慢性肾脏病患者24小时动态血压的特点分析

目的采用24h动态血压监测的方法,分析慢性肾脏病（CKD）不同分期患者24h动态血压特点。方法将152例CKD患者分为5组：CKD1期组（A组）15例;CKD2期组（B组）29例;CKD3期组（C组）42例;CKD4期（D组）组34例;CKD5期组（E组）32例。所有患者均无糖尿病、非肾脏替代治疗。采用携带式的动态血压检测仪测定各组患者动态血压参数和昼夜节律。结果①随着肾功能下降,24h、日间和夜间平均收缩压越来越高;②CKD患者总体非杓型血压比例为81．6o,4,肾功能下降组（CKD2～5期）非杓型血压比例显著高于肾功能正常组（CKD1期）;③夜间收缩压与24h尿蛋白定量呈正相关（r=0．427,P〈0．01）,与。肾小球滤过率（GFR）呈负相关（r=-0．352,P〈0．05）。结论CKD患者的血压非杓型节律现象比较普遍,并随着肾功能下降,其发生率逐渐升高;夜间收缩压与尿蛋白排泄、肾功能有相关性。     

早期慢性肾病患者动态血压变化与左心室肥厚的关系

目的：分析早期慢性肾脏病（CKD1期）患者24h动态血压变化与左心室肥厚（LVH）的关系。方法：以25例正常人作为对照组（N组）,71例肾功能稳定的CKD1期患者作为疾病组（D组）。收集肾功能、血脂、24h动态血压监测（ABPM）等临床资料;采用超声心动图检测早期CKD患者LVH有关指标,分析ABPM指标与LVH的关系。结果：（1）与N组相比,D组夜间收缩压,昼、夜及24h平均舒张压均升高（P均〈0.05）;夜间收缩压下降率（nDRS）及舒张压下降率（nDRD）均明显下降（P均〈0.05）;舒张末期左室内径（LVDd）及左心室质量指数（LVMI）均升高（P均〈0.05）。（2）D组高血压及非杓型血压发生率分别达47.9%、62.0%。（3）与杓型血压组（Dip组）相比,非杓型血压组（non-Dip组）LVMI值及LVH发生率均显著增高（P均〈0.05）。（4）与非高血压组（non-LVH组）相比,高血压组（LVH组）nDRS和nDRD均明显下降,血红蛋白（Hb）显著降低（P均〈0.05）。（5）相关性分析显示LVMI值与nDRS、nDRD和Hb均呈负相关（P均〈0.01）,昼间平均收缩压（dSBP）、夜间平均收缩压（nSBP）、夜间平均舒张压（nDBP）和24h平均舒张压（mSBP）均呈正相关（P均〈0.05）。多因素逐步回归分析显示：nDRS、Hb、nDRD和血肌酐（Scr）进入回归方程：y=123.429-2.290x1-0.47x2-0.768x3＋0.178x4（y=LVMI;123.429=常数,t=8.41,P=0.000;x1=nDRS,t=-5.43,P=0.000;x2=Hb,t=-4.77,P=0.000;x3=NDRD,t=-3.47,P=0.001;x4=Scr,t=2.08,P=0.041）。结论：早期CKD患者即已出现血压升高及血压节律改变;LVH发生与早期CKD患者夜间高血压及非杓型血压关系更为密切;贫血和肾功能减退本身也与早期CKD患者LVH发生有关。     

慢性肾脏病不同阶段的动态血压分析

目的：研究慢性肾脏病不同阶段的动态血压形态特征。方法：慢性肾脏病住院患者129例,患者入院后1h记录安静状态卧位诊室血压,并进行24h动态血压监测,血压〉140/90mmHg（1mmHg=0.133kPa）为诊室血压升高。24h动态血压平均值〉130/80mmHg,日间平均值〉135/85mmHg,夜间平均值〉125/75mmHg为血压升高。结果：本组资料显示,在CKD各期动态血压监测提示24h平均收缩压均超过130mmHg,各组间P〈0.01,提示各组平均收缩压间差异有统计学意义。而日间收缩压及夜间收缩压在CKD各期也有明显差异。但比较24h平均舒张压、日间平均舒张压、夜间平均舒张压在各阶段差异不大,P值均〉0.05。在CKD各期的病例中,正常的杓形血压只占少数,而在各期中比较（P〈0.05）,提示CKD早期病例中动态血压就可能已经发生了变化。结论：慢性肾脏病各期动态血压的形态均以非杓形,反杓形为主,随着肾小球滤过率下降,收缩压有逐渐升高趋势。     

糖尿病肾病患者24h动态血压临床特点分析

目的:分析比较由糖尿病(DN)肾病和非糖尿病导致的慢性肾脏病患者的动态血压变化情况,探讨糖尿病肾病患者动态血压变化的特点。方法:选择62例符合慢性肾脏病诊断标准的DN患者,均无肾脏替代治疗。观察其24 h动态血压监测结果,并与152例年龄、性别、肾功能等匹配的非糖尿病的CKD患者的动态血压结果相比较。结果:在对62例DN患者和152例非糖尿病CKD患者动态血压的分析中,我们发现:(1)DN组的24 h平均收缩压、日间平均收缩压、夜间平均收缩压均显著高于非DN组。(2)两组患者血压变异性差异无统计学意义;夜间血压下降率普遍较小,但差异无统计学意义。(3)DN组收缩压负荷均显著高于非DN组。(4)DN组非杓型节律的发生率为90.3%,非DN组为81.6%,两组血压节律类型差异无统计学意义。(5)非DN组和DN组24 h尿蛋白量与夜间收缩压均具有显著正相关。结论:中晚期DN患者收缩压控制较非糖尿病的CKD患者更差,血压非杓型节律现象比较普遍。夜间收缩压与24 h尿蛋白排泄量密切相关。     

慢性肾脏病患者血压昼夜节律异常的研究

目的 观察慢性肾脏病(CKD)患者24 h血压动态变化，探讨昼夜节律异常与肾功能损害的关系。方法 随机选择本院肾脏科CKD患者236例，高血压科原发性高血压住院患者43例。病例分组:正常对照组(NC)14例；原发性高血压组(EHC)43例；CKD血压正常组(NCKD)130例；CKD伴血压升高组(HCKD)106例。动态血压监测(ABPM)采用携带式的动态血压检测仪，ABP Report Mangement System Version 1.03.03进行数据分析。夜间血压下降率:(白昼平均值-夜间平均值)/白昼平均值，下降率≥10%，称勺型血压；<10%，称非勺型血压。结果 在血压正常的患者中，NCKD组的平均夜间收缩压和舒张压数值均高于NC组[(111.2±10.8)比 (91.6±7.5)，(68.7±9.5) 比 (56.2±4.6)mm Hg，P < 0.05]；而日间收缩压和舒张压无明显差异。在高血压患者中，HCKD组患者夜间收缩压和舒张压数值均高于EHC组[(141.9±16.5) 比(118.6±16.4)， (84.5±10.6)比(73.0±11.1)mm Hg， P < 0.05]。CKD患者无论血压正常或升高，其心率均较其对照组明显加快，尤其是夜间心率无明显下降。NCKD组、HCKD组与NC组、EHC组相比，夜间收缩压和舒张压下降数值较小，尤其是CKD伴血压升高组，呈典型的非勺型血压模式。NC组血压节律消失者占7.14%，EHC组为37.2%，NCKD组为70.0%，HCKD组为81.6%。结论 CKD患者无论血压正常或升高，夜间收缩压和舒张压下降减少或消失，呈典型的非勺型血压；血压昼夜节律异常率明显高于原发性高血压患者。在积极降低血压值的同时，还需降低血压负荷和调整血压昼夜节律，以延缓肾功能恶化。     

慢性肾脏病患者动态血压参数及血压变异的特点分析

目的 分析慢性肾脏病（chronic kidney disease,CKD）患者动态血压参数与肾小球滤过率（GFR）及尿蛋白定量的相关性,并探讨血压变异性参数特点.方法 收集首次治疗的伴有高血压及蛋白尿的CKD患者70例.测量肾功能、24 h尿蛋白定量等生化检测结果,采用动态血压监测仪监测24 h血压并记录参数.根据GFR将患者分为CKD1~2期组和CKD3~5期组.根据24 h尿蛋白定量分为以下3组：Ⅰ组＜1.0 g,Ⅱ组1.0～3.5 g,Ⅲ组＞3.5 g.比较各组动态血压参数,并探讨监测结果与肾功能及蛋白尿的关系.结果 随着患者肾功能恶化,24 h收缩压、舒张压、脉压差、白昼收缩压、夜间收缩压等指标明显升高（P＜0.05）,且与GFR成负相关,白昼收缩压是GFR下降的独立危险因素.Ⅲ组的白昼舒张压（92.94±15.32）mm Hg明显高于Ⅰ组的（85.25±8.64）mm Hg（P＜0.05）.白昼舒张压与蛋白尿水平呈正相关（r=0.257,P=0.032）.所有患者舒张压变异性均明显高于收缩压变异性（P＜0.05）.结论 本研究样本中收缩压与肾功能恶化明显相关,白昼收缩压和舒张压分别与GFR下降及蛋白尿有关,舒张压变异性应受到更多重视.     

慢性肾脏病1～2期血压昼夜节律变化的中医病因病机探讨

目的:观察慢性肾脏病(CKD)1~2期非高血压患者24 h血压变异情况,应用中医辨证方法分析CKD1~2期血压昼夜节律异常的中医病因病机。方法:收集47例CKD1~2期非高血压患者及30例健康人的24 h动态血压数据,比较两组血压昼夜异常节律的发生情况。对CKD组进行中医证候评分,根据中医基础理论,分析不同中医证素与非杓型血压的对应关系。结果:CKD组非杓型血压的发生率较正常对照组高(P0.05)。CKD组昼夜平均舒张压差、昼夜平均舒张压变化率低于正常对照组(P0.05)。CKD1~2期患者的主要病位为在肾、在脾,气虚、阴虚为其主要病因病机。在CKD组中反杓型血压患者脏腑辨证病位在肾及阳虚的发生率较非反杓型患者高(P0.05)。结论:CKD1~2期患者的主要病因病机为脾肾气阴两虚;肾阳亏虚,阴阳失调可能是CKD1~2期非高血压患者血压昼夜节律改变的中医病因病机。     

硝苯地平控释片和雷米普利降血压作用及对肾功能的影响

目的观察并比较硝苯地平控释片和雷米普利对慢性肾脏病（CKD）患者的降压效果以及对肾功能的影响。方法将46例CKD患者随机分为两组,雷米普利（2．5mg／d）组与硝苯地平（30mg／d）组,每组23例,连续使用8周,比较两组治疗前后24h平均收缩压（SBP）和平均舒张压（DBP）,昼、夜间SBP和DBP,24h尿蛋白定量及肾功能的变化。结果两组患者的SBP和DBP均有所下降。降压的同时,雷米普利组82％的患者、硝苯地平组78％的患者恢复了血压的昼夜节律,血肌酐、尿蛋白有所下降。雷米普利组24h尿蛋白定量减少幅度明显高于硝苯地平组。结论硝苯地平和雷米普利对CKD患者均有良好的降压效果和改善肾功能的作用,雷米普利降低尿蛋白的疗效明显强于硝苯地平。     

原发性慢性肾脏病患者动态血压特点及其与左心室肥厚的关系

目的：研究原发性慢性肾脏病（ CKD）肾脏替代治疗前患者动态血压特征,分析相关参数尤其是血压变异性与左心室肥厚（ LVH）的关系。方法：收集我科住院的非透析原发性CKD患者127例,按其内生肌酐清除率（ Ccr）水平分为早期组[CKD1～3期（n＝95,Ccr≥30 ml·min-1＆·1．73 m^-2）]和晚期组[CKD4～5期（n＝32,Ccr﹤30 ml·min^-1·1．73 m^-2）]。无创性便携式动态血压监测仪行动态血压监测（ ABPM）,超声心动图检测LVH有关指标,分析动态血压相关指标,尤其是血压变异性（ BPV）与LVH的关系。结果：（1）与早期组相比,晚期组24 h、昼间、夜间舒张压变异性（ mDBPV,dDBPV,nDBPV）和24 h收缩压变异性（mSBPV）均减小（P﹤0．05）;高血压和反杓型血压发生率均升高（P均﹤0．05）;舒张末期左室内径（LVDd）、室间隔厚度（IVST）、左室后壁厚度（PWT）、左心室质量指数（LVMI）均升高（P均﹤0．05）,LVH发生率升高（P﹤0．05）。（2）与非左心室肥厚组（ non-LVH组）相比：左心室肥厚组（ LVH 组）高血压和反杓型血压发生率升高（ P 均﹤0．05）;但BPV各指标变化不显著（ P均﹥0．05）。（3）与非高血压组（ non-H组）相比：高血压组（ H-组）LVMI值和LVH发生率均显著升高（P均﹤0．05）。（4）与非反杓型血压组相比,反杓型血压组 LVMI 值及 LVH发生率均显著升高（P均﹤0．05）。（5）单因素相关性分析显示,LVMI与年龄、mSBP、mDBP、dSBP、dDBP、nSBP和nDBP均呈正相关（ P均﹤0．05）,与Ccr、mDBPV、nDPS和nDPD 均呈负相关（ P均﹤0．05）;多因素逐步回归分析显示,Ccr和nSBP进入回归方程y＝51.772-0.289x1＋0.526x2（y＝LVMI;51．772＝常数,t＝3.616,P＝0.000;x1＝Ccr,t＝-5.984,P＝0.000;x2＝nSBP,t＝5.181,P＝0．000）。结论：随着肾功能减退,CKD患者高血压发生率升高;血压昼夜节     

中青年MHD患者血压变异性与左室肥厚的关系

目的:探讨中青年维持性血液透析(MHD)患者血压变异性与左室肥厚的关系。方法:收集我院透析中心符合病例选择标准的中青年MHD患者进行回顾性研究。根据心脏彩超测量结果,计算左室质量指数(LVMI),据LVMI分为左室肥厚组(LVH组)和非左室肥厚组(non-LVH组)。所有患者均行24 h动态血压监测,获得血压变异性参数。同时收集患者平均超滤量/干体重(MUF/BW,%)、透析充分性Kt/V、血常规、空腹血糖、血脂、肾功能、超敏C反应蛋白(hsCRP)、白蛋白(Alb)、血钙(Ca~(2+))、血磷(P~(3-))、甲状旁腺素(iPTH)等资料。用SPSS 22.0统计软件进行统计学分析,以P0.05为差异有统计学意义。结果:(1)共有95例符合病例选择标准的MHD患者,79例中青年MHD患者中男53例,女26例。平均年龄(40.72±11.40)岁(19岁~64岁)。中位透龄24月(3月~169月)。79例MHD患者中有高血压73例(92.4%),有LVH41例(51.9%)。(2)与non-LVH组比较,LVH组男性患者比例更高(P0.01),LVMI、MUF/BW、LDL-ch更高(P分别0.01,0.01,0.05)。两组年龄、透龄、基础疾病、糖尿病、高血压、高血脂的比例、KT/V、Hb、hsCRP、FBG、Alb、BUN、Scr、BUA、TC、TG、HDL-ch、Ca~(2+)、P~(3-)、iPTH差异均无统计学意义(P0.05)。(3)LVH组24 h收缩压变异性(24 h SBPs)、24 h平均收缩压(24 h SBPmbp)、白昼收缩压变异性(d SBPs)、白昼平均收缩压(d SBPmbp)、夜间平均收缩压(n SBPmbp)、24 h舒张压变异性(24 h DBPs)、24 h舒张压变异系数(24 h DBPcv)、白昼舒张压变异性(d DBPs)、白昼舒张压变异系数(d DBPcv)、夜间舒张压变异性(n DBPs)、夜间舒张压变异系数(n DBPcv)均显著高于non-LVH组(P均0.05),但两组24 h收缩压变异系数(24 h SBPcv)、白昼收缩压变异系数(d SBPcv)、夜间收缩压变异性(n SBPs)、夜间收缩压变异系数(n SBPcv)、24 h平均舒张压(24 h DBPmbp)、白昼平均舒张压(d DBPmbp)、夜间平均舒张压(nDBPmbp)差异无统计学意义(P均0.05)。(4)LVH组血压不达标、血压变异性大的比例、使用CCB、RASI比例均显著高于non-LVH组(P均﹤0.05)。两组间夜间血压下降不达标比例、使用β受体阻滞剂、α受体阻滞剂的比例差异无统计学意义(P均0.05)。(5)经Logistic单因素分析,性别、MUF/BW、LDL-ch、24 h SBPs、24 h SBPmbp、24 h DBPs、CCB和RASI的使用与LVH有关(P均﹤0.05),而年龄、透龄、24 h DBPmbp与LVH无关(P均0.05)。进一步多因素分析显示,24 h SBPmbp、24 h DBPs是LVH独立危险因子(OR值分别为1.098,1.306,95%CI分别为1.041~1.159,1.014~1.683,P分别0.01,0.05),性别(女性)是LVH独立保护因子(OR值为0.088,95%CI为0.014~0.567,P0.01)。结论:中青年MHD患者血压变异性与左室肥厚密切相关,SBPmbp、DBPs是LVH独立危险因素,舒张压的变异性对于LVH可能更为重要。在中青年MHD患者中,女性患者是LVH保护因素。     

股静脉测压法和膀胱测压法在危重患者腹内压监测中的比较

目的：比较股静脉测压法和膀胱测压法在危重患者腹内压（IAP）监测中的应用价值.方法：对2013年1-6月住院治疗的20例ICU重症患者,分别使用两种测压方法进行IAP监测,均每8 h 1次,连续测定3 d,每次随机选择两种方法的测量顺序,共测量720次,比较两种测压法在读数精准性、测压数值、操作时间、并发症和医护人员满意度等方面的异同.结果：股静脉测压法所测压力数值与膀胱测压法相近[（14.14±4.33）mmHg比（12.91±4.75）mmHg,P〉0.05];但是股静脉测压法的操作时间[（57.94±19.00）s]较膀胱测压法更短[（112.49±27.07）s,P〈0.05];股静脉测压法读数精准率（84.44%）较膀胱测压法（49.44%）高（P〈0.01）,操作并发症低至1.1%（4例次）,远低于膀胱测压法的5.3%（19例次,P〈0.05）;医护人员满意度达（3.90±0.26）分,优于膀胱测压法[（2.48±0.19）分,P〈0.01].结论：相对于膀胱测压法而言,股静脉测压法具有测压值相似、操作时间短、读数精准度高、操作并发症少、接纳度高等优点,值得在危重患者IAP监测中推广.     

Clinical evaluation of a simple epidural pressure sensor

Summary The Plastimed^® epidural pressure sensor was evaluated in 35 patients, twenty-eight of whom were suffering from head injury. In seven patients simultaneous intraventricular pressure measurements were obtained. The epidural pressure sensor was only functioning satisfactorily in approximately 2/3 of the patients, while it was malfunctioning or not functioning in the remainder. In seven comparable IVP/EDP studies significant differences up to 25 mm Hg were noted. In three patients IVP was greater than EDP. In two patients the opposite was true. No significant complications were observed.These unsatisfactory results have made us abandon the technique and resort to intraventricular or subarachnoidal pressure measurements.     

Clinical evaluation of a new epidural pressure monitor

Summary Comparative measuring of epidural pressure using the Spiegelberg probe 1 and ventricular fluid pressure was carried out in 15 neurosurgical intensive-care patients. Deviations in both directions were established, with a trend toward overestimating ventricular pressure in epidural pressure measuring (r=0.77). Individual pulsations, spontaneous wave courses and therapy-induced pressure changes were reflected without delays. There were no complications observed with probe implantation periods for up to 6 days. The system has been shown to be mechanically stable and easy to implant. We believe the device to be fit for trend monitoring of intracranial pressure. As with other epidural pressure monitoring systems, false assessments of ventricular pressure may lead to wrong decisions as to the required therapy.     

The Rotterdam teletransducer: State of the device

Summary The developments of a telemetric device for monitoring intracranial pressure, the Rotterdam Teletransducer, are described. The major problem in telemetric pressure sensing devices consists of diffusion of water into the transducer, resulting in unpredictable zero drift. Therefore, special attention was paid to bonding techniques for sealing the transducer.The results of improved epoxy sealing, active metal brazing and glass bonding are described. In vitro tests showed transducers sealed with epoxy resin to be stable for two months. Using the more complicated tchniques of glass bonding and active metal brazing, hermetic seals could be achieved with stable transducers for over one year. In vivo functioning of the Rotterdam Teletransducer was tested in acute and chronic animal experiments. The in vivo results corresponded to those obtained in the in vitro experiments. Regression analysis between epidural and ventricular fluid pressure showed a one to one ratio.Results of clinical application of the device in 22 patients are described. Accurate depth setting of the transducer on the dura, according to the pressure depth curve, was shown to be essential.The device has also been used with success for non-invasive fontanelle pressure measurements in infants. The depth positioning of the transducer on the fontanelle according to a pressure depth curve is described.This paper has been awarded by the 1985 Casey Holter Memorial Prize by the Society for Research in Hydrocephalus and Spina Bifida.     

Idiopathic normal pressure hydrocephalus: Analysis of factors related to cerebrospinal fluid dynamics determining functional prognosis

Summary This investigation has been undertaken to analyze the findings with both the cerebrospinal fluid (CSF) pressure (Pcsf) and CSF pulse pressure (PP) in order to predict the outcome of patients with the syndrome of idiopathic normal pressure hydrocephalus (NPH). Accordingly, a prospective clinical study was planned in which two groups of patients with NPH, having analogous prevalence of several matched clinical and radiological parameters, were separated on the basis of their positive or negative response to shunting. Both the resting Pcsf and CSF PP profiles were compared in these two groups, and between them and normal controls. CSF PP amplitude and CSF PP latency correlated directly in conditions associated with either normal or high compliance (controls and patients with Alzheimer-like disorders), whereas this correlation was inverse in states of low compliance (NPH). On the other hand, shunt-responders showed a resting Pcsf significantly higher than both non-responders and controls.The following conclusions were obtained: 1) CSF PP is a high-amplitude and relative low-latency wave in NPH when compared with controls; 2) CSF PP amplitude and latency correlate directly in normal subjects and in those with primary cerebral atrophy; 3) a non-reversible stage of NPH could be conceived in contradistinction to the reversible one, in both of which an inverse correlation between the amplitude and the latency takes place, the main difference between them being the resting Pcsf, which is significantly lower in the former than in the latter, depending on the degree of atrophic changes developed.     

膀胱压、胃内压与腹内压的相关性研究

目的 探讨利用膀胱压、胃内压来间接监测腹内压的可行性．以便于腹腔间隔室综合征(ACS)的诊断。方法 对24例行腹腔镜胆囊摘除术(LC)患者进行前瞻性对照研究。在行LC时，在腹内压为10、15、20及25mmHg时同时测定膀胱压和胃内压。结果 腹内压与膀胱压的回归方程为Y=-10.193 1.228X．相关系数为0.941；腹内压与胃内压的回归方程为Y=-7.408 1.478X，相关系数为0.996。由此表明．腹内压与膀胱压和胃内压呈显著正相关。结论 腹内压与胃内压和膀胱压有很好的相关性，可以利用胃内压和膀胱压来反映实际腹内压。     

间歇正压通气和呼气末正压通气对犬眼内压的影响

目的 探讨间歇正压通气(IPPV)和呼气末正压通气(PEEP)对犬眼内压(10P)的影响.方法 实验犬8只,麻醉后分别监测基础条件下和各种机械通气条件下的IOP、CVP、MAP.结果 实施20 ml/kg和30 ml/kg两种不同潮气量的IPPV时IOP差异无统计学意义.实施10、15、20cm H20三种不同压力值的PEEP时IOP均显著升高(P<0.01).结论 IPPV对IOP影响不大,PEEP可使IOP显著升高.     

防压疮气垫床压力选择的实证研究与分析

目的探讨临床防压疮气垫床的最佳压力。方法在改装设备测量气垫床压力和骶尾部压力的基础上,采用重复测量方法,选择76名健康志愿者仰卧于气垫床上,气垫床压力由充满逐渐降低,每降低5mmHg记录1次骶尾部压力;使用混合效应二次曲线模型分析气垫床压力与骶尾部压力的关系,通过固定效应确定最佳的气垫床压力,并根据个体随机效应分析气垫床压力的最佳范围。结果气垫床压力和骶尾部压力呈二次项分布,可以采用混合效应二次曲线模型进行分析;通过固定效应分析可得气垫床的最佳压力为24.55mmHg,根据个体随机效应分析可得气垫床的压力范围在20.23~29.40mmHg时,人体骶尾部所受的压力最低,与其他范围相比差异具有统计学意义(均P0.01)。结论气垫床最佳压力范围为20.23~29.40mmHg。     

A practical technique for continuous monitoring of cerebral tissue pressure in neurosurgical patients

Summary A new technique for continuous monitoring of cerebral tissue pressure is presented. It is based on a new type of piecoresistive microtransducer with low baseline and temperature drifts. In 7 patients cerebral tissue pressure and ventricular fluid pressure were recorded simultaneously.Comparison of these two different pressures showed extremely good correlation with coefficients always better than 0.95. Due to another type of pulsewave cerebral tissue pressure was constantly 4 to 12 mm Hg lower than ventricular fluid pressure. Routine use of cerebral tissue monitoring in 12 neurosurgical patients with brain tumours postoperatively showed good clinical correlation of cerebral tissue pressure without any additional complications.The authors recommend continuous monitoring of cerebral tissue pressure as a safe and simple method of intracranial pressure monitoring in neurosurgery.     

Telemetric recording of intrapleural pressure

BACKGROUND: Monitoring of intrapleural pressure (IPP) is used for evaluation of lung function in a number of pathophysiological conditions. We describe a telemetric method of non-invasive monitoring of the IPP in conscious animals intermittently or continuously for a prolonged period of time. MATERIALS AND METHODS: After IACUC approval, six mongrel dogs were used for the study. After sedation, each dog was intubated and anesthetized using 0.5% Isoflurane. A telemetric implant model TL11M2-D70-PCT from Data Science International was secured subcutaneously. The pressure sensor tip of the catheter from the implant was inserted into the pleural space, and the catheter was secured with sutures. The IPP signals were recorded at a sampling rate of 100 points/second for 30 to 60 min daily for 4 days. From these recordings, the total mean negative IPP (mmHg), and the total mean negative IPP for a standard time of 30 min were calculated. In addition, the actual inspiratory and expiratory pressures were also measured from stable recording of the IPP waveforms. RESULTS: In six dogs, the total mean +/- SD negative IPP was -10.8 +/- 10.6 mmHg. After normalizing with respect to acquisition time it was -13.2 +/- 11.2 mmHg/min. The actual inspiratory pressure was -19.7 +/- 15.3, and the expiratory pressure was -11.0 +/- 12.9. CONCLUSIONS: Our study demonstrates that telemetric monitoring of IPP can be performed reliably and non-invasively in conscious experimental animals. The values for IPP in our study are compatible with the results of other investigators who used different methods of IPP measurement. Further work may show this method to be helpful in understanding the pathophysiology of various breathing disorders.