宫腔镜诊治异常子宫出血432例中长期随访结果

目的 评价宫腔镜手术治疗异常子宫出血的中长期随访结果。方法 回顾分析我院2002年1月～2005年11月经宫腔镜诊治异常子宫出血且随访〉12个月的432例临床资料,诊断良性疾患391例[子宫内膜息肉96例（22.2%）,子宫黏膜下肌瘤38例（8.8%）,子宫内膜增生过长257例（59.5%）],行息肉或肌瘤切除、子宫内膜电切术;诊断子宫内膜腺癌41例（9.5%）,均为Ⅰ期,行经腹全子宫双附件切除、选择性盆腔淋巴结清扫术。结果 手术均获成功,未发生子宫穿孔等并发症。391例良性病变中,术后随访12～57个月,平均39个月,闭经占16.1%（63/391）,月经量少（每周期〈10片卫生巾）18.9%（74/391）,月经量正常（每周期10～20片卫生巾）58.3%（228/391）,术后改善不明显占6.6%（26/391）。26例月经量仍多者术后用孕酮治疗,7例有多发子宫肌瘤,术后32～44个月行全子宫切除术,8例复查阴道彩超子宫内膜厚度〉1.5 cm,术后5～19个月第2次行宫腔镜子宫内膜切除术,继续随访18～36个月,月经量少3例,闭经5例。41例子宫内膜癌Ⅰ期术后随访26～41个月,平均38个月,均无瘤存活。结论 异常子宫出血的治疗在结合病理学检查除外恶性病变后首选宫腔镜手术,严格B超监测是提高手术疗效和手术安全的保障。     

宫腔镜电切术治疗子宫黏膜下肌瘤及子宫内膜息肉

目的 探讨采用宫腔镜电切术治疗子宫黏膜下肌瘤及子宫内膜息肉的可行性、安全性及疗效. 方法 2002年1月～2004年7月,我院采用宫腔镜电切术治疗38例子宫黏膜下肌瘤和40例子宫内膜息肉,其中经宫颈子宫肌瘤切除术 （transcervical resection of myoma,TCRM）31例,TCRM联合经宫颈子宫内膜切除术（transcervical resection of the endometium,TCRE ）7例,经宫颈子宫内膜息肉切除术（transcervical resection of polyp, TCRP）35例,TCRP联合TCRE 5例. 结果 78例均一次顺利完成手术.术中出血≥400 ml 2例,水中毒1例,无子宫穿孔及术后感染.术后1、3、6、12个月随访,术后12个月时进行手术效果评定,闭经8例 （10.3%）,点滴月经12例 （15.4%）,少量月经33例 （42.3%）,正常月经量22例（28.2%）,无改善3例（3.8%）. 结论 宫腔镜电切术治疗子宫黏膜下肌瘤及子宫内膜息肉安全性高,并发症少.     

射频与滚球或滚筒电极电凝子宫内膜去除术治疗功能失调性子宫出血的比较

目的 探讨射频子宫内膜去除术治疗功能失调性子宫出血的效果.方法 回顾性分析2011年1月～2012年1月我院异常子宫出血65例,按手术方法不同分为射频组(射频子宫内膜去除术,采用美国HOLOGIC公司子宫内膜去除系统,n=33)和电凝组(滚球或滚筒电极电凝子宫内膜去除术,采用德国诺道夫公司子宫内膜去除系统,n=32),比较2种手术方法的疗效.结果 射频组术后48 h VAS评分明显低于电凝组[(2.1±0.7)分vs.(3.8±1.2)分,t=-7.003,P=0.000].术后6个月射频组月经情况:闭经17例,点滴量月经8例,少量月经6例,正常经量2例,治疗有效率100％;电凝组:闭经16例,点滴量月经8例,少量月经7例,正常经量1例,治疗有效率100％,2组比较无统计学差异(Z=-0.057,P=0.955).术后12个月射频组月经情况:闭经15例,点滴量月经7例,少量月经7例,正常经量4例,治疗有效率100％;电凝组:闭经15例,点滴量月经6例,少量月经8例,正常经量3例,治疗有效率100％,2组比较无统计学差异(Z=-0.105,P=0.916).结论 射频子宫内膜去除术治疗无生育要求的功能失调性子宫出血安全、有效.     

204例诺舒子宫内膜去除术治疗月经过多的远期疗效

目的探讨诺舒(Nova Sure)阻抗控制子宫内膜去除系统治疗月经过多的远期疗效。方法 2011年8月～2014年3月,因月经过多药物治疗无效行诺舒子宫内膜去除术349例,其中完成4年以上随访204例,包括月经情况和手术满意度,术后闭经、点状出血、经量少或正常经量且无需再次行诺舒子宫内膜切除术或子宫切除术者为手术有效。结果 204例随访时间(63. 5±8. 1)月(52～81个月)。总有效率93. 1%(190/204),其中闭经率67. 6%(138/204)。子宫切除率6. 9%(14/204),其中8例为子宫腺肌病。手术满意度91. 2%(186/204)。结论诺舒子宫内膜去除术治疗月经过多远期疗效好,子宫切除率低。     

宫腔镜子宫内膜切除治疗子宫腺肌病临床疗效研究

目的探讨宫腔镜子宫内膜切除术（transcervical resection of endometrium,TCRE）治疗子宫腺肌病的手术指征及疗效。方法对2004年11月-2007年10月因子宫腺肌病接受TCRE的31例临床资料进行回顾性分析,比较术前后痛经缓解率、月经量、血Hb、CA125水平。结果31例TCRE手术时间（14.4±1.4）min（10-28min）,术中出血量10-50ml。术后随访24-48个月,痛经缓解有效率93.5%（29/31）,2例痛经不能缓解,且子宫进行性增大,1例行全子宫切除术,另1例服用孕三烯酮仍在随访中。1例术后11个月宫腔粘连致宫腔积血,行宫腔扩创引流积血约10ml痊愈。月经量由术前（102.0±4.7）ml减少至术后（15.6±2.1）ml（t=223.77,P=0.000）,其中闭经7例,点滴状月经18例,月经量显著减少6例。22例术后3个月内贫血纠正,血红蛋白由术前（78.6±3.6）g/L上升至（126.8±8.9）g/L（t=-27.953,P=0.000）。术后血清CA125除2例持续〉35IU/ml,其余术后3个月降至正常范围。结论TCRE治疗子宫腺肌病能有效缓解痛经症状,治疗贫血,但术前应排除盆腔子宫内膜异位症,子宫大小≤8孕周。     

诺舒治疗心脏病术后异常子宫出血15例报告

目的探讨诺舒(Nova Sure)阻抗控制子宫内膜切除系统治疗心脏病术后异常子宫出血(abnormal uterine bleeding,AUB)的临床疗效。方法 2011年6月~2013年1月采用诺舒对15例心脏病术后AUB行子宫内膜去除术,术前排除子宫内膜及宫颈恶性病变,扩张宫颈后先行宫腔镜检查,然后将诺舒阻抗控制子宫内膜切除系统的双极消融器送入宫腔,测试通过后行子宫内膜去除,再次宫腔镜检查,了解子宫内膜去除情况。记录术前后情况,并进行1、3、6个月随访,观察月经情况和并发症。结果 15例术中生命体征平稳,手术顺利。血红蛋白术前(91.33±21.38)g/L,术后6个月升高至(113.89±19.32)g/L,有统计学差异(t=5.640,P=0.000),贫血状态明显好转。1例心功能由Ⅲ级变为Ⅱ级,2例心功能由Ⅱ级变为Ⅰ级,其余患者心功能未见变化。术后1、3、6个月随访15例,治疗均有效(参照月经改善评价标准),闭经率分别为66.7%(10/15)、73.3%(11/15)、80.0%(12/15)。结论诺舒阻抗子宫内膜切除术治疗心脏病术后AUB疗效确切,安全性高。     

宫腔镜手术治疗子宫内膜息肉85例临床观察

目的探讨宫腔镜手术治疗子宫内膜息肉的临床效果。方法因子宫内膜息肉行各类宫腔镜手术85例。其中单纯息肉切除25例,息肉切除+子宫内膜切除术41例,息肉切除+浅层内膜切除术17例,息肉切除+内膜剥除术6例。随访时间3~24个月。结果57例月经紊乱者术后闭经14例,点滴出血16例,月经减少27例。34例中、重度贫血患者术后1~3个月血红蛋白恢复正常,16例痛经患者术后7例症状消失,7例缓解,2例加重,6例不孕者4例妊娠。结论宫腔镜手术治疗子宫内膜息肉月经改善满意率达94.12%。无生育要求者,息肉切除同时应行子宫内膜电切术,可避免复发,需保留生育功能者可行单纯息肉切除,如合并内膜息肉样增生可行浅层内膜切除术。绝经后患者可行单纯息肉切除术,如合并内膜息肉样增生应行子宫内膜剥除术。     

诺舒治疗异常子宫出血38例

目的探讨诺舒治疗异常子宫出血的疗效。方法 2013年1月~2016年1月,因异常子宫出血行诺舒阻抗子宫内膜去除术38例,其中合并严重内科疾病22例(57.9%)。先行宫腔镜检查,评估宫腔情况,并取子宫内膜活检,待常规病理排除子宫内膜恶性病变后行宫腔镜诺舒阻抗子宫内膜去除术,术后门诊或电话随访,观察月经、血红蛋白改善及并发症情况。术后闭经、点滴出血、少量月经、正常月经认定为临床治疗有效。结果 38例均顺利完成手术,诺舒治疗时间66~122 s,(89.5±24.5)s,术中出血均30 ml,术中术后均无严重并发症发生。二次手术率5.3%(2/38)。术后3、6、12、36个月有效率分别为100%(37/37)、100%(29/29)、100%(24/24)、100%(8/8);闭经率分别为62.2%(23/37)、69.0%(20/29)、75.0%(18/24)、87.5%(7/8);满意率为97.3%(36/37)、96.6%(28/29)、100%(24/24)、100%(8/8)。术后3个月贫血纠正率为54.1%(20/37)(1例因原发病死亡)。32例非血液系统疾病患者术前血红蛋白为(84.37±21.58)g/L,术后3个月升高至(105.21±10.43)g/L(配对t检验,t=17.092,P=0.000)。结论诺舒操作简单,安全,微创,效果好,患者满意率高,特别适用于合并严重内科疾病无法采用药物及子宫切除术的患者。     

微波子宫内膜去除术前刮宫内膜预处理的临床及实验研究

目的探讨刮宫子宫内膜预处理在微波子宫内膜去除术(microwave endometrial ablation,MEA)中的应用价值。方法2001年6月～2005年6月对126例子宫异常出血行MEA之前刮宫预处理子宫内膜。同期12例因异常子宫出血行子宫切除术,先刮宫处理子宫内膜后行MEA,再切除子宫,取材进行组织病理学和酶组织化学检测子宫壁组织热损伤深度。结果126例术中无并发症发生,术后闭经78例(61.9%),正常月经46例(36.5%),少量不规则阴道出血2例(1.6%),治疗满意率98.4%(126/128)。术后10例子宫内膜炎,2例宫腔积血,2例术后因痛经行子宫切除术。126例术后随访6～28个月,(22±4)月,其中116例随访到术后2年以上,疗效稳定。MEA作用后子宫底的损伤深度为4.2～4.9mm,前壁的损伤深度为4.1～5.7mm,后壁的损伤深度为4.7～6.6mm,宫角的损伤深度为4.0～4.7mm。结论MEA术前全面刮宫预处理内膜,可以充分完整破坏子宫内膜全层,临床疗效好、满意率高,不增加组织过度损伤的危险。     

子宫镜子宫内膜切除术加点状烧灼电凝术治疗功血78例

目的 :探讨子宫镜子宫内膜切除术加点状烧灼电凝术治疗功血的效果及其安全性。方法 :选择有手术指征的功能失调性子宫出血患者 78例 ,采用子宫镜电切子宫内膜后对切面实施点状烧灼电凝术 ,观察其月经改善情况。结果 :术后随访 3～ 12个月 ,2 3例无月经 ;38例每月仅有点滴状月经 ;17例表现月经明显减少。月经改善满意。结论 :子宫镜子宫内膜切除术加点状烧灼电凝术治疗功血是较理想的方法 ,可提高手术成功率 ,减少术后并发症     

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.