmicker ◽  
Pamela Owens ◽  
Elizabete Aramendi ◽  
Ahamed Idris

Introduction: Defibrillators record important information about the quality of chest compressions during CPR. Software made for reviewing defibrillator files automatically annotate and measure chest compression metrics. However, evidence is limited regarding the accuracy of such measurements. Objective: To compare chest compression fraction (CCF) and rate measurements made with software annotation vs. manual annotation of defibrillator files. Methods: This is a retrospective, observational study from the Dallas Fort-Worth site of the Resuscitation Outcomes Consortium. We reviewed chest compression waveforms from the bioimpedance channel of defibrillator recordings (Physio-Control Lifepak 12 and 15, Redmond, WA) of 100 prehospital patients enrolled in the DFW Cardiac Arrest Registry from 9/8/2018 to 3/9/2019. Included cases were ≥18 years, had presumed cardiac cause of arrest, and continuous chest compressions. We assessed chest compression waveforms from the time of initial CPR until the time the defibrillator was removed. A trained reviewer revised the software annotations by marking the start and end of CPR and adding or removing chest compressions. Software annotated and manual reviewer annotated measurements were compared for CCF and rate using intraclass correlation coefficient (ICC) statistical analysis. Results: Mean patient age was 63 years with 59% male. The mean (±SD) duration of CPR was 30.4 ± 10.6 min. The overall mean CCF for files annotated by software vs. manual annotation was 0.64 ± 0.19 vs. 0.86 ± 0.07, respectively, and the ICC was 0.14. For software vs. manual annotation, the overall mean rate was 109 ± 10 vs. 108 ± 10, respectively, and ICC was 0.99. The software misidentified epochs before the start of chest compressions, failed to capture epochs after resuscitation ended, and after return of spontaneous circulation, resulting in low ICC for CCF. The ICC was excellent for compression rate because the software only counted epochs where chest compressions were actually given. Conclusions: Software annotation performed poorly for chest compression fraction and very well for chest compression rate. Defibrillator files must be reviewed and annotated manually before quality of chest compression measurements are calculated.


Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Claudius Balzer ◽  
Franz J Baudenbacher ◽  
Antonio Hernandez ◽  
Michele M Salzman ◽  
Matthias L Riess ◽  
...  

Introduction: A higher chest compression fraction (CCF) or percentage of time providing chest compressions is associated with improved survival after cardiac arrest (CA). Pauses in chest compression duration during cardiopulmonary resuscitation (CPR) to palpate a pulse can reduce the CCF. Peripheral Intravenous Analysis (PIVA) is a novel method for determining cardiac and volume status using waveforms from a standard peripheral intravenous (IV) line. We hypothesize that PIVA will demonstrate the onset of return of spontaneous circulation (ROSC) without interruption of CPR. Methods: Eight Zucker Diabetic Fatty (ZDF) rats (4 lean, 4 diabetic) were intubated, ventilated, and cannulated with a 24g IV in the tail vein and a 22g IV in the femoral artery, each connected to a TruWave pressure transducer. Mechanical ventilation was discontinued to achieve CA. After 8 minutes, CPR began with mechanical ventilation, IV epinephrine, and chest compressions using 1.5 cm at 200 times per minute until mean arterial pressure (MAP) increased to 120 mmHg per arterial line. All waveforms were recorded and analyzed in LabChart. PIVA was measured using a Fourier transform of the peripheral venous waveform. Data are mean ± SD. Statistics: Unpaired student’s t-test (two-tailed), α = 05. Results: CA and ROSC were achieved in all 8 rats. Within 1 minute of CPR, there was a 70 ± 35 fold increase/decrease in PIVA during CPR that was temporally associated with ROSC. Within 8 ± 13 seconds of a reduction in PIVA, there was a rapid increase in end-tidal CO 2 . In all rats, ROSC occurred within 38 ± 9 seconds of the maximum PIVA value. Peripheral venous pressure decreased by 1.2 ± 0.9 mmHg during resuscitation and ROSC, which was not significant different at p=0.05. Conclusion: In this pilot study, PIVA detected ROSC without interrupting CPR. Use of PIVA may obviate the need pause CPR for pulse checks, and may result in a higher CCF and survival. Future studies will focus on PIVA and CPR efficacy.


2019 ◽  
Author(s):  
Michał Ćwiertnia ◽  
Marek Kawecki ◽  
Tomasz Ilczak ◽  
Monika Mikulska ◽  
Mieczyslaw Dutka ◽  
...  

Abstract Background Maintaining highly effective cardiopulmonary resuscitation (CPR) can be particularly difficult when artificial respiration using a bag-valve-mask device, combined with chest compression have to be carried out by one person. The aim of the study is to compare the quality of CPR conducted by one paramedic using chest compression from the patient’s side, with compression carried out from behind the patient’s head. Methods The subject of the study were two methods of CPR – ‘standard’ (STD) and ‘over-the-head’ (OTH). The STD method consisted of 30 chest compressions from the patient’s side, and two attempts at artificial respiration after moving round to behind the patient’s head. In the OTH method, both compression and respiration were conducted from behind the patient’s head. Results Both CPR methods were conducted by 38 paramedics working in medical response teams. The average time of the interruptions between compression cycles (STD 9.184 s, OTH 7.316 s, p<0.001); the depth of compression 50–60 mm (STD 50.65%, OTH 60.22%, p<0.001); the rate of compression 100–120/min. (STD 46.39%, OTH 53.78%, p<0.001); complete chest wall recoil (STD 84.54%, OTH 91.46%, p<0.001); correct hand position (STD 99.32%, OTH method 99.66%, p<0.001). The remaining parameters showed no significant differences in comparison to reference values. Conclusions The demonstrated higher quality of CPR in the simulated research using the OTH method conducted by one person justifies the use of this method in a wider range of emergency interventions than only for CPR conducted in confined spaces.


Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Felipe Teran ◽  
Claire Centeno ◽  
Alex L Lindqwister ◽  
William J Hunckler ◽  
William Landis ◽  
...  

Background: Lifeless shock (LS) (previously called EMD and pseudo-PEA) is a global hypotensive ischemic state with retained coordinated myocardial contractile activity and an organized ECG. We have previously described our hypoxic LS model. The role of standard external chest compressions remains unclear in the setting of LS and its associated intrinsic hemodynamics. Although it is known the patients with LS have better prognosis compared to PEA, it is unclear what is the best treatment strategy. Prior work has shown that chest compressions (CC) when synchronized with native systole results in significant hemodynamic improvement, most notably coronary perfusion pressure (CPP), and hence it is plausible that standard dyssynchronous CC may be detrimental to hemodynamics. Furthermore, retrospective clinical data has shown that LS patients treated with vasopressors and no CC, may have better outcomes. We compared epinephrine only versus epinephrine and chest compression, in a porcine model of LS. Methods: Our porcine model of hypoxic LS has previously been described. We randomized pigs to episodes of LS treated with epinephrine only (control) (0.0015 mg/kg) versus epinephrine plus standard external chest compressions (intervention). Animals were endotracheally intubated and mechanically ventilated, and the fraction of inspired oxygen (FiO 2 ) was gradually lowered from room air (20-30% O 2 ) to a target FiO 2 of 3-7% O 2 . This target FiO 2 was maintained until the systolic blood pressure (SBP) dropped to 30 mmHg for 30 seconds, or the animal became bradycardic (HR less than 40), which was defined as the start of LS. FiO 2 was then raised to 100%, and then animal would receive control or intervention. Return of spontaneous circulation (ROSC) was defined as SBP 60 mmHg, stable after 2 minutes. Results: Twenty-six episodes of LS in 11 animals received epinephrine only control and 21 episodes the epinephrine plus chest compression intervention. The rates of ROSC in two minutes or less were 5/26 (19%) in the control arm vs 14/21 (67%) in the intervention arm (P=0.001;95% CI 19.7 %-67.2%). Conclusions: In a swine model of hypoxia induced LS, epinephrine plus CPR may be superior to epinephrine alone.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jakob E Thomsen ◽  
Martin Harpsø ◽  
Graham W Petley ◽  
Svend Vittinghus ◽  
Charles D Deakin ◽  
...  

Introduction: We have recently shown that Class 1 electrical insulating gloves are safe for hands-on defibrillation. Continuous chest compressions during defibrillation reduce the peri-shock pauses and increase the subsequent chance of successful defibrillation. In this study we have investigated the effect of these electrical insulation gloves on the quality of chest compressions, compared with normal clinical examination gloves. Methods: Emergency medical technicians trained in 2010 resuscitation guidelines delivered uninterrupted chest compressions for 6 min on a manikin, whilst wearing Class 1 electrical insulating gloves or clinical examination gloves. The order of gloves was randomized and each session of chest compressions was separated by at least 30 min to avoid fatigue. Data were collected from the manikin. Compression depth and compression rate were compared. Results: Data from 35 participants are shown in Figure 1. There was no statistically significant difference between Class 1 electrical insulating gloves in chest compression depth (median±range: 45 (28-61) vs 43 (28-61) p=0.69) and chest compression rate (113 (67-150) vs 113(72-145), p=0.87) when compared to clinical examination cloves. Conclusion: These preliminary data suggest that the use of Class 1 electrical insulation gloves does not reduce the quality of chest compressions during simulated CPR compared to clinical examination gloves.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Nutthapong Pechaksorn ◽  
Veerapong Vattanavanit

Background. The current basic life support guidelines recommend two-minute shifts for providing chest compressions when two rescuers are performing cardiopulmonary resuscitation. However, various studies have found that rescuer fatigue can occur within one minute, coupled with a decay in the quality of chest compressions. Our aim was to compare chest compression quality metrics and rescuer fatigue between alternating rescuers in performing one- and two-minute chest compressions. Methods. This prospective randomized cross-over study was conducted at Songklanagarind Hospital, Hat Yai, Songkhla, Thailand. We enrolled sixth-year medical students and residents and randomly grouped them into pairs to perform 8 minutes of chest compression, utilizing both the one-minute and two-minute scenarios on a manikin. The primary end points were chest compression depth and rate. The secondary end points included rescuers’ fatigue, respiratory rate, and heart rate. Results. One hundred four participants were recruited. Compared with participants in the two-minute group, participants in the one-minute group had significantly higher mean (standard deviation, SD) compression depth (mm) (45.8 (7.2) vs. 44.5 (7.1), P=0.01) but there was no difference in the mean (SD) rate (compressions per min) (116.1 (12.5) vs. 117.8 (12.4), P=0.08), respectively. The rescuers in the one-minute group had significantly less fatigue (P<0.001) and change in respiratory rate (P<0.001), but there was no difference in the change of heart rate (P=0.59) between the two groups. Conclusion. There were a significantly higher compression depth and lower rescuer fatigue in the 1-minute chest compression group compared with the 2-minute group. This trial is registered with TCTR20170823001.


2019 ◽  
Author(s):  
Michał Ćwiertnia ◽  
Marek Kawecki ◽  
Tomasz Ilczak ◽  
Monika Mikulska ◽  
Mieczysław Dutka ◽  
...  

Abstract Background: Maintaining highly effective cardiopulmonary resuscitation (CPR) can be particularly difficult when artificial ventilation using a bag-valve-mask device, combined with chest compression have to be carried out by one person. The aim of the study is to compare the quality of CPR conducted by one paramedic using chest compression from the patient’s side with compression conducted from the ‘over-the-head’ position. Methods: The subject of the study were two methods of CPR – ‘standard’ (STD) and ‘over-the-head’ (OTH). The STD method consisted of cycles of 30 chest compressions from the patient’s side, and two attempts at artificial ventilation after moving round to behind the patient’s head. In the OTH method, both compression and ventilation were conducted from behind the patient’s head. Results: Both CPR methods were conducted by 38 paramedics working in medical response teams. Statistical analysis was conducted on the data collected, giving the following results: the average time of the interruptions between compression cycles (STD 9.184 s, OTH 7.316 s, p < 0.001); the depth of compression 50–60 mm (STD 50.65%, OTH 60.22%, p < 0.001); the rate of compression 100–120/min. (STD 46.39%, OTH 53.78%, p < 0.001); complete chest wall recoil (STD 84.54%, OTH 91.46%, p < 0.001); correct hand position (STD 99.32%, OTH method 99.66%, p < 0.001). A statistically significant difference was demonstrated in the results to the benefit of the OTH method in the above parameters. The remaining parameters showed no significant differences in comparison to reference values. Conclusions: The demonstrated higher quality of CPR in the simulated research using the OTH method conducted by one person justifies the use of this method in a wider range of emergency interventions than only for CPR conducted in confined spaces.


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