scholarly journals 36: PEDIATRIC CHEST COMPRESSION DUTY CYCLE USING ARTERIAL PRESSURE WAVEFORMS

2021 ◽  
Vol 50 (1) ◽  
pp. 18-18
Author(s):  
Thomas Rappold ◽  
Ryan Morgan ◽  
Mary Weeks ◽  
Nicholas Widmann ◽  
Kathryn Graham ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Chest Compression ◽  
Duty Cycle ◽  
Pediatric Chest

Effects of tension, duty cycle, and arterial pressure on diaphragmatic blood flow in dogs

1989 ◽  
Vol 66 (2) ◽  
pp. 968-976 ◽  
Author(s):  
S. N. Hussain ◽  
C. Roussos ◽  
S. Magder
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Duty Cycle ◽  
Phrenic Nerve Stimulation ◽  
Gradual Decline ◽  
Transdiaphragmatic Pressure ◽  
Duty Cycles ◽  
Severe Hypotension ◽  
Internal Mammary ◽  
Pressure Part

We investigated the selective effects of changes in transdiaphragmatic pressure (Pdi) and duty cycle on diaphragmatic blood flow in supine dogs at normal arterial pressure (N), moderate hypotension (MH), and severe hypotension (SH) [mean arterial pressure (Part) of 116, 75, and 50 mmHg, respectively]. The diaphragm was paced at a rate of 12/min by bilateral phrenic nerve stimulation. Left phrenic (Qphr-T) and left internal mammary (Qim-T) arterial flows were measured by electromagnetic flow probes. Changes in Pdi and duty cycle were achieved by changing the stimulation frequencies and the duration of contraction, whereas Part changes were produced by bleeding. With N and at a duty cycle of 0.5, incremental increases in Pdi produced peaks in Qphr-T and Qim-T at 30% maximum diaphragmatic pressure (Pdimax) with a gradual decline at higher Pdi. With MH and SH, blood flow peaked at 10% Pdimax. At any given Pdi, blood flow was lower with MH and SH in comparison to N. The effect of duty cycle was tested at two levels of Pdi. With N and at low Pdi (25% Pdimax), blood flow rose progressively with increases in duty cycle, whereas at moderate Pdi level (50% Pdimax) blood flow peaked at a duty cycle of 0.3, with no increase thereafter. With MH, blood flow at low Pdi rose linearly with increasing duty cycle but to a lesser extent than with N, and at a moderate Pdi flow peaked at a duty cycle of 0.3. With SH, blood flow at low and moderate Pdi was limited at duty cycles greater than 0.3 and 0.1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Consistency and variability in human performance during simulate infant CPR: a reliability study

2020 ◽  
Vol 28 (1) ◽  
Author(s):  
Debora Almeida ◽  
Carol Clark ◽  
Michael Jones ◽  
Phillip McConnell ◽  
Jonathan Williams
Keyword(s):  
Chest Compression ◽  
Duty Cycle ◽  
Repeated Measures ◽  
Human Performance ◽  
Life Support ◽  
Intraclass Correlation ◽  
Minimal Detectable Change ◽  
Compression Rate ◽  
Quality Indices ◽  
Compression Depth

Abstract Background Positive outcomes from infant cardiac arrest depend on the effective delivery of resuscitation techniques, including good quality infant cardiopulmonary resuscitation (iCPR) However, it has been established that iCPR skills decay within weeks or months after training. It is not known if the change in performance should be considered true change or inconsistent performance. The aim of this study was to investigate consistency and variability in human performance during iCPR. Methods An experimental, prospective, observational study conducted within a university setting with 27 healthcare students (mean (SD) age 32.6 (11.6) years, 74.1% female). On completion of paediatric basic life support (BLS) training, participants performed three trials of 2-min iCPR on a modified infant manikin on two occasions (immediately after training and after 1 week), where performance data were captured. Main outcome measures were within-day and between-day repeated measures reliability estimates, determined using Intraclass Correlation Coefficients (ICCs), Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC95%) for chest compression rate, chest compression depth, residual leaning and duty cycle along with the conversion of these into quality indices according to international guidelines. Results A high degree of reliability was found for within-day and between-day for each variable with good to excellent ICCs and narrow confidence intervals. SEM values were low, demonstrating excellent consistency in repeated performance. Within-day MDC values were low for chest compression depth and chest compression rate (6 and 9%) and higher for duty cycle (15%) and residual leaning (22%). Between-day MDC values were low for chest compression depth and chest compression rate (3 and 7%) and higher for duty cycle (21%) and residual leaning (22%). Reliability reduced when metrics were transformed in quality indices. Conclusion iCPR skills are highly repeatable and consistent, demonstrating that changes in performance after training can be considered skill decay. However, when the metrics are transformed in quality indices, large changes are required to be confident of real change.

Abstract 358: Three-Sided Chest Compression is Beneficial to Rats Suffering From Cardiac Arrest

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Yu Okuma ◽  
Koichiro Shinozaki ◽  
Tsukasa Yagi ◽  
Kota Saeki ◽  
Tai Yin ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Arterial Pressure ◽  
Cardiac Function ◽  
Chest Compression ◽  
Cerebral Oxygenation ◽  
Intrathoracic Pressure ◽  
Spontaneous Circulation ◽  
Left Ventricular ◽  
Sprague Dawley ◽  
Targeted Interventions

Objective: Rat models are necessary to study targeted interventions to improve survivability in patients suffered from a cardiac arrest (CA). For translational researchers, increasing the rate of return of spontaneous circulation (ROSC) is important to reduce the number of rats being used to obtain sufficient data. Yet, few studies have demonstrated how to perform better chest compression on rats. Methods: Rats underwent 10 min of asphyxia to induce CA. All rats were placed in a supine position. Three types of chest compression were examined: 1-sided method (classic) with 2 fingers on the sternum; 2-sided method with 2 fingers on the chest from both sides; and the 3-sided method with 2 hands (2 fingers on the sternum and with 2 fingers on the chest). ROSC rates, cardiac function, arterial pressure(s), intrathoracic pressure, cerebral oxygenation, and end-tidal CO 2 (EtCO 2 ) were measured. In addition, survival after 14-min asphyxia was assessed. Results: Male Sprague-Dawley rats were used and there were no differences in chest compression rates among the three groups. The ROSC rate was 100% (8/8) with the 3-sided method, 80% (4/5) with the 1-sided method, and 60% (3/5) with the 2-sided method. The 3-sided group showed significantly shorter time to ROSC (105.0±36.0 sec for the 1-sided method vs.141.0±21.7 sec for the 2-sided method vs. 57.8±12.3 sec for the 3-sided method, p<.05). The 3-sided method significantly increased the left ventricular stroke volume (the ratio of baseline: 1.2±0.6, 1.3±0.1, vs. 2.1±0.6, p<.05) and pressure (24.0±5.5, 19.8±3.4, vs. 29.4±1.8 mmHg, p<.05), the difference of common carotid arterial pressure to femoral artery pressure (4.0±2.5, 0.3±1.6, vs. 8.4±2.6 mmHg, p<.01), intrathoracic pressure (esophagus: 7.6±1.9, 7.3±2.8, vs. 12.7±2.2 mmHg, p<.01), cerebral oxygenation (the ratio of baseline: 1.4±0.1, 1.3±0.2, vs. 1.6±0.04, p<.05) and EtCO 2 (the ratio of baseline: 12.4±2.0, 14.2±1.9, vs. 17.5±1.7 mmHg, p<.05). The 3-sided chest compression achieved 75% (3/4) ROSC from 14-min asphyxia CA. Conclusions: The 3-sided chest compression was associated with the most successful ROSC. It is likely that the 3-sided method increased intrathoracic pressure and stabilized cardiac function, which might be beneficial to the brain.

Abstract 206: Cardiopulmonary Resuscitation Process Measures Associated With Return of Spontaneous Circulation in Non-Shockable Out-of-Hospital Cardiac Arrest

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Jose M Juarez ◽  
Allison C Koller ◽  
Robert H Schmicker ◽  
Seo Young Park ◽  
David D Salcido ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cardiopulmonary Resuscitation ◽  
Chest Compression ◽  
Duty Cycle ◽  
Spontaneous Circulation ◽  
Research Network ◽  
Process Measures ◽  
Return Of Spontaneous Circulation ◽  
Shockable Rhythm ◽  
Hospital Cardiac Arrest

Purpose: Survival rates after non-shockable out-of-hospital cardiac arrest (OHCA) remain low despite advances in resuscitation. Cardiopulmonary resuscitation (CPR) process measures may inform treatment strategies. We hypothesized that CPR process measures would be associated with return of spontaneous circulation (ROSC) and patient electrocardiogram (ECG) transitions. Methods: We obtained defibrillator monitor data for emergency medical service (EMS)-treated non-shockable OHCA from the Resuscitation Outcomes Consortium (ROC), an OHCA research network (U.S./Canada). We extracted ECG data from EMS defibrillator files and parsed cases into compression-free analyzable segments using custom MATLAB software. Two data abstractors classified segment rhythms as PEA, asystole, ventricular fibrillation (VF), pulseless ventricular tachycardia (PVT), or ROSC. We calculated CPR process measures (average rate, depth, duration, leaning proportion, chest compression fraction, and duty cycle) for CPR bouts preceding every ECG segment. We used mixed effects models controlling for subject to test associations between individual CPR process measures and the bout-level outcomes ROSC and shockable rhythm. Results: We analyzed 1893 cases consisting of 7981 CPR bouts. Case initial rhythms were asystole (68.2%), PEA (24.9%), or NSA-AED (6.9%). Segment rhythm classifications were asystole (78.1%), PEA (20.4%), ROSC (5.5%), VF (1.4%), and PVT (0.07%). Regression model results are shown in Table 1. Chest compression fraction was most strongly associated with ROSC and shockable rhythm. Depth was also associated with shockable rhythm. Leaning proportion and duty cycle were not associated with either outcome. Conclusions: In cases of non-shockable OHCA, CPR quality measures were associated with ROSC and transition to a shockable rhythm at the bout level.

scholarly journals Combination of cardiac and thoracic pump theories in rodent cardiopulmonary resuscitation: a new method of three-side chest compression

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Yu Okuma ◽  
Koichiro Shinozaki ◽  
Tsukasa Yagi ◽  
Kota Saeki ◽  
Tai Yin ◽  
...  
Keyword(s):  
Cardiopulmonary Resuscitation ◽  
Arterial Pressure ◽  
Brain Tissue ◽  
Chest Compression ◽  
Intrathoracic Pressure ◽  
Left Ventricular ◽  
Side Group ◽  
Sprague Dawley ◽  
Tissue Oxygen ◽  
Brain Tissue Oxygen

Abstract Background High-quality cardiopulmonary resuscitation (HQ-CPR) is of paramount importance to improve neurological outcomes of cardiac arrest (CA). The purpose of this study was to evaluate chest compression methods by combining two theories: cardiac and thoracic pumps. Methods Male Sprague-Dawley rats were used. Three types of chest compression methods were studied. The 1-side method was performed vertically with 2 fingers over the sternum. The 2-side method was performed horizontally with 2 fingers, bilaterally squeezing the chest wall. The 3-side method combined the 1-side and the 2-side methods. Rats underwent 10 min of asphyxial CA. We examined ROSC rates, the left ventricular functions, several arterial pressures, intrathoracic pressure, and brain tissue oxygen. Results The 3-side group achieved 100% return of spontaneous circulation (ROSC) from asphyxial CA, while the 1-side group and 2-side group achieved 80% and 60% ROSC, respectively. Three-side chest compression significantly shortened the time for ROSC among the groups (1-side, 105 ± 36.0; 2-side, 141 ± 21.7; 3-side, 57.8 ± 12.3 s, respectively, P < 0.05). Three-side significantly increased the intrathoracic pressure (esophagus, 7.6 ± 1.9, 7.3 ± 2.8, vs. 12.7 ± 2.2; mmHg, P < 0.01), the cardiac stroke volume (the ratio of the baseline 1.2 ± 0.6, 1.3 ± 0.1, vs. 2.1 ± 0.6, P < 0.05), and the common carotid arterial pressure (subtracted by femoral arterial pressure 4.0 ± 2.5, 0.3 ± 1.6, vs. 8.4 ± 2.6; mmHg, P < 0.01). Three-side significantly increased the brain tissue oxygen (the ratio of baseline 1.4±0.1, 1.3±0.2, vs. 1.6 ± 0.04, P < 0.05). Conclusions These results suggest that increased intrathoracic pressure by 3-side CPR improves the cardiac output, which may in turn help brain oxygenation during CPR.

scholarly journals Can real-time feedback improve the simulated infant cardiopulmonary resuscitation performance of basic life support and lay rescuers?

2019 ◽  
Vol 104 (8) ◽  
pp. 793-801 ◽  
Author(s):  
Jeyapal Kandasamy ◽  
Peter S Theobald ◽  
Ian K Maconochie ◽  
Michael D Jones
Keyword(s):  
Cardiopulmonary Resuscitation ◽  
Real Time ◽  
Chest Compression ◽  
Duty Cycle ◽  
Basic Life Support ◽  
Life Support ◽  
Cycle Performance ◽  
Chest Compressions ◽  
High Quality ◽  
Single Measure

BackgroundPerforming high-quality chest compressions during cardiopulmonary resuscitation (CPR) requires achieving of a target depth, release force, rate and duty cycle.ObjectiveThis study evaluates whether ‘real time’ feedback could improve infant CPR performance in basic life support-trained (BLS) and lay rescuers. It also investigates whether delivering rescue breaths hinders performing high-quality chest compressions. Also, this study reports raw data from the two methods used to calculate duty cycle performance.MethodologyBLS (n=28) and lay (n=38) rescuers were randomly allocated to respective ‘feedback’ or ‘no-feedback’ groups, to perform two-thumb chest compressions on an instrumented infant manikin. Chest compression performance was then investigated across three compression algorithms (compression only; five rescue breaths then compression only; five rescue breaths then 15:2 compressions). Two different routes to calculate duty cycle were also investigated, due to conflicting instruction in the literature.ResultsNo-feedback BLS and lay groups demonstrated <3% compliance against each performance target. The feedback rescuers produced 20-fold and 10-fold increases in BLS and lay cohorts, respectively, achieving all targets concurrently in >60% and >25% of all chest compressions, across all three algorithms. Performing rescue breaths did not impede chest compression quality.ConclusionsA feedback system has great potential to improve infant CPR performance, especially in cohorts that have an underlying understanding of the technique. The addition of rescue breaths—a potential distraction—did not negatively influence chest compression quality. Duty cycle performance depended on the calculation method, meaning there is an urgent requirement to agree a single measure.

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