A pilot study examining the role of regional cerebral oxygen saturation monitoring as a marker of return of spontaneous circulation in shockable (VF/VT) and non-shockable (PEA/Asystole) causes of cardiac arrest

Background

Non-invasive monitoring of cerebral perfusion and oxygen delivery during cardiac arrest is not routinely utilized during cardiac arrest resuscitation. The objective of this study was to investigate the feasibility of using cerebral oximetry during cardiac arrest and to determine the relationship between regional cerebral oxygen saturation (rSO2) with return of spontaneous circulation (ROSC) in shockable (VF/VT) and non-shockable (PEA/asystole) types of cardiac arrest.

Methods

Cerebral oximetry was applied to 50 in-hospital and out-of-hospital cardiac arrest patients.

Results

Overall, 52% (n = 26) achieved ROSC and 48% (n = 24) did not achieve ROSC. There was a significant difference in mean ± SD rSO2% in patients who achieved ROSC compared to those who did not (47.2 ± 10.7% vs. 31.7 ± 12.8%, p < 0.0001). This difference was observed during asystole (median rSO2 (IQR) ROSC versus no ROSC: 45.0% (35.1–48.8) vs. 24.9% (20.5–32.9), p < 0.002) and PEA (50.6% (46.7–57.5) vs. 31.6% (18.8–43.3), p = 0.02), but not in the VF/VT subgroup (43.7% (41.1–54.7) vs. 42.8% (34.9–45.0), p = 0.63). Furthermore, it was noted that no subjects with a mean rSO2 < 30% achieved ROSC.

Conclusions

Cerebral oximetry may have a role as a real-time, non-invasive predictor of ROSC during cardiac arrest. The main utility of rSO2 in determining ROSC appears to apply to asystole and PEA subgroups of cardiac arrest, rather than VF/VT. This observation may reflect the different physiological factors involved in recovery from PEA/asytole compared to VF/VT. Whereas in VF/VT, successful defibrillation is of prime importance, however in PEA and asytole achieving ROSC is more likely to be related to the quality of oxygen delivery. Furthermore, a persistently low rSO2 <30% in spite of optimal resuscitation methods may indicate futility of resuscitation efforts.     

近红外光谱测量脑血氧饱和度与成人心脏骤停后接受目标体温管理患者神经系统预后的关系:系统评价和荟萃分析

目的研究脑血氧饱和度(rSO₂)在心脏骤停后综合征(PCAS)昏迷患者的目标体温管理(TTM)期间预测神经系统预后的作用。方法本研究根据PRISMA指南进行报告,检索了Pubmed、Embase、Cochane Library、Web of science、Google Scholar、Clinical gov、万方、维普、CNKI共9个数据库。除外研究类型为病例报告、综述和研究样本量小于5例的研究,收集所有在成人心脏骤停(CA)期间进行近红外光谱(NIRS)测量的研究。两名审稿人评估纳入文章的质量并提取数据。结果效应使用标准化平均差(SMD)进行标准化。结果本荟萃分析纳入11项研究,其中2项为随机对照研究,9项为观察性研究。共计681例患者。患者TTM期间NIRS测量的rSO₂值在TTM 24 h(低温结束)、TTM 24~36 h(复温阶段)和TTM 36~48 h(初始常温阶段)与神经系统预后相关(TTM 24 h:SMD=0.45,95%CI 0.29~0.61;TTM 24~36 h:SMD=1.17,95%CI 0.85~1.50;TTM 36~48 h:SMD=0.26,95%CI 0.10~0.43),良好的神经系统预后(CPC 1~2)组具有较高的rSO₂值。在TTM开始时、TTM期间和TTM 72 h的常温阶段,均未发现NIRS测量的rSO₂值与神经系统预后的相关性。结论对于行TTM的CA患者,在TTM 24~48 h期间良好神经系统预后患者NIRS测量的rSO₂值高于神经系统预后不良的患者,其中TTM 24~36 h(复温阶段)与良好神经系统预后有较强的关联。     

Regional cerebral oxygen saturation after cardiac arrest in 60 patients—A prospective outcome study

Introduction

Non-invasive near-infrared spectroscopy (NIRS) offers the possibility to determine regional cerebral oxygen saturation (rSO₂) in patients with cardiac arrest. Limited data from recent studies indicate a potential for early prediction of neurological outcome.

Methods

Sixty cardiac arrest patients were prospectively enrolled, 22 in-hospital cardiac arrest (IHCA) and 38 out-of-hospital cardiac arrest (OHCA) patients respectively. NIRS of frontal brain was started after return of spontaneous circulation (ROSC) during admission to ICU and was continued until normothermia. Outcome was determined at ICU discharge by the Pittsburgh Cerebral Performance Category (CPC) and 6 months after cardiac arrest.

Results

A good outcome (CPC 1–2) was achieved in 23 (38%) patients, while 37 (62%) had a poor outcome (CPC 3–5). Patients with good outcome had significantly higher rSO₂ levels (CPC 1–2: rSO₂ 68%; CPC 3–5: rSO₂ 58%; p < 0.01). For good and poor outcome median rSO₂ within the first 24 h period was 66% and 59% respectively and for the following 16 h period 68% and 59% (p < 0.01). Outcome prediction by area of rSO₂ below a critical threshold of rsO₂ = 50% within the first 40 h yielded 70% specificity and 86% sensitivity for poor outcome.

Conclusion

On average, rSO₂ within the first 40 h after ROSC is significantly lower in patients with poor outcome, but rSO₂ ranges largely overlap between outcome groups. Our data indicate limited potential for prediction of poor outcome by frontal brain rSO₂ measurements.     

心脏骤停后心肺复苏和心肺脑复苏成功病例的对比分析

目的 探讨影响心脏骤停患者成功脑复苏的相关因素.方法 回顾对比分析心脏骤停后成功心肺脑复苏(A组,n=38)和仅心肺复苏成功(B组,n=42)患者之间的相关指标,包括性别、年龄、原发疾病、心脏骤停原因、心脏骤停环境、心脏骤停相关时间和心肺复苏后相关治疗持续时间.结果 两组性别比和平均年龄比较差异无统计学意义(P＞0.05).原发疾病:A组以外科为主(78.9%),B组以内科为主(61.9%),两组比较差异有统计学意义(P＜0.005).心脏骤停原因:A组31例(81.6%)为急性缺氧、低血压、内脏神经反射和单纯心脏疾患, B组30例(71.4%)为慢性缺氧和慢性心脏病,两组比较差异有统计学意义(P＜0.005).心脏骤停环境:A组24例(63.2%)发生在手术室和ICU,B组22例(52.4%)发生在普通病房,两组比较差异有统计学意义(P＜0.005).心脏骤停相关时间:A组心脏骤停持续时间(8.2±8.7)min,自主心跳恢复时间(6.7±8.4)min,脑缺血缺氧时间(1.5±1.3)min,均明显短于B组[分别为(30.8±26.2)min、(27.7±24.9)min和(3.1±3.1)min,P＜0.001或P＜0.005].心肺复苏后相关治疗持续时间:A组亚低温持续时间(4.0±2.6)d,呼吸机持续时间(11.1±19.7)d,与B组[(5.9±3.8)d和(15.4±29.3)d]比较差异无统计学意义(P＞0.05).Logistic多因素回归分析显示,原发疾病(OR=6.22,95%CI 1.64～23.46)、心脏骤停持续时间(OR=1.11,95%CI 1.04～1.19)和心脏骤停发生环境(OR=4.51,95%CI 1.22～16.61)与成功脑复苏的关系更密切,成为三个独立影响因素.结论 没有明显慢性疾病,在手术室和ICU以急性缺氧、低血压和单纯心脏原因发生的心脏骤停,抢救及时有效,复苏后处理恰当、合理,尽早实施全面脑保护是成功脑复苏的有利因素.     

Regional cerebral oxygen saturation on hospital arrival is a potential novel predictor of neurological outcomes at hospital discharge in patients with out-of-hospital cardiac arrest

Aim To investigate the association between regional brain oxygen saturation (rSO₂) on hospital arrival and neurological outcomes at hospital discharge in patients with out-of-hospital cardiac arrest (OHCA).Methods A prospective cohort study was conducted, registering 179 patients with OHCA who were referred to Senri Critical Care Medical Centre between April 2009 and June 2010. Of these patients, 92 met the inclusion criteria. The primary end point was “neurological outcomes” at hospital discharge according to the “Utstein style” guidelines.Results The overall rate of good neurological outcome at hospital discharge was 14% (n = 13). Sixty-one patients with rSO₂ ≤25% showed poor neurological outcome in the receiver operating curve analysis (optimal cut-off point, 25%; sensitivity, 0.772; specificity, 1.000; positive predictive value, 1.000; area under the curve (AUC), 0.919; p < 0.0001). The AUC for rSO₂ was greater than that for base excess (p = 0.0461) or lactate (p = 0.0128) measured on hospital arrival. Since rSO₂ >40% was previously collated with good neurological outcome after cardiovascular surgery, we categorised our patients into three groups in a post hoc analysis: patients with rSO₂ ≤25% (n = 61); patients with rSO₂ 26-40% (n = 9) and patients with rSO₂ >40% (n = 22). Patients with good neurological outcome were as follows: 0 (0%)/61 with rSO₂ ≤25%; two (22.2%)/9 with rSO₂ 26-40% and 11 (50.0%)/22 with rSO₂ >40% (p < 0.0001).Conclusion rSO₂ on hospital arrival may help predict neurological outcomes at hospital discharge in patients with OHCA.     

Early jugular bulb oxygenation monitoring in comatose patients after an out-of-hospital cardiac arrest

Objective To determine the role of early jugular bulb oxygenation monitoring in comatose patients after cardiac arrest.Design Prospective sequential study.Setting Medical intensive care unit in a university hospital.Patients Thirteen patients comatose after out-of-hospital cardiac arrest.Interventions A standard hemodynamic protocol.Measurements and results Jugular bulb oxygen saturation levels and oxygen extraction ratios could not discriminate between patients with good (6) and poor (7) cerebral outcome. This was also true for the jugular bulb-arterial lactate difference. Survivors had significantly higher overall oxygen transport values than non-survivors.Conclusions Jugular bulb oxygenation monitoring during the first few hours after cardiac arrest cannot reliably discrininate between comatose patients with a good and poor cerebral outcome. Further studies with an extended monitoring period are thus required.     

Estimation of jugular venous O2 saturation from cerebral oximetry or arterial O2 saturation during isocapnic hypoxia

Objective.Near-infrared spectroscopy (NIRS) has the potential forproviding valuable information about oxygen delivery to the brain. However,questions have been raised about the accuracy of these measurements. Thisstudy was undertaken to compare noninvasive cerebral saturation measurementsto jugular venous saturation under conditions of hypoxia and hypercapnia.Methods.Data was obtain on forty-two subjects. Cerebral oxygenationwas measured with a Somanetics INVOS 4100-SSA placed on the forehead of thesubjects. PETCO₂ was controlled to approximately 2 and 7 mmHg aboveresting values and PETO₂ was controlled to 80, 45, 60 and 41 mmHgconsecutively for four of five minutes each. Internal jugular blood gasmeasurements were made via a retrograde catheter. Results.Both thecerebral oximetry measured saturation (rSO₂) and the jugular venoussaturation (Sj O₂) were significantly increasedby increasing the PETCO₂ at all levels of hypoxia. The increase inthe rSO₂ was less than the increase inSj O₂. The rSO₂ had a bias of 5.2%and a precision of 10.7% compared to the measuredSj O₂. Discussion.Cerebral oxygensaturation measured by cerebral oximetry compares well to the measuredSj O₂ in normal subjects, despite multiplephysiological reasons for differences. The closer relationship ofSj O₂ to rSO₂ than SaO₂under the conditions of these experiments indicates that the measurementreflects primarily intracranial saturation. However, outcome studies underclinical conditions are needed to determine the clinical utility of cerebraloximetry. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cerebral tissue oxygen saturation during therapeutic hypothermia in post-cardiac arrest patients

Aim of the study

This observational study was performed to assess the cerebral tissue oxygen saturation during and after therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest.

Methods

We performed a prospective observational study on the cerebral tissue oxygen saturation (SctO₂) in post-cardiac arrest patients treated with therapeutic hypothermia (TH) between March 2011 and April 2012. SctO₂ (measured by near-infrared spectroscopy) was non-invasively and continuously measured in 28 post-cardiac arrest patients during hypothermia and active rewarming.

Results

At the start of mechanically induced TH, SctO₂ was 68% (65–72) and PaCO₂ was 47.2 mmHg (36.9 – 51.4). SctO₂ and PaCO₂ significantly decreased to 59% (57–64; p = 0.006) and 36.6 mmHg (33.9–44.7; p = 0.002), respectively, within the first 3 h of mechanically induced TH. Cerebral tissue oxygen saturation was significantly lower in non-survivors (n = 10) compared with survivors (n = 18) at 3 h after induction of hypothermia (p = 0.02) while the decrease in PaCO₂ was similar in both groups. During TH maintenance, SctO₂ gradually returned to baseline values (69% (63–72)) at 24 h, with no differences between survivors and non-survivors (p = 0.65). Carbon dioxide remained within the range of mild hypocapnia (32–38 mmHg) throughout the hypothermic period. During rewarming, SctO₂ further increased to 71% (67–78).

Conclusions

Induction of TH in comatose post-CA patients changes the balance between oxygen delivery and supply. The decrease in SctO₂ was less pronounced in patients surviving to hospital discharge.     

Perturbation of the endothelial glycocalyx in post cardiac arrest syndrome

Background

The prognosis of immediate survivors of cardiac arrest remains poor, as the majority of these patients develops an inflammatory disorder known as the post-cardiac arrest syndrome (PCAS). Recently, the endothelial glycocalyx has been shown to be a key modulator of vascular permeability and inflammation, but its role in PCAS remains unknown.

Methods

Plasma levels of the glycocalyx components syndecan-1, heparan sulfate and hyaluronic acid were measured in 25 patients after immediate survival of cardiac arrest during different phases of PCAS. Twelve hemodynamically stable patients with acute coronary syndrome served as controls.

Results

Cardiac arrest resulted in a significant increase in syndecan-1, heparan sulfate and hyaluronic acid levels compared to controls, indicating a shedding of the endothelial glycocalyx as a pathophysiological component of the post cardiac arrest syndrome. The time course differed between the individual glycocalyx components, with a higher increase of syndecan-1 in the early phase of PCAS (2.8-fold increase vs. controls) and a later peak of heparan sulfate (1.7-fold increase) and hyaluronic acid (2-fold increase) in the intermediate phase. Only the plasma levels of syndecan-1 correlated positively with the duration of CPR and negatively with the glycocalyx-protective protease inhibitor antithrombin III. Plasma levels of both syndecan-1 and heparan sulfate were higher in eventual non-survivors than in survivors of cardiac arrest.

Conclusion

Our data for the first time demonstrates a perturbation of the endothelial glycocalyx in immediate survivors of cardiac arrest and indicate a potential important role of this endothelial surface layer in the development of post-cardiac arrest syndrome.     

Regional cerebral oxygen saturation monitoring for predicting interventional outcomes in patients following out-of-hospital cardiac arrest of presumed cardiac cause: A prospective,observational, multicentre study

AimThis study investigated the value of regional cerebral oxygen saturation (rSO₂) monitoring upon arrival at the hospital for predicting post-cardiac arrest intervention outcomes.MethodsWe enrolled 1195 patients with out-of-hospital cardiac arrest of presumed cardiac cause from the Japan-Prediction of Neurological Outcomes in Patients Post-cardiac Arrest Registry. The primary endpoint was a good neurologic outcome (cerebral performance categories 1 or 2 [CPC1/2]) 90 days post-event.ResultsA total of 68 patients (6%) had good neurologic outcomes. We found a mean rSO₂ of 21% ± 13%. A receiver operating characteristic curve analysis indicated an optimal rSO₂ cut-off of ≥40% for good neurologic outcomes (area under the curve 0.92, sensitivity 0.81, specificity 0.96). Good neurologic outcomes were observed in 53% (55/103) and 1% (13/1092) of patients with high (≥40%) and low (<40%) rSO₂, respectively. Even without return of spontaneous circulation (ROSC) upon arrival at the hospital, 30% (9/30) of patients with high rSO₂ had good neurologic outcomes. Furthermore, 16 patients demonstrating ROSC upon arrival at the hospital and low rSO₂ had poor neurologic outcomes. Multivariate analyses indicated that high rSO₂ was independently associated with good neurologic outcomes (odds ratio = 14.07, P < 0.001). Patients with high rSO₂ showed favourable neurologic prognoses if they had undergone therapeutic hypothermia or coronary angiography (CPC1/2, 69% [54/78]). However, 24% (25/103) of those with high rSO₂ did not undergo these procedures and exhibited unfavourable neurologic prognoses (CPC1/2, 4% [1/25]).ConclusionrSO₂ is a good indicator of 90-day neurologic outcomes for post-cardiac arrest intervention patients.     

241例心跳骤停与心肺脑复苏的回顾性分析

目的 探讨心跳骤停患者的临床特点及救治经验，以提高心肺脑复苏成功率。方法 回顾性分析我科1990年10月至2002年10月十二年间院内及院外急救的241例心跳骤停患者的临床资料，初步分析治疗与预后的关系。结果 241例心跳骤停患者中，初步复苏成功10例，最终复苏成功(心肺脑均复苏)仅4例，复苏率分别为4．62％、1．82％。1990至1998年间复苏成功率较低，初步复苏成功率1．38％，最终复苏成功率0。1999至2002年间复苏成功率明显提高，初步复苏成功率8．24％，最终复苏成功率4．12％。自1998年我科开展院外急救以来，尚无一例院外心跳骤停者复苏成功。结论 心跳骤停患者抢救成功与否与抢救人员专业水平、抢救开始时间、抢救措施正确与否、对室颤患者能否早期除颤及患者原发病是否可逆等因素密切相关。     

脑组织氧饱和度监测联合持续颅内压监测在脑出血患者手术中的应用

目的:探讨持续颅内压(continuous intracranial pressure,ICP)监测联合局部脑氧饱和度(regional cerebral oxygen saturation,rScO 2)监测在高血压脑出血患者小骨窗血肿清除术前后的应用及对患者预后的影响。 方法:选取2018年4...     

Intraaortic balloon occlusion during refractory cardiac arrest. A case report

Despite recent advances in its management, the outcome from cardiac arrest is often poor despite appropriate cardiopulmonary resuscitation (CPR). The coronary perfusion pressure (CPP) achieved during CPR is associated with successful return of spontaneous circulation (ROSC). Continuous balloon occlusion of the descending aorta is an experimental method that can occlude the ‘unnecessary’ part of the circulation, thus diverting generated pressure and blood flow to the heart and brain. We present a case report with a patient unresponsive to standard CPR in which constant intraaortic balloon occlusion achieved ROSC and successful survival.     

插入式腹主动脉按压对心搏骤停兔心肺脑复苏的实验研究

目的：探讨插入式腹主动脉按压心肺复苏（IAAC-CPR）对心搏骤停兔心肺脑复苏的效果。方法健康新西兰大白兔10只,雌雄不拘,按随机数字表法分为传统胸外按压心肺复苏（CC-CPR）组和IAAC-CPR组,每组5只。经颈静脉快速推注冰氯化钾并夹闭气管导管制备心搏骤停模型;心搏骤停3 min后开始实施心肺复苏（CPR）,CC-CPR组为呼吸机辅助通气+胸外按压;IAAC-CPR组为呼吸机辅助通气+胸外按压+腹主动脉按压。观察CPR过程中血流动力学和脑皮质血流的变化;记录自主循环恢复（ROSC）时间,观察动物24 h生存情况、24 h神经功能评分及腹部器官情况等。结果 IAAC-CPR组复苏后30、60、90、120 s时脑血流量（CBF,PU值）及平均动脉压（MAP,mmHg,1 mmHg＝0.133 kPa）均明显高于CC-CPR组（CBF 30 s：16.1±6.0比7.8±2.2,60 s：91.6±11.8比57.3±23.2,90 s：259.9±74.9比163.6±50.3,120 s：301.5±60.5比208.4±23.8;MAP 30 s：46.4±9.4比31.4±8.7,60 s：55.8±13.8比34.0±11.5,90 s：61.2±11.5比38.2±10.1,120 s：63.6±11.8比40.2±10.2;均P＜0.05）。与CC-CPR组比较,IAAC-CPR组ROSC所需时间明显缩短（s：182.0±59.0比312.6±86.6,t＝2.787,P＝0.024）,24 h神经功能评分明显下降（分：2.4±1.7比4.6±0.6,t＝2.974,P＝0.023）;而复苏成功率（80.0%比60.0%,χ2＝0.000,P＝1.000）、24 h存活率升高（80.0%比40.0%,χ2＝0.417,P＝0.519）,但差异无统计学意义。ROSC后24 h尸解动物均未发现肝脏损伤。结论在心搏骤停兔复苏早期,IAAC-CPR较CC-CPR取得了更好的脑血流灌注,明显减轻了心搏骤停兔的神经系统功能损伤,且无腹部器官损伤。     

有效人工通气在心脏疾患致心搏骤停心肺脑复苏中价值的探讨

目的　评价A(airway)、B(breath)、C(circulation)抢救步骤在心脏疾患致心搏骤停患者心肺脑复苏 (CPCR)中的价值。方法　收集因心脏疾患致心搏骤停行CPCR患者的临床资料 (4 4例 ,男 2 9例 ,女 15例 ,年龄 40～ 85岁 ,平均 70 .0± 11.6岁 ) ,按照CPCR实际操作过程中所采取的ABC先后顺序不同 ,将患者分为C、CAB、AB、ABC组。CAB组中 ,按照C与AB步骤采取的间隔时间不同 ,分 <5min、5～ 10min、>10min组。统计各组Ⅰ、Ⅱ、Ⅲ期复苏成功率 (% ) ,χ2 检验统计各组复苏成功率差异显著性。结果　C组 (32例次 ,11例 )中 ,各期复苏成功率均 >87.5 % ,显著高于其它各组 (P <0 .0 1)。CAB组 (2 4例 )C -AB间隔时间不等 ,各期复苏成功率不等 ,C -AB <5min组各期复苏成功率明显高于 >5min组 (P <0 .0 5～ 0 .0 1)。AB组 (3例 )与ABC组 (6例 )各期复苏成功率 33.3%～ 10 0 % ,显著高于CAB组 (P <0 .0 1)。结论　CAB是心脏疾患致心搏骤停患者CPCR中可取的抢救步骤 ,但 5min可能是进行有效人工通气的极限     

Miniaturized mechanical chest compressor improves calculated cerebral perfusion pressure without compromising intracranial pressure during cardiopulmonary resuscitation in a porcine model of cardiac arrest

Objective

One of the major goals of cardiopulmonary resuscitation (CPR) is to provide adequate oxygen delivery to the brain for minimizing cerebral injury resulted from cardiac arrest. The optimal chest compression during CPR should effectively improve brain perfusion without compromising intracranial pressure (ICP). Our previous study has demonstrated that the miniaturized mechanical chest compressor improved hemodynamic efficacy and the success of CPR. In the present study, we investigated the effects of the miniaturized chest compressor (MCC) on calculated cerebral perfusion pressure (CerPP) and ICP.

Methods

Ventricular fibrillation was electrically induced and untreated for 7 min in 13 male domestic pigs weighing 39 ± 3 kg. The animals were randomized to receive mechanical chest compression with the MCC (n = 7), or the Thumper device (n = 6). CPR was performed for 5 min before defibrillation attempt by a single 150 J shock. At 2.5 min of CPR, the epinephrine at a dose of 20 μg/kg was administered. Additional epinephrine was administered at an interval of 3 min thereafter. If resuscitation was not successful, CPR was resumed for an additional 2 min prior to the next defibrillation until successful resuscitation or for a total of 15 min. Post-resuscitated animals were observed for 2 h.

Results

Significantly greater intrathoracic positive and negative pressures during compression and decompression phases of CPR were observed with the MCC when compared with the Thumper device. The MCC produced significantly greater coronary perfusion pressure and end-tidal carbon dioxide. There were no statistically significant differences in systolic and mean ICP between the two groups; however, both of the measurements were slightly greater in the MCC treated animals. Interestingly, the diastolic ICP was significantly lower in the MCC group, which was closely related to the significantly lower negative intrathoracic pressure in the animals that received the MCC. Most important, systolic, diastolic and mean calculated CerPP were all significantly greater in the animals receiving the MCC.

Conclusions

In the present study, mechanical chest compression with the MCC significantly improved calculated CerPP but did not compromise ICP during CPR. It may provide a safe and effective chest compression during CPR.Protocol number: P1205.     

Tilting for perfusion: Head-up position during cardiopulmonary resuscitation improves brain flow in a porcine model of cardiac arrest

IntroductionCerebral perfusion is compromised during cardiopulmonary resuscitation (CPR). We hypothesized that beneficial effects of gravity on the venous circulation during CPR performed in the head-up tilt (HUT) position would improve cerebral perfusion compared with supine or head-down tilt (HDT).MethodsTwenty-two pigs were sedated, intubated, anesthetized, paralyzed and placed on a tilt table. After 6 min of untreated ventricular fibrillation (VF) CPR was performed on 14 pigs for 3 min with an automated CPR device called LUCAS (L) plus an impedance threshold device (ITD), followed by 5 min of L-CPR + ITD at 0° supine, 5 min at 30° HUT, and then 5 min at 30° HDT. Microspheres were used to measure organ blood flow in 8 pigs. L-CPR + ITD was performed on 8 additional pigs at 0°, 20°, 30°, 40°, and 50° HUT.ResultsCoronary perfusion pressure was 19 ± 2 mmHg at 0° vs. 30 ± 3 at 30° HUT (p < 0.001) and 10 ± 3 at 30° HDT (p < 0.001). Cerebral perfusion pressure was 19 ± 3 at 0° vs. 35 ± 3 at 30° HUT (p < 0.001) and 4 ± 4 at 30° HDT (p < 0.001). Brain–blood flow was 0.19 ± 0.04 ml min⁻¹ g⁻¹ at 0° vs. 0.27 ± 0.04 at 30° HUT (p = 0.01) and 0.14 ± 0.06 at 30° HDT (p = 0.16). Heart blood flow was not significantly different between interventions. With 0, 10, 20, 30, 40 and 50° HUT, ICP values were 21 ± 2, 16 ± 2, 10 ± 2, 5 ± 2, 0 ± 2, −5 ± 2 respectively, (p < 0.001), CerPP increased linearly (p = 0.001), and CPP remained constant.ConclusionDuring CPR, HDT decreased brain flow whereas HUT significantly lowered ICP and improved cerebral perfusion. Further studies are warranted to explore this new resuscitation concept.     

Cerebral cortical microvascular flow during and following cardiopulmonary resuscitation after short duration of cardiac arrest

AIM: To examine changes in cerebral cortical macro- and microcirculation and their relationship to the severity of brain ischaemia during and following resuscitation from a short duration of cardiac arrest. METHODS: Bilateral cranial windows were created in eight domestic pigs weighing 41+/-1 kg, exposing the frontoparietal cortex for orthogonal polarization spectral imaging together with estimation of cortical-tissue partial pressure of carbon dioxide, a quantitator of the severity of cerebral ischaemia. After 3 min of untreated ventricular fibrillation, cardiopulmonary resuscitation was begun and continued for 4 min before defibrillation. Aortic pressure, end-tidal and cortical-tissue partial pressure of carbon dioxide, and cortical microcirculatory blood flow in vessels of less and more than 20 microm in diameter were continuously measured. RESULTS: Cerebral microcirculatory blood flow progressively decreased over the 3-min interval that followed onset of ventricular fibrillation. Chest compression restored cortical microvascular flow to approximately 40% of the pre-arrest value. Following return of spontaneous circulation, microvascular flow velocity was restored to baseline values over 3 min. Reversal of cerebral ischaemia with normalisation of cerebral cortical-tissue partial pressure of carbon dioxide occurred over 7 min after resuscitation. Cortical microcirculatory blood flow in microvessels less than 20 microm was highly correlated with flow in vessels more than 20 microm together with mean aortic pressure and end-tidal partial pressure of carbon dioxide. CONCLUSION: Cerebral cortical microcirculatory flow ceased only 3 min after onset of cardiac arrest. Flow was promptly restored to 40% of its pre-arrest value after start of chest compression. After resuscitation, both macro- and microcirculatory flows were fully restored over 3 min, but cerebral ischaemia reversed more slowly.     

体外膜肺氧合治疗用于心肺复苏的临床研究

目的 总结体外膜肺氧合（ECMO）治疗对于常规心肺复苏（CPR）困难患者的临床治疗经验。方法 自2005-09-2006-05我院进行ECMO治疗37例患者，其中11例心脏骤停后实施电除颤和心脏按压等CPR措施无效或自主循环恢复后持续低心排而行ECMO循环辅助。结果 8例顺利停机，6例存活恢复出院，其中2例行心脏移植后康复出院。3例不能顺利撤机者在ECMO辅助期间由于循环功能恶化，最终因多器官功能衰竭死亡。顺利撤机和存活出院的患者治疗前乳酸水平较低。ECMO治疗后乳酸清除率较快（P〈0．05）。ECMO期间出现的并发症包括出血、神经精神系统异常、肢体缺血坏死和多脏器功能不全。4例患者因膜肺出现血浆渗漏而更换膜肺。结论 ECMO可为危重心脏病患者心脏骤停后复苏困难时提供心肺功能支持，提高危重心脏病患者CPR的存活率。CPR后动脉血乳酸值和ECMO治疗后乳酸清除率可以预测患者预后。