Abstract 139: Impedance Threshold Device and Active Decompression Improve Hemodynamics in a Swine Model of Prolonged CPR

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Joshua W Lampe ◽  
Yin Tai ◽  
Anja K Metzger ◽  
Christopher L Kaufman ◽  
Lance B Becker
Keyword(s):  
Blood Flow ◽  
Chest Compression ◽  
Zero Point ◽  
Swine Model ◽  
Carotid Blood Flow ◽  
Blood Flows ◽  
Lift Height ◽  
Threshold Device ◽  
Acd Cpr ◽  
Impedance Threshold Device

Introduction: Cardiopulmonary resuscitation with the impedance threshold device and active decompression (ITD-ACD CPR) has been shown to improve chest compression generated blood flow relative to standard chest compression. Using our high-fidelity swine model of cardiac arrest treated with prolonged mechanical chest compression (MCC) we studied the effect of different lift heights (amount of lift above the natural zero point of the sternum) during active decompression. Methods: CPR was performed on six domestic swine (~30 kg) using standard physiological monitoring. Flow was measured in the abdominal aorta, inferior vena cava (IVC), right common carotid and external jugular, and left femoral artery. Ventricular fibrillation (VF) was electrically induced. MCC were started after ten minutes of VF. Four MCC waveforms were used: Standard CPR (2”, 100 CPM), and ITD-ACD CPR (2”, 80 CPM) with 0.5”, 1.0”, and 1.5” lift past the zero point. MCC waveforms were changed every 2 min in a crossover design and delivered for 56 minutes. Data were analyzed in CPR cycles which included four epochs of CPR, one of each waveform, constituting 8 minutes of compressions. Results: Lift height had a significant (p<0.05) effect on carotid and jugular blood flow. Lift heights of 1.0 and 1.5” generated significantly more carotid blood flow in all 7 CPR cycles. A lift height of 1.5” generated significantly more jugular blood flow over all 7 CPR cycles. The interaction between duration of CPR and Jugular blood flow previously observed using this animal model was not observed. Carotid and jugular blood flow as a function of waveform and CPR cycle are shown in the figure. Conclusions: ITD-ACD CPR improved carotid and jugular blood flows, suggestive of improved cerebral perfusion. A lift height of 1.5” was required for significant improvement of jugular blood flows, while ITD-ACD CPR provided significantly better carotid blood flow than standard CPR at all lift heights.

Potential negative effects of epinephrine on carotid blood flow and ETCO2 during active compression–decompression CPR utilizing an impedance threshold device

Resuscitation ◽  
2012 ◽  
Vol 83 (8) ◽  
pp. 1021-1024 ◽  
Author(s):  
Aaron M. Burnett ◽  
Nicolas Segal ◽  
Joshua G. Salzman ◽  
M. Scott McKnite ◽  
Ralph J. Frascone
Keyword(s):  
Blood Flow ◽  
Negative Effects ◽  
Carotid Blood Flow ◽  
Threshold Device ◽  
Impedance Threshold Device

scholarly journals An impedance threshold device did not improve carotid blood flow in a porcine model of prolonged cardiac arrest

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Benedict Kjaergaard ◽  
Hans O. Holdgaard ◽  
Sigridur O. Magnusdottir ◽  
Søren Lundbye-Christensen ◽  
Erika F. Christensen
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Porcine Model ◽  
Carotid Blood Flow ◽  
Threshold Device ◽  
Impedance Threshold Device

Abstract 17: Controlled Progressive Elevation Maximizes Cerebral Perfusion Pressure During Head up CPR in a Swine Model of Cardiac Arrest

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Johanna C Moore ◽  
Bayert Salverda ◽  
Michael Lick ◽  
Carolina Rojas-Salvador ◽  
Guillaume Debaty ◽  
...  
Keyword(s):  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Coronary Perfusion Pressure ◽  
Swine Model ◽  
Coronary Perfusion ◽  
Sequence Effect ◽  
Optimal Angle ◽  
Threshold Device ◽  
Acd Cpr ◽  
Impedance Threshold Device

Background: Elevation of the head and thorax (HUP) during cardiopulmonary resuscitation (CPR) has been shown to result in a doubling of brain blood flow with higher Cerebral Perfusion Pressures (CerPP) after prolonged active compression-decompression (ACD) CPR with an impedance threshold device (ITD). However, the optimal angle and speed of elevation are unknown. Methods: In study A, in an anesthetized female 40 kg pig model of untreated ventricular fibrillation for 8 min, different HUP angles were assessed (20°, 30°, 40°) in a randomized manner each over a 5-minute periods of ACD+ITD CPR. Based upon study A results, study B was performed, wherein animals were randomized to the two following sequences: 20°, 30°, 40° or 40°, 30°, 20° using the same protocol. The primary endpoint was mean ± SD CerPP (mmHg) for both studies. Results: In study A, 18 pigs were studied. Overall, there was no optimal HUP angle: CerPP was 36 ± 19 for 20°, 42 ± 21 for 30°, and 44 ± 27 for 40° (p = 0.57). However, CerPPs were higher if 40 o HUP was performed during the last 5 minutes of the resuscitation (77 ± 17), versus 20 o HUP and 30 o HUP (44± 18, p = 0.003), suggestive of a sequence effect. To test this hypothesis, study B then enrolled additional animals to compare two elevation sequences 20°, 30°, 40° (n = 6) or 40°, 30°, 20° (n = 5). At 15 min of CPR, the CerPP for 20°, 30°, 40° group was 60 ± 17 and for 40°, 30°, 20° the CerPP was 23 ± 19 (p = 0.01). CerPPs were higher for the 20°, 30°, 40° group throughout the resuscitation (Figure 1). Coronary perfusion pressure was also significantly higher in the 20°, 30°, 40° group (50 ± 17 mmHg versus 22 ± 16 mmHg, p = 0.036) Conclusions: There did not appear to be an optimal HUP angle during ACD+ITD CPR. By contrast, there was an optimal HUP sequence (20,30,40) that resulted in significantly higher CerPP, suggesting controlled progressive elevation is important when performing HUP CPR as compared to an absolute immediate elevation of the head and thorax.

Abstract 2002: Dual Mechanism of Blood Flow Augmentation to the Brain using an Impedance Threshold Device in a Pediatric Model of Cardiac Arrest

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Carly Alexander ◽  
Demetris Yannopoulos ◽  
Tom Aufderheide ◽  
Scott McKnite ◽  
Tim Matsuura ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Sham Group ◽  
Intrathoracic Pressure ◽  
Forward Flow ◽  
Carotid Blood Flow ◽  
Airway Pressures ◽  
Threshold Device ◽  
The Brain ◽  
Impedance Threshold Device

Background: During cardiac arrest use of an impedance threshold device (ITD) increases circulation and the chances for survival. The ITD has not been systematically evaluated during conventional CPR in a pediatric animal model. We hypothesized that the ITD increases blood flow to the brain by lowering intrathoracic pressure during the CPR decompression phase thus enhancing venous return to the right heart and forward flow with the subsequent compression and maintaining or lowering diastolic intracranial pressure (ICP) thus reducing resistance to forward flow. In this manner ITD use was hypothesized to mimic the ‘gasping reflex’ during CPR. Methods: In the first study 9 female propofol anesthetized piglets (10–12 kg) were subjected to 6 min of untreated ventricular fibrillation, 6 min of conventional CPR (ventilation rate 10 bpm), then 6 min of CPR with an active ITD (resistance of −10 cm H20). A second study was similar except that a sham ITD was used in 8 piglets. Results: After 2 min of active ITD treatment, decompression phase airway pressures (surrogate for intrathoracic pressure) (mmHg) decreased from −0.5 ± 0.2 to −2.6 ± 0.5 (mean ± SEM, p < 0.001) and common carotid blood flow (mL/min) increased by 65% (59.2 ± 16.7 to 91.1± 27.9, p = 0.02). In the sham group, airway pressures were unchanged and carotid blood flow decreased from 39 ± 2.5 to 38.8 ± 4.3 (p = 0.47). ICP decreased more rapidly in time and to a greater degree in 6/9 piglets when comparing ITD use to measurements preceding its application, contributing to an increase in cerebral perfusion (CePP) (mmHg) in 5/9 active ITD piglets, while in the sham group, CePPs remained the same or decreased in 8/8 piglets (p = 0.03). Coronary perfusion pressures (CPP) (mmHg) increased in 5/9 piglets after 2 min of the active ITD and remained the same or decreased in 8/8 piglets treated with the sham device (p = 0.03). Return of spontaneous circulation was achieved with a single shock in 4/9 active ITD piglets and 1/8 sham ITD piglets (p = 0.29). Conclusions: Use of an active ITD during CPR in piglets significantly increased carotid blood flow and CPPs. The ITD also lowered ICP during the decompression phase, similar to the mechanism of the ‘last gasp’, thereby reducing resistance to forward blood flow to the brain.

Abstract 435: Controlled Sequential Elevation of the Head and Thorax Rapidly Achieves 50% of Baseline Cerebral Perfusion Pressure During Active Compression-Decompression Cardiopulmonary Resuscitation With an Impedance Threshold Device in a Swine Model of Cardiac Arrest

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Carolina Rojas-Salvador ◽  
Bayert Salverda ◽  
Johanna C Moore ◽  
Michael C Lick ◽  
Guillaume P Debaty ◽  
...  
Keyword(s):  
Cerebral Perfusion ◽  
Primary Outcome ◽  
Perfusion Pressure ◽  
Group Versus ◽  
Swine Model ◽  
Group 4 ◽  
Threshold Device ◽  
Acd Cpr ◽  
Impedance Threshold Device ◽  
Initial Results

Introduction: Controlled sequential elevation of the head and thorax (CSE) during active compression-decompression (ACD) CPR with an impedance threshold device (ITD) has previously resulted in sustained nearly normal cerebral perfusion pressures (CerPP) of 75 mmHg. However, the optimal speed of CSE remains unknown. It is also unknown if some CPR is needed to ‘prime the system’ prior to maximal CSE. Hypothesis: An optimized CSE will achieve 50% of baseline (50% BL) CerPP in <3 minutes from the start of CPR. Methods: Female farm pigs were intubated and anesthetized. Central vascular and intracranial access were obtained. After 8 min of untreated ventricular fibrillation, pigs were placed in a customized elevation device (CED). After 2 min of ACD+ITD CPR at the lowest CED level to prime the circulation, pigs were randomized to CSE over 1) 4-min or 2) 10-min until the CED reached its highest level. ACD ITD CPR was performed for a total of 19 minutes. Based upon initial results, two additional groups of pigs were studied: one with a CSE over 2-min after the 2 min ‘priming’ step, and the other with CSE over 24-sec without priming. The primary outcome was time in minutes to achieve 50% BL of CerPP values. Results: There were six pigs per study group (4-min, 10-min, 2-min and 24-sec). The 4-min CSE group achieved 50% BL CerPP faster (min ± SD) than the 10-min CSE group (2.53 ± 1.26 vs 5.98 ± 3.16 , p=0.04, Figure 1). The 2-min CSE group CerPP was similar to the 4-min group (2.36 ± 2.18, p=0.92). The time to 50% BL CerPP trended 4 min faster in the 2-min CSE group versus the 24-sec CSE group (6.6 ± 6.73, p=0.16), as shown in the figure. With CSE, CerPPs increased over time in all groups. All pigs were resuscitated. Conclusions: A 50% BL CerPP value was achieved in <3 minutes by combining a priming step and 2-min CSE time together with ACD+ITD CPR. This optimized approach is more advantageous than the 24-sec or 10-min elevation times.

Abstract 439: Using the Time Interval Between R-Wave Detection and Maximum Compression Pressure to Target and Validate Delivery of Synchronized Chest Compressions During Pseudo Electro-Mechanical Dissociation

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Joshua W Lampe ◽  
Jeff R Gould ◽  
Karen L Moodie ◽  
Zachary P Soucy ◽  
Peter S Burrage ◽  
...  
Keyword(s):  
Blood Flow ◽  
Time Interval ◽  
Hemodynamic Parameters ◽  
Chest Compressions ◽  
Compression Pressure ◽  
Carotid Blood Flow ◽  
Maximum Compression ◽  
Local Maxima ◽  
Blood Flows ◽  
Mechanical Dissociation

Introduction: The treatment of pseudo electro-mechanical dissociation (P-EMD) with standard chest compressions leads to some compressions that interfere with blood flow created by ventricular contraction and others that are synergistic. We have previously reported that the hemodynamics generated by standard chest compressions (StdCPR) depended on the time interval between the R-wave and the maximum compression pressure (t_int). Our goal was to use the t_int to identify the optimal timing for compression synchronization and to validate the delivery of synchronized chest compressions. Methods: Eight animals underwent surgical preparation and were exposed to hypoxia to induce P-EMD. The treatment period was divided into eight 45 sec epochs during which the P-EMD was left untreated or was treated with StdCPR or chest compressions synchronized to the R-wave in the ECG (SyncCPR). For each heart beat t_int was calculated as t peak AOP - t Rwave , blood pressures were averaged, and blood flows were integrated. 1,598 chest compressions were analyzed. The location of local extrema in hemodynamic parameters as a function of positive t_int values were identified recursively by dividing the range of t_int values into increasing numbers of bins and determining which bin had the highest mean value. Results: Blood flows and pressures exhibited a non-linear dependence on t_int. The maximum CPP occurred at t_int = 90 ±2.3 ms. The maximum aortic pressure occurred at t_int = 70 ±2.3 ms. The minimum right atrial pressure occurred at t_int = 280 ±2.3 ms. The maximum carotid blood flow occurred at t_int = 100 ±2.3 ms. The maximum jugular blood flow occurred at t_int = 400 ±2.3 ms. Unsynchronized chest compressions resulted in a t_int of -21 ± 170 ms. Synchronized chest compressions resulted in a t_int of 119 ± 13 ms. Conclusions: Local maxima and minima during StdCPR were identified in several hemodynamic parameters, but the extrema were not perfectly co-located. It appears that a t_int of 90-100 ms could be optimal. SyncCPR were delivered at 119 ms, which is not far from the local maxima observed for CPP and carotid blood flow.

scholarly journals Frontal EEG Changes with the Recovery of Carotid Blood Flow in a Cardiac Arrest Swine Model

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3052
Author(s):  
Heejin Kim ◽  
Ki Hong Kim ◽  
Ki Jeong Hong ◽  
Yunseo Ku ◽  
Sang Do Shin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Circulation ◽  
Life Support ◽  
Spontaneous Circulation ◽  
Swine Model ◽  
Carotid Blood Flow ◽  
Non Invasive ◽  
Entropy Measures ◽  
Palpable Pulse ◽  
Eeg Changes

Monitoring cerebral circulation during cardiopulmonary resuscitation (CPR) is essential to improve patients’ prognosis and quality of life. We assessed the feasibility of non-invasive electroencephalography (EEG) parameters as predictive factors of cerebral resuscitation in a ventricular fibrillation (VF) swine model. After 1 min untreated VF, four cycles of basic life support were performed and the first defibrillation was administered. Sustained return of spontaneous circulation (ROSC) was confirmed if a palpable pulse persisted for 20 min. Otherwise, one cycle of advanced cardiovascular life support (ACLS) and defibrillation were administered immediately. Successfully defibrillated animals were continuously monitored. If sustained ROSC was not achieved, another cycle of ACLS was administered. Non-ROSC was confirmed when sustained ROSC did not occur after 10 ACLS cycles. EEG and hemodynamic parameters were measured during experiments. Data measured for approximately 3 s right before the defibrillation attempts were analyzed to investigate the relationship between the recovery of carotid blood flow (CBF) and non-invasive EEG parameters, including time- and frequency-domain parameters and entropy indices. We found that time-domain magnitude and entropy measures of EEG correlated with the change of CBF. Further studies are warranted to evaluate these EEG parameters as potential markers of cerebral circulation during CPR.

Abstract 2059: Transthoracic Application of Medium Voltage Therapy Maintains Forward Blood Flow during Cardiac Arrest

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Giuseppe Ristagno ◽  
Yongqin Li ◽  
Hao Wang ◽  
Shijie Sun ◽  
Gilman Byron ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Cardiac Output ◽  
Ejection Fraction ◽  
Stroke Volume ◽  
Chest Compression ◽  
Entire Interval ◽  
Carotid Blood Flow ◽  
Medium Voltage ◽  
Threshold Levels

We have previously reported that transthoracic medium voltage therapy (MVT) generated coronary perfusion pressure (CPP), forward carotid blood flow (CBF) and end-tidal CO 2 (EtCO 2 ) comparable to those produced by manual chest compression. In the present study, we investigated the capability of MVT to generate and maintain forward blood flow for a longer interval, i.e. 1 min, in a porcine model of short duration cardiac arrest. MVT can maintain threshold levels of CPP, CBF and EtCO 2 , for a minute interval prior to defibrillation. In 7 domestic male pigs weighing 40 ± 1 kg, VF was electrically induced and untreated for 10 seconds. Animals were then subjected to receive MVT for one minute with the aid of a Galvani E-CPR device (Galvani Ltd, Edina, MN), after when a biphasic shock was delivered. The MVT pulsed packet was 400 msec, the pulsed packet rate was 80/min, the intra-packet pulse period was 25 ms and intra-packet pulse durations were 0.2 ms. CPP and EtCO2 were continuously measured during MVT. CBF and ejection fraction generated during MVT were measured by echo-Doppler technique, while cardiac output with stroke volume by thermodiluition method. MVT was able to maintain CPP and EtCO2 above the threshold levels for successful resuscitation for the entire interval of application (Table ). During MVT, excellent stroke volume, cardiac output and ejection fraction together with carotid blood flow were generated (Table ). MVT produced and maintained for one minute forward blood flow during cardiac arrest. This electrical therapy might represent a new approach intended to generate and/or maintain forward blood flow in lieu of or in association with chest compression in victims of cardiac arrest

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