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.

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

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

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.

Abstract 259: Controlled Sequential Elevation of the Head and Thorax Combined With Active Compression Decompression Cardiopulmonary Resuscitation and an Impedance Threshold Device Improves Neurological Survival in a Swine Model of Cardiac Arrest

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Johanna C Moore ◽  
Bayert Salverda ◽  
Michael Lick ◽  
Carolina Rojas-Salvador ◽  
Guillaume Debaty ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Survival Rates ◽  
Cerebral Performance Category ◽  
Intrathoracic Pressure ◽  
Venous Access ◽  
Circulation Rate ◽  
Swine Model ◽  
Threshold Device ◽  
Neurologically Intact ◽  
Impedance Threshold Device

Introduction: Survival rates after cardiac arrest with intact brain function remain poor and are not uniformly improved with a single intervention. A bundle of care approach to CPR that enhances cerebral and coronary circulation while simultaneously lowering intracranial pressure (ICP) provides new opportunity to improve neurological survival. Hypothesis: Active compression decompression (ACD) CPR and an impedance threshold device (ITD) to regulate intrathoracic pressure with controlled sequential elevation of the head and thorax (CSE) to lower ICP and increase cerebral and coronary (CoPP) perfusion pressures, will increase neurologically intact survival when compared to a conventional (C) CPR in the flat position in pigs. Methods: Female farm pigs were sedated, intubated, and anesthetized. Central arterial and venous access were continuously monitored. Regional brain tissue perfusion (CerO2) was also measured transcutaneously. Ventricular fibrillation was induced and untreated for 10 minutes. Pigs were randomized to 1) C-CPR flat or 2) CSE ACD+ITD CPR that included 2 min of ACD+ITD with the head and heart first elevated 10 and 8 cm, respectively, and then further elevation over 2 min to 22 and 9 cm, respectively. After 19 min of CPR, pigs were defibrillated and recovered. A veterinarian blinded to the intervention assessed cerebral performance category (CPC) at 24 hours. A neurologically intact outcome was defined as a CPC score of 1 or 2. Categorical outcomes were analyzed by Chi-Square and continuous outcomes with an unpaired student’s t-test. All p-values are unadjusted. Results: Return of spontaneous circulation rate was 8/8 (100%) with CSE and 2/8 (25%) for C-CPR (p = 0.002). For the primary outcome of neurologically intact survival, 6/8 (75%) pigs survived with CPC 1 or 2 with CSE versus 1/8 (12.5%) with C-CPR (p = 0.012). CoPP (mmHg, mean ± SD) was higher with CSE at 18 minutes (41 ± 24 vs 10 ± 5, p = 0.004). CerO2 (%, mean ± SD) and ETCO 2 (mmHg, mean ± SD) values were higher at 18 minutes with CSE (32.2 ± 8.5 vs 16.5 ± 2.1, p = 0.003, and 54.9 ± 8.6 vs 19.1 ± 7.0, p < 0.001), respectively. Conclusions: The novel bundled resuscitation approach of CSE with ACD+ITD CPR increased neurologically intact survival 6-fold versus C-CPR in a swine model of cardiac arrest.

Abstract 437: The Relation Between Cerebral Oxygenation and Blood Flow During CPR in Swine

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Jeffrey R Gould ◽  
Michael Lick ◽  
Joshua W Lampe ◽  
Paul S Berger ◽  
Anja Metzger
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Cerebral Blood Flow ◽  
Cerebral Oxygenation ◽  
Chest Compressions ◽  
Threshold Device ◽  
Increased Blood Flow ◽  
Domestic Swine ◽  
Impedance Threshold Device ◽  
Anterior Posterior

Introduction: The physiology underlying cerebral oxygenation and blood flow during resuscitation from cardiac arrest (CA) is poorly understood. This study examined the relation between cerebral oxygenation and blood flow during standard CPR (SCPR) and CPR with active decompression and lift (ACD) plus an impedance threshold device (ITD). Methods: Ventricular fibrillation (VF) was electrically induced in 15 domestic swine. Following 6 minutes of untreated VF, chest compressions were initiated at 100 cpm and 10% anterior-posterior distance. Depth increased to 20% anterior-posterior distance over a 2-min period, and was then maintained for 6 minutes (SCPR). ACD+ITD was performed for an additional 6 minutes at the same rate and depth as SCPR, but with 20% anterior-posterior distance of active lift. Microspheres were injected 2 minutes after the start of SCPR and ACD+ITD to measure blood flow. Cerebral oxygenation was measured using NIRS, and 8-sec averages collected 2 minutes following microsphere injection were used for comparison. Changes in oxygenation and blood flow that occurred in response to ACD+ITD relative to SCPR were analyzed using linear regression to predict oxygenation based on blood flow. Results: ACD+ITD increased blood flow in 13 animals and oxygenation in 12 animals relative to SCPR. Changes in cerebral oxygenation were directly proportional to changes in blood flow for 12 of 15 animals in response to ACD+ITD following SCPR. Cerebral blood flow explained 34% of the variance in cerebral oxygenation ( R 2 = 0.34, F (1, 13) = 6.7, P = 0.02). Conclusions: Changes in cerebral oxygenation during CA are associated with measured changes in cerebral blood flow, however 66% of the variance in cerebral oxygenation remains unexplained. Other physiological parameters should be considered to further understand how NIRS may provide clinically useful information during resuscitation.

scholarly journals Senkung des intrakraniellen Drucks durch Senkung des zentralvenösen Drucks: Bewertung möglicher Gegenmaßnahmen zum Raumfahrt-assoziierten neuro-okulären Syndrom

2021 ◽  
pp. 1-2
Author(s):  
Sebastian Siebelmann
Keyword(s):  
Intracranial Pressure ◽  
Venous Pressure ◽  
Intrathoracic Pressure ◽  
Free Breathing ◽  
Optic Disc Edema ◽  
Threshold Device ◽  
Inspiratory Resistance ◽  
Minimal Reduction ◽  
Clinical Conditions ◽  
Impedance Threshold Device

Spaceflight-associated neuro-ocular syndrome (SANS) involves unilateral or bilateral optic disc edema, widening of the optic nerve sheath, and posterior globe flattening. Owing to posterior globe flattening, it is hypothesized that microgravity causes a disproportionate change in intracranial pressure (ICP) relative to intraocular pressure. Countermeasures capable of reducing ICP include thigh cuffs and breathing against inspiratory resistance. Owing to the coupling of central venous pressure (CVP) and intracranial pressure, we hypothesized that both ICP and CVP will be reduced during both countermeasures. In four male participants (32 ± 13 yr) who were previously implanted with Ommaya reservoirs for treatment of unrelated clinical conditions, ICP was measured invasively through these ports. Subjects were healthy at the time of testing. CVP was measured invasively by a peripherally inserted central catheter. Participants breathed through an impedance threshold device (ITD, −7 cmH<sub>2</sub>O) to generate negative intrathoracic pressure for 5 min, and subsequently, wore bilateral thigh cuffs inflated to 30 mmHg for 2 min. Breathing through an ITD reduced both CVP (6 ± 2 vs. 3 ± 1 mmHg; <i>P</i> = 0.02) and ICP (16 ± 3 vs. 12 ± 1 mmHg; <i>P</i> = 0.04) compared to baseline, a result that was not observed during the free breathing condition (CVP, 6 ± 2 vs. 6 ± 2 mmHg, <i>P</i> = 0.87; ICP, 15 ± 3 vs. 15 ± 4 mmHg, <i>P</i> = 0.68). Inflation of the thigh cuffs to 30 mmHg caused no meaningful reduction in CVP in all four individuals (5 ± 4 vs. 5 ± 4 mmHg; <i>P</i> = 0.1), coincident with minimal reduction in ICP (15 ± 3 vs. 14 ± 4 mmHg; <i>P =</i>0.13). The application of inspiratory resistance breathing resulted in reductions in both ICP and CVP, likely due to intrathoracic unloading.

scholarly journals A Trial of an Impedance Threshold Device in Out-of-Hospital Cardiac Arrest

2011 ◽  
Vol 365 (9) ◽  
pp. 798-806 ◽  
Author(s):  
Tom P. Aufderheide ◽  
Graham Nichol ◽  
Thomas D. Rea ◽  
Siobhan P. Brown ◽  
Brian G. Leroux ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Threshold Device ◽  
Hospital Cardiac Arrest ◽  
Impedance Threshold Device

Abstract 138: A Before and After Study of Active Compression Decompression Cardiopulmonary Resuscitation With the Impedance Threshold Device in a Large Urban Pre-Hospital System

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Johanna C Moore ◽  
Michael Grahl ◽  
Tracy Marko ◽  
Ariel Blythe-Reske ◽  
Amber Lage ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cardiopulmonary Resuscitation ◽  
Response Time ◽  
First Responders ◽  
The United States ◽  
Threshold Device ◽  
Before And After ◽  
Mechanical Cpr ◽  
Impedance Threshold Device ◽  
Before And After Study

Introduction: Active Compression Decompression cardiopulmonary resuscitation with an impedance threshold device (ACD+ITD CPR) is available for use in the United States. However, little is known regarding integration of this CPR system into a large urban prehospital system with short response times, routine use of mechanical CPR and ITD, and transport of patients to cardiac arrest centers. This is an ongoing before and after study of the implementation of ACD+ITD CPR in non-traumatic cardiac arrest cases 6 months pre and post protocol change. Hypothesis: Neurologically intact rates of survival, defined by Cerebral Performance Category (CPC) score of 1 or 2, would be higher post protocol. Methods: Basic life support first responders (n = 420) and paramedics (n = 207) underwent training including didactic and hands-on sessions to learn ACD+ITD CPR. The protocol included ACD+ITD CPR initially, with the option to transition to mechanical CPR at 15 minutes. Demographics, response time, CPR duration, initial rhythm, signs of perfusion during CPR, and return of spontaneous circulation (ROSC) were recorded prospectively by first responders. Chart review was performed to determine survival to hospital admission and CPC score at discharge. Results: Training occurred October 2016 to March 2017, with protocol change on May 1, 2017. Cases from November 2016-April 2017 (n = 136) and May 2017-November 2017 (n= 103) were reviewed. Complete data were available for 128 subjects pre-protocol change (94%) and 96 subjects (94%) post. Age, gender, response time, rhythm, total CPR time, and rates of bystander CPR and witnessed arrest were similar between groups. Post protocol change, 87% (89/102) received ACD+ITD CPR with median ACD+ITD CPR time of 15 minutes (range 2-300). Pre-protocol, 6/128 (4.7%) subjects survived with CPC score 1 or 2, versus 8/96 (13.5%) subjects post (difference 8.8%, 95% CI 1%-17%). ROSC rates were similar (pre: 54/127, 42.5% post: 44/93, 47%, difference 4.8%, 95% CI -8% - 18%) Conclusions: The change in protocol was straightforward with a high rate of adherence of the system for the recommended duration of therapy. Results are suggestive of a higher rate of neurological survival with the routine use of ACD+ITD CPR in a small cardiac arrest patient population.

Abstract P22: An Impedance Threshold Device Combined with an Automated Active Compression Decompression CPR Device (LUCAS) Improves the Chances For Survival in Pigs in Cardiac Arrest

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Timothy R Matsuura ◽  
Scott H McKnite ◽  
Anja K Metzger ◽  
Demetris Yannopoulos ◽  
Tom P Aufderheide ◽  
...  
Keyword(s):  
Venous Blood ◽  
Blood Gases ◽  
Intrathoracic Pressure ◽  
Organ Damage ◽  
Coronary Perfusion Pressure ◽  
Spontaneous Circulation ◽  
Adverse Outcomes ◽  
Coronary Perfusion ◽  
Threshold Device ◽  
Impedance Threshold Device

Background: By lowering intrathoracic pressure during the chest recoil phase of CPR, the impedance threshold device (ITD) increases circulation and the rate of return of spontaneous circulation (ROSC). This study evaluated the ITD combined with a new automated CPR device, the US version of the LUCAS, that compresses the chest and then pulls upwards with a 3 lb force. Methods and Results: After 6 min of untreated ventricular fibrillation, anesthetized female pigs (40.0±0.7 kg) were randomized to 6 min of CPR (100 compressions/min with LUCAS and ventilation: 1.0 FiO2, tidal volume of 10ml/kg, rate 12/min) with an active (−10 cm H2O resistance) (n=12) or sham ITD (n=12), and then shocked once with 120 joules of direct current. Epinephrine (0.04 mg/kg) and more CPR and shocks were used if ROSC was not achieved. Results (in mmHg) after 6 min of CPR with an active vs. sham ITD were: coronary perfusion pressure (PP) 20.8±1.2 vs. 21.0±0.9 (p=0.94); cerebral PP 8.8±1.0 vs. 10.0±0.9 (p=0.62); and end tidal CO2 38.1±1.5 and 37.1±1.3 (p=0.61). Peak and mean carotid artery blood flow (ml/min) was 323.9±15.2 vs. 256.6±21.1 (p=0.17) and 95.3±5.4 vs. 77.0±6.0 (p=0.22) with an active vs. sham ITD, respectively. Mean endotracheal pressures (mmHg) during chest recoil with an active vs. sham ITD were −2.0±0.5 vs. −0.2±0.2 (p<0.01). Arterial and venous blood gases were similar after 6 min of CPR between groups. ROSC, the primary survival endpoint for comparing the active vs. sham ITD, was 7/12 vs. 2/12 after 1 shock (p= 0.09), 12/12 vs. 5/12 after 2 shocks (p<0.01), and 12/12 vs. 7/12 after 3 shocks (p=0.04). With up to 14 shocks, 10/12 sham animals had a ROSC. All animals with ROSC lived for 30 min. There was no evidence of pulmonary edema or organ damage on autopsy with either ITD. Conclusions: After 6 min of CPR, LUCAS and active ITD resulted in lower mean airway pressures during chest recoil versus controls but hemodynamic findings were similar. However, ROSC was significantly easier to achieve with an active ITD; with up to 3 shocks twice as many animals were resuscitated with an active ITD. This benefit is most likely explained by carotid blood flows that trended higher with the active ITD. These positive findings and lack of any adverse outcomes support the safety and efficacy of this device combination.

Abstract 64: A Tale of Seven EMS Systems: An Impedance Threshold Device and Improved CPR Techniques Double Survival Rates After Out-of-Hospital Cardiac Arrest

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Tom P Aufderheide ◽  
Marvin Birnbaum ◽  
Charles Lick ◽  
Brent Myers ◽  
Laurie Romig ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Hospital Discharge ◽  
Life Support ◽  
Survival Rates ◽  
Heart Association ◽  
Outcome Data ◽  
Therapeutic Interventions ◽  
Threshold Device ◽  
Hospital Cardiac Arrest ◽  
Impedance Threshold Device

Introduction: Maximizing outcomes after cardiac arrest depends on optimizing a sequence of interventions from collapse to hospital discharge. The 2005 American Heart Association (AHA) Guidelines recommended many new interventions during CPR (‘New CPR’) including use of an Impedance Threshold Device (ITD). Hypothesis: The combination of the ITD and ‘New CPR’ will increase return of spontaneous circulation (ROSC) and hospital discharge (HD) rates in patients with an out-of-hospital cardiac arrest. Methods: Quality assurance data were pooled from 7 emergency medical services (EMS) systems (Anoka Co., MN; Harris Co., TX; Madison, WI; Milwaukee, WI; Omaha, NE; Pinellas Co., FL; and Wake Co., NC) where the ITD (ResQPOD®, Advanced Circulatory Systems; Minneapolis, MN) was deployed for >3 months. Historical or concurrent control data were used for comparison. The EMS systems simultaneously implemented ‘New CPR’ including compression/ventilation strategies to provide more compressions/min and continuous compressions during Advanced Life Support. All sites stressed the importance of full chest wall recoil. The sites have a combined population of ~ 3.2 M. ROSC data were available from all sites; HD data were available as of June 2007 from 5 sites (MN, TX, Milwaukee, NE, NC). Results: A total of 893 patients treated with ‘New CPR’ + ITD were compared with 1424 control patients. The average age of both study populations was 64 years; 65% were male. Comparison of the ITD vs controls (all patients) for ROSC and HD [Odds ratios (OR), (95% confidence intervals), and Fisher’s Exact Test] were: 37.9% vs 33.8% [1.2, (1.02, 1.40), p=0.022] and 15.7% vs 7.9% [2.2, (1.53, 3.07), p<0.001], respectively. Patients with ventricular fibrillation had the best outcomes in both groups. Neurological outcome data are pending. Therapeutic hypothermia was used in some patients (MN, NC) after ROSC. Conclusion: Adoption of the ITD + ‘New CPR’ resulted in only a >10% increase in ROSC rates but a doubling of hospital discharge rates, from 7.9% to 15.7%, (p<0.001). These data represent a currently optimized sequence of therapeutic interventions during the performance of CPR for patients in cardiac arrest and support the widespread use of the 2005 AHA CPR Guidelines including use of the ITD.

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