Using an expiratory resistor, arterial pulse pressure variations predict fluid responsiveness during spontaneous breathing: an experimental porcine study

Introduction  

Fluid responsiveness prediction is difficult in spontaneously breathing patients. Because the swings in intrathoracic pressure are minor during spontaneous breathing, dynamic parameters like pulse pressure variation (PPV) and systolic pressure variation (SPV) are usually small. We hypothesized that during spontaneous breathing, inspiratory and/or expiratory resistors could induce high arterial pressure variations at hypovolemia and low variations at normovolemia and hypervolemia. Furthermore, we hypothesized that SPV and PPV could predict fluid responsiveness under these conditions.     

小型猪正常门静脉系统规范化磁共振血管成像实验研究

目的 以数字减影血管造影(DSA)为金标准,规范正常中国小型猪门静脉磁共振血管成像(MRA)技术.方法 实验用健康中国小型猪16只,在全麻下以门静脉主干为中心行MR灌注扫描,生成门静脉时间-信号曲线,以获得其MR最佳成像时间.待实验动物体内造影剂代谢24h后,依据前述成像时间,行MR冠状位脂肪抑制三维快速扰向梯度回波序列增强扫描,行多平面容积重建,显示门脉主干、属支,在MRA测量门静脉主干及属支直径.之后行经肠系膜上动脉及脾动脉DSA间接门静脉造影,并测量显影血管的管径;随机选择经肠系膜上动脉门静脉造影计算门静脉系统最佳显影时间.分别对比分析MRA及DSA两种技术下测量的门静脉系统直径、最佳显影时间.结果 (1)MRA与DSA门静脉最佳显影时间分别为(31.81±2.03)s与(14.32±0.71)s,MRA测得的门静脉最佳显影时间明显长于DSA(P ＜0.05),二者具有良好的相关性(r=0.749,P＜0.05).(2)MRA测得的门静脉主干、肠系膜静脉及脾静脉管径分别为(8.82±0.78)mm、(7.04±0.85)mm及(5.83±0.61)mm,DSA前述相应血管直径分别为(7.65±1.17)mm、(5.74±1.05)mm及(5.01±1.00) mm,MRA测定结果均高于DSA(P ＜0.05),二者均具有良好的相关性(r值0.949、0.910、0.906,均P＜0.05).结论 规范化门静脉MRA能准确评价门静脉系统,为实验性肝硬化门脉高压规范化MRA研究奠定基础.     

Effects of descending positive end-expiratory pressure on lung mechanics and aeration in healthy anaesthetized piglets

Introduction  

Atelectasis and distal airway closure are common clinical entities of general anaesthesia. These two phenomena are expected to reduce the ventilation of dependent lung regions and represent major causes of arterial oxygenation impairment in anaesthetic conditions. The behaviour of the elastance of the respiratory system (E _rs), as well as the lung aeration assessed by computed tomography (CT) scan, was evaluated during a descendent positive end-expiratory pressure (PEEP) titration. This work sought to evaluate the potential usefulness of E _rs monitoring to set the PEEP in order to prevent tidal recruitment and hyperinflation of healthy lungs under general anaesthesia.     

心理护理对高血压病病人血压控制水平及满意度的影响

[目的]探讨心理护理在高血压病病人中的应用效果。[方法]将收治的60例高血压病病人随机分为观察组和对照组,两组药物治疗方法相同,对照组采用常规护理,观察组在对照组的基础上加强心理护理,比较两组的心理状态、血压控制情况以及护理满意度。[结果]两组病人护理前的焦虑、抑郁评分和血压均无统计学意义(P>0.05)。观察组护理后的焦虑、抑郁评分、收缩压、舒张压均低于对照组,有统计学意义(P<0.05)。观察组的护理满意度高于对照组,有统计学意义(P<0.05)。[结论]心理护理有利于改善高血压病人治疗期间的不良心境,提高血压控制水平和病人的满意度。     

Continuous control of endotracheal cuff pressure and tracheal wall damage: a randomized controlled animal study

Background  

Intubation is frequently performed in intensive care unit patients. Overinflation of the endotracheal tube cuff is a risk factor for tracheal ischemia and subsequent complications. Despite manual control of the cuff pressure, overinflation of the endotracheal cuff is common in intensive care unit patients. We hypothesized that efficient continuous control of the endotracheal cuff pressure using a pneumatic device would reduce tracheal ischemic lesions in piglets ventilated for 48 hours through a high-volume, low-pressure endotracheal tube.     

Effects of an inverted position on blood pressure, pulse rate, and deep tendon reflexes of healthy young adults

This study reports the effects of an inverted position on pulse rate, blood pressure, and deep tendon reflexes of the biceps muscle, triceps muscle, and Achilles tendon. Twenty healthy adults were used as subjects. We collected data both before and after the subjects were in the inverted position for eight minutes on a specially designed tonic labyrinthine inverted table. A significant decrease in systolic blood pressure and all tendon reflexes was observed along with a significant increase in diastolic blood pressure (p less than .05). Pulse rate showed no change. The findings indicate that the inverted position is likely to be effective for decreasing muscle tone and systolic blood pressure. Although this study used healthy subjects, the inverted position may be used as a therapeutic technique, provided the clinician monitors closely the physiological effects on patients.     

Developing an algorithm for pulse oximetry derived respiratory rate (RRoxi): a healthy volunteer study

Objective The presence of respiratory information within the pulse oximeter signal (PPG) is a well-documented phenomenon. However, extracting this information for the purpose of continuously monitoring respiratory rate requires: (1) the recognition of the multi-faceted manifestations of respiratory modulation components within the PPG and the complex interactions among them; (2) the implementation of appropriate advanced signal processing techniques to take full advantage of this information; and (3) the post-processing infrastructure to deliver a clinically useful reported respiratory rate to the end user. A holistic algorithmic approach to the problem is therefore required. We have developed the RR_OXI algorithm based on this principle and its performance on healthy subject trial data is described herein.     

健康体检者2456名脉压、收缩压和舒张压与代谢综合征的关系

目的:探讨脉压、收缩压、舒张压和代谢综合征的关系。方法:对2456名健康体检者的脉压、收缩压、舒张压和代谢综合征进行观察。结果:在各年龄组代谢综合征患者(n=309)脉压明显升高犤40～54岁组、55～69岁组和≥70岁组分别为(49±11),(54±11)和(59±13)mmHg,1mmHg=0.133kPa犦,与对照组(n=2147)比较,差异有显著性意义(t=3.54,5.15,2.22;P<0.05～0.01);40～70岁代谢综合征组患者收缩压犤40～54岁组和55～69岁组分别为(135±17)和(139±15)mmHg犦和舒张压犤40～54岁组和55～69岁组分别为(86±9)和(85±10)mmHg犦明显升高,与对照组比较,差异有显著性意义(t=4.19,5.21,8.81,2.20;P<0.05～0.01),在年龄大于70岁时升高不明显(P>0.05)。结论:代谢综合征患者脉压、收缩压和舒张压明显升高,脉压升高,可能参与代谢综合征对心、脑血管疾病的损伤。     

有创中心动脉脉压对老年冠状动脉Gensini评分的影响研究

目的观察有创主动脉及桡动脉血压对老年冠心病Gensini评分的影响。方法选取同期行冠状动脉造影的老年高血压患者162例,根据冠状动脉狭窄程度将患者分为正常组(狭窄<50%)、冠心病组(狭窄≥50%)。冠状动脉造影时同时测定中心动脉压及外周动脉压,根据冠状动脉造影结果进行Gensini评分,并观察各种血压参数和冠状动脉病变严重程度之间的关系。结果冠心病组患者中心动脉脉压较正常组要大,差异有统计学意义[(74.4±27.4)mmHg vs.(69.5±26.2)mmHg,P<0.05],中心动脉脉压与冠状动脉Gensini评分有正相关性(r=0.316,P=0.007),中心动脉脉压和年龄有正相关性(r=0.462,P=0.005),冠状动脉Gensini评分和年龄有正相关性(r=0.298,P=0.013)。结论随着年龄增加,中心动脉脉压增大,增大的中心动脉脉压同冠状动脉粥样硬化病变程度有明显正相关性,可预测冠心病病变程度。     

Impact of norepinephrine on the relationship between pleth variability index and pulse pressure variations in ICU adult patients

Introduction  

Pleth Variability Index (PVI) is an automated and continuous calculation of respiratory variations in the perfusion index. PVI correlates well with respiratory variations in pulse pressure (ΔPP) and is able to predict fluid responsiveness in the operating room. ICU patients may receive vasopressive drugs, which modify vascular tone and could affect PVI assessment. We hypothesized that the correlation between PVI and ΔPP and the ability of PVI to identify patients with ΔPP > 13% is dependent on norepinephrine (NE) use.     

心理干预对包皮环切术病人血压及脉搏的影响

目的探讨心理干预对门诊包皮环切术病人血压和脉搏的影响。方法将90例病人随机分为干预组46与对照组44例,对照组病人给予常规术前检查及行包皮环切术,干预组病人除常规术前检查及行包皮环切术外,术中给予实施心理干预。比较两组病人术前后血压及脉搏情况。结果对照组病人术后脉搏和血压明显快于和高于干预组,两组比较,差异具有统计学意义(均P<0.05)。结论在包皮环切术过程实施有效的心理干预,可缓解病人紧张情绪,维持病人脉搏、血压平稳。     

Effects of continuous positive airway pressure/positive end-expiratory pressure and pressure-support ventilation on work of breathing,using an animal model

OBJECTIVE: Evaluate the effects of continuous positive airway pressure (CPAP)/positive end-expiratory pressure (PEEP) and pressure support ventilation (PSV) on work of breathing (WOB). METHODS: With 13 anesthetized lambs we measured WOB with an esophageal balloon and flow signals. All the animals were sedated, intubated, and ventilated, using 2 pediatric ventilators (Servo 300 and VIP Bird). Ventilator settings were CPAP of 0, 5, and 10 cm H(2)O and PSV of 5 and 10 cm H(2)O with PEEP of 0, 5, and 10 cm H(2)O. Data were analyzed with 2-way analysis of variance. RESULTS: With the Servo 300 the total WOB (WOB(T)) increased between CPAP/PEEP of 0 and 10 cm H(2)O (p 相似文献   

Effect of confounding factors on blood pressure estimation using pulse arrival time

Two confounding factors were selected and analyzed in blood pressure estimation using pulse arrival time (PAT) for each individual. The heart rate was used as the confounding factor for the cardiac cycle, and the duration from the maximum derivative point to the dicrotic peak (TDB) in the photoplethysmogram was used as another confounding factor representing arterial stiffness. By considering these factors with PAT in multiple regression analysis, the performance of blood pressure estimation is enhanced significantly in the diastolic phase as well as in the systolic phase. The reproducibility of this method was also validated with formerly obtained regression equations from the training set. The correlation between estimated and measured blood pressure decreased a little, but the validity was still maintained (r congruent with 0.8). This shows the value of the method in non-intrusive blood pressure estimation for individual patients and may be useful for various applications.     

Malignancy and silastic particles: an animal study

This paper describes the result of a study of the oncogenic property of silicone elastomer (silastic) particles within a synovial joint. Fifty rats had silastic particles placed in a knee and a comparable group of a further 50 rats were similarly treated with high density Polyethylene (HDP) particles. The rats were sacrificed at 21 months following implantation. There was no increase in the incidence of tumours in either group. However, it was noted that although the HDP particles and larger silastic particles stayed locally in the knee, the smaller silastic particles were partially cleared from the joint. We therefore conclude that in this animal model, intraarticular particulate silastic does not appear to be oncogenic, but that. further studies of the dynamics of silastic particles would be justified.     

不同腹内压水平对腹腔间隔室综合征患者预后的影响

目的:探讨不同腹内压(IAP)水平对腹腔间隔室综合征(ACS)患者临床预后的影响.方法:通过检索Cochrane、Embase、Medline临床试验数据库、CNKI和CBM等文献数据库,收集国内外不同IAP水平ACS患者的随机对照实验(RCT),提取资料并评估方法学质量.结果:共纳入9个RCT,756例ACS患者,高IAP组病死率为21.63%,低IAP组病死率为6.18%,两组比较差异有统计学意义(P<0.01).结论:降低IAP可以降低ACS患者病死率.     

多排螺旋CT血管造影在肝移植动脉解剖变异分析中的应用

目的:探讨多排螺旋CT血管造影(MSCTA)在分析肝移植动脉解剖变异中的应用价值.方法:分析100例预行肝移植术患者的动脉CT血管造影(CTA)资料,并与数字减影血管造影(DSA)(26例)或手术(19例)结果进行对照.所有病例均在Roshiba Aquilion 16层螺旋CT机上进行.动脉期层厚为1 mm,重建层厚为1 mm,螺距15,延迟时间25 s,对比剂用量为1.5 mL/kg.依据Michels分型对100例CTA进行分类,并记录CTA对不同动脉分支的显示率.结果:正常肝动脉解剖占79%,变异占21%.45例有DSA或手术结果者,CTA的诊断符合率为95.6%.结论:MSCTA在分析肝移植动脉解剖变异中有较高的符合率,可应用于肝移植术前的评价.