Normovolaemic induced hypertension therapy for cerebral vasospasm after subarachnoid haemorrhage

Summary We showed that normovolaemic induced hypertension therapy was effective in reducing ischaemic symptoms attributed to cerebral vasospasm in 41 patients after subarachnoid haemorrhage. By inducing hypertension to 25% to 50% above normal systolic arterial blood pressure, we observed that in 17 of 24 cases (71%) neurological deficits improved. In four cases of haemorrhagic infarction, the blood pressure rose to over 50% of systolic arterial pressure, and a low density area was confirmed on computerized tomography (CT) scan prior to vasospasm. Induced hypertension was therefore not considered when a low density area was revealed on CT scan.Restriction of fluid input is usually a factor in producing hypovolaemia after a neurosurgical operation. Intravascular volume expansion has been reported effective in reversing ischaemic deficits. However, according to Poiseuille's equation, increasing blood volume to a state of hypervolaemia can not enhance flow. The cerebral blood flow (CBF) was raised by increasing perfusion pressure, reducing viscosity, or increasing blood vessel diameter. Intravascular volume expansion elevates not only systemic arterial pressure, but also pulmonary artery wedge pressure over 18 mmHg and cardiac index over 2.2. Since pulmonary oedema and congestive heart failure may develop, one should monitor haemodynamic parameters with the Swan-Ganz catheter as a preventive measure.We emphasize that normovolaemic induced hypertension, maintaining haemodynamics subset 1 of the comparable haemodynamic subsets, is effective in raising perfusion pressure of CBF.     

Studies of intravascular components in cerebral vasospasm following subarachnoid hemorrhage

Summary Cerebral vasospasm with subsequent infarction gives important influence to the prognosis of patients with ruptured intracranial aneurysms. Many factors should be considered in the pathogenesis of cerebral infarction. Clinical and experimental studies of intravascular components with particular reference to platelet and coagulation factors were performed. Both studies revealed systemic platelet hyperactivity and a hypercoagulable state; in further experimental studies, crenated red blood cells were recognized in the course of cerebral vasospasm. These systemic changes of intravascular components are thought to accelerate cerebral ischemia through formation of microthrombosis, increased blood viscosity and reduced deformability of the red blood cells.This paper was presented in part at the Annual Meeting of the American Association of Neurological Surgeons in Los Angeles in April 1979.     

非体外循环冠状动脉旁路移植术患者FloTrac-Vigileo系统与肺动脉导管技术监测心指数的一致性

目的 评价非体外循环冠状动脉旁路移植术患者FloTrac- Vigileo( FV)系统与肺动脉导管(PAC)技术监测心指数(CI)的一致性.方法 拟行非体外循环冠状动脉旁路移植术患者43例,年龄53～75岁,身高150～ 183 cm,体重46～100 kg,ASA分级Ⅱ或Ⅲ级.静脉注射咪达唑仑、舒芬太尼、异丙酚和罗库溴铵行麻醉诱导,麻醉维持:静脉输注异丙酚和瑞芬太尼,间断静脉注射阿曲库铵.于锯胸骨后至搭桥开始前和搭桥完成后至闭合胸骨前,吸入1 MAC七氟醚,其余时间不吸入七氟醚.采用FV系统和PAC技术监测CI.于锯胸骨后未吸入七氟醚时、吸入七氟醚5、15 min时,冠状动脉搭桥完成后未吸入七氟醚时、吸人七氟醚5、15 min时记录两种方法监测的CI数据对,进行一致性分析.结果 FV系统和PAC技术测定CI共计258次配对数据,配对数据平均值的均数(2.8±0.6)L·min- ·m-2.配对数据差值的均数(平均偏差)为0.23 L· min-1·m-2,一致性限度(- 0.57,1.02)L·min-1·m-2,百分误差为28.6％,Kappa系数为0.546.结论 FV系统与PAC技术监测CI的一致性尚可,可替代PAC技术用于非体外循环冠状动脉旁路移植术患者CI的监测.     

经肺热稀释法与肺动脉热稀释法测定猪心排血量的一致性

目的 评价经肺热稀释法与肺动脉热稀释法测定猪心排血量(CO)的一致性.方法对13只未成年猪,麻醉诱导后气管插管,机械通气,通过设定的方法依次进行血液动力学干预,于每次干预前及干预过程中血液动力学稳定至少10 min时,同时采用经肺热稀释法和肺动脉热稀释法测定CO(COTP,COPA).采用Bland-Altman法进行一致性分析,设定两种测定方法可以互换的界限为COTP 的相对误差<20%.结果 共收集205对CO数据,COTP范围为1.4～7.06 L/min,COPA范围为1.25～6.55 L/min,COTP值比COPA值高约2%;COTP的偏离度为0.07 L/min,95%可信区间(CI)为0.03～0.11 L/min;一致性范围为-0.46～0.60 L/min,其下限的95%CI为-0.53～-0.40 L/min,其上限的95%CI为0.54～0.66 L/min;COTP的相对误差为15.3%.结论 经肺热稀释法和肺动脉热稀释法测定猪CO具有良好的一致性.     

肺动脉漂浮导管在冠状动脉旁路术中的应用

目的　评价肺动脉漂浮导管连续监测心排血量 (CO)、混合静脉血氧饱和度 (S VO2 )在冠状动脉旁路移植术 (CABG)中的应用。方法　CABG术者 32例 ,年龄 (6 1 31± 6 92 )岁 ,平均搭桥(3 19± 1 12 )支。麻醉诱导用芬太尼 2 0～ 30 μg/kg、维库溴铵 0 3mg/kg、咪唑安定 (3 5 8± 2 0 0 )mg ;术中以芬太尼、异氟醚维持。经右颈内静脉置CCO S VO2 肺动脉漂浮导管 ,连续监测CO、S VO2 、平均动脉压 (MAP)、肺动脉压 (PAP)、肺毛细血管楔压 (PCWP)和中心静脉压 (CVP)等 ,记录诱导前、插管后、心肺转流 (CPB)前、停CPB及关胸时的数据。结果　心排指数 (CI)、MAP和S VO2 在插管后各时段较诱导前明显下降 (P <0 0 5 ) ,CVP、PCWP及PAP停CPB后较插管后升高 (P <0 0 5 )。HR在插管后下降 (P <0 0 5 ) ,停CPB后升高 (P <0 0 5 )。结论　在CABG术中 ,利用肺动脉漂浮导管连续监测CO、S VO2 及各项相关指标 ,及时了解心脏功能、全身及心肌的氧供需平衡状况 ,并调整用药 ,以利于围手术期意外的处理 ,防止心肌缺血的发生     

Effects of vasospasm in the middle cerebral artery territory on flow velocity and volume flow. A computersimulation

Summary Recently blood flow velocity in large cerebral arteries became measurable non-invasively by transcranial Doppler sonography (TCD). The present study tries to quantify the relation between flow velocity and the more important volume flow in the middle cerebral artery (MCA) by means of Computersimulation. A mathematical model of the MCA territory was developed. The model is able to take into account the non-Newtonian behaviour of blood viscosity and is also able to handle turbulant and laminar flow. Autoregulation is simulated by increasing or decreasing diameter of arteries as an answer to intraluminal pressure changes. Two processes are simulated: Vasospasm in the stem of the MCA, and vasospasm in the entire MCA territory. Results show that the relation between flow velocity and volume flow is rather complicated. Vasospasm in the MCA stem first leads to an increase of flow velocity at a constant level of volume flow. At higher grades of vessel constriction volume flow and flow velocity start to fall.     

经动脉灌注尼莫地平治疗蛛网膜下腔出血后脑血管痉挛

目的探讨脑动脉瘤介入术后,经动脉内灌注尼莫地平(IAN)治疗蛛网膜下腔出血(SAH)后症状性脑血管痉挛的安全性及有效性。方法将62例SAH伴症状性脑血管痉挛患者随机分为干预组(n=37)和对照组(n=25)。干预组:在动脉瘤介入栓塞后,经颈内动脉灌注2.0mg IAN;对照组:经颈内动脉灌注10ml生理盐水。在动脉内灌注治疗前后,均行脑血管DSA。测量并计算脑循环时间(CCT)、末端周围循环的CCT(peri-CCT)、目标血管直径。对比两组患者出院时的格拉斯哥预后(GOS)评分。结果对照组:给药前后CCT值及peri-CCT值差异均无统计学意义(P均0.05),M1段血管直径略有减少,但与给药前的差异无统计学意义(P0.05);A1段血管直径减少,与给药前差异有统计学意义(t=-2.37,P=0.045);M4段血管直径减少,与给药前的差异有统计学意义(t=-3.50,P=0.008)。干预组:给药后CCT值及peri-CCT值较治疗前明显缩短,差异均有统计学意义(P均0.05),大脑中动脉M1段、大脑前动脉A1段、大脑中动脉M4段血管直径分别增加了(7.18±2.47)%、(6.78±4.35)%、(16.84±10.00)%(P均0.05)。两组患者出院时的GOS差异无统计学意义(χ2=0.094,P=0.760)。结论动脉瘤介入栓塞术后,予以IAN治疗,可在一定程度上舒张脑血管并改善脑微循环,但对最终临床预后影响不大。     

Intraoperative assessment of right ventricular volume and function

Objective: Right ventricular function is an important aspect of global cardiac performance which affects patients' outcome after cardiac surgery. Due to its geometrical complexity, the assessment of right ventricular function is still a very difficult task. Aim of this study was to investigate the value of a new technique for intraoperative assessment of right ventricle based on transesophageal 3D-echocardiography, and to compare it to volumetric thermodilution by using a new generation of fast response thermistor pulmonary artery catheters. Methods: Twenty-five patients with coronary artery disease underwent 68 intraoperative measurements by 3D-echocardiography and thermodilution simultaneously. Following parameters were analysed: right ventricular end-diastolic volume (RVEDV), end-systolic volume (RVESV) and ejection fraction (RVEF). Pulmonary, systemic and central venous pressures were simultaneously recorded. Segmentation of right ventricular volumes were obtained by the ‘Coons-Patches’ technique, which was implemented into the EchoAnalyzer^®, a multitask system developed at our institution for three-dimensional functional and structural measurements. Results: Right ventricular volumes obtained by 3D-echocardiography did not show significant correlations to those obtained by thermodilution. Volumetric thermodilution systematically overestimates right ventricular volumes. Significant correlations were found between RVEF measured by 3D-echocardiography and those obtained by thermodilution (r=0. 93; y=0.2+0.80x; SEE=0.03; P<0.01). Bland–Altmann analysis showed that thermodilution systematically underestimates RVEF. The bias for measuring RVEF was +15.6% with a precision of ±4.3%. The patients were divided into two groups according to left ventricular function. The group of patients with impaired function showed significantly lower right ventricular ejection fraction (44.1±4.6 vs. 55.1±3.9%; P<0.01). Conclusions: Three-dimensional echocardiography provides a useful non-invasive tool for intraoperative and serial assessment of right ventricular function. This new technique, which overcomes the limitations of previous methods, may offer key insights into management and outcome of patients with severe impairment of cardiac function.     

体外循环下冠状动脉旁路手术中连续与单次测定心排血量的对比观察

目的　分析体外循环下冠状动脉旁路手术中应用连续心排血量 /血氧饱和度肺动脉漂浮导管测定的连续心排血量 (CCO)与冷盐水稀释法测定的单次心排血量 (BCO)之间的相关性 ,并比较两种方法的优缺点。方法　选择ASAⅡ～Ⅲ级 ,拟行冠状动脉搭桥手术的病人 4 5例 ,于颈内静脉置放连续心排血量 /血氧饱和度肺动脉漂浮导管 ,于诱导前、插管前 (注药后 )、插管即刻、插管后 3min、切皮及锯胸骨时、转流前、停转流即刻和关胸后等 8个时点记录心率、血压以及CCO和BCO。采用SPSS1 0 0软件包行统计分析 ,CCO与BCO之间作一元线性相关与回归分析及t检验。结果　与诱导前相比 ,心率在插管即刻和切皮锯胸骨时略有增快 (P <0 0 5 ) ,平均动脉压在插管即刻和切皮时增高 (P <0 0 1 ) ,而在插管后 3min及转流前后有所下降 (P <0 0 5 )。CCO与BCO除停转流即刻不具有相关性外 (r=0 4 2 3,P >0 0 5 ) ,其余各时点差异没有显著性意义 ,两者之间具有高度相关性 ,相关系数为 0 6 2 9～ 0 90 6 (P <0 0 1 ) ,一元线性回归方程为CCO =0 84 2BCO +0 86 6。结论　在体外循环下冠状动脉旁路手术中CCO与BCO相关性良好 ,但易受温度因素的干扰。血液动力学的变化不影响CCO的准确性及其与BCO的相关性。BCO反映心排血量的变化迅速     

Effects of increased intra-abdominal pressure and volume expansion on renal function in the rat.

BACKGROUND: The effects of increased intra-abdominal pressure (IAP) and volume expansion on renal function in the rat were studied to gain more knowledge of the oliguria seen during laparoscopic procedures and to reduce the detrimental renal effects of IAP. METHODS: IAP was elevated to 5 or 10 mmHg by insufflation of CO(2) and maintained for 2 h in anaesthetized and mechanically ventilated rats. Rats with normal IAP served as controls. An angiotensin II receptor I antagonist, candesartan, was given as a bolus injection and a 5% volume expansion was achieved by i.v. saline infusion. An angiotensin-converting enzyme (ACE) inhibitor was also given. Renal parameters were the glomerular filtration rate (GFR), urine production, the urinary concentrations of sodium and potassium and the osmolality in the urine. The arterial acid-base balance and blood pressure were also monitored. RESULTS: The GFR deteriorated by 70% during pneumoperitoneum (PP) of 10 mmHg. There was a dramatic drop in sodium excretion (88-97%). With candesartan and elevated IAP, there was a drop in mean arterial pressure (from 90 to 55 mmHg) and the negative renal effects were very pronounced. Renal function was better preserved during elevated IAP in combination with volume expansion. CONCLUSIONS: Capnoperitoneum suppresses renal function, especially in combination with angiotensin II receptor 1 blockade and ACE inhibition. Volume expansion reduces the deleterious effects of PP on renal function during elevated IAP. The results suggest that patients should not be given pharmaceuticals blocking the renin-angiotensin-aldosterone system prior to procedures that may increase IAP. It may be beneficial, however, to reduce angiotensin II tension by volume expansion.     

Rheographic assessment of cerebral blood volume and correlations with changes in intracranial pressure

Summary The authors present a four electrode rheographic technique for semiquantitative continuous measurement of CBV, by examining changes in cerebral tissue impedance induced by changes in blood content of the brain parenchyma.Correlation between the data obtained and ICP measurements permits conclusions regarding the behaviour of the cerebral blood bed. pCO₂ regulates CBV, and the phenomenon is reversible according to a hystereris shaped time course in acute experiments. The rebound of ICP after sudden injections of CSF into the cisterna magna is of a vasogenic nature. Changes in CSF volume induce contrary changes in CBV. Pharmacological effects can be studied. The validity of the method is discussed.     

每搏量变异度联合CI及CVP对胃肠道肿瘤手术患者容量治疗的指导效果

目的 评价每搏量变异度(Svv)联合CI及CVP对胃肠道肿瘤手术患者容量治疗的指导效果.方法 择期胃肠道肿瘤手术患者60例,ASA分级Ⅰ或Ⅱ级,年龄40 ～ 64岁,体重55 ～ 80 kg,采用随机数字表法,将其分为3组(n=20):常规补液组(R组)、SVV指导补液组(S组)和SVV联合CI、CVP指导补液组(C组).R组输入液体总量=补偿性扩容量+生理需要量+累计缺失量+继续损失量+第三间隙丢失量.S组以羟乙基淀粉130/0.4氯化钠注射液维持SVV 10％～15％.C组依据SVV、CI和CVP指导容量治疗.于麻醉诱导前(T0)和术毕(T2)采集肘静脉血样,测定血清β2-微球蛋白(β2-MG)、IL-4、IL-8和TNF-α的浓度;于气管插管后即刻(T1)和T2时记录CO,采集中心静脉血样和动脉血样行血气分析,检测乳酸(Lac)浓度并计算氧供(DO2)、氧耗(VO2)和氧摄取率(ERO2);记录术中心血管不良事件的发生情况、术后肠蠕动恢复时间及并发症的发生情况.结果 与R组比较,S组和C组T2时TNF-α、IL-8、β2-MG和Lac浓度降低,DO2、VO2、ERO2和IL-4浓度升高,术中心动过缓和低血压的发生率降低,术后肠蠕动恢复时间缩短(P＜0.05);S组和C组上述指标比较差异无统计学意义(P＞0.05);3组术后并发症发生率比较差异无统计学意义(P＞0.05).结论 单纯SVV指导下的容量治疗用于胃肠道肿瘤手术患者,不仅能维持有效的循环血容量和组织灌注,还能减轻机体炎性反应,有助于改善预后;无需联合CI及CVP指导容量治疗.     

Negative effect of insufflation on cardiac output and pulmonary blood volume

In 14 anaesthetized young pigs the changes in pulmonary blood flow and pulmonary blood volume (Qp) during mechanical ventilation were quantified. Ventilation was performed at 10 cycles per min and tidal volume (VT) was adjusted to an arterial PCO2 of about 40 mmHg (5.3 kPa). In 4 animals, 7 ventilatory cycles with an inspiratory pause (IP) of 7.2 s but different tidal volumes were inserted at intervals of 5 min to determine the decrease in Qp (delta Qp) from the differences between right ventricular (Qs,rv) and left ventricular (Qs,lv) stroke volume, and to relate delta Qp to VT. We measured pressure in the aorta (Pao), central veins (Pcv), right and left ventricles (Prv, Plv) pericardium (Pit), and trachea (PT). Blood flow was measured electromagnetically (EM) in the pulmonary artery (Q'pa) and aorta (Q'ao). Stroke volumes were derived from the EM-flow curves. In the other 10 experiments, Qs,lv was derived from the aortic pulse contour. Beat-to-beat analyses of Qs,rv and Qs,lv and blood pressures during the normal ventilatory cycles and those with an IP revealed the following: 1) The end-expiratory RV output and LV output were constant and were defined as baseline values. 2) The accumulated decrease in Qs,rv during insufflation caused a mean deficit in cardiac output of 10.3 +/- 3.2% (s.d.), n = 135; the same was found for Qs,lv, indicating the pulse contour as a useful method to estimate the variations in cardiac output during a ventilatory cycle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evaluation of an ensemble-averaging impedance cardiograph for monitoring stroke volume during spontaneous breathing

Simultaneous determination of stroke volume (SV) with an ensemble-averaging impedance cardiograph (AIGG) and the thermodilution technique (TD) was compared in 10 patients scheduled for major vascular surgery. A small, successive increase in SV was achieved by a step-wise infusion of dextran-70 and elevation of the patient's legs. The patients were allowed to breathe normally during the measurement procedures. There was no difference between the ability of AICG and TD to monitor changes in SV and the correlation coefficient for the measurement of changes in SV by the two methods was 0.88. There was no difference between the reproducibility of AICG- (4.6 ml) and TD- (9.2 ml) determined SV or between the coefficient of variation for AICG (4.8%) and TD (9.9%). The mean difference between AICG- and TD-determined SV at the different measurement points (range 1.3-4.2 ml) was well within acceptable limits. In conclusion, the ensemble-averaging impedance cardiograph described in this study was found to be reliable for monitoring changes in SV during uninterrupted, spontaneous breathing.     

呼气末正压对不同血容量状态猪颅高压模型颅内压和脑氧代谢影响的实验研究

目的:观察不同血容量状态下颅高压的急性呼吸窘迫综合征(ARDS)猪模型,增加呼气末正压(PEEP)后,其血流动力学状态、颅内压(ICP)及脑氧分压(PtiO 2)的变化。 方法:选取雄性14～16月龄巴马小型猪12头,随机数字表法随机分成低血容量组和正常血容量组。建立ARDS和颅高压模型。自5 c...     

Prevention of cerebral vasospasm with OKY-046 an imidazole derivative and a thromboxane synthetase inhibitor. A preliminary co-operative clinical study

Summary The prevention of cerebral vasospasm with OKY-046, an imidazole derivative and a thromboxane synthetase inhibitor, was studied co-operatively at ten neurosurgical services. Intravenous administrations of 2, 5 or 10 /kg/minute of OKY-046 were given continuously from the earliest possible day to the 14th SAH-day to 82 pateints with ruptured cerebral aneurysm. Sixty-eight patients (83%) showed moderate to high high-density (SAH) in their initial CTs. Angiographic vasospasms were seen in 58 patients, representing 71% of all cases or 81% of the 72 cases for which angiograms were available; the vasospasms of 45 patients (55 or 63%) were moderate to severe. Symptomatic vasospasm occurred, however, only in 27 patients (33%); in 18 of those cases, moreover, the symptoms were mild or transient. The conditions of the patients at one month after the SAH were classified into 9 grades from 0 (normal) to 8 (deceased). Fifty-two patients (63%) were classified as 0 or 1, and 64 (78%) as better than 3 (possible daily life unaided). The administration of OKY-046 was proven to decrease TXB₂ in the blood.This paper emphasizes the effectiveness of the drug for symptomatic vasospasm, and supports our previous contention that cerebral microthrombosis may play an important role in the pathogenesis of cerebral vasospasm.