Resuscitation from cardiac arrest in cats: influence of epinephrine dosage on brain recovery

The quality of brain recovery after cardiac arrest depends crucially on the speed of cardiac resuscitation because the low cerebral perfusion pressure during the resuscitation procedure facilitates the development of no-reflow. To accelerate return of spontaneous circulation, high dose epinephrine has been recommended but the effect on the dynamics of early brain recovery is still unknown. We, therefore, studied the dynamics of brain resuscitation after cardiopulmonary resuscitation (CPR) with standard and high dose epinephrine using non-invasive NMR techniques. Fifteen min cardiac arrest was induced in normothermic cats by ventricular fibrillation. CPR was performed using an inflatable pneumatic vest for cyclic chest compression. With the beginning of CPR the standard dose group received 0.02 mg/kg epinephrine (n = 6) and the high dose group received 0.2 mg/kg (n = 8). Brain recovery was monitored by magnetic resonance imaging of the apparent diffusion coefficient (ADC) of water for 3 h. Although high dose epinephrine treatment led to a significantly higher blood pressure during early reperfusion, rapidly changing heterogeneities of early brain recovery were observed in both groups. High dose epinephrine thus does not improve the quality of post-cardiac arrest brain recovery during the first 3 h of reperfusion.     

Neurologically intact survivor of prolonged ventricular fibrillation: a case for intermediate dose epinephrine and postresuscitation infusion.

The authors point out that our understanding of the optimal dose of epinephrine used in the resuscitation of patients in cardiac arrest continues to evolve. Doses greater than the standard 1 mg of epinephrine every 5 minutes have been studied and shown to increase the rate of return of spontaneous circulation. However, reports of neurologically intact survivors of prolonged cardiac arrest are rare. The authors report a neurologically intact survivor of prolonged ventricular fibrillation with severe mixed acidosis who responded to intermediate doses of epinephrine and epinephrine infusion, where standard amounts had failed. Further research should be directed into the relationship between postresuscitation epinephrine infusions and neurologic outcome.     

Cardiovascular response to epinephrine varies with increasing duration of cardiac arrest

OBJECTIVE: Epinephrine (adrenaline) is widely used as a primary adjuvant for improving perfusion pressure and resuscitation rates during cardiopulmonary resuscitation (CPR). Epinephrine is also associated with significant myocardial dysfunction in the post-resuscitation period. We tested the hypothesis that the cardiac effects of epinephrine vary according to the duration of cardiac arrest. METHODS AND MATERIALS: Cardiac arrest (CA) was induced in Sprague-Dawley rats with an IV bolus of KCl (40 microg/g). Three series of experiments were performed with CPR begun after 2, 4, or 6 min of cardiac arrest. Epinephrine (0.01 mg/kg) IV or placebo was given immediately in the 2 and 4 min CA groups. In the 6 min group, CPR was started after 6 min CA and epinephrine was given at 15 min if no return of spontaneous circulation (ROSC) occurred. Time to ROSC was recorded in all groups. Cardiac function was determined with trans-thoracic echocardiography at baseline, 5, 30 and 60 min after ROSC. RESULTS: After 2 min CA, 8/8 (100%) placebo animals and 8/8 (100%) epinephrine animals attained ROSC. Cardiac index was significantly increased during the first 60 min in the epinephrine group compared with the placebo group (p<0.01). After 4 min of cardiac arrest, 14/29 (48%) placebo animals and 14/16 (88%) epinephrine animals attained ROSC (p<0.01). Cardiac index after ROSC returned to baseline in both groups, although tended to be lower in the epinephrine group. After 6 min CA, 10/31 (32%) animals attained ROSC without epinephrine and 17/21 (81%) animals with epinephrine (p<0.01). Post-ROSC depression of cardiac index was greatest in the epinephrine group (p<0.05). CONCLUSIONS: As the duration of cardiac arrest increases, a paradoxical myocardial epinephrine response develops, in which epinephrine becomes increasingly more important to attain ROSC, but is increasingly associated with post-ROSC myocardial depression.     

延迟使用升压素与肾上腺素在窒息家兔心肺复苏中的疗效比较

目的 观察心肺复苏时延迟使用升压素或肾上腺素对自主循环恢复率的影响，比较两者对窒息性心跳停搏家兔心肺复苏的疗效。方法 62只家兔均在呼气末夹闭气管8min，造成窒息性心脏停搏模型后，开始人工胸外心脏按压及机械通气，期间不用任何药物，复苏5min内恢复自主循环的家兔定义为常规心肺复苏成功，对5min内复苏不成功者，再随机分为两组，分别给予升压素（0．8IU／kg）或肾上腺素（0．2mg／kg）静脉注射，并继续常规心肺复苏：结果 常规心肺复苏的自主循环恢复率为24．19％（15／62），加用升压素和肾上腺素后总的自主循环恢复率提高到48．39％（30／62）。其中升压素组23只家兔中2只复苏成功（8．70％），肾上腺素组24只家兔中13只复苏成功（54．16％），肾上腺素组复苏成功率明显高于升压素组（P=0．001）。结论 对窒息性心脏停搏的家兔心肺复苏时应用升压素或肾上腺素可提高自主循环恢复率。肾上腺素在提高窒息家兔冠脉灌注压及复苏成功率方面明显优于升压素。     

不同剂量肾上腺素对大鼠心肺复苏的影响

[目的]探讨不同剂量肾上腺素对大鼠心肺复苏的影响.[方法]选用清洁级雄性SpragueDawley（SD）大鼠32只分为两组,采用呼气末夹闭气管窒息致大鼠心脏骤停,夹闭5 min后开始心肺复苏,给予不同剂量肾上腺素（0.02 mg/kg,小剂量组;0.2 mg/kg,大剂量组）,记录心率、血压的变化,自主循环恢复（ROSC）的时间,1 h和6 h存活率.[结果]造模后约1～2 min所有大鼠均出现心脏骤停,小剂量组与大剂量组复苏成功率分别为69%和74%,ROSC时间分别为（155±78）s、（85±25）s,1 h存活率分别为89%和86%,6 h存活率分别为44%和57%.两组复苏成功率,6 h存活率相比较差异无显著性（P〉0.05）;而1 h存活率,ROSC时间相比较差异有显著性（P〈0.05）.[结论]0.2 mg/kg肾上腺素用于大鼠心肺复苏较0.02 mg/kg可明显减少心脏按压时间,缩短ROSC时间,但对提高复苏成功率和6 h存活率无明显差异,反而会降低1 h存活率.     

Vasopressin improves vital organ blood flow after prolonged cardiac arrest with postcountershock pulseless electrical activity in pigs

OBJECTIVE: Although a benefit of vasopressin when compared with epinephrine was shown during cardiopulmonary resuscitation (CPR) after a short duration of ventricular fibrillation cardiac arrest, the effect of vasopressin during prolonged cardiac arrest with pulseless electrical activity is currently unknown. DESIGN: Prospective, randomized laboratory investigation using an established porcine model with instrumentation for measurement of hemodynamic variables, vital organ blood flow, blood gases, and return of spontaneous circulation. SETTING: University hospital laboratory. SUBJECTS: Eighteen domestic pigs. INTERVENTIONS: After 15 mins of cardiac arrest and 3 mins of chest compressions, 18 animals were randomly treated with either 0.8 units/kg vasopressin (n = 9) or 200 microg/kg epinephrine (n = 9). MEASUREMENTS AND MAIN RESULTS: Compared with epinephrine, vasopressin resulted, at both 90 secs and 5 mins after drug administration, in significantly higher (p < .05) median (25th-75th percentiles) left ventricular myocardial blood flow (120 [range, 96-193] vs. 54 [range, 11-92] and 56 [range, 41-80] vs. 21 [range, 11-40] mL/min/100 g, respectively) and total cerebral blood flow (85 [78-102] vs. 24 [18-41] and 50 [44-52] vs. 8 [5-23] mL/min/100 g, respectively). Spontaneous circulation was restored in eight of nine animals in the vasopressin group and in one of nine animals in the epinephrine group (p = .003). CONCLUSIONS: Compared with a maximum dose of epinephrine, vasopressin significantly increased left ventricular myocardial and total cerebral blood flow during CPR and return of spontaneous circulation in a porcine model of prolonged cardiac arrest with postcountershock pulseless electrical activity.     

Association of delay to first intervention with return of spontaneous circulation in a swine model of cardiac arrest

OBJECTIVE: No single drug improves survival after cardiac arrest, despite success in animal studies. We sought to determine the duration of circulatory arrest after which maximal drug treatment and a rescue shock would fail to achieve return of spontaneous circulation (ROSC). DESIGN/SUBJECTS: Retrospective analysis of 271 swine (20-30 kg) resuscitation attempts during ventricular fibrillation. Protocols were divided into five categories: immediate countershock, cardiopulmonary resuscitation (CPR) with standard-dose drugs, CPR alone, CPR and high-dose epinephrine (CPR+HDE) (0.1 mg/kg), and CPR with a drug cocktail (CPR+DC) of propanolol (1 mg), epinephrine (adrenaline) (0.1 mg/kg) and vasopressin (40IU). Time to first CPR, time to first drug administration, time to first shock, and protocol were examined as predictors of ROSC using logistic regression with Hosmer-Lemeshow test of fit. Probability of ROSC was calculated from logistic curves. MAIN RESULTS: ROSC occurred in 119 of the 271 swine (44%). Time to first drug and the CPR+DC group were predictors of ROSC. Time to first CPR, the CPR+DC group, and the CPR+HDE group were also predictors of ROSC. Time to first rescue shock, the CPR+DC group, and the CPR+HDE groups were predictors of ROSC. In the CPR+DC group, 50% ROSC occurred at a first CPR time of 13.4 min, first drug time of 14.1 min and first rescue shock time of 17.5 min. CONCLUSIONS: Pre-shock delivery of CPR+DC increases the likelihood of ROSC, and reaches 50% with a time of drug delivery of 14.1 min. ROSC rates of 50% may be achievable using an optimized resuscitation in experimental CPR.     

Dose-response of vasopressin in a rat model of asphyxial cardiac arrest

The advantage of vasopressin over epinephrine in the treatment of cardiac arrest (CA) is still being debated, and it is not clear whether a high dose of vasopressin is beneficial or detrimental during or after cardiopulmonary resuscitation (CPR) in a rat model of CA. In this study, asphyxial CA was induced in 40 male Sprague-Dawley rats. After 10 minutes of asphyxia, CPR was initiated; and the effects of different doses of vasopressin (low dose, 0.4 U/kg; medium dose, 0.8 U/kg; and high dose, 2.4 U/kg; intravenous; n = 10 in each group) and a saline control (isotonic sodium chloride solution, 1 mL, intravenous) were compared. Outcome measures included the rate of restoration of spontaneous circulation (ROSC) and changes of hemodynamic and respiratory variables after ROSC. The rates of ROSC were 1 of 10 in the saline group and 8 of 10 in each of the 3 vasopressin groups. There were no differences in mean aortic pressure or changes of respiratory function after CPR among the vasopressin groups. However, the heart rate was lower in the high-dose vasopressin group than in the low- and medium-dose groups. These findings indicate that different doses of vasopressin result in a similar outcome of CPR, with no additional benefits afforded by a high dose of vasopressin during or after CPR, in a rat model of asphyxial CA. The mechanism and physiologic significance of the relative bradycardia that occurred in the high-dose vasopressin group are currently unknown and require further investigation.     

窒息家兔心肺复苏疗效与血浆内皮素变化的关系

目的探讨窒息家兔心肺复苏(cardiopulmonaryresuscitation,CPR)疗效与血浆内皮素(endothelin,ET)变化的关系。方法对62只家兔均在呼气末夹闭气管8min,造成窒息性心脏停搏模型后,开始人工胸外心脏按压及机械通气,期间不用任何药物,复苏5min内恢复自主循环(restorationof spontaneouscirculation,ROSC)的家兔定义为常规CPR成功;对5min内未能ROSC者再随机分为两组,分别给予肾上腺素(0.2mg kg)和加压素(0.8U kg)静脉注射,并继续行常规CPR。分别在窒息前和CPR15、60、120min采血测血浆ET浓度。结果常规CPR的家兔ROSC率为24.16%(1562),加用肾上腺素和加压素后总的ROSC率提高到48.39%(3062)。对常规CPR失败的家兔而言,肾上腺素疗效明显优于加压素(ROSC率分别为54.16%和8.70%,P=0.001)。但复苏成功组和复苏失败组家兔血浆ET的比较,差异无显著性。结论对窒息性心脏停搏的家兔CPR时应用肾上腺素或加压素可提高ROSC率,但肾上腺素疗效明显优于加压素。窒息家兔CPR疗效与血浆内皮素变化无明显相关关系。     

加压素与肾上腺素在小鼠心肺复苏中的疗效比较

目的 比较加压素与肾上腺素在小鼠心肺复苏中的疗效.方法 30只雄性昆明小鼠经食道快速起搏心窒诱发室颤、建立心搏骤停模型,起搏开始后4 min将小鼠随机分成3组(n=10/组):对照组(Sal-gro)、加压素组(Vas-gro)、肾上腺素组(Epi-gro),分别经动脉注射药物(生理盐水、加压素0.4 U/kg和肾上腺素0.04mg/kg)1次,开始胸外心脏按压及机械通气,观察自主循环恢复情况,10min无效则放弃复苏.自主循环恢复的小鼠连续监测心电和血压60 min,观察血压、心率、呼吸恢复情况及生存时间.结果 加压素与肾上腺素组小鼠的自主循环恢复率均显著高于对照组(9/10,10/10和3/10,P＜0.05,P＜0.01).加压素与肾上腺素组组间比较差异无统计学意义(P＞0.05).肾上腺素组小鼠在自主循环恢复后全部出现自主呼吸,而加压素组小鼠只有4只出现自主呼吸(P＜0.05).肾上腺素组小鼠的生存时间明显长于加压素组和对照组小鼠(P＜0.05,P＜0.05).结论 加压素和肾上腺素均可显著提高心搏骤停小鼠的自主循环恢复率,但0.04 mg/kg的肾上腺素对自主循环恢复后小鼠呼吸功能及生存时间的影响明显优于0.4 U/k的加压素,其机制尚不清楚,还有待进一步研究.     

Effects of epinephrine in a pig model of hypothermic cardiac arrest and closed-chest cardiopulmonary resuscitation combined with active rewarming

OBJECTIVE: The aim of the current study was to assess the effects of epinephrine in a pig model of hypothermic cardiac arrest followed by closed-chest cardiopulmonary resuscitation combined with active rewarming, simulating the clinical management of an arrested hypothermic patient in a hospital without cardiopulmonary bypass facilities. DESIGN: Prospective, randomized animal study. SETTING: University research laboratory. SUBJECTS: Twelve 12- to 16-week-old domestic pigs. INTERVENTIONS: Pigs were surface cooled to a body core temperature of 28 degrees C. After 4 min of untreated cardiac arrest, manual closed-chest CPR and thoracic lavage with 40 degrees C warmed fluid were started. After 3 min of external chest compression animals were randomly assigned to receive epinephrine (45, 45 and 200 microg/kg) or saline placebo in 5-min intervals. MEASUREMENTS AND MAIN RESULTS: Coronary perfusion pressure was about 15 mmHg in placebo group pigs. Coronary perfusion pressure was significantly higher after epinephrine, but restoration of spontaneous circulation was not more frequent (one of six epinephrine versus three of six saline placebo pigs, P=0.34). After 45 microg/kg epinephrine the arterial PO(2) was significantly lower when compared to the saline placebo. The third 200 microg/kg epinephrine dose resulted in a significantly enhanced mixed venous hypercarbic acidosis. CONCLUSIONS: After a short 4-min period of hypothermic cardiac arrest, epinephrine may not be necessary to maintain coronary perfusion pressure around the threshold usually correlating with successful defibrillation, even during prolonged closed-chest CPR combined with active rewarming. The enhanced mixed venous hypercarbic acidosis in epinephrine-treated animals may support the argument against repeated or high dose epinephrine administration during hypothermic CPR.     

在院前心肺复苏中血管加压素的临床研究

目的：研究血管加压素在院前心肺复苏（CPR）中的疗效。方法：在103例心脏骤停患者中随机分为3组，标准肾上腺素组（A组）38例，血管加压素组（B组）34例，肾上腺素＋血管加压素组（C组）31例，各组分别观察自主循环恢复率、24h存活率、出院存活率、脑复苏率、自主循环恢复时间及复苏后心肌酶变化。结果：B组（44％）、C组（42％）自主循环恢复率明显高于A组（16％），B组（38％）、C组（39％）24h存活率也明显高于A组（13％），C组出院存活率（23％）高于A组（8％）、B组（12％）；脑复苏率3组无差异；B组、C组自主循环恢复时间明显短于A组；复苏后心肌酶变化3组无差异。结论：在心肺复苏期间应用血管加压素比用肾上腺素可明显提高自主循环恢复率、24h存活率，缩短自主循环恢复时间，与肾上腺素联合应用还可提高出院存活率。     

Aortic-carotid artery pressure differences and cephalic perfusion pressure during cardiopulmonary resuscitation in humans.

OBJECTIVE: Animal studies have shown an aortic-carotid artery pressure difference during cardiopulmonary resuscitation (CPR), which compromises cerebral perfusion. This pressure difference is most marked with prolonged CPR and can be abolished with administration of high doses of epinephrine. To better understand the mechanism of cerebral blood flow during CPR in humans, we determined the aortic-carotid artery pressure difference, the cephalic perfusion pressure (the carotid artery-jugular vein pressure difference), and thoracic inlet venous "valving" (the central venous-jugular vein pressure difference), while administering standard doses of epinephrine. DESIGN: Prospective study with randomization as to which side the carotid artery was catheterized. SETTING: The resuscitation room of a large urban hospital's emergency department. PATIENTS: Fifteen adults in normothermic, nontraumatic prehospital cardiac arrest treated according to Advanced Cardiac Life Support guidelines, including administration of 1 mg epinephrine iv every 5 mins. INTERVENTIONS: The descending aorta, cervical common carotid artery, internal jugular vein, and central venous system were catheterized. Pressures were recorded during standard CPR for 5 mins after administration of 1 mg epinephrine iv. MEASUREMENTS AND MAIN RESULTS: Most patients received CPR for greater than 20 mins before the first epinephrine dose and for greater than 45 mins before pressure recording as described above. There was no significant difference between aortic and carotid artery compression and relaxation phase pressures. The mean +/- SD compression central venous-jugular vein pressure difference was 22.1 +/- 15.0 mm Hg, and the mean cephalic perfusion pressure was 20.8 +/- 19.5 mm Hg. CONCLUSIONS: There is no clinically important aortic-carotid artery pressure difference during human CPR using the standard dose of epinephrine, even with prolonged CPR. Despite carotid artery patency and thoracic inlet venous valving, the cephalic perfusion pressure is low during CPR in humans.     

Beneficial effects of vasopressin in prolonged pediatric cardiac arrest: a case series

Children who suffer cardiac arrest have a poor prognosis. Based on laboratory animal studies and clinical data in adults, vasopressin is an exciting new vasopressor treatment modality during cardiopulmonary resuscitation (CPR). In particular, vasopressin has resulted in short term resuscitation benefits as a "rescue" pressor agent in the setting of prolonged out-of-hospital CPR for ventricular fibrillation in adults. This retrospective series presents the first evidence for resuscitation benefit of bolus vasopressin therapy in the specific setting of pediatric cardiac arrest. All episodes of CPR initiated in a 120-bed tertiary care children's hospital over a three-year period (1997-2000) were reviewed. Four children in the pediatric ICU received vasopressin boluses as rescue therapy during six cardiac arrest events, following failure of conventional CPR, advanced life support, and epinephrine vasopressor therapy. Return of spontaneous circulation for greater than 60 min occurred in three of four patients (75%) and in four of six CPR events (66%) following vasopressin administration. Two of four vasopressin recipients survived >24 h; one survived to hospital discharge and one had withdrawal of supportive therapies following family discussion. Our observations are AHA level 5 (retrospective case series) evidence that vasopressin administration may be beneficial during prolonged pediatric cardiac arrest. Such reports should pave the way for prospective clinical trials comparing vasopressor medications in the setting of pediatric cardiac arrest.     

Comparison of epinephrine and norepinephrine in the treatment of asphyxial or fibrillatory cardiac arrest in a porcine model

Many animal experiments have shown that alpha-receptor stimulation is a prerequisite for the improvement of myocardial perfusion during CPR. As there are no recent reports on the effectiveness of norepinephrine in the treatment of cardiac arrest, we investigated the effectiveness of epinephrine and norepinephrine after asphyxial or ventricular fibrillation cardiac arrest using a porcine model. After 3 min of asphyxial cardiac arrest, seven animals each received either 45 micrograms/kg epinephrine, 45 micrograms/kg norepinephrine, or placebo (controls). All drugs were given blind. All seven animals given epinephrine could be resuscitated after 174 +/- 53 sec, whereas six of seven given norepinephrine could be resuscitated after 473 +/- 116 sec. None of the seven given the placebo could be resuscitated. After 4 min of ventricular fibrillation cardiac arrest, none of the seven animals that received defibrillating countershocks at 4 min without either mechanical measures or drug therapy, and none of the seven that received CPR and countershocks but no drugs, could be resuscitated. In the group that received CPR plus 45 micrograms/kg epinephrine, defibrillation and restoration of spontaneous circulation were achieved in six of seven animals in 667 +/- 216 sec. In the group that received CPR plus 45 micrograms/kg norepinephrine, defibrillation and restoration of spontaneous circulation were achieved in all seven animals in the significantly shorter time of 86 +/- 18 sec. In this porcine model, norepinephrine appeared superior to the same dose of epinephrine in the treatment of ventricular fibrillation, with respect to resuscitation time.     

Successful extracorporeal life support in cardiac arrest with recurrent ventricular fibrillation unresponsive to standard cardiopulmonary resuscitation

Extracorporeal life support has been used as an extension of conventional cardiopulmonary resuscitation (CPR). However, the appropriate indications for extracorporeal CPR (ECPR) including the duration of CPR are unknown. We present a case of a male, 37-year-old out-of-hospital cardiac arrest patient who received prolonged CPR followed by ECPR. Despite advanced cardiac life support, he did not regain a sustained spontaneous circulation and had recurrent ventricular fibrillation (VF) during the prolonged CPR. VF was unresponsive to CPR, defibrillation, adrenaline (epinephrine), and antiarrhythmics. The CPR time before ECPR was approximately 2h. During extracorporeal life support, the VF did not recur and percutaneous coronary angioplasty was achieved. Ultimately, the patient was discharged without neurological complications. Although cardiac arrest occurred out-of-hospital and CPR was performed for a long time, a patient might be a candidate for ECPR if perfusing rhythms are restored transiently but not successfully maintained due to recurrent VF. ECPR may be used for VF unresponsive to standard CPR techniques.     

Impact of cardiopulmonary resuscitation training on resuscitation.

Restoration of adequate spontaneous circulation after "arrest" and cardiopulmonary resuscitation (CPR) of 546 patients before and 460 patients after initiation of a CPR training course in a 500-bed city hospital is reported. Between January 1972 and June 1976, adequate circulation after CPR was present in 38.6% of patients before and 50.4% after training ICU nurses and house physicians in modern resuscitation techniques. Factors crucial to resumption of adequate circulation are: (1) CPR training of all hospital personnel so that effective CPR can be started immediately after recognition of an arrest situation, (2) production of a palpable pulse with closed chest cardiac massage, and (3) prompt effective therapy so that the time interval between arrest and resumption of adequate spontaneous circulation is short.     

What is the optimal dose of epinephrine during cardiopulmonary resuscitation in a rat model?

Objective

Because different species may require different doses of drug to produce the same physiologic response, we were provoked to evaluate the dose-response of epinephrine during cardiopulmonary resuscitation (CPR) and identify what is the optimal dose of epinephrine in a rat cardiac arrest model.

Methods

Rat cardiac arrest was induced via asphyxia, and then the effects of different doses of epinephrine (0.04, 0.2, and 0.4 mg/kg IV, respectively) and saline on the outcome of CPR were compared (n = 10/each group). The primary outcome measure was restoration of spontaneous circulation (ROSC), and the secondary was the change of spontaneous respiration and hemodynamics after ROSC.

Results

Rates of ROSC were 9 of 10, 8 of 10, 7 of 10, and 1 of 10 in the low-dose, medium-dose, and high-dose epinephrine groups and saline group, respectively. The rates of withdrawal from the ventilator within 60 minutes in the low-dose (7 of 9) and medium-dose epinephrine groups (7 of 8) were higher than in the high-dose epinephrine group (1 of 7, P < .05). Mean arterial pressures were comparable, but the heart rate in the high-dose epinephrine group was the lowest among epinephrine groups after ROSC. These differences in part of time points reached statistical significance (P < .05).

Conclusion

Different doses of epinephrine produced the similar rate of ROSC, but high-dose epinephrine inhibited the recovery of spontaneous ventilation and caused relative bradycardia after CPR in an asphyxial rat model. Therefore, low and medium doses of epinephrine were more optimal for CPR in a rat asphyxial cardiac arrest model.     

Factors influencing outcomes after cardiopulmonary resuscitation in emergency department

BACKGROUND:

The outcome of cardiopulmonary resuscitation (CPR) may depend on a variety of factors related to patient status or resuscitation management. To evaluate the factors influencing the outcome of CPR after cardiac arrest (CA) will be conducive to improve the effectiveness of resuscitation. Therefore, a study was designed to assess these factors in the emergency department (ED) of a city hospital.

METHODS:

A CPR registry conforming to the Utstein-style template was conducted in the ED of the First Affiliated Hospital of Wenzhou Medical College from January 2005 to December 2011. The outcomes of CPR were compared in various factors groups. The primary outcomes were rated to return of spontaneous circulation (ROSC), 24-hour survival, survival to discharge and discharge with favorable neurological outcomes. Univariate analysis and multivariable logistic regression analysis were performed to evaluate factors associated with survival.

RESULTS:

A total of 725 patients were analyzed in the study. Of these patients, 187 (25.8%) had ROSC, 100 (13.8%) survived for 24 hours, 48 (6.6%) survived to discharge, and 23 (3.2%) survived to discharge with favorable neurologic outcomes. A logistic regression analysis demonstrated that the independent predictors of ROSC included traumatic etiology, first monitored rhythms, CPR duration, and total adrenaline dose. The independent predictors of 24-hour survival included traumatic etiology, cardiac etiology, first monitored rhythm and CPR duration. Previous status, cardiac etiology, first monitored rhythms and CPR duration were included in independent predictors of survival to discharge and neurologically favorable survival to discharge.

CONCLUSIONS:

Shockable rhythms, CPR duration ≤15 minutes and total adrenaline dose ≤5 mg were favorable predictors of ROSC, whereas traumatic etiology was unfavorable. Cardiac etiology, shockable rhythms and CPR duration ≤15 minutes were favorable predictors of 24-hour survival, whereas traumatic etiology was unfavorable. Cardiac etiology, shockable rhythms, CPR duration ≤15 minutes were favorable predictors of survival to discharge and neurologically favorable survival to discharge, but previous terminal illness or multiple organ failure (MOF) was unfavorable.KEY WORDS: Cardiac arrest, Cardiopulmonary resuscitation, Utstein-style, Logistical regression analysis, Outcome     

Outcome of cardiopulmonary resuscitation in a pediatric cardiac intensive care unit

OBJECTIVE: To determine the eventual outcome of children with heart disease who had cardiopulmonary resuscitation (CPR) in a specialized pediatric cardiac intensive care unit (CICU), and to define the influence of any prearrest variables on the outcome. DESIGN: A retrospective review of patients' medical records. SETTING: A pediatric CICU of a tertiary pediatric teaching hospital. PATIENTS AND METHODS: Patients were all children who presented with cardiopulmonary arrest and who were administered CPR in the pediatric CICU between June 1995 and June 1997. Prearrest variables such as age, diagnosis, prior cardiac surgery, and inotropic support with epinephrine, as well as cause of arrest, were evaluated. MEASUREMENTS AND MAIN RESULTS: Thirty-two patients, ranging in age from 1 day to 21 yrs (median, 1 month), satisfied criteria for inclusion in the study group. These 32 patients had a total of 38 episodes of cardiopulmonary arrest. Twenty-five of these patients (78%) had cardiac surgery before arrest. Inotropic support with continuous infusion of epinephrine was being administered at the time of arrest in 18 of 38 (47%) arrests. These prearrest variables did not influence outcome of CPR. Of the 38 episodes of CPR, 24 episodes (63%) were successful, with 20 episodes resulting in return of spontaneous circulation and four patients being successfully placed on mechanical cardiopulmonary support. Fourteen children, including all four patients who were rescued with mechanical cardiopulmonary support, survived to discharge. At 6-month follow-up, 11 patients were still alive, with three having neurologic impairment. CONCLUSIONS: After cardiopulmonary resuscitation in this pediatric CICU, the rate of success was 63% and the rate of survival was 42%. Prior cardiac surgery and use of epinephrine before arrest did not influence the outcome of CPR. The availability of effective mechanical cardiopulmonary support can improve the outcome of CPR.