Modulation of nitric oxide expression with methylene blue does not improve outcome after hypovolemic cardiac arrest

Aim of the study

We recently reported that female sex protects against cerebral and cardiac injury after hypovolemic cardiac arrest (CA), independent of sex hormone effects. As female sex was also associated with a smaller increase in inducible and neuronal nitric oxide synthase (NOS), we hypothesised that nitric oxide inhibition with methylene blue (MB) improves the outcome, primarily in male animals.

Methods

Twenty sexually immature piglets (10 males and 10 females) were bled to mean arterial blood pressure of 35 mmHg, and were subjected to 2 min of untreated CA followed by 8 min of open chest cardiopulmonary resuscitation (CPR). Volume resuscitation was started during CPR with intravenous administration of 3 ml kg⁻¹ hypertonic saline-dextran. Methylene blue was then administered as bolus of 2.5 mg kg⁻¹ over 20 min, followed by 1.5 mg kg⁻¹ infusion over 40 min. Historical data from 21 animals were used as control (no MB). Hemodynamic parameters, myocardial injury (troponin I), and short-term survival (3-h) were evaluated. Histopathological evaluation of heart specimens was performed.

Results

There were no differences between male and female animals in survival or resuscitation rate. After CA female piglets had significantly greater systolic and mean arterial pressures, and had lower troponin I plasma concentrations compared to male piglets, with or without MB. No difference was observed in histopathological analysis of heart specimens between sexes.

Conclusions

After resuscitation from hypovolemic CA, female sex protects against cardiac injury, independent of sex hormones. Modulation of NO expression with MB does not improve survival or myocardial histological injury in either sex.     

Ischemic post-conditioning and vasodilator therapy during standard cardiopulmonary resuscitation to reduce cardiac and brain injury after prolonged untreated ventricular fibrillation

Aim of the study

We investigated the effects of ischemic postconditioning (IPC) with and without cardioprotective vasodilatory therapy (CVT) at the initiation of cardiopulmonary resuscitation (CPR) on cardio-cerebral function and 48-h survival.

Methods

Prospective randomized animal study. Following 15 min of ventricular fibrillation, 42 Yorkshire farm pigs weighing an average of 34 ± 2 kg were randomized to receive standard CPR (SCPR, n = 12), SCPR + IPC (n = 10), SCPR + IPC + CVT (n = 10), or SCPR + CVT (n = 10). IPC was delivered during the first 3 min of CPR with 4 cycles of 20 s of chest compressions followed by 20-s pauses. CVT consisted of intravenous sodium nitroprusside (2 mg) and adenosine (24 mg) during the first minute of CPR. Epinephrine was given in all groups per standard protocol. A transthoracic echocardiogram was obtained on all survivors 1 and 4 h post-ROSC. The brains were extracted after euthanasia at least 24 h later to assess ischemic injury in 7 regions. Ischemic injury was graded on a 0–4 scale with (0 = no injury to 4 ≥50% neural injury). The sum of the regional scores was reported as cerebral histological score (CHS). 48 h survival was reported.

Results

Post-resuscitation left ventricular ejection (LVEF) fraction improved in SCPR + CVT, SCPR + IPC + CVT and SCPR + IPC groups compared to SCPR (59% ± 9%, 52% ± 14%, 52% ± 14% vs. 35% ± 11%, respectively, p < 0.05). Only SCPR + IPC and SCPR + IPC + CVT, but not SCPR + CVT, had lower mean CHS compared to SCPR (5.8 ± 2.6, 2.8 ± 1.8 vs. 10 ± 2.1, respectively, p < 0.01). The 48-h survival among SCPR + IPC, SCPR + CVT, SCPR + IPC + CVT and SCPR was 6/10, 3/10, 5/10 and 1/12, respectively (Cox regression p < 0.01).

Conclusions

IPC and CVT during standard CPR improved post-resuscitation LVEF but only IPC was independently neuroprotective and improved 48-h survival after 15 min of untreated cardiac arrest in pigs.     

Sex differences in outcome after ventricular fibrillation in out-of-hospital cardiac arrest

INTRODUCTION: Previous studies have shown that early defibrillation programs improve survival after an out-of-hospital cardiac arrest (OHCA). Reports also suggest that women fare worse than men do after cardiovascular events, but there is no population-based study of sex differences after an OHCA with early defibrillation. We, therefore, compared the short- and long-term survival and quality-of-life (QOL) in women and men after an OHCA. METHODS: All patients with a ventricular fibrillation (VF) OHCA who received early defibrillation in Olmstead County, Minnesota between November 1990 and December 2000 were included. Using medical records and the cardiac arrest database, the short- and long-term survival and QOL based on a SF-36 survey of each sex were compared. Adjusted QOL scores were obtained by using age- and sex-specific norms from a sample of the general U.S. population; an adjusted score of 50 (normalized mean) was considered normal. RESULTS: Thirty-seven female and 163 male patients presented with a VF OHCA and early defibrillation. Survival to hospital admission was significantly better for women than men [30 female survivors to admission (81%), 112 male (69%), p = 0.04]. Paradoxically, survival to discharge among those admitted was worse for women [13 female survivors to discharge (43%), 66 male (61%), p = 0.04]. The average length of follow-up was 4.8+/-3.0 years. The 5-year expected survival was 83% in women and 78% in men (p = 0.48). There was no difference in call-to-shock time (6+/-2, 6+/-2 min, p = 0.6) or whether the arrest was witnessed (86, 82%, p = 0.64). There was no statistical difference between women and men in age (64+/-17, 65+/-14 years), ejection fraction (40+/-17, 40+/-18%), diabetes (17, 29%, p = 0.16), hypertension (23, 28%, p = 0.58) or known CAD (27, 48%, p = 0.06). Adjusted QOL scores were similar between women and men in terms of pain (52+/-9, 52+/-10) vitality (47+/-11, 40+/-9), general health (49+/-9, 44+/-7), social function (51+/-10, 51+/-8), and mental health (50+/-10, 49+/-6). CONCLUSION: Women are more likely to survive to hospital admission following an OHCA. However, admitted women less likely to survive their hospital stay. Long-term survival and QOL are equally favorable in both sexes.     

猪室颤心脏骤停模型心肺复苏后急性肺损伤CT表现与病理对照

目的对照分析猪室颤(5~10 min)心脏骤停模型心肺复苏后急性肺损伤的CT征象及其病理学表现。方法选用健康雄性家猪16只,利用电刺激诱导室颤5~10 min后进行CPR,自主循环恢复后8~10 h行CT扫描,后立刻处死猪留取肺标本进行病理观察,分析其CT征象及病理学特征。结果 16头猪室颤心脏骤停模型均制作成功,CT扫描:16头猪(100%)均可见"磨玻璃征"及肺实变征象,"磨玻璃征"占全肺体积18.4%~42.3%(平均27.3%);肺实变病灶占全肺体积13.8%~40.5%(平均24%)。2头猪气胸(12.5%),5头猪肋骨骨折(31.3%),5头猪胸腔积液(31.3%)。病理镜下见病变区肺泡水肿、出血、肺泡塌陷、透明膜形成、肺毛细血管充血等。结论心跳骤停CPR后可造成不同程度的急性肺损伤,主要包括肺挫裂伤及肺缺血-再灌注损伤。CT检查可敏感反映上述病理表现,主要表现为不同程度的磨玻璃样病变及肺实变。     

高渗盐干预心脏骤停后心肺复苏的研究进展及前景

心脏骤停的诊治是急诊医生面临的重要难题。除指南推荐的传统药物,如肾上腺素、血管加压素外,近年研究发现,高渗盐可能有利于心肺复苏的治疗。本文就高渗盐干预心脏骤停的机制、相关动物及临床研究进展进行综述。     

Causes for the declining proportion of ventricular fibrillation in out-of-hospital cardiac arrest

AimsThe reported proportion of ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OHCA) has declined worldwide. VF decline may be caused by less VF at collapse and/or faster dissolution of VF into asystole. We aimed to determine the causes of VF decline by comparing VF proportions in relation to delay from emergency medical services (EMS) call to initial ECG (call-to-ECG delay), and VF dissolution rates between two study periods.MethodsData from the AmsteRdam REsuscitation STudies (ARREST), an ongoing OHCA registry in the Netherlands, were used. We studied cardiac OHCA in the study periods 1995–1997 (n = 917) and 2006–2012 (n = 5695). Cases with available ECG and information on call-to-ECG delay were included. We tested whether initial VF proportion and VF dissolution rates differed between both study periods using logistic regression.ResultsDespite a 15% VF decline between the periods, VF proportion around EMS call remained high in 2006–2012 (64%). The odds ratio (OR) for VF proportion in 2006–2012 vs. 1995–1997 was 0.52 (95%-CI 0.45–0.60, P < 0.001), with similar rates of VF dissolution in both periods (P = 0.83). VF decline was higher for unwitnessed collapse (OR 0.41, 95%-CI 0.28–0.58) and collapse at home (OR 0.50, 95%-CI 0.42–0.59), but not for categories of bystander CPR, age or sex.ConclusionVF proportion early after collapse remains high. VF decline is explained by the occurrence of less initial VF, rather than faster dissolving VF. An increase in unwitnessed OHCA and collapse at home contributes to the observed VF decline.     

Assessment of a three-phase model of out-of-hospital cardiac arrest in patients with ventricular fibrillation

AIM: Cardiac arrest with ventricular fibrillation (VF) has been divided into three phases in which phase-specific therapy may improve outcome. The aim of this study was to assess the relationship between call-to-shock time, bystander CPR (BCPR), and cardiac arrest outcomes. METHODS: In a retrospective analysis of prospectively-acquired data from witnessed VF out-of-hospital cardiac arrests (OHCA), patients were classified as phases 1, 2, or 3 based on call-to-shock time (<5, 5-8, and >8 min) and further stratified based on performance of BCPR. Groups were compared with regard to survival, neurological outcome, and restoration of spontaneous circulation (ROSC) with defibrillation only (no ALS interventions to achieve sustained ROSC). RESULTS: Survival, neurologically intact survival, and ROSC with defibrillation were different between phases 1 and 2 (p=0.014 and p=0.005, p<0.01) but not between phases 2 and 3. Patients were further classified as having received BCPR (N=111) or no BCPR (N=107). Neurologically intact survival with and without BCPR, respectively, was 61% versus 72% (phase 1), 44% versus 41% (phase 2), and 42% versus 29% (phase 3). ROSC with defibrillation only with and without BCPR, respectively, was 64% versus 56% (phase 1), 37.0% versus 29% (phase 2), and 33% versus 8% (phase 3). ROSC with defibrillation alone was statistically higher in univariate analysis in phase 3 with BCPR (p=0.033) but not in multivariate analysis (p=0.068). CONCLUSIONS: BCPR did not significantly improve survival in any phase of OHCA, though there was a trend toward increased neurologically intact survival and increased ROSC with defibrillation alone in phase 3.     

Ischemic postconditioning at the initiation of cardiopulmonary resuscitation facilitates functional cardiac and cerebral recovery after prolonged untreated ventricular fibrillation

Objectives

Ischemic postconditioning (PC) with “stuttering” reintroduction of blood flow after prolonged ischemia has been shown to offer protection from ischemia reperfusion injury to the myocardium and brain. We hypothesized that four 20-s pauses during the first 3 min of standard CPR would improve post resuscitation cardiac and neurological function, in a porcine model of prolonged untreated cardiac arrest.

Methods

18 female farm pigs, intubated and isoflurane anesthetized had 15 min of untreated ventricular fibrillation followed by standard CPR (SCPR). Nine animals were randomized to receive PC with four, controlled, 20-s pauses, during the first 3 min of CPR (SCPR + PC). Resuscitated animals had echocardiographic evaluation of their ejection fraction after 1 and 4 h and a blinded neurological assessment with a cerebral performance category (CPC) score assigned at 24 and 48 h. All animals received 12 h of post resuscitation mild therapeutic hypothermia.

Results

SCPR + PC animals had significant improvement in left ventricular ejection fraction at 1 and 4 h compared to SCPR (59 ± 11% vs 35 ± 7% and 55 ± 8% vs 31 ± 13% respectively, p < 0.01). Neurological function at 24 h significantly improved with SCPR + PC compared to SCPR alone (CPC: 2.7 ± 0.4 vs 3.8 ± 0.4 respectively, p = 0.003). Neurological function significantly improved in the SCPR + PC group at 48 h and the mean CPC score of that group decreased from 2.7 ± 0.4 to 1.7 ± 0.4 (p < 0.00001).

Conclusions

Ischemic postconditioning with four 20-s pauses during the first 3 min of SCPR improved post resuscitation cardiac function and facilitated neurological recovery after 15 min of untreated cardiac arrest in pigs.     

Adenosine A1 receptor antagonism hastens the decay in ventricular fibrillation waveform morphology during porcine cardiac arrest

BACKGROUND: Endogenous adenosine (ADO) is known to be cardioprotective during acute myocardial ischemia. Coronary sinus ADO concentration has recently been shown to increase nearly 13-fold over baseline levels after 5 min of untreated ventricular fibrillation (VF). The role of ADO in VF has never been previously examined. The objective of this study was to determine the effect of ADO receptor antagonism, as measured by the scaling exponent (ScE), on the degeneration of VF over time during the circulatory phase of cardiac arrest. METHODS AND RESULTS: A well-established swine model of prolonged VF arrest was used for this experiment. Eighteen domestic mixed-breed swine were assigned by block randomization to receive either DTI-0017 (5mg/kg), a potent ADO A(1) receptor antagonist or placebo in a double-blind fashion. The animals were instrumented under general anesthesia and acclimatized. The assigned solution was infused over 5 min. One minute after the infusion was completed, VF was induced with a 3s, 60 Hz, 100 mA transthoracic shock and left untreated. Lead II ECG was monitored continuously and recorded at 1000 samples/s. It was determined a priori that evaluation of the plots would be limited to a previously observed plateau phase historically occurring between 5 and 8 min corresponding to the circulatory phase of cardiac arrest. The scaling exponent values over this period were calculated for each of the 18 recordings using custom MATLAB routines. Using the Wald statistic to produce the Chi square distributions the null hypothesis, that there was no difference between the two groups, was tested. The Wald statistic calculation based on eight epochs from 300 to 475 s in placebo and DTI groups was significant to reject the null hypothesis of no difference in the groupxtime interaction at the 0.015 level (Chi square distribution for Wald=17.49, d.f.=7). CONCLUSIONS: In this swine model, adenosine A(1) receptor antagonism accelerated the natural decay in the ECG VF waveform during the circulatory phase of cardiac arrest. Our findings would suggest that endogenous adenosine has cardioprotective effects during sudden cardiac arrest by slowing the time-dependent degeneration of VF.     

Use of esmolol after failure of standard cardiopulmonary resuscitation to treat patients with refractory ventricular fibrillation

Introduction

We compare the outcomes for patients who received esmolol to those who did not receive esmolol during refractory ventricular fibrillation (RVF) in the emergency department (ED).

Methods

A retrospective investigation in an urban academic ED of patients between January 2011 and January 2014 of patients with out-of-hospital or ED cardiac arrest (CA) with an initial rhythm of ventricular fibrillation (VF) or ventricular tachycardia (VT) who received at least three defibrillation attempts, 300 mg of amiodarone, and 3 mg of adrenaline, and who remained in CA upon ED arrival. Patients who received esmolol during CA were compared to those who did not.

Results

90 patients had CA with an initial rhythm of VF or VT; 65 patients were excluded, leaving 25 for analysis. Six patients received esmolol during cardiac arrest, and nineteen did not. All patients had ventricular dysrhythmias refractory to many defibrillation attempts, including defibrillation after administration of standard ACLS medications. Most received high doses of adrenaline, amiodarone, and sodium bicarbonate. Comparing the patients that received esmolol to those that did not: 67% and 42% had temporary return of spontaneous circulation (ROSC); 67% and 32% had sustained ROSC; 66% and 32% survived to intensive care unit admission; 50% and 16% survived to hospital discharge; and 50% and 11% survived to discharge with a favorable neurologic outcome, respectively.

Conclusion

Beta-blockade should be considered in patients with RVF in the ED prior to cessation of resuscitative efforts.     

Sex differences in injury severity and outcome measures after traumatic brain injury

OBJECTIVE: To investigate the effect of a patient's sex on various measures of injury severity and outcome after rehabilitation in a matched sample of patients with traumatic brain injury (TBI). DESIGN: Retrospective data were retrieved from a database that contains information routinely collected on all patients admitted for inpatient rehabilitation. SETTING: Inpatient rehabilitation unit of major teaching hospital in Australia. PARTICIPANTS: Fifty-four women with TBI after a motor vehicle crash (MVC) were identified from the Brain Injury Rehabilitation Database. An equal number of men were then matched for age and years of education. All subjects met the study admission criteria of having being involved in a high-speed MVC. Exclusion criteria included history of a previous head injury, chronic amnesia, psychiatric disturbance, and significant alcohol and/or substance abuse. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Differences, by sex, in patient scores on measures of injury severity and outcome after TBI. RESULTS: Men had significantly greater levels of injury severity as indicated by the Glasgow Coma Scale scores (U=994.0, P=.002) and length of posttraumatic amnesia (U=880.0, P=.016) when compared with women. No significant sex differences existed in the outcome measures or in injuries not associated with the central nervous system. CONCLUSIONS: Few investigations exist on the effect of patient sex on measures of injury severity and outcome after a TBI. In the present study, men's levels of injury severity were greater than women's despite the same admission criteria (high-speed MVC) being applied to both sexes.     

Hypertonic saline during CPR: Feasibility and safety of a new protocol of fluid management during resuscitation

BACKGROUND AND PURPOSE: In experimental studies infusion of hypertonic saline during cardiopulmonary resuscitation (CPR) increased resuscitation success rate and improved myocardial and cerebral reperfusion during CPR. We tested the feasibility and the safety of this new therapeutic measure in a randomised, preclinical pilot study. METHODS: The study was performed in the EMS system of Bonn after approval of the local ethical committee. Study inclusion criteria were out-of-hospital cardiac arrest (CA) of non-traumatic origin, age > or =18 years, application of adrenaline (epinephrine) during CPR, duration of CA < or = 15 min, and estimated body weight < or = 125 kg. Patients randomly received 2 ml/kg/10 min HHS (7.2% NaCl with 6% hydroxy ethyl starch 200,000/0.5 [HES]) or HES alone. Haemoglobin, blood gases, plasma sodium and potassium concentrations were measured before and 10 min after infusion, and after admission to hospital. Feasibility and safety of the new fluid management was evaluated by looking for side effects and determination of resuscitation success and admission rates. RESULTS: Sixty-six patients were included. After infusion of HHS, plasma sodium concentration increased to 168+/-29 mmol/l at 10 min after application but already decreased to near normal (147+/-5.5 mmol/l) at admission to hospital. Patients receiving HHS showed a trend to higher resuscitation success and hospital admission rates (ROSC: HHS 66.7%, HES 51.5%, p = 0.21; admission: HHS 57.6%, HES 39.4%, p = 0.14). The benefit of HHS was more pronounced if duration of untreated CA was >6 min or if initial rhythm was asystole or pulseless electrical activity (PEA). Negative side-effects were not observed after HHS. CONCLUSIONS: HHS after CA is feasible and safe and might improve short term survival after CPR. However, whether giving HHS could be a useful measure to increase resuscitation success after out-of-hospital CA requires a larger preclinical trial.     

窒息法与室颤法复苏模型心脏损伤的比较研究

目的 对比大鼠窒息法和室颤法心搏骤停模型在复苏后不同时期心脏的损伤及恢复情况.方法 动物模型在中山大学心肺脑复苏研究所病理生理实验室完成;35只SD雄性大鼠随机(随机数字法)分组制作窒息法与室颤法诱导8 min心搏骤停的心肺复苏模型及假手术组,于复苏成功后4、24、72 h行心肌HE染色、心肌线粒体呼吸控制率(RCR)、心脏彩超的比较.计量资料用均数±标准差(-x±s)表示,两组均数比较采用t检验,多组比较采用单因素方差分析,以P＜0.05为差异具有统计学意义.结果 HE染色4h室颤组肌溶解较窒息组明显,72 h二组肌纤维排列紊乱;RCR4h室颤组低于窒息组,24 h恢复且两组间差异无统计学意义;心脏彩超示左室射血分数(LVEF)室颤组4h低于窒息组(29.68％ vs.42.16％,P=0.031),24 h室颤组与假手术组无异,而窒息组72 h方与假手术组间差异无统计学意义,72 h两组左室前壁厚度均较假手术组增加(2.41 mm vs.1.72 mm,P=0.013; 2.61 mmvs.1.72 mm,P=0.007),组间差异无统计学意义.结论 室颤模型在复苏后早期心肌损伤较窒息模型严重;中间期两种模型均有所恢复,且室颤组较窒息组更早恢复;复苏后后期两组均出现代偿性心肌肥厚,心功能差异无统计学意义.     

高渗盐水联合羟乙基淀粉治疗严重脓毒症的研究

目的 评价7.5%高渗盐水(HS)联合6%羟乙基淀粉(HES)130/0.4对严重脓毒症患者早期液体复苏的效果.方法 采用前瞻性随机对照研究.选取江汉大学附属医院重症监护病房(ICU)135例严重脓毒症患者,入ICU时随机分成3组,每组45例.HS+HES组输注7.5%HS后输注6%HES 130/0.4 500 ml,再输注平衡液HES组输注6%HES 130/0.4后输注平衡液;平衡液组(RL组)仅输注平衡液.比较3组患者入ICU后6 h、24 h平均动脉压(MAP)、氧合指数(PaO2/FiO2)、动脉血乳酸、乳酸清除率、急性生理学与慢性健康状况评分系统Ⅱ(APACHE Ⅱ)评分、输液量、尿量以及多器官功能障碍综合征(MODS)发生率和住院病死率.结果 入ICU后6 h,HS+HES组MAP[mm Hg(1 mm Hg=0.133 kPa):68.7±3.0]、PaO2/FiO2(mm Hg:262.2±17.4)、乳酸清除率[(21±4)%]较HES组[MAP:63.8±3.5,PaO2/FiO2:252.0±21.2,乳酸清除率:(11±2)%]和RL组[MAP:62.6±3.6,PaO2/FiO2:248.4±17.0,乳酸清除率:(9±1)%]显著增高(均P＜0.01),动脉血乳酸(mmol/L:3.5±0.7)较HES组(4.1±0.7)和RL组(4.0±0.7)显著下降(均P＜0.01);APACHE Ⅱ评分(分:13.2±1.9)与HES组(14.0±1.6)无明显差异,但显著低于RL组(15.2±1.7,P＜0.01).入ICU后24 h,HS+HES组PaO2/FiO2(mm Hg:303.3±17.3)显著高于HES组(282.9±21.1)和RL组(268.9±15.2,均P＜0.01),但3组间MAP、动脉血乳酸、乳酸清除率和APACHE Ⅱ评分均无差异.人ICU后6 h、24 h,HS+HES组输液量(ml,6 h:1 877.8±215.2,24 h:5 475.6±208.8)显著低于HES组(6 h:2 505.6±276.2,24 h:6 383.3±287.4)和RL组(6 h:3 496.7±325.5,24 h:7 439.6±229.6);尿量(ml,6 h:294.2±36.9,24 h:2 793.8±37.1)显著高于HES组(6 h:248.9±25.3,24 h:2 248.9±25.3)和RL组(6 h:178.9±14.8,24 h:2 000.4±147.0,均P＜0.01).HS+HES组MODS发生率(6.7%)远低于RL组(28.9%,P＜0.05),与HES组(17.8%)无差异(P＞0.05);3组间病死率无显著差异(HS+HES组2.2%,HES组4.4%,RL组8.9%,均P＞0.05).结论 7.5%HS联合6%HES 130/0.4能提高严重脓毒症患者早期液体复苏的效果,降低MODS发生率.

Abstract：

Objective To evaluate the effect of 7. 5% hypertonic saline(HS)and 6% hydroxyethyl starch (HES)130/0.4 on early fluid resuscitation for severe sepsis. Methods Prospective randomized control trial was carried out in intensive care unit(ICU)of the Affiliated Hospital of Jianghan University. One hundred and thirty-five patients with severe sepsis were randomly divided into three groups, each group consisted of 45 patients. Patients in HS+HES group received lactated Ringer solution following 4 ml/kg of 7. 5%HS and 6%HES 130/0. 4 500 ml, those in HES group received lactated Ringer solution following 6%HES 130/0.4500 ml, and those in the lactated Ringer group(RL group)received lactated Ringer solution only. Mean arterial pressure(MAP), oxygenation index(PaO2/FiO2), arterial lactate(Lac), lactate clearance rate,acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ)score, fluid infusion volume, urine output as well as incidence of multiple organ dysfunction syndrome(MODS), and mortality were compared among three groups at 6 hours and 24 hours after ICU admission. Results At 6 hours after ICU admission, MAP [mm Hg(1 mm Hg=0. 133 kPa): 68. 7±3. 0], PaO2/FiO2(mm Hg: 262.2±17.4), lactate clearance rate [(21±4)%]in HS+HES group were significantly higher than those in HES group[MAP: 63. 8±3.5,PaO2/FiO2: 252.0 ± 21.2, lactate clearance rate:(11± 2)%]and RL group[MAP: 62.6 ± 3. 6, PaO2/FiO2 :248. 4±17.0, lactate clearance rate:(9± 1)%, all P＜0. 01]. Arterial Lac in HS+HES group(mmol/L:3. 5±0. 7)was significantly lower than that in HES group(4. 1±0. 7)and RL group(4. 0±0. 7, both P＜0. 01). There was no significant difference in APACHE Ⅱ score between HS+HES group(13. 2±1.9)and HES group(14.0±1.6), and the APACHE Ⅱ score in HS+HES group was significantly lower than that in RL group(15. 2 ± 1.7, P＜ 0. 01). At 24 hours after ICU admission, PaO2/FiO2(mm Hg: 303.3 ± 17.3)was significantly higher in HS+HES group than that in HES group(282.9 ± 21.1)and RL group(268. 9 ±15.2,both P＜ 0.01). There was no significant difference in MAP, arterial Lac, lactate clearance rate and APACHE Ⅱ score among three groups. At 6 hours and 24 hours after ICU admission, fluid infusion volume in HS+HES group(ml, 6 hours: 1 877. 8±215. 2, 24 hours: 5 475.6±208.8)was markedly less than that in HES group(6 hours: 2 505.6±276.2, 24 hours: 6 383. 3±287.4)and RL group(6 hours: 3 496. 7±325.5, 24 hours: 7 439.6±229.6), yet urine output in HS+HES group(ml, 6 hours: 294.2±36.9,24 hours: 2 793.8 ±37.1)was significantly higher than that in HES group(6 hours: 248.9 ± 25. 3,24 hours: 2 248. 9±25. 3)and RL group(6 hours: 178. 9±14.8, 24 hours: 2 000. 4±147.0, all P＜0. 01).The incidence of MODS in HS+HES group(6.7%)was statistically lower than that in RL group(28. 9%,P＜0. 05), while no obvious difference was found between HS+HES group and HES group(17.8%, P＞0. 05). There was no significant difference in mortality among three groups(HS+HES group: 2.2%, HES group: 4.4%, RL group: 8.9%, all P＞0. 05). Conclusion 7.5%HS and 6%HES 130/0. 4 could improve the effect of early fluid resuscitation on severe sepsis, and it could lower the incidence of MODS.     

小剂量高渗液在烧伤休克复苏中的临床观察

目的探讨小剂量高渗液在烧伤休克患者复苏中的临床效果和安全性。方法60例烧伤患者随机分为观察组和对照组,各30例,观察组给予高渗盐溶液,对照组给予平衡盐溶液,其余复苏方式相同;复苏总量采用复苏补液公式计算,根据尿量调整液体总量;比较两组患者的临床治疗效果。结果经过治疗后,观察组患者的血压、尿量、乳酸值和红细胞渗透脆性等方面与对照组差异有统计学意义（P〈0．05）。结论小剂量高渗液具有明显的抗休克和稳定红细胞膜作用,有一定的临床应用价值。     

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.     

二维超声观察主动性心肺复苏对心室颤动犬心功能的影响

目的 探讨主动性心肺复苏对犬心室颤动(室颤)时心功能的影响.方法 应用经胸二维超声心动图分别测量犬室颤时主动性心肺复苏组(ACD-CPR组,12只)和标准心肺复苏组(S-CPR组,12只)左心室舒张末期容积、左心室收缩末期容积,计算左心室射血分数(LVEF),比较两组间各项测量结果.结果 室颤时,两组左心室舒张末期容积较室颤前均有下降,但差异均无统计学意义(P＞0.05);两组左心室收缩末期容积较室颤前显著增大,差异有统计学意义(P＜0.001).CPR时,ACD-CPR组比S-CPR组左室舒张末期容积增加,但差异无统计学意义(P＞0.05);前者比后者左室收缩末期容积减少,但差异无统计学意义(P＞0.05).CPR时,ACD-CPR组与S-CPR组LVEF较室颤前显著下降,差异有统计学意义(P＜0.001);前者LVEF较后者显著增加,差异有统计学意义(P=0.019).结论 主动性心肺复苏较常规心肺复苏有助于改善左心室功能.     

The association between blood lactate concentration on admission, duration of cardiac arrest, and functional neurological recovery in patients resuscitated from ventricular fibrillation

Objective: To assess the association between arterial lactate concentration on admission and the duration of human ventricular fibrillation cardiac arrest, and to what degree the arterial lactate concentration on admission is an early predictor of functional neurological recovery in human cardiac arrest survivors. Design: Cohort study. Arterial lactate concentrations and out-of-hospital data concerning cardiac arrest and cardiopulmonary resuscitation were collected retrospectively according to a standardized protocol. Functional neurological recovery was assessed prospectively at regular intervals for 6 months. Setting: Emergency department of an urban tertiary care hospital. Patients: A total of 167 primary survivors of witnessed out-of-hospital ventricular fibrillation cardiac arrest. Measurements: The association between arterial lactate concentration on admission, the duration of cardiac arrest, and functional neurological recovery was assessed. Further, we assessed whether admission concentrations of arterial lactate and duration of cardiac arrest can predict unfavorable functional neurological recovery. Functional neurological recovery was measured in cerebral performance categories (CPC). No or minimal functional impairment (CPC 1 and 2) was defined as favorable outcome; the remaining categories (CPC 3, 4 and 5) were defined as unfavorable functional neurological recovery. Results: In 167 patients, a weak association between total duration of cardiac arrest and admission levels of lactate (r = 0.49, P < 0.001) could be shown. With increasing admission concentrations of arterial lactate functional neurological recovery was more likely to be unfavorable (OR 1.15 per mmol/l increase, 95 % CI 1.04–1.27). Nevertheless, only at very high levels of lactate (16.3 mmol/l) could unfavorable neurological recovery be detected with 100 % specificity, yielding a very low sensitivity of 16 %. Conclusions: The arterial admission lactate concentration after out-of-hospital ventricular fibrillation cardiac arrest is a weak measure of the duration of ischemia. High admission lactate levels are associated with severe neurological impairment. However, this parameter has poor prognostic value for individual estimation of the severity of subsequent functional neurological impairment. Received: 13 March 1997 / Accepted: 7 August 1997