Abstract 148: The Time Interval Between the R-Wave and Maximum Aortic Pressure Affects Chest Compression Hemodynamics in a Swine Model of Pseudo Electro-Mechanical Dissociation

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Joshua W Lampe ◽  
Karen L Moodie ◽  
Jeffrey R Gould ◽  
Christopher L Kaufman ◽  
Norman A Paradis
Keyword(s):  
Chest Compression ◽  
Nearest Neighbor ◽  
Aortic Pressure ◽  
The Other ◽  
Time Interval ◽  
Swine Model ◽  
Coronary Perfusion ◽  
Ventricular Contraction ◽  
Mechanical Dissociation ◽  
Blood Pressures

Introduction: The prevalence of pseudo electro-mechanical dissociation (P-EMD) as an initial cardiac arrest state is increasing. P-EMD manifests a weak ventricular contraction, which is not sufficient to sustain life. However, the presence of a weak ventricular contraction may lead to interference with or synergy with the blood flow generated by a chest compression depending on the time interval between the compression and ventricular contraction. Hypothesis: We hypothesize that the interval between a chest compression and the ventricular contraction during P-EMD will influence the hemodynamics created by the chest compression. Methods: Using our well established hypoxic P-EMD model, we measured blood pressures and ECG during mechanical chest compression (100 CPM, 2”). A nearest-neighbor analysis determined the time interval between the R-wave and the peak aortic pressure, defined as t peak AOP - t Rwave . Peak aortic pressures that had more than one R-wave nearest neighbor were excluded. 1,497 chest compressions were analyzed. Intervals were divided into quartiles, and hemodynamic parameters were compared between the quartiles using a repeated measure ANOVA with Bonferroni correction. Results: Interval (int) quartiles were defined as: Q1: int > 100 ms; Q2: 100 ms > int > 0.0 ms; Q3: 0.0ms > int > -90 ms; Q4: - 90 ms > int. Mean arterial pressures (MAP) in mmHg as a function of interval are: Q1: 33.8±0.6; Q2: 41.1±0.6; Q3: 38.3±0.6; Q4: 33.1±0.6. The MAP value for compressions with an interval in Q2 was higher than the other quartiles ( p > 0.05). Coronary perfusion pressures (CPP) in mmHg as a function of interval are: Q1: 11.7±0.5; Q2: 15.3±0.5; Q3: 15.6±0.5; Q4: 12.9±0.5. The CPP values for compressions with an interval in Q2 or Q3 was higher than the other quartiles ( p > 0.05). Conclusions: The interval between the R-wave and the peak aortic pressure generated by a chest compression has a significant effect on the resulting hemodynamics. Shorter intervals, both positive and negative are associated with improved blood pressures during resuscitation from P-EMD. These data suggest that delivery of standard CPR during P-EMD can result in a mix of effective and less effective compressions.

Abstract 167: Epinephrine Plus Chest Compressions May Be Superior to Epinephrine Alone in a Hypoxia-Induced Porcine Model of Lifeless Shock

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Felipe Teran ◽  
Claire Centeno ◽  
Alex L Lindqwister ◽  
William J Hunckler ◽  
William Landis ◽  
...  
Keyword(s):  
Chest Compression ◽  
Porcine Model ◽  
Contractile Activity ◽  
Coronary Perfusion Pressure ◽  
Spontaneous Circulation ◽  
Swine Model ◽  
Coronary Perfusion ◽  
Chest Compressions ◽  
Fraction Of Inspired Oxygen ◽  
External Chest Compressions

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.

scholarly journals Effect of Co-Inoculation of Bacillus sp. Strain with Bacterial Endophytes on Plant Growth and Colonization in Tomato Plant (Solanum lycopersicum)

2021 ◽  
Vol 12 (2) ◽  
pp. 480-490
Author(s):  
Ahsanul Salehin ◽  
Ramesh Raj Puri ◽  
Md Hafizur Rahman Hafiz ◽  
Kazuhito Itoh
Keyword(s):  
Plant Growth ◽  
Solanum Lycopersicum ◽  
Plant Growth Promotion ◽  
Tomato Plant ◽  
Growth Promotion ◽  
Growth Parameters ◽  
The Other ◽  
Time Interval ◽  
Bacillus Sp ◽  
F 33

Colonization of a biofertilizer Bacillus sp. OYK strain, which was isolated from a soil, was compared with three rhizospheric and endophytic Bacillus sp. strains to evaluate the colonization potential of the Bacillus sp. strains with a different origin. Surface-sterilized seeds of tomato (Solanum lycopersicum L. cv. Chika) were sown in the sterilized vermiculite, and four Bacillus sp. strains were each inoculated onto the seed zone. After cultivation in a phytotron, plant growth parameters and populations of the inoculants in the root, shoot, and rhizosphere were determined. In addition, effects of co-inoculation and time interval inoculation of Bacillus sp. F-33 with the other endophytes were examined. All Bacillus sp. strains promoted plant growth except for Bacillus sp. RF-37, and populations of the rhizospheric and endophytic Bacillus sp. strains were 1.4–2.8 orders higher in the tomato plant than that of Bacillus sp. OYK. The plant growth promotion by Bacillus sp. F-33 was reduced by co-inoculation with the other endophytic strains: Klebsiella sp. Sal 1, Enterobacter sp. Sal 3, and Herbaspirillum sp. Sal 6., though the population of Bacillus sp. F-33 maintained or slightly decreased. When Klebsiella sp. Sal 1 was inoculated after Bacillus sp. F-33, the plant growth-promoting effects by Bacillus sp. F-33 were reduced without a reduction of its population, while when Bacillus sp. F-33 was inoculated after Klebsiella sp. Sal 1, the effects were increased in spite of the reduction of its population. Klebsiella sp. Sal 1 colonized dominantly under both conditions. The higher population of rhizospheric and endophytic Bacillus sp. in the plant suggests the importance of the origin of the strains for their colonization. The plant growth promotion and colonization potentials were independently affected by the co-existing microorganisms.

Role of Autonomic Nervous System in Maintenance of Cerebral and Renal Hypertension

1957 ◽  
Vol 188 (2) ◽  
pp. 371-374 ◽  
Author(s):  
Sol Rothman ◽  
Douglas R. Drury
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Renal Hypertension ◽  
The Other ◽  
Peripheral Vasculature ◽  
Blood Pressures ◽  
Sympathetic Nervous ◽  
Blood Pressure Responses

The blood pressure responses to various drugs were investigated in renal hypertensive, cerebral hypertensive and normotensive rabbits. Hexamethonium bromide and Dibenamine reduced the blood pressures of renal and cerebral hypertensives. Effects in the normal were insignificant. The cerebral hypertensive's blood pressure was slightly affected by benzodioxane. Blood pressure was not reduced at all in the other groups. Blood pressure of the renal hypertensive rabbit was greatly reduced by Veriloid and dihydroergocornine. Blood pressures of cerebral and normal animals were affected to a lesser degree. The results suggest that maintenance of hypertension in the cerebral hypertensive rabbit depends on an overactive sympathetic nervous system, possibly due to the release of medullary pressor centers from inhibitory impulses originating in higher centers; whereas, the maintenance of hypertension in the renal hypertensive rabbit may be attributed to an increased reactivity of the peripheral vasculature to a normal sympathetic tone.

THE EMISSION OF IONIZING RADIATION DURING A SPARK DISCHARGE

1957 ◽  
Vol 35 (3) ◽  
pp. 324-331 ◽  
Author(s):  
W. A. Prowse ◽  
G. R. Bainbridge
Keyword(s):  
Ionizing Radiation ◽  
High Voltage ◽  
Voltage Pulse ◽  
High Voltage Pulse ◽  
Spark Discharge ◽  
The Other ◽  
Time Interval ◽  
Delay Lines

A high voltage pulse lasting 0.35 microsecond is applied to a pair of delay lines, so that two pulses can be picked up from adjustable points of connection on the lines. One is applied to an irradiating gap and the other to a longer test gap, the gaps being so arranged that only mid-gap irradiation occurs. The sparking probability, P, of the test gap is used to indicate the presence of ionizing radiation. Variations of P with the time interval between the two pulses are recorded. They indicate that ionizing radiation is emitted in repeated short flashes. Photographic observations support this view.

Effects of Light on Schooling and Feeding of Jack Mackerel, Trachurus symmetricus

1968 ◽  
Vol 25 (2) ◽  
pp. 393-407 ◽  
Author(s):  
John R. Hunter
Keyword(s):  
Motion Picture ◽  
Nearest Neighbor ◽  
Motion Pictures ◽  
Separation Distance ◽  
The Other ◽  
Angular Deviation ◽  
Jack Mackerel ◽  
A Value

Schools of six jack mackerel each were photographed with infrared film at eight levels of luminance and also in darkness. Three indices were used to measure the behavior of the school from motion pictures. Two of the indices, mean distance to nearest neighbor and mean separation distance, were measures of the distances between individuals in a school; the other, mean angular deviation, was a measure of differences in orientation between individuals. A value for each index was calculated for each motion picture frame.From 12.1 to 6 × 10−6 ft-L no differences existed in the angular deviation of the school or in the distances between fish. At 6 × 10−7 ft-L the intervals between fish were much larger than at higher levels of brightness and groups showed little uniformity in their orientation. Below 6 × 10−7 ft-L (darkness) schools were dispersed and the distributions of values of angular deviation were random.The ability of jack mackerel to feed on live adult Artemia was also tested at eight levels of luminance and in darkness. The number of Artemia eaten at 6 × 10−5 ft-L was about half of that eaten at the normal daytime level of 12.1 ft-L. Few Artemia were eaten at 6 × 10−7 ft-L and none in darkness.Comparison of these data with measurements of light in the sea indicated that jack mackerel probably would be able to maintain schools near the surface on a moonless starlit night and that they probably could feed effectively near the surface on a full moonlight night.

ABSENCE OF PHASE TRANSITIONS ON TREE STRUCTURES

1993 ◽  
Vol 07 (29n30) ◽  
pp. 1947-1950 ◽  
Author(s):  
RAFFAELLA BURIONI ◽  
DAVIDE CASSI
Keyword(s):  
Long Range ◽  
Nearest Neighbor ◽  
Linear Chain ◽  
Mean Field ◽  
Range Order ◽  
The Other ◽  
Long Range Order ◽  
Field Phase ◽  
Tree Structures ◽  
Bethe Lattices

We rigorously prove that the correlation functions of any statistical model having a compact transitive symmetry group and nearest-neighbor interactions on any tree structure are equal to the corresponding ones on a linear chain. The exponential decay of the latter implies the absence of long-range order on any tree. On the other hand, for trees with exponential growth such as Bethe lattices, one can show the existence of a particular kind of mean field phase transition without long-range order.

Abstract 17334: The Detrimental Effect of Chest Compression Interruptions on Coronary Perfusion Pressure Dynamics

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Norman A Paradis ◽  
Karen L Moodie ◽  
Christopher L Kaufman ◽  
Joshua W Lampe
Keyword(s):  
Blood Flow ◽  
Chest Compression ◽  
Detrimental Effect ◽  
Perfusion Pressure ◽  
Vena Cava ◽  
Coronary Perfusion Pressure ◽  
Right Atrial ◽  
Coronary Perfusion ◽  
Chest Compressions ◽  
Over Time

Introduction: Guidelines for treatment of cardiac arrest recommend minimizing interruptions in chest compressions based on research indicating that interruptions compromise coronary perfusion pressure (CPP) and blood flow and reducing the likelihood of successful defibrillation. We investigated the dynamics of CPP before, during, and after compression interruptions and how they change over time. Methods: CPR was performed on domestic swine (~30 Kg) using standard physiological monitoring. Blood flow was measured in the abdominal aorta (AAo), the inferior vena cava, the right common carotid and external jugular. Ventricular fibrillation (VF) was electrically induced. Mechanical chest compressions (CC) were started after four minutes of VF. CC were delivered at a rate of 100 compressions per minute (cpm) and at a depth of 2” for a total of 12 min. CPP was calculated as the difference between aortic and right atrial pressure at end-diastole per Utstein guidelines. CPP was determined for 5 compressions prior to the interruption, every 2 seconds during the CC interruption, and for 7 compressions after the interruption. Per protocol, 12 interruptions occurred at randomized time points. Results: Across 12 minutes of CPR, averaged CPP prior to interruption was significantly greater than the averaged CPP after the interruption (22.4±1.0 vs. 15.5±0.73 mmHg). As CPR continued throughout the 12 minutes, CPP during compressions decreased (First 6 min = 24.1±1.4 vs. Last 6 min = 20.1±1.3 mmHg, p=0.05), but the effect of interruptions remained constant resulting in a 20% drop in CPP for every 2 seconds irrespective of the prior CPP. The increase (slope) of CPP after resumption of compressions was significantly reduced over time (First 6 min = 1.47±0.18 vs. Last 6 min = 0.82±0.13 mmHg/compression). Conclusions: Chest compression interruptions have a detrimental effect on coronary perfusion and blood flow. The magnitude of this effect increases over time as a resuscitation effort continues. These data confirm the importance of providing uninterrupted CPR particularly in long duration resuscitations.

Abstract 13248: The Impact of Instructions for Covering the Mouth and the Nose on Dispatch-Assisted Cardiopulmonary Resuscitation

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
Hidetada Fukushima ◽  
Hideki Asai ◽  
Koji Yamamoto ◽  
Yasuyuki Kawai
Keyword(s):  
Cardiopulmonary Resuscitation ◽  
Median Time ◽  
Chest Compression ◽  
Fire Department ◽  
Emergency Call ◽  
Time Interval ◽  
Time Intervals ◽  
Median Time Interval ◽  
Study Results ◽  
The Impact

Introduction: Under the SARS-CoV-2 pandemic, rescuers are recommended to cover their mouth and nose with a facemask or a cloth as well as victim’s mouth and nose when performing cardiopulmonary resuscitation (CPR). However, its impact on dispatch-assisted CPR (DACPR) has not been investigated well. Hypothesis: DACPR including the instruction for covering the rescuer’s and the victim’s mouth and nose can significantly delay the start of the first chest compression. Methods: We retrospectively analyzed DACPR records of the Nara Wide Area Fire Department, covering population of 853,000/3361km 2 , in Japan. We investigated the key time intervals of 505 DACPR records between May 2020 and March 2021. We also compared the results to that of the same period in 2019 (535 records). Results: Dispatchers failed to provide mask instruction in 322 cases (63.8%). The median time interval from the emergency call and the start of CPR instruction was longer in 2020 (197 seconds vs 190 seconds, p=0.641). The time to the first chest compression was also delayed in 2020 (264 seconds vs 246 seconds, p=0.015). Among the cases that dispatchers successfully provided mask instruction (183 cases, 36.2%), median time intervals to the start of instruction and the first chest compression were relatively faster than cases without mask instruction (177 seconds vs 211 seconds and 254 seconds vs 269.5 seconds, respectively). Conclusions: Dispatchers failed to provide mask instruction in the majority of CA cases. However, our study results indicate that the impact of mask instruction on DACPR can be minor in terms of immediate CPR provision.

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.

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