经胫后肌腱鞘建立踝关节镜后方共轴入路的解剖学研究

目的进行经胫后肌腱鞘建立踝关节镜后方共轴入路的解剖学研究。方法在20具踝关节标本上以克氏针建立共轴入路,测量克氏针与后方重要神经、肌腱、血管的距离。在5具新鲜踝关节标本上,以2.7mm30°关节镜建立共轴入路,镜下观察并测量以上距离。结果内侧关节镜入路的体表标志为内踝尖上方5～12mm(平均8mm),外侧入路的体表标志为外踝尖上方8～24mm(平均15mm)。经过胫后肌腱鞘、腓骨后缘建立共轴入路,不但把关节镜、镜下器械与后方重要神经血管结构与后关节囊隔开,同时增加了它们之间的距离。经过此入路可以观察到距骨关节面的后1/2～2/3、外侧踝关节间隙、内侧踝关节间隙、后关节囊、胫距关节间隙,能清楚地看到踝穴与距骨的动态关系。可以通过后外侧入路进入手术器械进行镜下手术。结论经胫后肌腱鞘的踝关节镜后方共轴入路,具有操作简便、安全性好、镜下视野清楚、操作空间大的优点。     

髋关节后外侧入路中软组织松解对髋关节张力的影响

目的 研究髋关节后外侧入路中不同软组织结构松解对髋关节伸直位张力的影响.方法 新鲜冰冻尸体5具10个髋关节,均采用髋关节后外侧入路显露.在骨盆髂前上棘位置垂直于床面固定一枚克氏针,在股骨干侧方固定另一枚克氏针.测量不同软组织松解操作前后两枚克氏针之间的位移变化.结果 单纯进行牵引、外旋肌切断、后关节囊切开和臀大肌止点切断等操作前后,位移没有明显变化.股骨头切除、阔筋膜髂胫束切断、关节囊全部切除和髂腰肌腱切断后,两枚克氏针距离平均延长1.5mm(1～3mm)、8.0mm(2～19mm)、5.5mm(1～13mm)、1.8mm(1～3mm).同时切断关节囊和阔筋膜髂胫束前后位移变化最大,测量距离平均延长13.5 mm(11～20mm).结论 前关节囊、阔筋膜髂胫束和髂腰肌腱的松解可以降低髋关节伸直位的软组织张力,其中前关节囊和阔筋膜髂胫束的作用最大.髋关节周围的软组织对张力的影响相互制约,单一松解其中一种结构不能获得满意的松解效果.阔筋膜和髂胫束的紧张度可以帮助判断肢体的延长情况.     

放置内踝螺钉的安全区

背景：骨折固定时放置金属物会使软组织处于损伤或相接触的危险之中。突起的金属物是踝关节骨折内固定术后引起疼痛的常见原因。本研究设计的目的是评价放置内踝螺钉后胫后肌腱损伤或相接触的危险度。方法：使用10具不配对的在膝关节处离断的尸体肢体，通过切开皮肤暴露内踝。在X线透视和直视深筋膜情况下，将3根克氏针自内踝尖置入并从内踝关节面平行进入，第一根针入点在前丘部的中心，另外两根针平行置入并间隔前一根后面5mm，克氏针退出后，在克氏针的轨道上拧入4．0mm螺钉。切开标本以观察胫后肌腱损伤情况和螺钉与胫后肌腱的接近程度。内踝按照解剖标志分成3个区：1区是前丘部，2区是丘间沟，3区是后丘部。结果：置于1区（前丘部）的螺钉在所有标本上不与胫后肌腱接触。置于2区（丘间沟）的螺钉平均距离胫后肌腱2mm，置于3区（后丘部）的螺钉在所有标本均会引起肌腱接触，并有5个标本引起肌腱损伤。结论：在前丘部之后置入的螺钉会使胫后肌腱有损伤或相接触的危险。临床实用性：基于这三个结果，我们建议在前丘部后面置入内踝螺钉时，应直视胫后肌腱。     

腰椎极外侧微创手术的解剖学研究及其临床价值

目的明确国人腰椎侧方解剖层次以及重要组织结构的毗邻关系,评价腰椎极外侧椎体间融合术(XLIF)的可行性和安全性。方法选取10具新鲜尸体标本和2具福尔马林固定的尸体标本,取侧卧位(XLIF体位),在C臂机透视下模拟XLIF手术入路,将克氏针打入L2~5椎间盘中央,沿克氏针方向逐层解剖。测量腰椎侧面正中线腰神经与腰椎前缘交感干之间的距离、腰椎侧面正中线相邻腰节段血管之间的距离以及腰椎各椎体中线位置前后缘距离。结果 XLIF的手术入路相对安全,入路周围未见神经、血管等重要结构。在腰椎侧方,腰节段血管、交感干和腰神经之间存在着一个相对无血管、神经的"安全范围",其大小约为29 mm×30 mm;交感干至腰神经的垂直距离左右两侧差异无统计学意义(P0.05);椎体侧面相邻节段血管的距离左右侧差异无统计学意义(P0.05)。腰椎侧面XLIF微创手术操作的安全范围:L_(2 ~ 3):27 mm×30 mm(修正值0.72 mm×0.65 mm),L_(3 ~ 4):30 mm×32 mm(修正值0.76 mm×0.71 mm),L_(4~5):29 mm×32 mm(修正值0.76 mm×0.69 mm)。结论在XLIF入路周围,腰椎侧方"安全范围"较大,在该范围内进行XLIF手术操作安全性较高。     

踝内侧韧带损伤

<正>踝关节内侧韧带又称三角韧带或三角韧带复合部,分为浅、深两部分,浅部为屈肌支持带,从内踝前下方约25~31 mm,向后下斜向跟骨内下方,抵止部宽32~50 mm,呈梯形,途经并覆盖从前到后宽为胫后肌腱、趾长屈肌腱和?母长屈肌腱,形成腱间隔,融于各肌腱外被的滑液鞘上,分隔并约束三腱和胫后动、静脉与胫后神经,维持踝内侧各部组织不会前后移位和叠压[1](图1)。深部是维持踝关节内侧稳定     

正常踝关节及常见病变的影像学诊断

踝关节（ankle joint）是全身第三大持重关节,由胫骨下端和内、外踝构成的踝穴及距骨体共同组成榫眼状关节。踝关节周围有坚强的韧带固定,有趾、拇屈、伸肌腱、腱鞘及胫前后动脉环抱（包绕）。踝关节与距跟舟关节互有韧带连接,互相协调活动,因此,踝关节是运动创伤、肌腱、腱鞘磨损、关节退变、骨折脱位和感染病变的好发部位。     

输液器管结合克氏针引导手指屈肌腱断裂近端回缩的临床应用

目的 探讨手指屈肌腱断裂致近端回缩时应用无菌输液器管结合克氏针引导方法的应用效果.方法 2019年1月-2020年12月对43例50指屈肌腱断裂,且肌腱近端回缩较远距离的患者,根据回缩距离大致判断,在肌腱断裂区域以近的一个或多个区域处作横行小切口,找到近端肌腱断端并予以抽出,通过克氏针套入无菌输液器管引导方法,由原伤口...     

鞘管区屈指肌腱断伤的修复

我科用改进的Bunell氏缝合方法缝合屈肌腱,同时修复腱鞘,并配合早期功能练习,基本上解决了肌腱一期修复后出现的粘连问题。将断裂的肌腱两端找到,用Bunell氏法缝合指深屈肌腱,但缝线在吻合口的远端保留,沿腱鞘内输送到深肌腱止点处穿出,     

踝关节跖屈、背屈运动的研究

目的:研究Pilon骨折在治疗中评价踝关节功能,诊断下胫腓联合分离、踝关节前后脱位的影像学依据。方法:35例正常成人,男21例(42踝),女14例(28踝);年龄21-48岁,平均31.6岁。踝关节常规摄正、侧位X线片;测量踝关节主动跖屈、背屈运动的最大角度,下胫腓联合间隙的宽度,胫骨外侧与腓骨的胫侧重叠影宽度,距骨踝关节面几何中心偏离胫骨中轴线的距离。结果:跖屈主动运动的最大角度,男(40.8°±3.1°),女(43.9°±4.8°);背屈主动运动的最大角度,男(27.6°±5.2°),女(26.5°±6.1°)。下胫腓联合间隙的宽度平均(3.2±0.5)mm。胫骨外侧与腓骨的胫侧重叠影宽度平均(6.9±2.2)mm。踝关节的跖屈下胫腓联合有逐渐变窄的变化,平均2 mm。距骨中心中轴距:男性跖屈最大值2.4 mm、背屈2.5 mm,女性跖屈最大值1.9 mm、背屈2.0 mm,最小值均为0 mm。结论:男女之间无论是背屈还是跖屈均无显著性差异(P>0.05),即踝关节在运动灵活性上无性别差异。踝关节主动跖屈、背屈运动的最大角度为Pilon骨折术中踝关节功能评定提供参考,下胫腓联合宽度>3.5 mm为下胫腓联合分离,胫骨外侧与腓骨的胫侧重叠影宽度<5.5 mm时,有下胫腓联合分离的可能。距骨中心中轴距>2 mm提示踝关节前后脱位。Pilon骨折在恢复骨折解剖复位的同时要注意这两个指标,对于恢复踝关节的侧方稳定、前后方向稳定有重要意义,能指导踝关节骨折治疗和康复。     

胫骨远端关节囊外克氏针的置入

胫骨远端关节骨折行外固定时常需要作环关节置入克氏针 ,关节内置针可将针道感染引入关节内。作者研究了12具新鲜冻干尸体和 3例志愿者正常踝关节。使用钆溶液加压注入关节腔 ,使关节囊膨胀 ,再行高分辨率MRI检查。测量软骨下骨至关节囊滑膜反折处的垂直距离。另一组对MRI检查不了解的人进行尸体解剖 ,直接测量软骨下骨至关节囊滑膜反折处的垂直距离。结果显示 :前外侧关节囊达最近端 (平均9 3mm ,最远 12 2mm ) ,前内侧稍短(平均 3 3mm ,最远 5 5mm) ,后内侧及后外侧均 <2mm。下胫腓关节与胫距关节交通 ,向近端延伸最大距离为 2 0 6m…     

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.