中老年男性代谢综合征与前列腺增生关系的研究

目的 探讨中老年男性人群中代谢综合征和前列腺增生(benign prostatic hyperplasia, BPH)的关系。方法 随机选择2015年5月至2016年2月本院体检中心体检的中老年男性350例作为研究对象。调查所有研究对象的一般情况,包括年龄、身高、体质量、血压、既往史、国际前列腺症状评分(IPSS)等;抽取空腹静脉血检测血糖、三酰甘油、高密度脂蛋白和前列腺特异性抗原(PSA);腹部超声测量前列腺体积, 并检测Qmax。比较代谢综合征组和非代谢综合征组BPH患病率及严重程度。结果 代谢综合征组100例,合并BPH者30例（30%）;非代谢综合征组250例,合并BPH者35例（14%）。代谢综合征组的BPH患病率较高,与非代谢综合征组相比,代谢综合征组IPSS、前列腺体积和血清PSA值存在差异,差异有统计学意义（P<0.05）,两组间Qmax差异无统计学意义（P=0.057）。结论 代谢综合征患者的BPH患病率较高,代谢综合征影响BPH患者的IPSS、前列腺体积和PSA。肥胖、高脂血症、高血压、空腹血糖高或糖尿病是BPH的危险因素。BPH患者诊疗的同时还需要考虑是否合并代谢综合征。     

前列腺增生症相关下尿路症状与各临床影响因素关系的研究

目的 探讨不同的临床因素与前列腺增生症(BPH)相关下尿路症状(LUTS)之间的关系,了解影响BPH有关LUTS的危险因素.方法 对2003年7月至2009年10月收治的548例前列腺增生症患者的资料进行回顾性研究.分析不同年龄、病史、最大尿流率(Qmx)、前列腺总体积、移行区体积、移行区指数、总PSA、游总比(f/tPSA)、组织炎症对IPSS值的影响,并进行多元线性回归分析.结果 年龄、移行带体积、Qmax、PSA及前列腺组织炎症对IPSS评分影响显著.随着年龄增大和移行带体积的增加,IPSS值变大;随着最大尿流率的减少,IPSS值显著增加(P＜0.05).当PSA ≥4 ng/mL时,IPSS值要显著大于＜4 ng/mL组(P＜0.05),但是介于4～10 ng/mL组和≥10 ng/mL组的IPSS评分并无差异(P＞0.05).合并前列腺组织炎症患者的IPSS值要显著高于非炎症组(P＜0.05).进一步通过多元线性回归分析,发现所有可能影响IPSS评分的因素中,Qmax和前列腺组织炎症与IPSS评分密切相关(β=-0.807,5.736;P＜0.001).结论 前列腺组织炎症和Qmax对下尿路症状的影响最显著.其他的临床因素如患者年龄、移行带体积和PSA值对BPH患者的下尿路症状影响有限,经过多因素回归分析发现并无显著性.     

良性前列腺增生合并前列腺炎患者的临床特点分析

目的 探讨合并前列腺炎的良性前列腺增生(BPH)患者的临床特点. 方法 BPH患者100例.按是否合并前列腺炎分为单纯组(34例)和合并组(66例).比较2组患者年龄、前列腺体积、PSA与前列腺特异性抗原密度(PSAD)、国际前列腺症状评分(IPSS)的差异,同时分析B超检查对BPH合并前列腺炎的检出情况. 结果单纯组患者年龄为(66.5±6.4)、合并组为(69.9±7.2)岁;单纯组平均前列腺体积为(47.5±26.7)、合并组为(71.4±39.3)ml.单纯组患者PSA和PS-AD中位数分别为3.40和0.08 ng/ml,合并组分别为8.07和0.12 ng/ml;平均IPSS分别为19.9和22.2.2组患者平均年龄、前列腺体积、PSA与PSAD值及IPSS评分比较,差异均有统计学意义(P<0.05).合并前列腺炎患者前列腺体积与炎症浸润程度及腺体破坏程度具有相关性(r分别为0.29,0.25,P<0.01).PSA与前列腺炎浸润分级和破坏分级均具有相关性(r分别为0.319和0.214,P值均<0.05).PSAD与浸润分级具有相关性(r=0.212,P<0.05).B超诊断BPH合并前列腺炎的敏感性为21.2%,特异性82.4%. 结论 BPH患者多伴前列腺炎,且以慢性炎性细胞浸润为主;合并前列腺炎的患者临床检测指标明显高于单纯BPH患者.B超对BPH合并前列腺炎的检出能力不令人满意.     

BPH患者组织学前列腺炎与PSA、前列腺体积、PSAD、IPSS、Qmax及PVR的相关性研究

目的:探讨BPH患者组织学前列腺炎与PSA、前列腺体积、PSA密度(PSAD)、IPSS、最大尿流率(Qmax)及残余尿量(PVR)的相关性。方法:手术切除或经尿道前列腺电切术(TURP)治疗的BPH患者673例。按照是否伴有组织学前列腺炎将患者分为两组:A组:BPH伴组织学前列腺炎;B组:BPH不伴有组织学前列腺炎。比较两组患者PSA、前列腺体积、PSAD、IPSS、Qmax及PVR。结果:A组PSA水平为(5.64±2.48)μg/L,前列腺体积(43.66±13.11)ml,PSAD 0.129±0.048,IPSS(24.72±5.39)分,Qmax(6.94±3.23)ml/s,PVR(124.90±49.80)ml;B组PSA水平为(4.97±1.99)μg/L,前列腺体积(40.41±11.44)ml,PSAD 0.123±0.034,IPSS(23.40±6.21)分,Qmax(7.75±3.52)ml/s,PVR(112.73±50.03)ml。A组PSA水平、前列腺体积、IPSS和PVR均明显高于B组(P<0.05);A组Qmax明显低于B组(P<0.05);PSAD两组间差异无统计学意义(P>0.05)。结论:组织学前列腺炎能明显增加患者的PSA水平、前列腺体积、IPSS和PVR,降低患者Qmax。但是组织学前列腺炎与PSAD无关;组织学前列腺炎是影响BPH临床进展的重要因素。     

良性前列腺增生患者合并前列腺炎与膀胱出口梗阻的相关性研究

目的 探讨BPH患者合并前列腺炎与膀胱出口梗阻(BOO)的相关性.方法 选取2008年1月至2012年1月BPH患者300例.年龄47 ～ 93岁,平均69岁.按是否合并前列腺炎分为单纯BPH组136例,PSA(4.9±8.3) μg/L,前列腺体积(41.4±18.1)ml,IPSS评分(21.9 ±7.0)分;合并前列腺炎组164例,PSA(7.0±8.5) μg/L,前列腺体积(48.7±20.7) ml,IPSS评分(27.5±5.1)分.比较两组尿动力学检查梗阻指标的差异.结果 单纯BPH组与合并前列腺炎组的Qmax分别为(8.8±4.8)ml/s和(6.3±3.7) ml/s,差异有统计学意义(P＜0.05);最大尿流率时逼尿肌压力分别为(96.7±33.0)cm H2O(1 cm H2O=0.098 kPa)和(113.2 ±39.8)cmH2O,差异有统计学意义(P＜0.05);Abrams-Griffiths(A-G)指数分别为77.7 ±31.9和93.9 ±39.6,差异有统计学意义(P＜0.05);Schafer分级值分别为3.3±1.5和4.4±1.2,差异有统计学意义(P＜0.05).Logistic回归分析显示前列腺炎症(OR=2.66,P=0.002)、前列腺体积(OR=1.37,P=0.000)、Qmax(OR =0.72,P=0.000)与Schafer分级有相关性.结论 前列腺炎会加重BPH患者BOO程度.     

膀胱内前列腺突入度对BPH患者TURP手术效果的预测评估作用

目的探讨超声测定膀胱内前列腺突入度(IPP)对前列腺增生(BPH)患者行前列腺电切(TURP)手术效果的预测评估作用。方法 136例患者因BPH入院行TURP,经腹超声测量IPP,根据IPP程度将患者分为突入组(IPP10mm)66例,对照组(IPP≤10mm)70例,比较2组术前前列腺体积(PV)、前列腺特异性抗原(PSA)差异,统计、分析2组术前和TURP术后6个月国际前列腺症状评分(IPSS)、生活质量评分(Qo L)、最大尿流率(Qmax)、残余尿量(PVR)变化;多因素分析IPP与手术效果的相关性。结果两组年龄、术前IPSS、Qo L相比无差异(P0.05),但突入组PV、PSA、Qmax、PVR与对照组相比有统计学差异(P0.05),两组TURP术后随访6个月,突入组IPSS下降、PVR减少和Qmax提高与对照组相比有统计学差异(P0.05);多因素分析显示IPP程度与TURP术后IPSS下降(OR=2.98,95%=1.05~6.89)、Qmax提高(OR=5.96,95%=2.85~9.55)相关。结论IPP程度可影响BPH患者PVR和Qmax,相对于IPP≤10mm,IPP10mm的BPH患者TURP术后IPSS下降、PVR减少和Qmax提高更加明显,IPP程度可预测BPH患者TURP术后IPSS下降、Qmax提高。     

单纯良性前列腺增生与合并慢性前列腺炎患者临床特点分析

目的:探讨单纯良性前列腺增生(BPH)与合并慢性前列腺炎(CP)患者的临床特点及其意义。方法:回顾性分析2011年10月~2013年06月我院泌尿外科行经尿道前列腺等离子电切术(TURP)治疗BPH的患者236例,按照病理诊断分为单纯BPH(35例)和合并CP(201例)两组,采用SPSS 17.0软件进行统计学分析,比较两组患者在年龄、前列腺体积、最大尿流率(Qmax)、剩余尿量(RUV)、国际前列腺症状评分(IPSS)(术前及术后3个月)、生活质量评分(QOL)、是否发生急性尿潴留(AUR)、前列腺特异性抗原(PSA)、前列腺特异性抗原密度(PSAD)等指标上是否存在差异。结果:合并CP组患者在前列腺体积、RUV、IPSS、QOL、AUR发生率等方面指标高于单纯BPH组患者,Qmax低于单纯BPH组,差异有统计学意义。而在年龄及PSA、PSAD等方面指标差异无统计学意义。手术治疗后3个月两组IPSS评分均较术前明显降低,且合并CP组较单纯组评分高,差异均有统计学意义。结论:CP可能是BPH临床进展的重要因素之一,同时也可能是导致BPH患者下尿路症状(LUTS)的重要原因之一。     

良性前列腺增生并发急性尿潴留研究进展

良性前列腺增生(BPH)是老年男性的常见病,易并发急性尿潴留(AUR).常与年龄增加、IPSS评分增高、最大尿流率(Qmax)减少、前列腺体积增大及血清PSA升高等有关.在处理上国内外无统一的方法,通常首选留置导尿术或耻骨上膀胱造瘘术,TWQC被推荐对所有前列腺增生合并急性尿潴留患者使用.α受体阻滞剂常在TWOC前服用,如果需要急诊手术宜采用微创手术为主.     

良性前列腺增生并发急性尿潴留研究进展

良性前列腺增生(BPH)是老年男性的常见病,易并发急性尿潴留(AUR).常与年龄增加、IPSS评分增高、最大尿流率(Qmax)减少、前列腺体积增大及血清PSA升高等有关.在处理上国内外无统一的方法,通常首选留置导尿术或耻骨上膀胱造瘘术,TWQC被推荐对所有前列腺增生合并急性尿潴留患者使用.α受体阻滞剂常在TWOC前服用,如果需要急诊手术宜采用微创手术为主.     

慢性前列腺炎在前列腺增生症发病与进展中的作用探讨

目的 探讨慢性前列腺炎在前列腺增生症发病与进展中的可能作用.方法 回顾性分析本院2011年5月至2014年12月期间因前列腺增生就诊患者356例,根据术后病理结果分为前列腺增生并慢性前列腺炎组及单纯性前列腺增生组,统计分析两组临床特征,包括:年龄(Age)、前列腺体积(PV)、PSA、IPSS评分、是否合并急性尿潴留(AUR).结果 前列腺增生并慢性前列腺炎121/356例(34.0％),发生急性尿潴留48/121例(39.7％);单纯前列腺增生235/356例(66.0％),发生尿潴留60/235例(25.5％).两组对比年龄差别无统计学意义(P＞0.05);但前列腺增生合并慢性前列腺炎组较单纯前列腺增生组PV、PSA、IPSS评分、尿潴留发生率均高,差别具有统计学意义(P＜0.05).结论 前列腺增生合并慢性前列腺炎通常具有更大的体积、更高的PSA及IPSS评分、更易发生尿潴留.因此,前列腺慢性炎症在前列腺增生的发病、进展中可能起作用.     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). Methods: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre-and intra-operative arterial blood gases and O₂ flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg^?1· h^?1 vs. 6.6 ± 4.8 μg · kg^?1· h^?1), a lower O₂ supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd?/procedure). Intraoperative PaCO₂ was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.