OBJECTIVE: To compare the effects of different chest compression rates (60-140 times/min) on hemodynamic parameters, return of spontaneous circulation (ROSC), resuscitation success, and survival in a porcine model of cardiac arrest (CA) followed by cardiopulmonary resuscitation (CPR). METHODS: Forty healthy male domestic pigs were randomly divided into five groups based on chest compression rate: 60, 80, 100, 120, and 140 times/min (n = 8). All animals underwent standard anesthesia and tracheal intubation. A catheter was inserted via the left femoral artery into the thoracic aorta to monitor aortic pressure (AOP), and another via the right external jugular vein into the right atrium to monitor right atrial pressure (RAP). In each group, animals were implanted with a stimulating electrode via the right external jugular vein to the endocardium, and ventricular fibrillation (VF) was induced by delivering alternating current stimulation, resulting in CA. After a 1-minute, manual chest compressions were performed at the assigned rate with a compression depth of 5 cm. The first defibrillation was delivered after 2 minutes of CPR. No epinephrine or other pharmacologic agents were administered during the entire resuscitation process. From 1 minute before VF induction to 10 minutes after ROSC, dynamic monitoring of AOP, coronary perfusion pressure (CPP), and partial pressure of end-tidal carbon dioxide (P_ETCO₂). Cortical ultrastructure was examined 24 hours post-ROSC using transmission electron microscopy. RESULTS: With increasing compression rates, both the total number of defibrillations and cumulative defibrillation energy significantly decreased, reaching their lowest levels in the 120 times/min group. The number of defibrillations decreased from (4.88±0.83) times in the 60 times/min group to (2.25±0.71) times in the 120 compressions/min group, and energy from (975.00±166.90)J to (450.00±141.42)J. However, both parameters increased again in the 140 times/min group [(4.75±1.04)times, (950.00±207.02)J], the differences among the groups were statistically significant (both P < 0.01). As compression frequency increased, P_ETCO₂, pre-defibrillation AOP and CPP significantly improved, peaking in the 120 times/min group [compared with the 60 times/min group, P_ETCO₂ (mmHg, 1 mmHg≈0.133 kPa): 18.69±1.98 vs. 8.67±1.30, AOP (mmHg): 95.13±7.06 vs. 71.00±6.41, CPP (mmHg): 14.88±6.92 vs. 8.57±3.42]. However, in the 140 times/min group, these values declined significantly again [P_ETCO₂, AOP, and CPP were (10.59±1.40), (72.38±11.49), and (10.36±4.57) mmHg, respectively], the differences among the groups were statistically significant (all P < 0.01). The number of animals achieving ROSC, successful resuscitation, and 24-hour survival increased with higher compression rates, reaching a peak in the 120 times/min group (compared with the 60 times/min group, ROSC: 7 vs. 2, successful resuscitation: 7 vs. 2, 24-hour survival: 7 vs.1), then decreased again in the 140 times/min group (the animals that ROSC, successfully recovered and survived for 24 hours were 3, 3, and 2, respectively). Transmission electron microscopy revealed that in the 60, 80, and 140 times/min groups, nuclear membranes in cerebral tissue were irregular and incomplete, nucleoli were indistinct, and mitochondria were swollen with reduced cristae and abnormal morphology. In contrast, the 100 times/min and 120 times/min groups exhibited significantly attenuated ultrastructural damage. CONCLUSIONS Among the tested chest compression rates of 60-140 times/min, a chest compressions frequency of 120 times/min is the most favorable hemodynamic profile and outcomes during CPR in a porcine CA model. However, due to the wide spacing between groups, further investigation is needed to determine the optimal compression rate range more precisely.
Animals ; Cardiopulmonary Resuscitation/methods* ; Swine ; Male ; Heart Arrest/therapy* ; Heart Massage/methods* ; Hemodynamics

OBJECTIVE: This study examined the efficacy of new delta carotid sinus massage (CSM) versus conventional CSM (CM). METHODS: This prospective, cross-over study was conducted on 26 healthy volunteers with a normal sinus rhythm. CM and delta CSM (DM) were performed in all participants. In both cases, the CSM was performed, where the maximal carotid pulse was palpated. DM differed from CM in that the physician moves the palpating finger in the opposite direction of the carotid pulse at least twice. The mean and longest R-R intervals and mean and lowest heart rates (HRs) at the baseline and during the procedure for each technique were compared. The mean differences between the baseline and procedure R-R intervals and the HRs for each technique were also evaluated. RESULTS: The baseline mean and longest R-R intervals and baseline mean and lowest HRs were similar both groups (P>0.05). The procedure DM mean and longest R-R intervals (22.7±3.1, 26.4±4.9) were significantly greater than the CM corresponding values (22.0±3.1, 24.6±3.5; P<0.001, P=0.003). Procedure DM mean and lowest HRs (67.3±9.7, 58.6±10.7) were significantly lower than the CM corresponding values (69.4±10.0, 61.8±8.9; P=0.001, P=0.003). The differences in the R-R interval and HR between the procedure and baseline were significant (mean and longest R-R intervals with CM [1.3±1.5 and 2.1±1.9] vs. DM [2.0±1.4 and 3.8±3.1], P<0.001, P=0.004; mean and lowest HRs with CM [4.2±4.3 and 5.8±4.6] vs. DM [6.3±4.6 and 9.1±6.5], P<0.001, P=0.005). CONCLUSION: DM is more effective in generating a more potent vagal tone than CM.
Carotid Sinus ; Cross-Over Studies ; Electrocardiography ; Fingers ; Healthy Volunteers ; Heart Rate ; Massage ; Methods ; Pilot Projects ; Prospective Studies

The change of compressing personnel will inevitably accompany hands off time when cardiopulmonary resuscitation (CPR) is performed by two or more rescuers. The present study assessed whether changing compression by a second rescuer located on the opposite side (OS) of the first rescuer can reduce hands-off time compared to CPR on the same side (SS) when CPR is performed by two rescuers. The scenario of this randomized, controlled, parallel simulation study was compression-only CPR by two laypersons in a pre-hospital situation. Considering sex ratio, 64 participants were matched up in 32 teams equally divided into two gender groups, i.e. , homogenous or heterogeneous. Each team was finally allocated to one of two study groups according to the position of changing compression (SS or OS). Every team performed chest compression for 8 min and 10 sec, with chest compression changed every 2 min. The primary endpoint was cumulative hands-off time. Cumulative hands-off time of the SS group was about 2 sec longer than the OS group, and was significant (6.6 +/- 2.6 sec vs. 4.5 +/- 1.5 sec, P = 0.005). The range of hands off time of the SS group was wider than for the OS group. The mean hands-off times of each rescuer turn significantly shortened with increasing number of turns (P = 0.005). A subgroup analysis in which cumulative hands-off time was divided into three subgroups in 5-sec intervals revealed that about 70% of the SS group was included in subgroups with delayed hands-off time > or = 5 sec, with only 25% of the OS group included in these subgroups (P = 0.033). Changing compression at the OS of each rescuer reduced hands-off time compared to the SS in prehospital hands-only CPR provided by two bystanders.
Cardiopulmonary Resuscitation/methods/*statistics & numerical data ; Clinical Competence/*statistics & numerical data ; Emergency Medical Services/*statistics & numerical data ; Female ; Heart Arrest/epidemiology/*prevention & control ; Heart Massage/methods/*statistics & numerical data ; Humans ; Male ; Republic of Korea/epidemiology ; Treatment Outcome ; Workload/*statistics & numerical data ; Young Adult

Cardiopulmonary resuscitation (CPR) is series of rescue measures for saving cardiac arrest patients. Early initiation and good quality of CPR is crucial for increasing chance of survival from out-of-hospital cardiac arrest. In recent years, the CPR guidelines have changed a lot, especially in basic life support. The guideline now pays more attention on chest compression and less to ventilation. CPR with chest compression only and without mouth-to-mouth ventilation is more popular. In this article, we outline the development and recent researches of CPR. As depriving oxygen from a collapsed patient for 6 min may result in poor outcome, the average time for ambulance transport is longer (about 10 to 16 min) in China, which makes rescuers easy to feel fatigue, chest compression only CPR is not suitable in China. Though non-professional rescuers have difficulty to perform mouth-to-mouth ventilation, they generally show a willingness to do so. To strengthen public standard CPR training including mouth-to-mouth ventilation and chest compression, is most important to promote CPR in China.
Cardiopulmonary Resuscitation ; methods ; China ; Heart Arrest ; Heart Massage ; Humans ; Oxygen ; Respiration, Artificial

To realize the measurement of the chest compression depth during the administration of manual cardiopulmonary resuscitation, two 3-axis digital accelerometers were applied for chest compression acceleration and environment acceleration acquisition, with one placed in the chest compression sensor pad, and the other placed in the back sensor pad. Then double integration was made for the acceleration-to-depth conversion with both of the accelerations after preprocessing. The method further included integration reset mechanism based on compression force, with the force point of a pre-determined threshold and the maximum force point as the starting point and the ending point of the integration, respectively. Moreover, a software compensation algorithm was implemented to further increase the accuracy of the depth estimation and reliability of the acceleration. The final performance of the compression depth estimation is within +/- 0.6 cm with 95% confidence of a total of 283 compressions. Accurate and real-time estimation of chest compression depth greatly facilitates the control of compression depth for the lifesaver during manual cardiopulmonary resuscitation.
Acceleration ; Cardiopulmonary Resuscitation ; instrumentation ; methods ; Heart Arrest ; therapy ; Heart Massage ; methods ; standards ; Humans ; Pressure ; Thorax

No study has examined the effectiveness of backboards and air deflation for achieving adequate chest compression (CC) depth on air mattresses with the typical configurations seen in intensive care units. To determine this efficacy, we measured mattress compression depth (MCD, mm) on these surfaces using dual accelerometers. Eight cardiopulmonary resuscitation providers performed CCs on manikins lying on 4 different surfaces using a visual feedback system. The surfaces were as follows: A, a bed frame; B, a deflated air mattress placed on top of a foam mattress laid on a bed frame; C, a typical air mattress configuration with an inflated air mattress placed on a foam mattress laid on a bed frame; and D, C with a backboard. Deflation of the air mattress decreased MCD significantly (B; 14.74 +/- 1.36 vs C; 30.16 +/- 3.96, P < 0.001). The use of a backboard also decreased MCD (C; 30.16 +/- 3.96 vs D; 25.46 +/- 2.89, P = 0.002). However, deflation of the air mattress decreased MCD more than use of a backboard (B; 14.74 +/- 1.36 vs D; 25.46 +/- 2.89, P = 0.002). The use of a both a backboard and a deflated air mattress in this configuration reduces MCD and thus helps achieve accurate CC depth during cardiopulmonary resuscitation.
Beds ; Cardiopulmonary Resuscitation/*instrumentation/methods ; *Compressive Strength ; Equipment Design ; Heart Massage/*instrumentation/methods ; Humans ; Intensive Care Units ; Manikins ; Prospective Studies

PURPOSE: Dispatcher-assisted telephone instruction during cardiopulmonary resuscitation (CPR) improves the quality of CPR performed by laypersons. However, in Korea, CPR instruction guidelines for bystanders have not made. We therefore studied the effects of verbal instruction on the quality of chest compression. METHODS: Data from two randomized, double-blinded, controlled trials using identical methodology were combined to obtain 175 records for analysis. Subjects were randomized into either a "push as hard as you can and fast" (n=87) or "push down 5~6 cm, 100~120 rate/min" (n=88), verbal instructions in the 2011 Korea Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC). Data were recorded via a Resusci(R) Anne SkillReporter(TM), Laerdal Medical mannequin. Primary outcome measures included chest compression depth and chest compression rate per minute. RESULTS: The average compression depth and speed of chest compressions did not significantly differ between the two verbal instructions. CONCLUSION: The verbal istructions provided by telephone based on the 2011 Korean Guidelines for CPR and ECC are not effective. The instructions for high quality CPR of layperson should therefore be studied.
Cardiopulmonary Resuscitation* ; Emergencies ; Heart Massage ; Korea ; Manikins ; Methods ; Outcome Assessment (Health Care) ; Telephone* ; Thorax ; Verbal Learning

PURPOSE: To evaluate the cooling efficacy and safety of a comprehensive combination method for cooling induction in post-cardiac arrest patients. METHODS: Adult out-of-hospital cardiac arrest (OHCA) patients cooled using combination methods in a tertiary teaching hospital from January 2009 to June 2011were enrolled in the study. Patients were placed into one of two groups: 1) a typical combination (combination I) group, in which cold saline infusion, ice bags,and endovascular cooling were applied, and 2) acomprehensive combination (combination II) group, in which cold saline infusion, ice bags, endovascular cooling, skin exposure, and fanning with ice-water massage were applied. The time from cardiac arrest, return of spontaneous circulation (ROSC), and cooling start to 34degrees C, as well asadverse events during cooling, were recorded. RESULTS: Forty-two out of 125(34%) of OHCA patients with ROSC were cooled usingcombination methods. There were no differences in baseline characteristics between the two combination groups. The time [median (IQR)] from arrest, ROSC, and cooling to 34degrees C of the combination II group were significantly shorter than those of the combination I group [215 min(range 156~270 min) vs. 320 min (range 263-385) for median IQR, p=.002; 189 min (range 135-220 min) vs. 288 min (range 227-358 min) for ROSC, p=.002; 150min (range 120-180 min) vs. 210 min (range 180-260 min) for cooling to 34degrees C, p=.030, respectively]. There were no statistical differences in adverse events during and after cooling induction between the two groups. CONCLUSION: A comprehensive combination cooling method is feasible and capable of reducing the induction time for endovascular cooling in post-cardiac arrest patients.
Adult ; Feasibility Studies* ; Heart Arrest* ; Hospitals, Teaching ; Humans ; Hypothermia ; Ice ; Massage ; Methods ; Out-of-Hospital Cardiac Arrest ; Skin

PURPOSE: To evaluate the cooling efficacy and safety of a comprehensive combination method for cooling induction in post-cardiac arrest patients. METHODS: Adult out-of-hospital cardiac arrest (OHCA) patients cooled using combination methods in a tertiary teaching hospital from January 2009 to June 2011were enrolled in the study. Patients were placed into one of two groups: 1) a typical combination (combination I) group, in which cold saline infusion, ice bags,and endovascular cooling were applied, and 2) acomprehensive combination (combination II) group, in which cold saline infusion, ice bags, endovascular cooling, skin exposure, and fanning with ice-water massage were applied. The time from cardiac arrest, return of spontaneous circulation (ROSC), and cooling start to 34degrees C, as well asadverse events during cooling, were recorded. RESULTS: Forty-two out of 125(34%) of OHCA patients with ROSC were cooled usingcombination methods. There were no differences in baseline characteristics between the two combination groups. The time [median (IQR)] from arrest, ROSC, and cooling to 34degrees C of the combination II group were significantly shorter than those of the combination I group [215 min(range 156~270 min) vs. 320 min (range 263-385) for median IQR, p=.002; 189 min (range 135-220 min) vs. 288 min (range 227-358 min) for ROSC, p=.002; 150min (range 120-180 min) vs. 210 min (range 180-260 min) for cooling to 34degrees C, p=.030, respectively]. There were no statistical differences in adverse events during and after cooling induction between the two groups. CONCLUSION: A comprehensive combination cooling method is feasible and capable of reducing the induction time for endovascular cooling in post-cardiac arrest patients.
Adult ; Feasibility Studies* ; Heart Arrest* ; Hospitals, Teaching ; Humans ; Hypothermia ; Ice ; Massage ; Methods ; Out-of-Hospital Cardiac Arrest ; Skin

PURPOSE: The objective of this study is to evaluate the effects of heat and massage application on autonomic nervous system. MATERIALS AND METHODS: One hundred thirty-nine subjects volunteered and completed this study. Heat and massage was daily applied for 40 minutes, 5 days a week for 2 weeks. Primary-dependent measures included heart rate variability, sympathetic skin response, and serum cortisol and norepinephrine levels. RESULTS: Serum cortisol levels were significantly decreased at 2 weeks compared to baseline (p=0.003). Plasma norepinephrine levels at 4 weeks were significantly decreased compared to baseline (p=0.010). Heart rate, using the power spectra, increased significantly after 2 weeks compared to baseline. Of autonomic nerve conduction measures, latency was significantly increased at 2 and 4 weeks compared to baseline (p=0.023, 0.012), and amplitude was significantly decreased at 4 weeks compared to baseline (p=0.008). There were no serious adverse events such as burns or other major complications. CONCLUSION: The results of this study suggest that heat and massage applications provide relaxation to the autonomic nervous system without serious adverse events.
Autonomic Nervous System/*physiopathology ; Female ; Heart Rate/*physiology ; Hot Temperature/adverse effects/*therapeutic use ; Humans ; Hydrocortisone/blood ; Male ; Massage/adverse effects/*methods ; Norepinephrine/blood