Assessment of dynamic cerebral autoregulation based on spontaneous fluctuations in arterial blood pressure and intracranial pressure

Assessments of dynamic cerebral autoregulation usually measure the cerebral blood flow velocity (CBFV) response to changes in arterial blood pressure (ABP). We studied the effect of substituting ABP by cerebral perfusion pressure (CPP), expressed as the difference between ABP and intracranial pressure (ICP), in estimates of dynamic autoregulation obtained by transfer function analysis. CBFV, ABP and ICP were recorded during periods of physiological stability in 30 patients with severe head injury. Transfer function analysis was performed using the following combinations of input-output variables: ABP-CBFV, CPP-CBFV and CBFV-ICP. Frequency and time-domain (step response) functions were averaged for recordings with mean ICP < 20 mmHg (group A) and mean ICP > or = 20 mmHg (group B). The ABP-CBFV transfer function parameters and step response for group A were similar to previous studies in normal subjects, but group B showed deterioration of dynamic autoregulation. Radically different step responses were obtained from both groups for the CPP-CBFV transfer function and the coherence was not significantly improved. The CBFV-ICP transfer function had the highest values of coherence and indicates that changes in CBFV are the cause of spontaneous fluctuations in ICP. Furthermore, the ICP step response plateau was significantly higher for group B than for group A. An alternative calculation of the CBFV step response to changes in CPP resembled the corresponding responses for the ABP input. For spontaneous fluctuations in ABP, ICP and CBFV, it is not possible to calculate the CPP-CBFV transfer function directly due to the high positive correlation between ICP and CBFV, but an alternative estimate can be obtained by using the CBFV-ICP transfer function. The latter could also be useful as a method to assess intracranial compliance in head injury patients.     

Reliability of dynamic cerebral autoregulation measurement using spontaneous fluctuations in blood pressure

Spontaneous fluctuations in BP (blood pressure) and subsequent change in CBFV (cerebral blood flow velocity) in the MCA (middle cerebral artery) can be used to assess dynamic cerebral autoregulation using transfer function analysis; however, the reliability of this technique has not been assessed, in particular the contribution of intra-subject variability relative to inter-subject variability. Three bilateral CBFV, BP and RR interval recordings were performed in ten healthy volunteers on four separate occasions over a 2-week period. Data were analysed to provide the ARI (autoregulatory index), CBFV, RAP (resistance-area product) and CrCP (critical closing pressure). We also measured systolic and diastolic BP, and resting HR (heart rate). We calculated the SEM (standard error of measurement) and the ICC (intra-class correlation coefficient) and their 95% CIs (confidence intervals) for each parameter to assess their absolute (intra-subject) and relative (inter-subject) reliability. The CV (coefficient of variation) of SEM ranged from 1.7% (for CBFV) to 100.0% (for RAP), whereas the ICC was <0.5 for ARI, rising to >0.8 for CBFV and diastolic BP. These data demonstrate excellent absolute and relative reliability of CBFV, whereas ARI is of comparable reliability with the measurement of HR. Using these results it is possible to determine the sample size required to demonstrate a change in ARI, with a sample of 45 subjects in each group required to show a change in ARI of 1, whereas to detect a change in ARI >2 would require only 11 subjects per group. The results of the present study could be valuable to the future planning of cerebral autoregulation studies, but more work is needed to understand the determinants of intra-subject variability in autoregulatory parameters.     

运动锻炼对社区临界高血压老年人血压的影响

目的探讨运动锻炼对临界高血压老年人血压的影响。方法观察108例临界高血压老年人运动锻练前后3个月、6个月的血压变化。结果运动后3个月及6个月的收缩压、运动后6个月的舒张压(DBP)均明显下降。结论运动锻炼降低血压的作用是较为肯定的。     

腹型肥胖对高血压患者血压变异性的影响

目的评估腹型肥胖对原发性高血压患者血压变异性的影响。方法选择2014年1月至2014年4月核工业416医院收治的单纯性高血压患者159例,根据患者腹围分组,腹围正常者(男性90 cm,女性85 cm)72例为对照组,其中男38例,女34例;合并腹围增高者(男性≥90 cm,女性≥85 cm)87例为观察组,其中男45例,女42例。所有患者行24 h动态血压监测(ABPM),观察患者血压变异性(BPV)的特点。结果观察组24 h收缩压变异系数、日间平均收缩压变异系数均高于对照组,差异有统计学意义(P0.05);两组男性患者夜间平均舒张压变异系数均高于女性患者,差异有统计学意义(P0.05);且观察组男性患者24 h收缩压变异系数高于女性患者,差异有统计学意义(P0.05)。结论腹型肥胖时,高血压患者BPV增高,且男性患者较女性患者明显。     

个体化治疗模式对高血压维持性血液透析患者居家血压变异度的影响

目的 了解高血压血液透析（hemodialysis,HD）患者居家血压变异度状况,并观察根据HD患者高血压发病机制进行个体化治疗后,HD患者居家血压变异度的变化情况.方法 选取北京朝阳医院肾内科透析室部分稳定维持性HD患者进行家庭血压（Home-BP）监测,了解HD患者居家血压变异度情况,以居家血压的变异系数表示血压变异度.并以家庭收缩压≥150mmHg （1mmHg=0.133kPa）为未控制的高血压的诊断标准,对未控制的高血压患者进行生物电阻抗监测、透析前后血清钠测定、药物使用情况调查,了解水、钠负荷及药物应用合理性情况,进而针对性地分别进行降低干体质量、应用低钠透析液和合理使用降压药物的干预措施.随访2个月,观察患者血压及血压变异度情况. 结果 共有105例稳定维持HD患者进行家庭血压监测,患者居家血压变异度为（4.8±2.2/5.0±2.4）％.未控制的高血压患者有60例（57.1％）,经个体化降压治疗后,居家血压从（166.3±12.6/87.5±11.7） mmHg降至（154.1±14.2/82.6±11.4）mmHg（P＜0.001,t=7.223; t=4.796,P＜0.001）,收缩压变异度由（4.9±2.2）％降至（4.6±2.5）％ （P=0.340,t=0.961）.其中30例容量超负荷患者,予降低干体质量后,家庭收缩压和舒张压明显降低,变异系数分别下降0.4％和0.1％（P=0.027,t=2.329;P=0.041,t=2.138）.12例患者应用低钠透析液（136mmol/L）后,居家血压下降,血压变异度无明显改变.其余18例容量负荷正常、未使用低钠透析的患者通过增加肾素-血管紧张素抑制剂和αβ受体阻滞剂等,居家血压下降,血压变异度减小,但未达统计学差异.结论 针对高血压HD患者高血压的病因进行治疗,能够有效地改善患者的家庭血压及血压变异度.     

护理干预对高血压病患者血压控制及生活方式的影响

目的：探讨护理干预对高血压病患者血压控制及生活方式的影响,防止高血压并发症的发生,控制高血压病的进展。方法：随机选择120例高血压病患者,将其随机分为干预组和对照组,各60例。对照组采用常规治疗,干预组在常规治疗的基础上实施护理干预。于干预前后分别进行问卷调查。结果：护理干预后患者在规律服药、戒烟、饮酒、低脂、低盐饮食、体育锻炼、血压监测等方面效果显著（P〈0.01）,两组患者干预前血压无明显差异（P〉0.05）,干预后血压有明显差异（P〈0.01）。结论：积极的护理干预措施,使患者树立了正确的健康理念,改变了不良的生活方式,提高了生活质量。     

过度通气对脑血流脑代谢颅内压影响的临床研究

目的　观察过度通气对颅脑手术病人脑血流 (CBF)、脑代谢 (CMR)、颅内压 (ICP)的影响。方法　 2 0例择期行颅脑手术病人 ,行七氟醚麻醉 ,待 1 3MAC时 ,调整呼吸频率 ,使呼气末二氧化碳分压 (PetCO2 )达 30、2 5、2 0mmHg(1kPa =7 5mmHg) ,每阶段稳定 30min。根据颈内静脉球部血、桡动脉血差值计算出CBF、CMRO2 、CMRglu、Clact值的变化。结果　与清醒时通气状态相比 ,在血流动力学维持稳定前提下PetCO2 2 5mmHg时CBF减少 36 %、CMRO2 减少 4 9% ,使CMRglu减少 36 % (P<0 0 5 )。PetCO2 30和 2 0mmHg时CBF比PetCO2 2 5mmHg时增加 2 9% (P <0 0 5 )和减少了 9% (P >0 0 5 )。CMRglu麻醉前与麻醉后相比有显著差异 (P <0 0 5 ) ,但麻醉各时段相比无统计学意义 (P >0 0 5 )。麻醉后不同时段ICP与麻醉前相比有极显著差异 (P <0 0 1) ,PetCO2 2 5和 2 0mmHgICP无明显差异 (P >0 0 5 )。麻醉后颈静脉球部氧饱和度 (SjvO2 )和动脉氧饱和度(PaO2 )与麻醉前相比明显增加 (P <0 0 5 )。麻醉前后SaO2 、pH、Hb、体温 (T)、Clact无明显差异 (P >0 0 5 )。结论　过度换气可降低颅脑手术病人CBF、CMR和ICP ,短时间 (30min)过度换气至PetCO2 2 0mmHg时 ,不仅可以降低ICP ,而且不会引起脑缺氧 ,是过度换气的最低     

晨练活动对轻症高血压病患者血压的影响

目的：探讨运动锻炼对轻症高血压病患者血压影响的一般规律性。方法：观察６８ 例轻症高血压病患者晨练前和晨练后１ 个月、３ 个月的血压变化。结果：运动后１ 个月的ＳＢＰ和运动后３ 个月的ＳＢＰ和ＤＢＰ均明显下降,但对性别影响不大,运动持续时间长者（ ≥１ ｈ／ｄ） 的ＳＢＰ和ＤＢＰ下降幅度明显高于持续时间短者（＜ １ｈ／ｄ）。结论：运动疗法降低血压的作用是较为肯定的。     

Effect of propranolol on blood pressure and renin in renal hypertension in the rat

1. Propranolol was administered to groups of mature rats before and during the development of renal hypertension induced by ligation of the aorta between the renal arteries. 2. At a dose 10 mumol (3 mg) of propranolol/kg, administered by intraperitoneal injection, the onset and severity of hypertension were not affected, although plasma renin concentration was significantly lower than in the untreated hypertensive rats in the first 5 days after the operation. 3. With 200 mumol (60 mg) of propranolol/kg, administered in the drinking water, peak blood pressure 5 days after aortic ligation was lower than in the untreated control rats, but plasma renin concentration was no lower than with the smaller dose. 4. The development of severe hypertension despite reduction in plasma renin concentration on the low dose of propranolol suggests the participation of renal vasopressor factors other than renin in this model. 5. A higher dose of propranolol reduced the rise in plasma concentration to an equal extent but the rise of blood pressure at 5 days was also reduced, which supports this concept.     

亚低温治疗对实验性脑梗死大鼠血压的影响

背景：亚低温在脑梗死的治疗中已经得到广泛应用，实施体表亚低温是否会影响血压，此影响有利还是有弊，需要进一步研究考证。 目的：观察亚低温治疗实验性脑梗死大鼠血压的变化，进一步探讨其对脑保护功能的影响。 设计：随机对照实验。 单位：武汉大学人民医院神经内科。 材料：实验在武汉大学人民医院神经内科实验室进行。选择SD大鼠120只，随机分为对照组和实验组，每组60只。 方法：实验组在大脑中动脉闭塞后3h将动物置于4℃环境中，使肛温控制在（34&;#177;1．0）℃：对照组置于室温（20℃）环境中。所有动物在大脑中动脉阻塞后2h开始再灌注。用监护仪监浏心率、呼吸、血氧饱和度、肛温和血压。24h后麻醉下处死动物，取脑组织作梗死灶总体积测定。 主要观察指标：①两组大鼠实验前后心率、呼吸、血氧饱和度、平均动脉血和血压变化。②两组大鼠梗死灶体积。 结果：①两组阻塞后的血压均较阻塞前明显升高[（150&;#177;7．2），（129&;#177;5．7）mmHg；（149&;#177;7．5），（130&;#177;2．2）mmHg，P〈0．01]，两组比较差异无显著性意义（P〉0．05）。开始亚低温后，亚低温组的血压明显降低（P〈0.01）。②亚低温组的脑梗死体积明显小于对照组[（153．17&;#177;26．83）mm^3对（251．45&;#177;36．70）mm^3，P〈0．01]。 结论：亚低温在缩小脑梗死体积的同时，能引起血压明显降低。     

亚低温治疗对实验性脑梗死大鼠血压的影响

背景:亚低温在脑梗死的治疗中已经得到广泛应用,实施体表亚低温是否会影响血压,此影响有利还是有弊,需要进一步研究考证。目的:观察亚低温治疗实验性脑梗死大鼠血压的变化,进一步探讨其对脑保护功能的影响。设计:随机对照实验。单位:武汉大学人民医院神经内科。材料:实验在武汉大学人民医院神经内科实验室进行。选择SD大鼠120只,随机分为对照组和实验组,每组60只。方法:实验组在大脑中动脉闭塞后3h将动物置于4℃环境中,使肛温控制在(34±1.0)℃;对照组置于室温(20℃)环境中。所有动物在大脑中动脉阻塞后2h开始再灌注。用监护仪监测心率、呼吸、血氧饱和度、肛温和血压。24h后麻醉下处死动物,取脑组织作梗死灶总体积测定。主要观察指标:①两组大鼠实验前后心率、呼吸、血氧饱和度、平均动脉血和血压变化。②两组大鼠梗死灶体积。结果:①两组阻塞后的血压均较阻塞前明显升高[(150±7.2),(129±5.7)mmHg;(149±7.5),(130±2.2)mmHg,P<0.01],两组比较差异无显著性意义(P>0.05)。开始亚低温后,亚低温组的血压明显降低(P<0.01)。②亚低温组的脑梗死体积明显小于对照组[(153.17±26.83)mm3对(251.45±36.70)mm3,P<0.01]。结论:亚低温在缩小脑梗死体积的同时,能引起血压明显降低。     

动态血压监测评价硝苯地平控释片对亚急性期脑梗死合并高血压患者血压参数的影响

目的 通过无创性动态血压检测(ABPM)研究硝苯地平控释片对亚急性期脑梗死合并高血压患者血压参数的影响及其降压疗效.方法 应用ABPM观察51例脑梗死合并原发性高血压患者,根据所得数据分析硝苯地平控释片(拜新同)治疗前及治疗后第14天的血压变异性(BPV)、平滑指数、晨峰血压控制及谷峰比值等血压参数的变化.结果 (1)服用硝苯地平控释片(拜新同)后第14天的收缩压(SBP)、日间收缩压(dSBP)、夜间收缩压(nSBP)、舒张压(DBP)、日间舒张压(dDBP)、夜间舒张压(nDBP)较用药前均有明显降低[(144.70±14.89) mm Hg比(163.10±16.48) mm Hg,(145.67±15.20) mm Hg比(164.55±16.81) mm Hg,(140.85±19.46) mm Hg比(156.73±20.55) mm Hg,(81.24±8.88) mm Hg比(89.49±10.06) mm Hg,(81.25±9.40) mm Hg比(90.18±10.64) mm Hg,(81.34±12.10)mm Hg比(86.28±12.11) mm Hg;t值分别为11.01、11.53、5.29、8.71、7.53、2.31,P均＜0.05)];(2)以标准差作为BPV的指标,治疗后第14天收缩压的24h收缩压变异性(SBPV)、日间收缩压变异性(dSBPV)、夜间收缩压变异性(nSBPV)较治疗前有显著下降[(16.52±4.38)mm Hg比(19.78±6.72) mm Hg,(15.45±4.71) mm Hg比(17.88±7.25) mrn Hg,(14.94±5.89) mm Hg比(19.17 ±8.27) mm Hg;t值分别为3.38、2.19、2.99,P均＜0.05)],舒张压的BPV治疗前、后差异无统计学意义;(3)平滑指数与BPV存在负相关(r≤-0.28;P均＜0.05);(4)用药治疗后的收缩压晨峰血压[(22.65±12.77) mm Hg]较治疗前[(31.94±16.36) mm Hg]得以明显控制(t=3.20,P＜0.01);(5)整体法计算24 h的谷峰比值(T/P),收缩压和舒张压分别是0.721和0.676;个体计算法得到的T/P比值,SBP为0.588±0.360,DBP为0.628±0.433.两种方法均＞0.5.结论 有效控制血压及BPV对脑卒中患者有着重要的意义,硝苯地平控释片能恒定释放药物,平稳降压的同时可以有效降低BPV及晨峰血压.     

Ambulatory blood pressure monitoring in hypertension

Compared with blood pressure measurements in the office setting, ambulatory blood pressure monitoring offers a more accurate and reliable method of diagnosing and managing hypertension. Indications for ambulatory blood pressure monitoring include borderline hypertension, a discrepancy between home and office blood pressure measurements, persistent blood pressure elevation in the office with no end-organ damage, episodic elevations of blood pressure or suggestive symptoms, hypertension resistant to treatment, episodic angina not related to exercise, end-organ damage but normal office blood pressure readings, and evaluation of the efficacy of antihypertensive agents. Several cases are presented for review.     

纳洛酮的稳压效应及在脑出血急性期的应用价值

目的　观察纳洛酮对血压的作用机制及实际疗效 ,探讨脑出血患者急性期应用纳洛酮的价值。方法　①随机将院前急救的 10 0例脑出血患者分为纳洛酮治疗组和对照组各 5 0例 ,前者以常规抢救为基础 ,再给予纳洛酮0 .8～ 1.6mg静脉注射 ,另选择 5 0例血压无明显变化的脑梗死患者作为参考组 1,5 0例血压低于正常的乙醇、一氧化碳中毒的患者作为参考组 2 ,参考组均在常规治疗的基础上加用纳洛酮。②监测四组患者发病及抢救后不同时间血压变化及意识、呼吸和心率的改变。结果　不论高血压、低血压患者使用纳洛酮后 ,血压均趋向正常。脑出血治疗组在配合应用纳洛酮后血压稳步下降 (P <0 .0 5 ) ,与对照组相比 ,在用药 30分钟后作用显现 (P <0 .0 5 ) ,收缩压与舒张压下降幅度大致同步 ,参考组 1血压波动不大 (P >0 .0 5 ) ,参考组 2血压在用药后 1小时内回升至正常 ,收缩压升幅明显 (P <0 .0 1)。结论　纳洛酮作为阿片受体拮抗剂 ,从多个环节对血压产生稳定作用 ,脑出血急性期应用纳洛酮可明显改善患者的血压、意识、呼吸和心率 ,有助于提高抢救成功率     

Effect of fish oil on blood pressure and blood lipids in men with mild to moderate hypertension

Forty men with mild to moderate hypertension were given one of two dietary supplements for 6 weeks: 20 capsules of fish oil (MaxEPA) or placebo (olive and corn oil). The MaxEPA supplement provided about 7 g omega-3-fatty acids pr day, whereas the placebo contained about 7 g omega-6-fatty acids and only 0.2 g omega-3-fatty acids. A clinical insignificant reduction in blood pressure was noted in both groups. In the fish oil group, the serum triglyceride levels fell by 30%. A decrease in the ratio total cholesterol/high density lipoprotein (HDL-) cholesterol was noted in both groups, most pronounced in the placebo group. No significant effect on total serum cholesterol level was observed during this study.     

老年高血压病患者心脑血管并发症与血压控制率相关性分析

Hypertension is a serious disease threatening the health of the aged and often leads to disability and even death due to serious diseases of heart,brain and kidney . From 1999, 213 cases of senile hypertension were treated in our department.     

针刺治疗对原发性高血压患者血压和心率变异性的影响

目的:探讨针刺治疗对原发性高血压患者血压变异性和心率变异性的影响。方法:选择符合条件的60例原发性高血压患者进行针刺治疗,疗程为30 d,采用自身前后对照,分别于治疗前后完善24 h动态血压及24 h动态心电图检查。结果:针刺治疗后血压变异性各指标(24 h平均收缩压、24 h平均舒张压、24 h收缩压标准差、24 h舒张压标准差、白昼收缩压标准差、白昼舒张压标准差、夜间收缩压标准差、夜间舒张压标准差)均较治疗前降低,差异具有统计学意义(P0.05);心率变异性各指标(连续RR间期标准差、平均5 min RR间期标准差、平均5 min RR间期标准差的平均值、连续RR间期差值的均方根值、相邻RR间期大于50ms的百分数)均较治疗前有所改善,差异具有统计学意义(P0.05)。结论:针刺治疗能显著降低原发性高血压患者的血压变异性,改善心率变异性,从而可能改善高血压患者的靶器官损害。     

放松疗法对稳定手术麻醉前非高血压患者血压的作用

目的探讨放松疗法对稳定手术麻醉前非高血压患者血压的作用。方法选择100例手术麻醉前血压升高的非高血压患者,随机分为实验组和对照组,每组各50例。两组患者均实施常规护理方法,实验组在此基础上实施放松疗法。干预30 min后测量患者的血压并比较两组患者高血压治疗效果的差异。结果实施放松疗法后,实验组高血压治疗有效率为86.0%高于对照组的64.0%,两组比较,χ2=6.453,P〈0.05,差异具有统计学意义。结论非高血压患者出现手术麻醉前紧张性血压升高时,实施放松疗法可有效维持血压稳定,有助于麻醉及手术的顺利进行。     

Effects of nadolol beta-blockade on blood pressure in hypertension

Nadolol, a nonselective beta adrenoceptor antagonist, was evaluated in 9 normal sybjects with essential hypertension for ability to inhibit exercise-induced changes in double-product (systolic pressure x heart rate). Propranolol and placebo were included as positive and negative controls. The beta antagonists were administered orally in single doses at 10, 20, 40, and 80 mg on a crossover basis. Both nadolol and propranolol induced comparable dose-related inhibition of double-product. Duration of beta receptor blockade was greater with nadolol than with propranolol; significant inhibition of double-product occurred 24 hr after a single 80-mg dose of nadolol. The antihypertensive effect of nadolol was evaluated in another series of 46 subjects with essential hypertension. The dose of nadolol ranged from 80 to 320 mg once daily. Consistent decreases in supine heart rate (20%) and diastolic blood pressure (9%) from baseline were observed. During steady state, the oral daily dose of nadolol was proportional to the minimum steady-state serum concentration (Cmin) of nadolol (r = 0.75, p less than 0.001) obtained just before the next dose of nadolol. Statistically significant correlation was observed between the antihypertensive effect and the Cmin for nadolol (r = 0.45, p less than 0.05).