Immediate defibrillation versus interventions first in a swine model of prolonged ventricular fibrillation

OBJECTIVES: we compared time-dependent rescue shock success when delivered immediately, to defibrillation preceded by 3 min of CPR, with and without high dose epinephrine (HDE) in a swine model of prolonged ventricular fibrillation (VF). Our hypotheses were that pretreatment with CPR and HDE would produce higher rates of successful first-shock defibrillation and would prevent decay of the VF waveform, as measured by the scaling exponent (ScE), when compared to immediate defibrillation. We also sought to determine the predictive value of the ScE in determining post-shock outcomes. METHODS: we anesthetized and instrumented 60 domestic swine (19.6-26.4 kg). VF was induced electrically and was untreated for 8, 11 or 14 min. ECG was recorded digitally at a rate of 1000 samples/s with 5-s epochs used to calculate the ScE. We assigned randomly swine to seven groups (number denotes timing of first rescue shock). Three groups had rescue shocks as the first intervention (RSF) after 8 min of VF (RSF-8), 11 min of VF (RSF-11), or 14 min of VF (RSF-14): two groups had CPR for 3 min (then rescue shock) beginning at 8 min (CPR-11) or 11 min of VF (CPR-14); and two groups got CPR for 3 min with 0.1 mg/kg epinephrine (adrenaline) (then rescue shock) beginning at 8 min of VF (HDE-11) or 11 min of VF (HDE-14). Fixed-dose 70 J BDW rescue shocks were used for all shocks. Defibrillation outcome was classified immediately and 30 s post-shock as successful (either restoration of spontaneous circulation [ROSC] or restoration of organized electrical activity [ROEA]), or failed (remained in VF, or asystole). Data were analyzed with RMANOVA, multiple logistic regression, Fisher's exact tests, and ROC curves. RESULTS: successful first-shock defibrillation occurred in 3/8 (38%) RSF-8; 1/9 (11%) RSF-11; 2/9 (22%) CPR-11; 7/9 (77%) HDE-11; 0/9 (0%) RSF-14; 0/7 (0%) CPR-14; and 1/8 (13%) HDE-14, (p=0.059 IRS-8 vs. HDE-11). First-shock ROSC occurred in 5/9 (56%) HDE-11 animals, 1/8 (13%) HDE-14 and zero in all other groups (p=0.03). Mean ScE values at 11 min VF for the RSF-11 (1.46) was higher than both CPR-11 (1.26), and HDE-11 (1.27); and RSF-14 (1.60) was higher than CPR-14 (1.47) and HDE-14 (1.46); group by time p=0.002. ROC areas under the curves using the ScE as a predictor of shock outcome were 0.84 for immediate success, 0.85 for sustained success, and 0.81 for ROSC. CONCLUSIONS: HDE-11 showed a tendency for producing a higher rate of first-shock success and ROSC. Interventions prior to rescue shock prevented deterioration of the VF waveform and improved rescue shock outcomes. The ScE accurately predicted 81-85% of post-rescue shock outcomes.     

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.     

Differences in the pharmacodynamics of epinephrine and vasopressin during and after experimental cardiopulmonary resuscitation

Vasopressin has been investigated as a possible alternative to epinephrine during cardiopulmonary resuscitation (CPR). We tested the hypothesis that vasopressin, in comparison with epinephrine, would improve cerebral blood flow and metabolism during CPR as well as after restoration of spontaneous circulation (ROSC). A total of 22 anaesthetised piglets were subjected to 5 min of ventricular fibrillation followed by 8 min of closed-chest CPR. The piglets were randomly allocated to receive repeated boluses of either 45 microg/kg epinephrine or 0.4 U/kg vasopressin IV. Haemodynamic parameters, cerebral cortical blood flow and cerebral tissue pH and PCO(2) were continuously monitored during CPR and up to 4 h after ROSC. Cerebral oxygen extraction ratio was calculated. Cerebral cortical blood flow increased transiently after each bolus of epinephrine, while only the first bolus of vasopressin resulted in a sustained increase. The peak in cerebral cortical blood flow was reached approximately 30 s later with vasopressin. During the initial 5 min following ROSC, cerebral cortical blood flow was greater in the vasopressin group. In conclusion, there is a difference between epinephrine and vasopressin in the time from injection to maximal clinical response and the duration of their effect, but their overall effects on blood pressures and cerebral perfusion do not differ significantly during CPR. In contrast, vasopressin results in a greater cerebral cortical blood flow during a transient period after ROSC.     

Selective Aortic Arch Perfusion Using Serial Infusions of Perflubron Emulsion

Objective : To determine whether selective aortic arch perfusion (SAAP) using serial infusions of oxygenated perflubron emulsion combined with aortic epinephrine (AoE) administration is more effective than conventional therapy in treating cardiac arrest.
Methods : An experimental cardiac arrest model (10 min ventricular fibrillation and 2 min CPR) was used with 12 mixed-breed canines, randomized into 2 groups: control ( n = 6), CPR and IV epinephrine, 0.01 mgkg, at 12 rnin and then every 3 min; or AoE-SAAP ( n = 6), CPR and aortic epinephrine, 0.01 mgkg, at 12 rnin and then every 3 min, and serial SAAP with oxygenated 60% weightholume (w/v) perflubron emulsion as follows: 300 mL over 30 sec at 12 rnin as continuous SAAP without CPR; 150 mL over 20–30 sec at 15 min and 18 rnin as pulsed diastolic SAAP during CPR.
Results : AoE-SAAP resulted in increased coronary perfusion pressure (CPP) and return of spontaneous circulation (ROSC) compared with control. CPR-diastolic (release phase) CPP during pulsed diastolic SAAP was similar to or greater in magnitude than the CPP generated during the initial SAAP infusion without CPR. ROSC for control was 0/6 and for AoE-SAAP was 416 (p < 0.05, Fisher's exact test). Time from initiation of CPR to ROSC with a sustained systolic aortic pressure >60 mm Hg was 8.0 ± 1.2 rnin in the 4 resuscitated AoE-SAAP animals.
Conclusion : The combination of AoE with SAAP infusions of oxygenated perflubron emulsion was more effective than conventional resuscitation therapy. Pulsed diastolic SAAP is a promising method for performing SAAP.     

短时程复合亚低温改善长时间室颤家猪复苏预后的研究

目的 比较短时程亚低温对长时间室颤家猪短期复苏预后的影响.方法 采取体质量34～ 36 kg左右健康雄性种猪14头,通过右心室致颤电极诱发室颤并维持11 min,之后采取人工胸外按压及球囊面罩通气,按压通气比为30:2,每2 min轮换操作者.复苏6 min后给予120 J双向波除颤,若未能获得自主循环恢复(return of spontaneous circulation,ROSC),继续给予心肺复苏及必要时电除颤.连续复苏12 min仍无ROSC认为复苏失败.对ROSC家猪,随机(随机数字法)分为常温组(normothermia group,NT)及复合降温组(combined hypothermia group,CH).CH组立即给予4℃生理盐水静脉输注并联合体表物理降温,在120 min内将核心体温降至32 ～ 34℃并维持2h后主动复温,2h将体温升至基础体温水平.记录两组家猪致颤前基础状态下血流动力学、血气及乳酸.记录ROSC后心输出量、心率、核心体温变化.每24h评估动物神经功能直至观察终点.组间比较采用Fisher检验或方差分析,以P＜0.05为差异有统计学意义.结果 两组动物基础状态下体质量、平均动脉压、心输出量、Ph、呼气末二氧化碳水平、血乳酸水平差异均无统计学意义(P＞0.05).在复苏过程中,两组动物在总复苏时间、首次除颤成功率、ROSC比例、首次除颤ROSC比例、总除颤次数及肾上腺素用量差异均无统计学意义(P＞0.05).存活时间上,CH组明显长于NT组[(96.00±0.00) h vs.(49.71 ±43.65)h,P=0.031],同时NT组96 h生存率亦高于NT组,差异有统计学意义(P＜0.05).神经功能方面,CH组在复苏后96 h内各时间段均优于NT组,差异有统计学意义(P＜0.05).结论 即使2h短时程的亚低温,也可以明显改善11 min室颤家猪的短期复苏预后.     

Effects of vasopressin and epinephrine on splanchnic blood flow and renal function during and after cardiopulmonary resuscitation in pigs

OBJECTIVE: To compare the effects of vasopressin versus epinephrine on splanchnic blood flow during and after cardiopulmonary resuscitation (CPR), and to evaluate the effects of these vasopressors on renal function in the postresuscitation phase. DESIGN: Prospective, randomized laboratory investigation using an established porcine CPR model with instrumentation for continuous measurement of splanchnic and renal blood flow. SETTING: University hospital experimental laboratory. SUBJECTS: A total of 12 anesthetized, 12- to 16-wk-old domestic pigs weighing 30-35 kg. INTERVENTIONS: After 4 mins of cardiac arrest, and 3 mins of CPR, 12 pigs were randomly assigned to receive either 0.4 units/kg vasopressin (n = 6) or 45 microg/kg epinephrine (n = 6). Defibrillation was performed 5 mins after drug administration; all animals were observed for 6 hrs after return of spontaneous circulation (ROSC). MEASUREMENTS AND MAIN RESULTS: Mean +/- SEM superior mesenteric artery blood flow was significantly (p < .05) lower after vasopressin compared with epinephrine at 90 secs after drug administration (13+/-3 vs. 129+/-33 mL/min); at 5 mins after drug administration (31+/-18 vs. 155+/-39 mL/min); at 5 mins after ROSC (332+/-47 vs. 1087+/-166 mL/min); and at 15 mins after ROSC (450+/-106 vs. 1130+/-222 mL/min); respectively. Mean +/- SEM left renal and hepatic artery blood flow after ROSC was comparable in both groups ranging between 120-290 mL/min (renal blood flow), and 150-360 mL/min (hepatic blood flow), respectively. Median urine output after ROSC showed no difference between groups, and highest values (180-220 mL/hr) were observed in the first 60 mins after ROSC. Median calculated glomerular filtration rate showed no difference between groups with values ranging between 30 and 80 mL/min in the postresuscitation phase. Calculated fractional sodium excretion and osmolar relationship between urea and plasma indicated no evidence for renal tubular dysfunction. CONCLUSIONS: In the early postresuscitation phase, superior mesenteric blood flow was temporarily impaired by vasopressin in comparison with epinephrine. With respect to renal blood flow and renal function after ROSC, there was no difference between either vasopressor given during CPR. Vasopressin given during CPR did not result in an antidiuretic state in the postresuscitation phase.     

对院前心肺复苏效果影响的多因素分析

目的 探讨影响心肺复苏(cardiopulmonary resuscitation,CPR)效果的独立影响因素.方法 研究对象为做过CPR的1376例心搏骤停(cardiac arrest,CA)患者,行回顾性调查,用EpiData软件建数据库,用SPSS 13.0软件行两分类Logistic回归分析,选取变量为单因素分析有意义的影响CPR效果的因素.结果 对恢复自主循环(return of spontaneous circulation,ROSC)--第一目击者急救是保护因素,OR=2.21(P<0.01,95.0%C/=1.356～3.602);与女性比较男性是危险因素,OR=0.515(P<0.01,95.0%CI=0.320～0.826);20～29岁组较≥81岁组ROSC可能性大,OR=3.241(P<0.05,95.0%CI=1.146～9.138);CPR术前心跳骤停时间是危险冈素,OR=0.913(P<0.01,95.0%CI=0.887～0.948);与心脏静止比较,室颤是保护因素,OR=5.092(P<0.01,95.0%CI=2.927～8.861);电击是保护因素,OR=3.384(P<0.01,95.0%CI=2.033～5.635);肾上腺素0～4 mg组ROSC可能性高于≥5 mg组,OR=3.255(P<0.01,95.0%CI=1.606～6.597).对生存到院--2～12岁和13～19岁组生存到院可能性分别比≥81岁组高,OR=12.818(P<0.05,95.0%CI=1.299～126.508)和OR=10.505(P<0.05,95.0%CI=1.161～95.058);CPR前CA时间是危险因素,OR=0.862(P=<0.01,95.0%CI=0.82～0.906);室颤患者生存到院的可能性较心脏静止患者高,OR=7.330(P=<0.01,95.0%CI=3.962～13.560).结论 院前CA患者ROSC的独立影响因素有CPR前ECG、第一目击者急救、电击、CPR前CA时间、肾上腺素剂量、性别、年龄分组.院前CA患者生存到院独立影响冈素有CPR前ECG、CPR前CA时间、年龄分组.     

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。     

山莨菪碱对心搏骤停大鼠复苏的影响

目的 观察山莨菪碱对心搏骤停大鼠自主循环恢复(ROSC)及复苏成功率的影响,旨在探寻心肺复苏的新方法.方法 采用盲法将45只成年SD大鼠随机分为对照组、肾上腺素组和肾上腺素+山莨菪碱组(联用组),每组15只.实验采用经食道心脏起搏诱发心室纤颤或心室静止,使用电动机械胸外按压机进行胸外按压.盲法给药,肾上腺素剂量200 μg/kg,山莨菪碱为10 mg/kg,对比各组ROSC率及复苏成功率.结果 联用组ROSC率(93.3%比46.7%)、复苏成功率(80.0%比33.3%)及3 h存活率(83.3%比20.O%)均高于肾上腺素组,差异有统计学意义(P均<0.05);对照组仅1只大鼠ROSC.ROSC即刻肾上腺素组平均动脉压(MAP)明显高于联用组(P<0.05);ROSC后两组MAP均呈逐渐下降趋势,且自5 min开始,肾上腺素组MAP明显低于联用组,至ROSC后30 min,两组比较差异仍有统计学意义(P均<0.05).结论 肾上腺素合用山莨菪碱可以提高心搏骤停ROSC率和复苏成功率.     

生脉注射液对家兔心搏骤停模型自主循环恢复和复苏早期血流动力学的影响

目的 探索生脉注射液对心搏骤停动物模型的自主循环恢复和复苏后早期血流动力学的影响,为心搏骤停复苏后动物的后续研究提供稳定循环的辅助支持.方法 将家兔30只随机(随机数字法)分成两组各15只,采用窒息法建立心搏骤停动物模型;生脉组在复苏开始即刻给予2mL/kg生脉注射液静注,自主循环恢复后10 min再次给予相同剂量一次;盐水组给药时间和盐水剂量与生脉组相同.记录家兔心搏骤停时间、自主循环恢复时间和自主呼吸恢复时间,分别记录窒息前和自主循环恢复即刻、ROSC后30 min,60 min和120 min的左室收缩压(LVSP)、左室等容收缩期最大上升速率(+dp/dtmax)和等容舒张期最大下降速率(-dp/dtmax)、左室舒张末压(LVEDP)等血流动力学指标的变化.计算自主循环恢复率与6 h存活率.结果 生脉组和盐水组家兔在心搏骤停时间、自主呼吸恢复时间、自主循环恢复率以及6 h存活率等指标之间的比较,差异无统计学意义(P＞0.05),但生脉组家兔自主循环恢复时间要明显早于盐水组;两组家兔在自主循环恢复30 min,60min和120 min的左室收缩压(LVSP)、左室等容收缩期最大上升速率(+dp/dtmax)和等容舒张期最大下降速率(-dp/dtmax)与窒息前相比明显降低,但左室舒张末压(LVEDP)升高(P＜0.05);生脉组在相应时间点的左室收缩压(LVSP)、左室等容收缩期最大上升速率(+dp/dtmax)和等容舒张期最大下降速率(-dp/dtmax)高于盐水组,左室舒张末压(LVEDP)低于盐水组(P＜0.05).结论 生脉注射液辅助用于心搏骤停家兔心肺复苏,可缩短家兔自主循环恢复时间,并且可改善其自主循环恢复后心肌舒缩功能,有利于复苏后血流动力学的稳定.     

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.     

Periodic acceleration (pGz) CPR in a swine model of asphyxia induced cardiac arrest. Short-term hemodynamic comparisons

BACKGROUND: Asphyxia is one of the most common causes of pediatric cardiac arrest, and becoming a more frequently recognized cause in adults. Periodic acceleration (pGz) is a novel method of cardiopulmonary resuscitation (CPR). pGz is achieved by rapid motion of the supine body headward-footward that generates adequate perfusion and ventilation during cardiac arrest. In a swine ventricular fibrillation cardiac arrest model, pGz produced a higher return of spontaneous circulation (ROSC), superior neurological outcome, less echocardiography evidence of post resuscitation myocardial stunning, and decreased indices of tissue injury. In contrast to standard chest compression CPR, pGz does not produce rib fractures. We investigated the feasibility of pGz in severe asphyxia cardiac arrest and assessed whether beneficial effects seen in the VF model of cardiac arrest could be realized. METHODS AND RESULTS: Sixteen swine weight 4+/-1 kg were anesthetized, tracheally intubated, and instrumented to measure, hemodynamics and echocardiography. Asphyxia was induced by occlusion of the tracheal tube. After loss of aortic pulsations (median time 10 min) animals were observed for three additional minutes following which all were in cardiac arrest. The animals were then randomized to receive 10 min of pGz or standard chest compression ventilation performed with a commercial device (Thumper). A single dose of epinephrine (adrenaline) and sodium bicarbonate were given and defibrillation attempted if appropriate for a maximum of 10 min. Both groups received fractional inspired O2 concentration of 100% during CPR and after resuscitation. Four animals in each group (50%) had an initial ROSC, however only two of the four initial survivors remained alive 3h after ROSC. There were no significant differences in blood pressure, coronary perfusion pressure during CPR and after early ROSC between groups. pGz treated animals had significantly lower pulmonary artery pressure; 20+/-4 mmHg compared to Thumper 46+/-5 mmHg, 30 min after ROSC (p<0.01). Surviving animals in both groups had severe myocardial dysfunction at 30 min after ROSC. At necropsy, 25% of the Thumper treated animals had rib fractures, while none occurred in the pGz group. CONCLUSIONS: In a lethal model of asphyxia cardiac arrest, pGz is equivalent to standard CPR, with respect to acute outcomes and resuscitation survival rates but is associated with significantly lower pulmonary artery pressures and does not produce traumatic rib fractures.     

“一医两护”心肺复苏抢救流程在临床的应用效果观察

目的探讨"一医两护"心肺复苏抢救流程在临床上的应用效果。方法选择2007年1月-2008年12月本院急诊科发生心跳呼吸骤停患者100例为实验组,选择2009年1月-2010年8月100例患者为对照组,对照组采用常规心肺复苏抢救流程,实验组采用"一医两护"配合的心肺复苏抢救流程。比较两组患者的存活率和实施心肺复苏、除颤、气管插管及静脉输液时间。结果实验组患者存活率高于对照组,实施除颤时间及气管插管时间短于对照组(均P<0.05);两组患者实施心肺复苏及静脉输液时间比较,均P>0.05,差异无统计学意义。结论 "一医两护"配合的心肺复苏抢救流程能提高患者的抢救成功率,缩短抢救时间,是一种较好的心肺复苏抢救流程。     

心肺复苏后组织因子和组织因子途径抑制物的动态变化和临床意义

目的 观察院内心肺复苏后不同时间点组织因子(TF)和组织因子途径抑制物(TFPI)水平的动态变化特点并探讨其临床意义.方法 选择2005年9月至2007年9月温州医学院附属第一医院急诊科收治的年龄>16岁明确心搏停止时间的心肺复苏患者24例,依据是否达到自主循环恢复标准随机分为ROSC和末ROSC两组,分别记录小同患者心搏停止的病因和临床特点,并用ELISA方法 检测心肺复苏(CPR)后30 min,60 min,6 h,24 h,48 h血清TF和TFPI抗原浓度,10例来自健康体检的健康自愿者为对照组.计量数据用均数±标准差((-x)±s)来表示,两组计量数据的比较采用独立样本t检验,三组及以上计量数据比较采用单因素方差分析法,计数数据的比较采用旧格表精确x2榆验,以P<0.05为差异具有统计学意义.结果 与对照组比较,ROSC组患者在CPR 30 min血TF水平显著升高(P<0.01),在CPR 6 h达高峰,在CPR48 h时已下降;与对照组及ROSC组同时点比较,末ROSC组血TF水平更是显著升高(P<0.01).与对照组比较,在CPR后30 min,ROSC和未ROSC两组血清TFPI水平差异无统计学意义(P>0.05),60 min后ROSC组血清TFPI水平逐渐升高并有显著差别(P<0.01或<0.05).与对照组比较,未ROSC组和ROSC组患者在CPR 30 min时的TF/TFPI水平均显著性升高(P<0.01),且前者显著高于后者(P<0.01),在ROSC组IF/TFPI值在CPR后6 h有显著升高(P<0.01),在48 h下降.结论 血清TF和TFPI水平在院内心肺复苏的患者中明显升高,CPR后半小时的TF和TF/TFPI的水平可用于判断预后.     

The place of general practitioners in the management of out-of-hospital cardiopulmonary resuscitation

Intra-aortic balloon occlusion during experimental cardiopulmonary resuscitation (CPR) improves coronary perfusion pressure and resuscitability and provides unique access to the central circulation. It has been hypothesized that administration of epinephrine into the aortic arch in combination with aortic occlusion would further improve haemodynamics during CPR, resuscitability and 24 h survival. In 16 anaesthetised dogs intravascular catheters were placed for hemodynamic and blood gas monitoring. An aortic balloon catheter was placed by femoral artery insertion with its tip just distal to the left subclavian artery. Ventricular fibrillation for 7.5 min without CPR, 2.5 min of Basic Life Support with chest compressions and ventilation with 100% oxygen were followed by 30 min of Advanced Cardiac Life Support (ACLS) with systemic canine drug dosages. The intra-aortic balloon was inflated when ACLS started and gradually deflated shortly after restoration of spontaneous circulation (ROSC). Epinephrine, in 100 microg/kg boluses every 5 min until the heart was restarted or 30 min had elapsed was administered through the intra-aortic catheter in the experimental group (n = 8) and via a central venous catheter in the control group (n = 8). Coronary perfusion pressure increased during the ACLS period in both groups (P < 0.05) with no difference between the groups and there was no difference in the frequency of ROSC (experimental group 5/8, control group 4/8). Furthermore with respect to 24 h survival, there was no difference between the experimental group (2/8) and the control group (3/8). Severe macroscopic haemorrhagic necrosis of the myocardium in the dogs with ROSC was found in 4/5 in the experimental group compared to 1/4 in the control group. In conclusion, intra-aortic administration of 100 microg/kg epinephrine doses combined with aortic occlusion during experimental CPR did not alter outcome.     

Pharmacokinetic effects of endotracheal,intraosseous, and intravenous epinephrine in a swine model of traumatic cardiac arrest

IntroductionLimited prospective data exist regarding epinephrine's controversial role in managing traumatic cardiac arrest (TCA). This study compared the maximum concentration (Cmax), time to maximum concentration (Tmax), plasma concentration over time, return of spontaneous circulation (ROSC), time to ROSC, and odds of ROSC of epinephrine administered by the endotracheal (ETT), intraosseous (IO), and intravenous (IV) routes in a swine TCA model.MethodsForty-nine Yorkshire-cross swine were assigned to seven groups: ETT, tibial IO (TIO), sternal IO (SIO), humeral IO (HIO), IV, CPR with defibrillation (CPRD), and CPR only. Swine were exsanguinated 31% of their blood volume and cardiac arrest induced. Chest compressions began 2 min post-arrest. At 4 min post-arrest, 1 mg epinephrine was administered, and blood specimens collected over 4 min. Resuscitation continued until ROSC or 30 min elapsed.ResultsThe Cmax of IV epinephrine was significantly higher than the TIO group (P = 0.049). No other differences in Cmax, Tmax, ROSC, and time to ROSC existed between the epinephrine groups (P > 0.05). Epinephrine levels were detectable in two of seven ETT swine. No significant difference in ROSC existed between the epinephrine groups and CPRD group (P > 0.05). Significant differences in ROSC existed between all groups and the CPR only group (P < 0.05). No significant differences in odds of ROSC were noted.ConclusionsThe pharmacokinetics of IV, HIO, and SIO epinephrine were comparable. Endotracheal epinephrine absorption was highly variable and unreliable compared to IV and IO epinephrine. Epinephrine appeared to have a lesser role than volume replacement in resuscitating TCA.     

Dynamics and state transitions during resuscitation in out-of-hospital cardiac arrest

BACKGROUND: The state or rhythm during resuscitation, i.e. ventricular fibrillation/tachycardia (VF/VT), asystole (ASY), pulseless electrical activity (PEA), or return of spontaneous circulation (ROSC) determines management. The state is unstable and will change either spontaneously (e.g. PEA-->ASY) or by intervention (e.g. VF-->ASY after DC shock); temporary ROSC may also occur. To gain insight into the dynamics of this process, we analyzed the state transitions over time using real-life data. METHODS: Detailed recordings from 304 episodes of attempted resuscitation from out-of-hospital cardiac arrests of presumed cardiac etiology were obtained from modified Heartstart 4000 defibrillators. State transitions were visualized and described, and analyzed in terms of a Markov probability model. RESULTS: The median number of state transitions was 5 (range 1-39), and more transitions were observed with VF than PEA or asystole as the initial rhythm. Of 105 patients (35%) who regained ROSC at some point during CPR, only 65 (21%) achieved sustained ROSC; suggesting an unrealized survival potential. A 3-min transition probability matrix was estimated: for example, a patient early in VF has a probability of 31% to be in ASY, 32% of still being in VF, 5% to have temporary ROSC, and 2% to have sustained ROSC after 3 min. CONCLUSION: The dynamics of resuscitation can be described in terms of state transitions and a Markov probability model. This framework enables prediction of short-term clinical development, supports informed decisions during CPR, and suggests a novel area for research.