The effect of standard- and high-dose epinephrine on coronary perfusion pressure during prolonged cardiopulmonary resuscitation

We studied the effect of standard and high doses of epinephrine on coronary perfusion pressure during cardiopulmonary resuscitation in 32 patients whose cardiac arrest was refractory to advanced cardiac life support. Simultaneous aortic and right atrial pressures were measured and plasma epinephrine levels were sampled. Patients remaining in cardiac arrest after multiple 1-mg doses of epinephrine received a high dose of 0.2 mg/kg. The increase in the coronary perfusion pressures was 3.7 +/- 5.0 mm Hg following a standard dose, not a statistically significant change. The increase after a high dose was 11.3 +/- 10.0 mm Hg; this was both statistically different than before administration and larger than after a standard dose. High-dose epinephrine was more likely to raise the coronary perfusion pressure above the previously demonstrated critical value of 15 mm Hg. The highest arterial plasma epinephrine level after a standard dose was 152 +/- 162 ng/mL, and after a high dose, 393 +/- 289 ng/mL. Because coronary perfusion pressure is a good predictor of outcome in cardiac arrest, the increase after high-dose epinephrine may improve rates of return of spontaneous circulation.     

腹部加压联合胸外按压对窒息猪复苏效果的研究

目的 比较标准胸外按压(standard cardiopulmonary resuscitation, STD-CPR)和腹部加压联合胸外按压(interposed abdominal compression cardiopulmonary resuscitation, IAC-CPR)的方法对窒息性心脏骤停猪血流动力学的影响,对窒息性心脏骤停的复苏效果和复苏方法进行初步评估。方法 健康实验用近交系五指山小型猪18只,通过气管夹闭法制作8 min窒息型心脏骤停模型。采用数字表法随机分为2组,每组9只,分别实施STD-CPR和IAC-CPR,记录基础状态、CPR期间和复苏后15 min心率(heart rate, HR)、主动脉收缩压(systolic blood pressure, SBP)和舒张压(diastolic blood pressure, DBP)、中心静脉压(central venous pressure, CVP)、动脉血氧饱和度(arterial oxygen saturation, SaO₂),计算主动脉平均动脉压(mean arterial pressure, MAP)、冠状动脉灌注压(coronary perfusion pressure, CPP),观察2组动物的自主循环恢复率(return of spontaneous circulation, ROSC)和复苏后合并症。结果 STD-CPR组与IAC-CPR组比较,MAP(46.30±13.49)mmHg vs (54.04±13.07) mmHg(P>0.05, 1 mmHg=0.133 kPa),差异无统计学意义;CPP(20.44±19.63)mmHg vs (29.56±11.57)mmHg,差异有统计学意义。2组动物的自主循环恢复率,差异无统计学意义。2组实验动物都出现了明显胸腹部的合并症,包括肺出血、肺梗死、肋骨骨折、癫痫发作、腹部脏器的缺血坏死。结论 在心肺复苏初期,腹部加压联合胸外按压的方法可以有效地改善CPP,但并不能改善ROSC成功率。     

End-tidal carbon dioxide monitoring during cardiopulmonary resuscitation. A prognostic indicator for survival

The effectiveness of ongoing cardiopulmonary resuscitation efforts is difficult to evaluate. Recent studies suggest that carbon dioxide excretion may be a useful noninvasive indicator of resuscitation from cardiac arrest. A prospective clinical study was done to determine whether end-tidal carbon dioxide monitoring during cardiopulmonary resuscitation could be used as a prognostic indicator of resuscitation and survival. Thirty-five cardiac arrests in 34 patients were monitored with capnometry during cardiopulmonary resuscitation during a 1-year period. Nine patients who were successfully resuscitated had higher average end-tidal carbon dioxide partial pressures during cardiopulmonary resuscitation than 26 patients who could not be resuscitated (15 +/- 4 vs 7 +/- 5 mm Hg). The 3 patients who survived to leave the hospital had a higher average end-tidal carbon dioxide partial pressure than the 32 nonsurvivors (17 +/- 6 vs 8 +/- 5 mm Hg). All 9 patients who were successfully resuscitated had an average end-tidal carbon dioxide partial pressure of 10 mm Hg or greater. No patient with an average end-tidal carbon dioxide partial pressure of less than 10 mm Hg was resuscitated. Data from this prospective clinical trial indicate that findings from end-tidal carbon dioxide monitoring during cardiopulmonary resuscitation are correlated with resuscitation from and survival of cardiac arrest.     

Buffer solutions may compromise cardiac resuscitation by reducing coronary perfusion presssure

OBJECTIVE.--To investigate the effects of hypertonic buffer solutions on coronary perfusion pressure (CPP) and resuscitability during experimental closed-chest cardiac resuscitation. DESIGN.--Randomized, placebo-controlled trial. SETTING.--Mammalian research laboratory. PARTICIPANTS.--Forty-four domestic pigs. INTERVENTIONS.--Cardiac arrest was induced by ventricular fibrillation in mechanically ventilated pigs anesthetized with pentobarbital sodium. Precordial compression was started at the third minute of untreated ventricular fibrillation and maintained for an interval of 8 minutes. A hypertonic solution of sodium bicarbonate, Carbicarb (an equimolar mixture of sodium bicarbonate and sodium carbonate [International Medication Systems, Ltd]), or sodium chloride or an isotonic solution of sodium chloride was infused into the right atrium over a 1-minute interval starting at the sixth minute of ventricular fibrillation. Restoration of spontaneous circulation was attempted by DC transthoracic countershock after 11 minutes of ventricular fibrillation. MAIN OUTCOME MEASURES.--Plasma osmolality, CPP, and cardiac resuscitability. RESULTS.--Infusion of hypertonic buffer and sodium chloride solutions increased plasma osmolality from an average of 280 to 330 mOsm/kg. This was accompanied by a significant decrease in the aortic pressures and CPPs generated during precordial compression. No such changes occurred after infusion of isotonic sodium chloride. Restoration of spontaneous circulation, as in earlier studies, was contingent on the levels of CPP prior to attempted defibrillation. Accordingly, none of 13 animals in which the CPP declined to less than 10 mm Hg after infusion of the hypertonic solutions were successfully resuscitated. This contrasted with nine animals that received isotonic sodium chloride and served as controls. Coronary perfusion pressure consistently exceeded 10 mm Hg in these control animals, and spontaneous circulation was restored in each instance. CONCLUSIONS.--Hypertonic solutions and specifically buffer solutions administered in the absence of vasopressor agents may adversely affect cardiac resuscitation efforts by reducing CPP below critical thresholds.     

IAC-CPR和标准CPR在心脏骤停病人的应用对比研究

目的 :明确院内心脏骤停的病人在行标准CPR的同时附加IAC能否提高复苏成功率并探讨IAC -CPR下冠脉灌注压的变化。方法 :5 1例院内发生的心脏骤停病人随机分为IAC -CPR组 (即实验组n =2 5 )和标准CPR组(即对照组n =2 6)。对照组按照ABC程序紧急行标准心肺复苏术 (S -CPR) ;实验组在进行S -CPR的同时 ,在胸部按压放松时行一次腹部按压 ,按压力度为 15 0mmHg～ 2 0 0mmHg(1Kpa =7.5mmHg) ,按压频率为 10 0次 /分～12 0次 /分 ,压胸与压腹交替进行。两组均监测有创动脉压及右房压。结果 :实验组自主循环恢复率为 84% ,对照组为 5 4% ,两组比较差异有显著性 ,P <0 .0 5 ;2 4h生存率分别为 68%、2 7% ,两组比较差异有显著性 ,P <0 .0 1;实验组冠脉最高灌注压为 3 1.4mmHg± 11.4mmHg对照组为 13 .0mmHg± 6.9mmHg ,两组比较差异有显著性 ,P <0 .0 1。结论 :IAC -CPR可明显地提高冠脉灌注压 ,增加自主循环恢复率和 2 4h生存率 ,未发现明显并发症     

End-tidal carbon dioxide monitoring during cardiopulmonary resuscitation

The end-tidal carbon dioxide (CO2) concentration has been found to correlate with cardiac output during and after cardiopulmonary resuscitation (CPR) in animal models. We monitored end-tidal CO2 values continuously during cardiac resuscitation in 23 humans while ventilation was held constant with a computer-controlled CPR Thumper. This report focuses on ten of the 23 patients who experienced return of spontaneous circulation (ROSC) during monitoring. There was no significant difference in the end-tidal CO2 value of patients without ROSC (1.8% +/- 0.9%) and the end-tidal CO2 value of patients before ROSC in patients who had ROSC (1.7% +/- 0.6%). The end-tidal CO2 concentration increased immediately in all patients who had ROSC, from 1.7% +/- 0.6% to 4.6% +/- 1.4%, then gradually returned to a new baseline (3.1% +/- 0.9%). Change in the end-tidal CO2 value was often the first clinical indicator that ROSC had occurred. Our findings suggest that end-tidal CO2 monitoring may provide clinically useful information that can be used to guide therapy during CPR.     

An Experimental Comparative Study on the Characteristicsof Ventricular Fibrillation during Cardiac Arrest and Methoxamine Administration

Ventricularfibrillation(VF)isthemostcommoncauseofprimarycardiacar-rest.VFisusua1lyfatalunlessitisprompt-lydiagnosedandappropriatelytreatedwithdefibrillation.Theannualincidenceofcar-diacarrestisestimatedtobeaboutl24/1OOoooinUSA,ofwhichmorethanhalfwascausedbyVF[l'2].VFamplitudemaybere-latedtotheadequacyofmyocardialperfu-sionduringcardiopulmonaryresuscitation(CPR).HighamplitudeVFisknowntofa-cilitatedefibrillation.Methoxamineincreasecoronaryperfusionpressure(CPP)andsur-vivalaftercardiacarr…     

二氧化硫对大鼠离体灌注心脏心功能的影响

目的 观察二氧化硫(SO2)对大鼠离体心脏心功能的影响及可能的机制.方法 应用Langendorff大鼠离体心脏灌流模型,以不同浓度SO2供体(Na2SO3/NaHSO3)(1、10、100、1000μmoL/L)或0.5 μmol/L天冬氨酸异羟肟酸(HDX)灌流心脏5 min,并以生理浓度SO2供体(NA2SO3/NaHSO,)(10 μmol/L)持续灌流20 min,测量心率、左心室内压差(左心室收缩末压-舒张末压)、左心室内压变化速率(±dp/dtmax)以及冠脉流量;应用钙离子通道阻断剂尼卡地平预灌流后再给予生理剂量SO2供体(Na2SO3/NaHSO3)灌注,观察尼卡地平是否可以阻断SO2的心脏效应.结果 SO2呈浓度依赖性地抑制左心室±dp/dtmax、左心室内压差、心率以及冠脉流量(均P＜0.01);生理剂量SO2供体(Na2SO3/NaHSO3)持续灌流20 min,灌流20 min时,左心室内压差,+dp/dtmax、-dp/dtmax及心率分别为:(15±3)mm Hg(1 mm Hg=0.133 kPa),(485 ±74)mm Hg/s,(339 ±64)mm Hg/s,(114 ±26)次/min;均明显低于灌流5 min时的左心室内压差[(23±7)mm Hg]、+dp/dtmax[(595±93)mm Hg/s]、-dp/dtmax[(436±83)mm Hg/s]及心率[(159±31)次/min],均P＜0.05;0.5 μmol/L HDX灌注后左心室内压差降低,左心室±dp/dtmax减少、冠脉流量减少(P＜0.05或P＜0.01);尼卡地平可阻断生理剂量SO2对心功能的抑制效应.结论 外源性SO2对大鼠离体心脏的心功能具有负性肌力作用,其作用机理与电压门控钙通道有关.     

搏动性双向腔静脉肺动脉吻合手术的临床应用

目的　评价搏动性双向腔静脉肺动脉吻合（Gleen）手术的临床应用价值。方法　1994年6月～2000年1月,作者对41例单心室等复杂先天性心脏畸形患者,进行了搏动双向Gleen手术。男31例,女10例。平均年龄5岁±4岁（7个月～16岁）,体表面积0.64m2±0.25m2（0.35～1.48m2）,术前经皮测血氧饱和度为70%±11%（25%～89%）,术中肺动脉测压12.5mm Hg±2.7mmHg（8～17mmHg）。其中35例在低温体外循环下手术,6例在常温下完成手术。结果　1例患者术后早期死亡,3例患者出现乳糜胸。所有存活患者紫绀明显减轻,顺利出院。出院时动脉血氧饱和度为90%±4%（77%～96%）。常温手术组术后呼吸机辅助时间明显少于体外循环手术组。结论　搏动性双向Gleen手术操作较为简便,术后早期效果良好。     

Active compression-decompression. A new method of cardiopulmonary resuscitation. Cardiopulmonary Resuscitation Working Group.

OBJECTIVE--To describe and compare with standard cardiopulmonary resuscitation (CPR) in humans a new form of CPR that involves both active compression and active decompression of the chest. DESIGN--Patients in cardiac arrest in whom standard advanced cardiac life support failed were randomized to receive 2 minutes of either standard or active compression-decompression (ACD) CPR using a custom, hand-held suction device, followed by 2 minutes of the alternate technique. The ACD device was applied midsternum and used to perform CPR according to the guidelines of the American Heart Association: 80 compressions per minute, compression depth of 3.8 to 5 cm, 50% duty cycle, and constant-volume ventilation. Mechanical Thumper CPR was also compared in five patients. End-tidal carbon dioxide (ETCO2) concentrations and hemodynamic variables were measured. Transesophageal Doppler echocardiography was used to assess contractility, the velocity time integral (an analogue of cardiac output), and diastolic myocardial filling times. RESULTS--Ten patients were enrolled. The mean +/- SD ETCO2 was 4.3 +/- 3.8 mm Hg with standard CPR and 9.0 +/- 3.9 mm Hg with ACD CPR (P less than .0001). Systolic arterial pressure with standard CPR was 52.5 +/- 14.0 mm Hg and with ACD CPR, 88.9 +/- 24.7 mm Hg (P less than .003). The velocity time integral increased from 7.3 +/- 2.6 cm with standard CPR to 17.5 +/- 5.6 cm with ACD CPR (P less than .0001), and diastolic filling times increased from 0.23 +/- .09 seconds with standard CPR to 0.37 +/- .12 seconds with ACD CPR (P less than .004). Mechanical Thumper CPR consistently underperformed both standard and ACD CPR. Minute ventilation obtained in four patients during ACD CPR without endotracheal ventilation was 6.6 +/- 0.9 L/min. After 1 hour of standard CPR failed, three of 10 patients randomized to ACD CPR rapidly converted to a hemodynamically stable rhythm following 2 minutes of ACD CPR. CONCLUSION--ACD CPR is a simple manual technique that improved cardiopulmonary circulation in 10 patients during cardiac arrest. Although ACD CPR may have produced a return of spontaneous circulation in three patients refractory to standard measures, its impact on survival when used early in cardiac arrest remains to be determined.