Abstract 240: Comparison of Hemodynamics Generated by Synchronized and Interposed Compressions During Treatment of Pseudo Electro-mechanical Dissociation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Joshua W Lampe ◽  
Jill K Badin ◽  
Lyra Clark ◽  
Jeff R Gould ◽  
Karen L Moodie ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Chest Compression ◽  
Right Atrial ◽  
Compression Rate ◽  
Chest Compressions ◽  
Blood Flows ◽  
Mechanical Dissociation ◽  
Life Threatening ◽  
Integrated Or

Introduction: Pseudo electro-mechanical dissociation (P-EMD) is a cardiac arrest variant characterized by a life-threatening reduction in cardiac output in the presence of organized electrical activity. Synchronization of chest compressions to the R-wave in the ECG may be preferable to the delivery of standard CPR. However, in the bradycardic P-EMD state, synchronization may result in inadequate blood flow due to the low compression/heart rate. This pilot study examined the hemodynamic effect of interposing additional chest compressions between synchronized chest compressions during bradycardic P-EMD to increase the compression rate. Methods: P-EMD was induced via hypoxia in three female swine (~30 kg) and treated with synchronized compressions until the onset of asystole (HR<12 BPM). Interposed compressions were added when the heart rate fell below 60 BPM. A chest compression was classified as synchronized or interposed depending on the presence or absence of a co-incident R-wave. Hemodynamic parameters were integrated or averaged over each compression interval. Results: Synchronized compressions tended to produce larger aortic pressures, larger carotid blood flows, and lower right atrial pressures than interposed compressions. Data from one experiment are shown in Figure 1. The relative hemodynamic benefit of a synchronized chest compression appears to depend on the effectiveness of the underlying heart contraction. The interposed chest compressions generated forward carotid blood flow and increased the compression rate during bradycardia. Discussion: During bradycardic P-EMD, synchronized compressions may generate better hemodynamics than interposed compressions, and the combination of synchronized and interposed compressions may result in more blood flow than the delivery of synchronized compressions alone. Figure 1. Comparison of hemodynamics generated by synchronized compressions (blue) and interposed compressions (red).

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 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.

Chest compression efficacy of child resuscitators

2021 ◽  
Vol 13 (11) ◽  
pp. 448-455
Author(s):  
Tiffany Wai Shan Lau ◽  
Anthony Robert Lim ◽  
Kyra Anne Len ◽  
Loren Gene Yamamoto
Keyword(s):  
Blood Flow ◽  
Cardiopulmonary Resuscitation ◽  
Chest Compression ◽  
Minimum Weight ◽  
Success Rates ◽  
Compression Force ◽  
Chest Compressions ◽  
Traditional Methods ◽  
Video Review ◽  
Brief Training

Background: Chest compression efficacy determines blood flow in cardiopulmonary resuscitation (CPR) and relies on body mechanics, so resuscitator weight matters. Individuals of insufficient weight are incapable of generating a sufficient downward chest compression force using traditional methods. Aims: This study investigated how a resuscitator's weight affects chest compression efficacy, determined the minimum weight required to perform chest compressions and, for children and adults below this minimum weight, examine alternate means to perform chest compressions. Methods: Volunteers aged 8 years and above were enrolled to perform video-recorded, music-facilitated, compression-only CPR on an audible click-confirming manikin for 2 minutes, following brief training. Subjects who failed this proceeded to alternate modalities: chest compressions by jumping on the lower sternum; and squat-bouncing (bouncing the buttocks on the chest). These methods were assessed via video review. Findings: There were 57 subjects. The 30 subjects above 40kg were all able to complete nearly 200 compressions in 2 minutes. Success rates declined in those who weighed less than 40kg. Below 30 kg, only one subject (29.9 kg weight) out of 14 could achieve 200 effective compressions. Nearly all of the 23 subjects who could not perform conventional chest compressions were able to achieve effective chest compressions using alternate methods. Conclusion: A weight below 40kg resulted in a declining ability to perform standard chest compressions effectively. For small resuscitators, the jumping and squat-bouncing methods resulted in sufficient compressions most of the time; however, chest recoil and injuries are concerns.

The effects of artificial lung inflation on pulmonary blood flow and heart rate in the turtle Trachemys scripta.

1997 ◽  
Vol 200 (19) ◽  
pp. 2539-2545
Author(s):  
J Herman ◽  
T Wang ◽  
A W Smits ◽  
J W Hicks
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Lung Volume ◽  
Pulmonary Blood Flow ◽  
Trachemys Scripta ◽  
Spontaneous Ventilation ◽  
Lung Inflation ◽  
Cardiovascular Changes ◽  
Blood Flows ◽  
Stimulation Of

As for most ectothermic vertebrates, the breathing pattern of turtles is episodic, and pulmonary blood flow (Qpul) and heart rate (fH) normally increase several-fold during spontaneous ventilation. While some previous studies suggest that these cardiovascular changes are caused by stimulation of pulmonary stretch receptors (PSRs) during ventilation, it has been noted in other studies that blood flows often change prior to the initiation of breathing. Given the uncertainty regarding the role of PSRs in the regulation of central vascular blood flows, we examined the effect of manipulating lung volume (and therefore PSR stimulation) on blood flows and heart rate in the freshwater turtle Trachemys scripta. Turtles were instrumented with blood flow probes on the left aortic arch and the left pulmonary artery for measurements of blood flow, and catheters were inserted into both lungs for manipulation of lung volume. In both anaesthetized and fully recovered animals, reductions or increases in lung volume by withdrawal of lung gas or injection of air, N2, O2 or 10% CO2 (in room air) had no effect on blood flows. Furthermore, simulations of normal breathing bouts by withdrawal and injection of lung gas did not alter Qpul or fH. We conclude that stimulation of PSRs is not sufficient to elicit cardiovascular changes and that the large increase in Qpul and fH normally observed during spontaneous ventilation are probably caused by a simultaneous feedforward control of central origin.

Abstract 133: Electrical Insulating Gloves for Safe Hands-on Defibrillation Do Not Compromise the Quality of Chest Compressions

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jakob E Thomsen ◽  
Martin Harpsø ◽  
Graham W Petley ◽  
Svend Vittinghus ◽  
Charles D Deakin ◽  
...  
Keyword(s):  
Clinical Examination ◽  
Chest Compression ◽  
Electrical Insulation ◽  
Compression Rate ◽  
Chest Compressions ◽  
Compression Depth ◽  
Resuscitation Guidelines ◽  
Hands On ◽  
Class 1

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.

Regional blood flow in conscious resting rats determined by microsphere distribution

1993 ◽  
Vol 74 (1) ◽  
pp. 203-210 ◽  
Author(s):  
I. Kuwahira ◽  
N. C. Gonzalez ◽  
N. Heisler ◽  
J. Piiper
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Regional Blood Flow ◽  
Sampling Technique ◽  
Organ Blood Flow ◽  
Sprague Dawley ◽  
Blood Flows ◽  
Hindlimb Muscles ◽  
Acclimation Period ◽  
The Difference

To determine organ blood flow in the resting state, a box was designed to keep conscious untrained rats minimally disturbed. Blood pressure, heart rate, and organ blood flow, determined by the microsphere distribution and reference sampling technique, were measured in 11 Sprague-Dawley rats. After an acclimation period, 15-microns-diameter microspheres labeled with 113Sn were infused into the ascending aorta, a reference blood sample was withdrawn from the caudal artery, and organ blood flows were computed according to standard procedures. The average values of heart rate (365 beats/min) and blood flow to the brain (45 ml.min-1.100 g-1) and hindlimb muscles (15 ml.min-1.100 g-1) were significantly lower than most values reported earlier, whereas splanchnic blood flow was significantly higher (106 ml.min-1.100 g-1). Blood flow to the soleus muscle, which is considered the most active for postural maintenance, was relatively high (99 ml.min-1.100 g-1). The combination of low skeletal muscle and high visceral blood flows observed in these experiments suggests a low sympathetic tone, which is consistent with the low level of circulating catecholamines also observed in this study. It is hypothesized that the difference between our present and previous results is a lower level of stress, attributable to a more complete acclimation to the experimental environment.

scholarly journals CPR Compression Rotation Every One Minute Versus Two Minutes: A Randomized Cross-Over Manikin Study

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Nutthapong Pechaksorn ◽  
Veerapong Vattanavanit
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Chest Compression ◽  
Life Support ◽  
Chest Compressions ◽  
Compression Depth ◽  
End Points ◽  
The One ◽  
Support Guidelines

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.

Estimated regional blood flow by rubidium 86 distribution during arousal from hibernation

1962 ◽  
Vol 203 (2) ◽  
pp. 266-270 ◽  
Author(s):  
Robert W. Bullard ◽  
Gordon E. Funkhouser
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Ground Squirrel ◽  
Regional Blood Flow ◽  
Regional Distribution ◽  
Arousal Level ◽  
Blood Flows

The local organ or tissue blood flows during the process of arousal from hibernation have been estimated in the 13-lined ground squirrel by the Sapirstein method, which consists of the measurement of the regional distribution of injected rubidium 86. The studies demonstrated that during arousal there is a confinement of blood flow to the thoracic regions. After the heart rate has attained 100 beats/min, blood flow increases to the anterior portions of the animal. At the arousal level characterized by a heart rate of 200 beats/min, blood flow to anterior and thoracic tissue had attained levels almost equal to control flows. Posterior tissue flows were still much lower than control flows. The centralization of blood flow to thoracic and anterior tissues did not occur in the rat in the hypothermic state.

Effects of inotropic agents on arterial resistance and venous compliance in anesthetized dogs

1982 ◽  
Vol 60 (7) ◽  
pp. 968-976 ◽  
Author(s):  
R. I. Ogilvie
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Time Constant ◽  
Right Atrial ◽  
Fast Time ◽  
Vascular Effects ◽  
Venous Compliance ◽  
Peripheral Vasculature ◽  
Arterial Resistance ◽  
Flat Dose

Systemic vascular effects of dopamine, dobutamine, and prenalterol were studied in 45 anesthetized open-chest dogs. Blood flow [Formula: see text] and right atrial pressure (Pra) were independently controlled by a right heart bypass. Transient changes in central blood volume after an acute reduction in Pra at a constant [Formula: see text] showed that blood was draining from two vascular compartments with different time constants, one fast and the other slow. Dopamine (2.5–10 μg∙kg−1∙min−1) was the most active drug with dose-related increases in heart rate 6–19%, arterial pressure (Pa) 3–36%, and venous compliance 2–25%. Small doses of dopamine (2.5 and 5 μg∙kg−1∙min−1) reduced arterial resistance of the slow time-constant compartment increasing [Formula: see text] distribution to that compartment 21–42%, whereas larger doses increased both arterial resistance and venous compliance in that compartment. Arterial resistance in the fast time-constant compartment increased with all doses of dopamine. Dobutamine (2.5–10 μg∙kg−1∙min−1) modestly increased heart rate 2–11% and Pa 9–12%) without altering [Formula: see text] distribution demonstrating a relatively flat dose response. Dobutamine 2.5–5 μg∙kg−1∙min−1 increased venous compliance 5–10% while 10 μg∙kg−1∙min−1 had no effect or decreased compliance of both compartments. Prenalterol 3 μg∙kg−1∙min−1 increased Pa 9% primarily by increasing arterial resistance in the fast time-constant compartment without altering heart rate or blood flow distribution. Doses of prenalterol 10–100 times greater caused dose-dependent reductions in Pa and vascular compliance. In this animal model of the circulation with a fixed cardiac output, dopamine had the greatest effect on the peripheral vasculature and chronotropy.

Sign in / Sign up

Export Citation Format

Share Document