Assessing the relationship between release velocity, compression depth and decompression time in manual chest compressions

Aim: The relationship between force and depth during manual chest compressions depends on the patient and on the dynamics with which the rescuer applies the force. Force-depth models with many fitting parameters have been proposed making physical interpretation complicated. The aim of this work was to design a simpler force-depth model, accommodating anticipated differences in compression and recoil phases. Materials and Methods: Force and acceleration signals were extracted from out-of-hospital-cardiac arrest (OHCA) defibrillator recordings (TVF&R, OR, USA), equipped with CPR technology. Compression depth and velocity signals were computed from acceleration. We analyzed intervals of 20-s within the 1st min of chest compressions. Our model decomposes the applied force as the sum of an elastic and a damped term, considering different damping coefficients for the compression and recoil phases. Coefficient of elasticity was calculated at the instant of maximum compression depth (null velocity) and damping coefficients at the instants of maximum compression and recoil velocities. The estimated depth signal is shown in the figure. The goodness of the model was assessed through the determination coefficient R 2 . Results: We analyzed 1,074 compressions from 30 OHCA recordings. Median (IQR) compression depth was 4.6 (4.0-5.4) cm; compression rate was 107 (102–113) cpm; coefficient of elasticity was 100.67 (78.95–125.01) N/cm; compression damping coefficient was 2.57 (1.84–3.29) N/(cm/s) and recoil damping coefficient was 3.59 (2.58–4.90) N/(cm/s). Median R 2 was 0.993 (0.984–0.996). Conclusions: This model, derived using fewer parameters, could help with the interpretation of the mechanical properties of the chest during CPR. It may also be useful for the assessment of inter-patient differences with age, sex, and body constitution, as well as of the evolution of elasticity and damping of patient’s chest during the course of resuscitation.

Download Full-text

Abstract 122: Compression-Induced Ventilation Volumes Decrease with Chest Compression Depth and Prolonged CPR

Circulation ◽

10.1161/circ.130.suppl_2.122 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Simone Ordelman ◽

Paul Aelen ◽

Paul van Berkom ◽

Gerrit J Noordergraaf

Keyword(s):

Gas Exchange ◽

Endotracheal Tube ◽

Chest Compression ◽

Minute Ventilation ◽

Time Effect ◽

Chest Compressions ◽

Initial Value ◽

Compression Depth ◽

Minute Period ◽

Over Time

Introduction: Compression-induced ventilation may aid gas exchange during CPR. We hypothesized that the amount of gas moving in and out of the lungs depends on chest compression depth. Methods: VF was induced in five female, anesthetized and intubated pigs of about 30 kg. After 30 seconds of non-intervention time, chest compressions were started and maintained at a rate of 100 compressions per minute. Every two minutes chest compression depth was altered, resulting in 14 minutes of CPR with a depth sequence of 4 cm, 3 cm, 4 cm, 5 cm, 5.5 cm, 5 cm and 4 cm. Ventilations were performed manually with a bag-valve device 10 times per minute during continuous chest compressions by a dedicated expert. Airway flow was measured at the end of the endotracheal tube. Compression-induced ventilation was determined from the periods between the manual ventilations. The average compression-induced minute ventilation volume was determined over the last minute of each two minute period of CPR at each specific chest compression depth. Results: The compression-induced ventilation volume in the first period of CPR at 4 cm of depth was 1.6 ± 0.9 L/min (about 4% of total ventilation volume). The figure shows how the compression-induced ventilation volume decreases with increasing chest compression depth, relative to this initial value. CPR with a chest compression depth of 4 cm was performed three times in each pig, and the corresponding compression-induced ventilation volumes decreased with time. This suggested that there might be just a time effect (e.g. atelectasis). However, the final compression depth of 4 cm resulted in larger compression-induced ventilation volumes than the preceding 5 cm and 5.5 cm compression depths, indicating that the decreased volume over time could not purely be a time effect, but must also be an effect of the depth. Conclusion: In conclusion, compression-induced ventilation volume appears to decrease with deeper chest compressions as well as with prolonged CPR.

Download Full-text

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

Circulation ◽

10.1161/circ.130.suppl_2.133 ◽

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.

Download Full-text

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

Emergency Medicine International ◽

10.1155/2020/5479209 ◽

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.

Download Full-text

The Ability to Provide Quality Chest Compressions Over Lacrosse Shoulder Pads

Journal of Athletic Training ◽

10.4085/1062-6050-346-16 ◽

2018 ◽

Vol 53 (2) ◽

pp. 122-127 ◽

Cited By ~ 1

Author(s):

Richard J. Boergers ◽

Thomas G. Bowman ◽

Monica R. Lininger

Keyword(s):

Cardiopulmonary Resuscitation ◽

Patient Outcomes ◽

Perceived Exertion ◽

Outcome Measure ◽

Athletic Trainers ◽

Sudden Cardiac Arrest ◽

Rating Of Perceived Exertion ◽

Chest Compressions ◽

Compression Depth ◽

Placement Accuracy

Context: Performance of quality cardiopulmonary resuscitation is essential for improving patient outcomes. Performing compressions over football equipment inhibits compression depth and rate, but lacrosse equipment has not yet been studied. Objective: To assess the effect of lacrosse shoulder pads on the ability to provide quality chest compressions on simulation manikins. Design: Crossover study. Setting: Simulation laboratory. Patients or Other Participants: Thirty-six athletic trainers (12 men: age = 33.3 ± 9.7 years; 24 women: age = 33.4 ± 9.8 years). Main Outcome Measure(s): No shoulder pads (NSP), Warrior Burn Hitman shoulder pads (WSP), and STX Cell II shoulder pads (SSP) were investigated. Outcomes were chest-compression depth (millimeters), rate (compressions per minute), rating of perceived exertion (0−10), hand-placement accuracy (%), and chest recoil (%). Results: We observed a difference in mean compression depth among shoulder-pad conditions (F2,213 = 3.73, P = .03, ω2 = 0.03), with a shallower depth during the WSP (54.1 ± 5.8 mm) than the NSP (56.8 ± 5.7 mm; P = .02) trials. However, no differences were found in mean compression rate (F2,213 = 0.87, P = .42, ω2 = 0.001, 1–β = .20). We noted a difference in rating of perceived exertion scores (F2,213 = 16.41, P < .001, ω2 = 0.12). Compressions were more difficult during the SSP condition (4.1 ± 1.3) than during the NSP (2.9 ± 1.2; P < .001) and WSP (3.3 ± 1.1; P = .002) conditions. A difference was present in hand-placement accuracy among the 3 shoulder-pad conditions (χ22 = 11.14, P = .004). Hand-placement accuracy was better in the NSP than the SSP condition (P = .002) and the SSP than the WSP condition (P = .001). Conclusions: Lacrosse shoulder pads did not inhibit the ability to administer chest compressions with adequate rate and depth. With appropriate training to improve hand placement, the pads may be left in place while cardiopulmonary resuscitation is initiated during sudden cardiac arrest.

Download Full-text

Comparison of Chest Compression Quality Using Wing Boards versus Walking Next to a Moving Stretcher: A Randomized Crossover Simulation Study

Journal of Clinical Medicine ◽

10.3390/jcm9051584 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1584

Author(s):

Yukako Nakashima ◽

Takeji Saitoh ◽

Hideki Yasui ◽

Masahide Ueno ◽

Kensuke Hotta ◽

...

Keyword(s):

Blood Pressure ◽

Chest Compression ◽

Vital Signs ◽

Borg Scale ◽

Chest Compressions ◽

High Quality ◽

Compression Depth ◽

Hands On ◽

Before And After ◽

Randomized Crossover Study

Background: When a rescuer walks alongside a stretcher and compresses the patient’s chest, the rescuer produces low-quality chest compressions. We hypothesized that a stretcher equipped with wing boards allows for better chest compressions than the conventional method. Methods: In this prospective, randomized, crossover study, we enrolled 45 medical workers and students. They performed hands-on chest compressions to a mannequin on a moving stretcher, while either walking (the walk method) or riding on wings attached to the stretcher (the wing method). The depths of the chest compressions were recorded. The participants’ vital signs were measured before and after the trials. Results: The average compression depth during the wing method (5.40 ± 0.50 cm) was greater than during the walk method (4.85 ± 0.80 cm; p < 0.01). The average compression rates during the two minutes were 215 ± 8 and 217 ± 5 compressions in the walk and wing methods, respectively (p = ns). Changes in blood pressure (14 ± 11 vs. 22 ± 14 mmHg), heart rate (32 ± 13 vs. 58 ± 20 bpm), and modified Borg scale (4 (interquartile range: 2–4) vs. 6 (5–7)) were significantly lower in the wing method cohort compared to the walking cohort (p < 0.01). The rescuer’s size and physique were positively correlated with the chest compression depth during the walk method; however, we found no significant correlation in the wing method. Conclusions: Chest compressions performed on the stretcher while moving using the wing method can produce high-quality chest compressions, especially for rescuers with a smaller size and physique.

Download Full-text

Manual CPR Vs Mechanical CPR: Which One Is More Effective During Ambulance Transport?

10.21203/rs.3.rs-29271/v1 ◽

2020 ◽

Author(s):

İshak Şan ◽

Burak Bekgöz ◽

Mehmet Ergin ◽

Eren Usul

Keyword(s):

Chest Compression ◽

Training Model ◽

Chest Compressions ◽

Compression Depth ◽

Compression Device ◽

Mechanical Chest Compression ◽

Ambulance Transport ◽

Mechanical Cpr ◽

Off Time ◽

Trial Setting

Abstract Objectives We aimed to evaluate and compare the qualities of chest compressions performed manually by healthcare professionals and by a mechanical chest compression device on a training model during an ambulance transfer. DesignThis is an experimental trial. Setting This study was performed by the EMS of Ankara City (Capital of Turkey). 20 (10 male and 10 female) paramedic participated the study. We used LUCAS 2 as mechanical chest compression device in the study. A total of 40 rounds were driven on the track; in that moving ambulance, the model was applied chest compression in 20 rounds by paramedics, while in 20 rounds were applied by mechanical chest compression device. The depth, rate and hands-off time of chest compression were measured by means of the model's recording system. Results The median chest compression rate was 120.1 compressions per minute (IQR 25–75%=117.9–133.5) for the paramedics, whereas it was 102.3 compressions per minute for the mechanical chest compression device (IQR 25–75%=102.1–102.7) (p<0.001). The median chest compression depth was 38.9 millimeters (IQR 25–75%=32.9–45.5) for the paramedics, whereas it was 52.7 millimeters for the mechanical chest compression device (IQR 25–75%=51.8–55.0) (p<0.001). The median hands-off time during cardiopulmonary resuscitation was 6.9% (IQR 25–75=5.0–10.1%) for the paramedics and 9% (IQR 25–75%=8.2–12.5%) (p=0.09). Conclusion Chest compressions performed by the mechanical chest compression device were found to be within the range recommended by the guidelines in terms of both speed and duration.

Download Full-text

Kinect Modelling of Chest Compressions - A Feasibility Study for Chest Compression Depth Measurement Using Digital Strategies

2018 25th IEEE International Conference on Image Processing (ICIP) ◽

10.1109/icip.2018.8451387 ◽

2018 ◽

Author(s):

Oyvind Meinich-Bache ◽

Kjersti Engan ◽

Trygve Eftestol ◽

Ivar Austvoll

Keyword(s):

Feasibility Study ◽

Chest Compression ◽

Chest Compressions ◽

Compression Depth ◽

Depth Measurement

Download Full-text

Abstract 68: Compression Depth Was Correlated with SNR in VF but Not in Nonshockable Rhythms During CPR

Circulation ◽

10.1161/circ.130.suppl_2.68 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Yongqin Li ◽

Yushun Gong ◽

Bihua Chen ◽

Mi He

Keyword(s):

Cardiac Arrest ◽

Adaptive Filters ◽

Signal To Noise Ratio ◽

Pearson Correlation ◽

Pulseless Electrical Activity ◽

Correlation Coefficients ◽

High Sensitivity ◽

Compression Depth ◽

Rhythm Analysis ◽

The Relationship

Introduction: Artifacts produced by chest compression (CC) during cardiopulmonary resuscitation (CPR) preclude reliable automated ECG rhythm analysis. Several filtering techniques have been proposed to remove the artifact with the use of compression related signals as reference. In order to test the performance of the filters, CPR-corrupted signals were usually generated at different signal-to-noise ratio (SNR) levels and the improvements in SNR were evaluated. However, SNR in real cardiac arrest data and the relationship between compression depth (CD) and SNR are still unknown. Method: ECG, together with CD signals were recorded through defibrillators in 146 patients who experienced cardiac arrest and CPR. A total of 306 segments (6 seconds length, sample rate 250Hz), including 152 ventricular fibrillation (VF), 91 pulseless electrical activity (PEA) and 63 asystole were analyzed. Each segment consisted of 3 seconds corrupted and adjacent 3 seconds artifact-free signal. The power of signal was calculated from the artifact-free signal and the power of artifact was obtained through subtracting the power of corrupted ECG by the power of artifact-free signal. The relationship between CD and SNR was tested with Pearson correlation coefficients. Results: The average CD was 4.76±1.24cm. SNR of asystole was significantly lower compared to that of VF and PEA (-21.93±7.37 dB vs. -5.04±8.53 dB and -3.70±7.16 dB, p<0.01). As shown in the Figure, the correlation coefficient was -0.16 (p<0.01) between CD and SNR. When each of the rhythms was investigated individually, negative correlation between CD and SNR was only observed in VF (r =–0.21, p < 0.01). Conclusion: In this patient population, SNR of corrupted ECG was not correlated with CD when the underlying rhythms were non-shockable. This may, at least in part, accounted for the reported high sensitivity but low specificity when adaptive filters were used to remove artifact using CD related signals as reference.

Download Full-text