有效人工通气时机对心肺脑复苏的影响

目的　评价有效人工通气的时机与心肺脑复苏预后的关系。方法　收集 6 0例心搏骤停行心肺脑复苏患者的临床资料 ,按心搏骤停至成功气管插管实施有效人工通气的间隔时间 ,分三组 ,即 <5min组、 5～ 10min组、 >10min组。比较每组中各期的复苏成功率。结果　 <5min组分别与 5～ 10min组和 >10min组比较 ,三期复苏成功率均有显著差异 (P <0 0 5或 0 0 1) ,而 5～ 10min和 >10min组三期间的复苏成功率无显著差异 (P >0 0 5 )。结论　及时有效的人工通气是心搏骤停CPCR成功的关键 ,5min内行有效人工通气可显著提高复苏成功率     

心肺复苏中机械通气选择时机对院内心脏骤停患者预后的影响

目的:探讨心肺复苏过程中机械通气的选择时机对院内心脏骤停患者预后的影响.方法:以院内心脏骤停自主循环恢复的机械通气患者48例为研究对象,按开始机械通气的时间不同分为早期上机组22例和晚期上机组26例.统计两组患者年龄、性别、心脏骤停心律类型以及心脏骤停原因;统计两组患者的心肺复苏成功率、心脏骤停第24小时有无角膜反射、有无瞳孔反射、有无疼痛躲避反应、有无运动反应、出院时神经功能分类(CPC)以及成活出院率.比较两组患者上述指标之间有无差异性.结果:两组患者年龄、性别、心脏骤停心律类型以及心脏骤停原因之间差异无统计学意义(P＞0.05):两组患者的心肺复苏成功率、第24小时角膜反射(+)、第24小时瞳孔反射(+)、第24小时疼痛躲避反应(+)、第24小时运动反应(+)以及出院时神经功能(CPC)分类等指标差异具有统计学意义,早期上机组明显优于晚期上机组(P＜0.05);两组患者成活出院率(45.45% VS 23.08%)之间差异无显著性(P＞0.05),共计成活出院16例(33.33%).结论:尽早给予有效的机械通气呼吸支持,可提高院内心脏骤停患者的心肺复苏成功率和改善神经功能预后.     

机械通气时机选择对心肺复苏的影响

目的探讨机械通气的时机选择对心肺复苏的影响。方法分析58例心肺复苏患者的临床资料。结果及时通气成功组的SpO2、MAP、窦性心律恢复及心肺复苏成功例数明显高于延时通气成功组。结论早期机械通气有利于提高心肺复苏的成功率。     

心肺复苏患者院内急救以及院外急救效果观察

资料选自2012年8月~2014年4月我院急诊科室接诊的院内和院外急救的心脏呼吸骤停患者80例,将院内急救的40例心脏骤停患者当作院内组,院外急救的40例心脏骤停患者当作院外组,给予所有患者进行胸外按压、开放气道、人工通气和静脉通道、心电除颤等心肺复苏的急救措施,观察比较两组的复苏效果。结果院内组的复苏到位时间为(3±0.6)min,院外组的复苏到位时间为(30±1.8)min。院内组的心电除颤、气管插管、复苏用药和快速建立静脉通道的比率明显比院外组高;院内组和院外组的心肺复苏总有效率分别为55%、15%,两组比较差异明显,有统计学意义(P0.05)。对心肺复苏患者及早进行胸外按压、开放气道、人工通气和静脉通道、心电除颤等心肺复苏的急救措施,可有效提高患者的心肺复苏成功率和有效率。     

初级心肺复苏44例分析

目的:分析本院两年来急诊初级心肺复苏情况,为进一步提高心肺复苏成功率提供依据。方法:回顾性分析本科2004年1月～2005年12月间44例心肺复苏病例。观察其心跳骤停发生地点、骤停时间、病因、肾上腺素用量、有无电除颤及机械通气等指标。结果:成功组复苏前骤停时间比失败组短(P<0.05);在院内发生骤停的复苏成功率比院外要高(P<0.01);成功组需要的胸外按压时间和肾上腺素总量均低于失败组(P<0.05)。结论:影响心肺复苏成功的基础因素包括心肺复苏前骤停的时间、地点、基础病,在心肺复苏过程中是否及时开放气道、进行胸外按压的时间、肾上腺素的用量等可预测复苏的成功率。     

抢救呼吸心跳骤停51例分析

目的：分析影响心肺脑复苏的各种因素，进一步提高其成功率。方法：院前给予气管插管气囊或机械辅助呼吸，院内给予心电监护、CPR用药、心脏、三联针静推或心内注射，肾上腺素大剂量3mg／次，视病情应用，5％碳酸氢钠、阿托品、纳络酮按常规剂量应用；结果：51例呼吸心跳骤停的患者，心肺复苏成功21例(41．2％)．脑复苏成功16例(21．4％)，最短昏迷10min．最长达72h。结论：及早进行心肺复苏，开放气道人工通气、合理用药、心电监护。注意早期保护脑细胞是心肺脑复苏成功的关键。     

心肺脑复苏成功的相关因素分析

目的:探讨脑复苏与心肺复苏开始时间、早期除颤、病发场所、年龄、通气方式等相关因素临床意义.方法:回顾性分析我科2005年12月-2010年12月因心跳骤停行心肺复苏(CPR)283例的临床资料.结果:283例中心肺脑复苏成功41例,心肺脑复苏成功率与心跳骤停发生场所(院内、院外),CPR开始时间、早期电除颤、气道通气方式、年龄等因素相关.结论:开始心肺复苏时间越早,自主循环恢复时间愈快,GCS评分愈高.     

食管气管联合气管插管在急诊科的应用

迅速开放气道建立人工气道行机械通气是心肺复苏的首要步骤.现在广泛应用的是气管内插管,但这种方法常因操作者技术熟练程度而影响插管成功率,延长建立人工通气道时间.目前,常规使用的气管插管方法即使是熟练的医生操作也仍有3%左右的失败率,且至少需要1 min～3 min.应用食管气管联合气管插管行盲探置管仅需要(30±10)s即可成功置管,且插管成功率100%,近年来在我院院前急救及院内急诊科已广泛应用.     

食道-气管联合导气管在院前急救中的应用

目的　观察食道 -气管联合导气管在院前急救心肺复苏中应用的临床效果。方法　 4 3例心脏骤停的病人随机分为两组。Ⅰ组用食道 -气管联合导气管行机械通气 ,Ⅱ组常规气管插管行机械通气。观察插管难易程度 ,插管所需时间 ,一次插管成功率、复苏成功率。结果　食道 -气管联合导气管行机械通气操作简单 ,所需时间、一次插管成功率和复苏成功率均优于常规气管插管。结论　食道 -气管联合导气管行机械通气操作简单、迅速、有效 ,并可提高复苏成功率 ,在院前急救中可完全代替常规气管插管。     

心跳骤停家猪复苏后自主呼吸压力时间乘积的改变

目的:观察心跳骤停家猪模型复苏后自主呼吸时胸腔内压的压力时间乘积(PTP)的改变。方法:8头健康家猪应用电刺激法诱发室颤,不处理10min,心肺复苏6min,复苏后予机械通气,测量并计算复苏前以及复苏后1 h、2 h、4 h、6 h猪模型自主呼吸时胸腔内压的压力时间乘积。结果:复苏后各时间点压力时间乘积均较复苏前显著升高(P0.05),各时间点之间未见显著差异。结论:心肺复苏后肺损伤致呼吸做功增加,常规机械通气治疗6h未见明显改善。     

Patients with cardiac arrest are ventilated two times faster than guidelines recommend: An observational prehospital study using tracheal pressure measurement

Aim

To measure ventilation rate using tracheal airway pressures in prehospitally intubated patients with and without cardiac arrest.

Methods

Prospective observational study. In 98 patients (57 with and 41 without cardiac arrest) an air-filled catheter was inserted into the endotracheal tube and connected to a custom-made portable device allowing tracheal airway pressure recording and subsequent calculation of ventilation rate.

Results

In manually ventilated patients with cardiac arrest 39/43 (90%) had median ventilation rates higher than 10/min (overall median 20, min 4, max 74). During mechanical ventilation, 35/38 (92%) had ventilation rates higher than 10/min. The ventilation rate in patients with cardiac arrest was higher than in patients without cardiac arrest, both for manual and mechanical ventilation. Subanalysis comparing episodes with and without compression in cardiac arrest patients showed no clinically significant difference in ventilation rate after compressions were terminated.

Conclusion

Cardiac arrest patients were ventilated two times faster than recommended by the guidelines. Tracheal airway pressure measurement is feasible during resuscitation and may be developed further to provide real-time feedback on airway pressure and ventilation rate during resuscitation.     

Do we hyperventilate cardiac arrest patients?

INTRODUCTION: Hyperventilation during cardiopulmonary resuscitation is detrimental to survival. Several clinical studies of ventilation during hospital and out-of-hospital cardiac arrest have demonstrated respiratory rates far in excess of the 10 min(-1) recommended by the ERC. We observed detailed ventilation variables prospectively during manual ventilation of 12 cardiac arrest patients treated in the emergency department of a UK Hospital. METHODS: Adult cardiac arrest patients were treated according to ERC guidelines. Ventilation was provided using a self-inflating bag. A COSMOplus monitor (Respironics Inc.) was inserted into the ventilation circuit at the beginning of the resuscitation from which ventilation data were downloaded to a laptop. RESULTS: Data were collected from 12 patients (7 male; age 47-82 years). The maximum respiratory rate was 9-41 breaths per minute (median 26). The median tidal volume was 619 ml (374-923 ml) and the median respiratory rate was 21 min(-1) (7-37 min(-1)). The corresponding median minute volume was 13.0 l/min (4.6-21.3 min(-1)). Median peak inspiratory pressures were 60.6 cmH(2)O (range 46-106). Airway pressure was positive for 95.3% of the respiratory cycle (range 87.9-100%). CONCLUSIONS: Hyperventilation was common, mostly through high respiratory rates rather than excessive tidal volumes. This is the first study to document tidal volumes and airway pressures during resuscitation. The persistently high airway pressures are likely to have a detrimental effect on blood flow during CPR. Guidelines on respiratory rates are well known, but it would appear that in practice they are not being observed.     

Relative importance of alpha and beta adrenergic receptors during resuscitation.

Successful resuscitation from cardiac arrest in the asphyxiated dog model has been ascribed to the use of artificial ventilation, closed chest cardiac massage, and administration of a vasopressor. Controversy remains over whether the most commonly employed vasopressor, epinephrine, exerts its effects primarily by elevating diastolic pressure and reestablishing coronary flow, or by exciting cardiac pacemaker cells and enhancing myocardial contractility. To observe pure alpha and beta adrenergic receptor influences during resuscitation, three groups (alpha-blocked, beta-blocked, unblocked) of dogs were studied. beta-blocked dogs resuscitated with phenylephrine and unblocked dogs resuscitated with epinephrine experienced 100% successful resumption of spontaneous circulation after 5 min of asphyxia-induced arrest. Only 27% of alpha-blocked animals resuscitated with isoproterenol were successfully revived. The appearance of the ECG during cardiac arrest and resuscitation could in no way be used to predict the outcome of resuscitation attempts. Results suggest that, initially, alpha receptor stimulation with concomitant diastolic pressure elevation is more important to the success of resuscitation than beta receptor stimulation.     

Two-stage resuscitation of the cat brain after prolonged cardiac arrest

Following prolonged cardiac arrest, reperfusion of the brain is endangered by the low blood perfusion pressure during the early resuscitation phase. In order to avoid low perfusion brain injury, a two-stage resuscitation protocol was applied to cats submitted to 30 min potassium chloride induced cardiac arrest: first, the heart was resuscitated, followed — after stabilisation of blood pressure — by recirculation of the brain. During cardiac resuscitation the brain was disconnected from the general circulation by inflating a pneumatic cuff around the neck. The results were compared with the outcome of conventional one-stage resuscitation following 15 min cardiac arrest. Cardiac resuscitation was successful in 5 out of 8 animals with 15 min and in 6 out of 13 animals with 30 min cardiac arrest. In successfully resuscitated animals of both groups, brain energy metabolism recovered to normal within 3 h although two-stage resuscitation increased brain ischemia time to 37–61 min. Twostage resuscitation, in consequence, is a promising approach for revival of the brain after prolonged cardiac arrest.     

Precordial compression without airway management induces lung injury in the rodent cardiac arrest model with central apnea.

To investigate whether the lung injury induced by precordial compression without ventilation or not, in the cardiac-arrest animal model with central apnea. Thirty male Sprague-Dawley rats were anesthetized with halothane. The cardiac arrest was induced by 100 mg/kg ketamine (IV) and accompanied with central apnea. They were allocated to four groups by means of resuscitation. Group A was treated with only precordial compression without the other treatments. In group B with tracheotomy and precordial compression. In group C was performed tracheotomy, oxygenation, and precordial compression. The animals in group D were treated with tracheotomy, oxygen administration, artificial ventilation, and precordial compression. Four minutes after cardiac arrest, the resuscitation was started and continued for 20 min. PaCO(2) in the group without mechanical ventilation increased significantly after the start of the resuscitation. All animals were sacrificed after resuscitation procedure. The wet/dry weight ratio of lung in group A (6.9+/-0.8) was significantly higher than that of the other groups B, C and D (5.9+/-0.6, 5.7+/-0.4 and 5.6+/-0.4, P<0.05 in each). The pathological findings also demonstrated the lung injuries, such as edema, migration, and destruction of structure in group A. The precordial compression alone did not improve CO(2) elimination in the gasping-less cardiac arrest model, as well as maybe inducing more severe lung injury than that with the protective management. This experimental model raises the possibility that chest compressions without airway management might result in lung injury.     

Hypercarbic acidosis reduces cardiac resuscitability

BACKGROUND AND METHODS: Marked increases in myocardial hypercarbia and acidosis accompany cardiac arrest and resuscitation. To investigate whether hypercarbic acidosis independent of oxygenation is of itself detrimental to cardiac resuscitation, three groups of six Sprague-Dawley rats were ventilated with gas mixtures containing concentrations of inspired CO2 (FICO2) of 0.0, 0.3, or 0.5, with oxygen fractions held constant at 0.5. After 4 mins of ventricular fibrillation, mechanical chest compressions were initiated with a pneumatic thumper; 2 mins later, transthoracic defibrillation was attempted. RESULTS: Each animal ventilated with FICO2 of 0.0 or 0.3 was successfully resuscitated. However, none of the animals ventilated with FICO2 of 0.5, in which aortic pH was less than 6.67 and aortic PCO2 was greater than 200 torr (greater than 26.7 kPa), was resuscitated (p less than .001). This finding contrasted with a second control group of seven identically treated animals which, in the absence of cardiac arrest, demonstrated no adverse effects after ventilation with an FICO2 of 0.5. CONCLUSIONS: Increases in FICO2 to levels of 0.5 under conditions of constant arterial oxygenation and controlled coronary perfusion pressure preclude successful resuscitation in this rodent model of CPR.     

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.     

Presumed futility in paramedic-treated out-of-hospital cardiac arrest: an Utstein style analysis in Tampere, Finland

AIM: To report prospectively the outcome from prehospital cardiac arrest according to the Utstein template in the city of Tampere, Finland, with special reference to those patients in whom resuscitation was not attempted. MATERIALS AND METHODS: In Tampere (population 203,000), a two-tiered emergency medical service (EMS) system provides first response and basic life support (BLS), supported by advanced life support (ALS) units staffed with nurse-paramedics. We analysed all out-of-hospital cardiac arrests considered for resuscitation during a 12-month period. RESULTS: Of 191 patients with prehospital cardiac arrest, resuscitation was not attempted in 98 patients (51%). Reasons to withhold from resuscitation were estimated futility (97 cases) and a do-not-attempt-resuscitation order (1). Sixty percent of the patients with no resuscitation had secondary signs of death, 97% had asystole as the initial cardiac rhythm and 98% had suffered an unwitnessed cardiac arrest. Resuscitation was successful in 45 of the remaining 93 patients with attempted resuscitation. Twelve patients were discharged (overall survival rate 13%), nine of them with a CPC score of 1 or 2. Fifteen patients were treated with therapeutic hypothermia. Of the bystander-witnessed cardiac arrests with VF as initial rhythm, 29% survived. CONCLUSIONS: The Tampere EMS system initiated resuscitation less frequently than reported from other EMS systems, but the reasons to withhold resuscitation seemed justified. The overall and Utstein's 'golden standard' survival rates were comparable with previous reports.     

与胸外心脏按压同时和非同时机械通气对心肺复苏影响的比较

目的：探讨与胸外心脏按压同时和非同时机械通气在心肺复苏中应用的效果。方法：将12例心跳呼吸骤停患者随机分为与胸外心脏按压同时控制机械通气组和与胸外按压非同时手控机械通气组。采用控制通气模式机械通气与持续循手胸外心脏按压同时进行;后者采用手控通气模式机械通气（MAMV）与间断徒手胸外心脏按压非同时配配合进行心肺复苏,胸外心脏按压每5次后暂停1次,在暂停间期给予MAMV1次,之后通气与按压依此比例进行。2组均进行无创动脉血压、心电、经皮氧饱和度（SpO2)、潮气量（VT)、气道峰压（Ppeak)等监测。结果：与胸外心脏按压非同时手控机械通气组的SpO2、VT均明显高于与胸外心脏按压同时模式通气组的SpO2和VT,P均＜0．05;而peak则明显低于后者,P＜0．05;2组的平均动脉压无显著差别。结论：与胸外心脏按压非同时手控机械通气在提高SpO2、VT,降低Ppeak,恢复窦性心律及提高心肺复苏成功率等方面明显优于与胸外心脏按压同时控制机械通气。     

No-reflow after cardiac arrest

Objective Successful resuscitation of the brain requires unimpaired blood recirculation. The study addresses the question of the severity and reversibility of no-reflow after cardiac arrest.Design Adult normothermic cats were submitted to 5, 15 and 30 min cardiac arrest by ventricular fibrillation. The extent of no-reflow was assessed in each cardiac arrest group after 5 min closed chest cardiac massage in combination with 0.2 mg/kg epinephrine or after successful resuscitation followed by 30 min recirculation.Measurements and results Reperfusion of the brain was visualized by labelling the circulating blood with FITC-Albumin. Areas of no-reflow, defined as absence of microvascular filling, were identified by fluorescence microscopy at 8 standard coronal levels of forebrain, and expressed as percent of total sectional area. During cardiac massage, noreflow affected 21±5%, 42±38% and 70±27% of forebrain after 5, 15 and 30 min cardiac arrest, respectively. After 30 min spontaneous recirculation following successful resuscitation of the heart, no-reflow significantly declined to 7±11% after 5 min cardiac arrest (p<0.05) but persisted in 30±11% and 65±21% of forebrain after 15 and 30 min cardiac arrest, respectively (n.s.).Conclusion Our observations demonstrate that resuscitation of the heart by closed chest massage causes severe (and after prolonged cardiac arrest irreversible) no-reflow of the brain. This suggests that no-reflow is an important cause of postresuscitation brain pathology.