严重烧伤大鼠精氨酸治疗的实验研究

为探讨精氨酸在严重烧伤治疗中的意义，采用大鼠３０％ＴＢＳＡⅢ度烧伤模型，观察并分析了严重烧伤大鼠外周血Ｔｈ／Ｔｓ比值的变化及精氨酸对该变化的调节作用和对大鼠存活率的影响。结果表明：①严重烧伤后第３天起即有Ｔｈ／Ｔｓ比值的下降，第１０天下降最为明显。②精氨酸能防止烧伤后Ｔｈ／Ｔｓ比值下降，这种作用在伤后第５天起就比较显著。③精氨酸能提高伤后动物的存活率。提示严重烧伤后补充精氨酸是增强机体免疫力和抗感染能力，提高存活率的有效的治疗手段。     

严重烧伤大鼠精氨酸治疗的实验研究

为探讨精氨酸在严重烧伤治疗中的意义，采用大鼠３０％ＴＢＳＡⅢ度烧伤模型，观察并分析了严重烧伤大鼠外周血Ｔｈ／Ｔｓ比值的变化及精氨酸对该变化的调节作用和对大鼠存活率的影响，结果表明：（１）严重烧伤后第３天起即有Ｔｈ／Ｔｓ比值的下降，第１０天下降最为明显；（２）精氨酸能防止烧伤后Ｔｈ／Ｔｈ比值下降，这种作用在伤后第５天起就比较显著，（３）精氨酸能提高后动物的存活率，提示严重烧伤后补充精氨酸是增强机体免     

烧伤创面应用硝酸铈的实验研究

为探讨硝酸铈的应用价值,比较了烧伤创面行硝酸铈湿敷和早期切痂对严重烧伤后大鼠存活率和 T 细胞亚群变化的影响。结果表明:大鼠30%TBSA Ⅲ度烧伤后第14天,存活率低,外周血 Th/Ts 比值显著降低,而烧伤后早期手术切痂或创面硝酸铈湿敷则能明显提高大鼠存活率和外周血 Th/Ts比值。认为,早期切痂或创面硝酸铈湿敷均有防止烧伤后 T 细胞 Th/Ts 比值下降和提高存活率的作用。烧伤休克期,如不具备早期手术切痂的条件,用硝酸铈湿敷是一种简便有效的治疗方法。     

烧伤创面应用硝酸铈的实验研究

为探讨硝酸铈的应用价值，比较了烧伤创面行硝酸铈湿敷和早期切痂对严重烧伤后大鼠存活率和Ｔ细胞亚群变化的影响。结果表明：大鼠３０％ＴＢＳＡⅢ度烧伤后第１４天，存活率低，外周血Ｔｈ／Ｔｓ比值显著降低，而烧伤后早期手术切痂或创面硝酸铈湿敷则能明显提高大鼠存活率和外周血Ｔｈ／Ｔｓ比值。认为，早期切痂或创面硝酸铈湿敷均有防止烧伤后Ｔ细胞Ｔｈ／Ｔｓ比值下降和提高存活率的作用。烧伤休克期，如不具备早期手术切痂的条件，用硝酸铈湿敷是一种简便有效的治疗方法。     

烧伤创面应用硝酸铈的实验研究

为探讨硝酸铈的应用价值，比较了烧伤创面硝酸铈湿敷和早期切痂对严重烧伤后大鼠存活率和Ｔ细胞亚群变化的影响。结果表明：大鼠３０％ＴＢＳＡⅢ度烧伤后第１４天，存活率低，外周血Ｔｈ／Ｔｓ比值显著降低，而烧伤后早期手术切痂或创面硝酸铈湿敷则能明显提高和大鼠存活率和外周血Ｔｈ／Ｔｓ比值。     

烧伤后大鼠不同骨骼肌凋亡相关蛋白的转录表达变化

目的:通过检测烧伤大鼠不同骨骼肌组织中凋亡相关蛋白的转录变化,探讨细胞凋亡对烧伤后骨骼肌高消耗的影响机制。方法:180只大鼠随机分为5组,通过建立大鼠烧伤模型,分别在烧伤后6h、1天、3天、7天及14天切取大鼠伸趾长肌和比目鱼肌,采用RT-PCR方法测定骨骼肌组织Akt、Bcl-2、Caspase-3的转录表达。结果:伸趾长肌Akt转录表达在伤后前期变化不明显,在第14天显著下降;Bcl-2转录表达在初期轻度上升,在后期下降;Caspase-3转录表达在伤后第7天和第14天显著增高。比目鱼肌Akt转录表达在烧伤后6h、1天、4天、7天无明显变化,在烧伤后14天显著下降;Bcl-2转录表达在烧伤后6h、1天和4天呈逐渐表达显著增强趋势,而后逐渐下降,;Caspase-3转录表达各个时间点无显著变化。结论:在严重烧伤大鼠,快白肌组织凋亡明显,而且随着病程的延长,凋亡越显著;慢红肌组织凋亡不明显,尽管随着病程的延续,有上升的趋势。     

细胞免疫与烧伤创面愈合的实验研究

为探讨免疫低下对烧伤创面愈合的影响,设计了用低剂量钴源照射的方法建立的免疫抑制模型,并在该模型的基础上观察了免疫抑制大鼠Ⅱ度烧伤创面愈合的情况。结果表明:①大鼠接受2Gy~(60)Co 照射后20天内,Th/Ts 比值和 T 细胞肿瘤花环率持续下降。照射后皮肤组织 DNA 含量及细胞周期均无明显改变。②免疫抑制大鼠胶原修复能力下降,创面愈合百分率低于正常大鼠。由此证实了免疫功能低下对创面愈合的抑制作用。     

不同剂量L-精氨酸对严重烧伤患者辅助性T淋巴细胞型细胞因子的影响

目的 了解不同剂量L-精氨酸对严重烧伤患者血清辅助性T淋巴细胞1(Th1)/Th2型细胞因子水平的影响.方法 选择笔者单位收治的伤后20 h内入院、烧伤总面积为50%～80%TBSA的患者29例,按随机数字表法分为对照组[10例,经鼻肠管给予葡萄糖盐水500 mL(含50 g/L葡萄糖及9 g/L氯化钠,下同)]、L-精氨酸200 mg组(10例,经鼻肠管给予L-精氨酸200 mg/kg+葡萄糖盐水500 mL)、L-精氨酸400 mg组(9例,经鼻肠管给予L-精氨酸400 mg/kg+葡萄糖盐水500mL).于伤后1 d(行肠内营养前)及3、5、7 d,取各组患者空腹静脉血,用放射免疫法及酶联免疫吸附测定法检测血清Th1型细胞因子TNF-α、IL-1β和Th2型细胞因子TGF-β_1、IL-4含量.结果 各组患者血清TNF-α及IL-1β含量伤后均呈快速上升趋势,L-精氨酸200 mg组血清TNF-α及IL-1β含量伤后5 d达高峰[(318±57)ng/mL、(218±47)pg/mL],但仍显著低于同时相点对照组[(389±34)ng/mL、(272±40)pg/mL,P<0.05],伤后7 d此2种细胞因子含量下降;L-精氨酸400 mg组各时相点血清TNF-α及IL-1β含量与对照组相近(P>0.05).各组患者血清TGF-β_1及IL-4含量伤后呈较缓慢上升趋势;伤后5 d,L-精氨酸200 mg组血清TGF-β_1含量为(110±16)pg/mL,显著高于对照组[(83±20)pg/mL,P<0.05],L-精氨酸400mg组各时相点血清TGF-β_1含量与对照组相近(P>0.05).结论 在严重烧伤患者感染期,相对于400 mg/kg的用量,200 mg/kg的L-精氨酸通过调节血清Th1/Th2型细胞因子释放,能更有效地保持两者之间的比例,从而产生更好的免疫调理作用.     

盐酸精氨酸和醋酸精氨酸对烧伤家兔免疫功能及酸碱平衡影响的对比研究

目的观察盐酸精氨酸与醋酸精氨酸对严重烧伤家兔机体免疫功能和酸碱平衡的影响。方法选用110只大耳白兔,取其中8只作为正常对照组;余下102只造成30%TBSAⅢ度烧伤后,根据灌喂不同种类及不同剂量的药物分为烧伤对照组,0.3、0.6、1.2、2.4g/kg盐酸精氨酸组和同种剂量的醋酸精氨酸组,每组兔数10~14只。烧伤对照组家兔伤后仅腹腔注射林格液抗休克,不灌喂药物;其他各组除同烧伤对照组行抗休克处理外,还分别按上述剂量灌喂药物,2次/d,连续7d。观察各组家兔免疫功能、血气分析、Cl-代谢及死亡率的变化。结果烧伤对照组家兔免疫功能紊乱,变化趋势呈先高后低,伤后7d淋巴细胞转化率、CD4/CD8比值、白细胞吞噬率和白细胞趋化指数均明显低于正常对照组(P<0.01);1.2、2.4g/kg盐酸精氨酸、醋酸精氨酸组伤后7d前述4项指标均明显高于烧伤对照组(P<0.05或0.01)。伤后7d,2.4g/kg盐酸精氨酸组pH值、剩余碱、缓冲碱、HCO3-浓度均较同剂量醋酸精氨酸组明显降低(P<0.05或0.01);前组各项指标均明显低于正常对照组(P<0.05或0.01),后组与正常对照组比较变化不明显。2.4g/kg盐酸精氨酸组伤后5、7d血浆Cl-含量明显高于同剂量醋酸精氨酸组和正常对照组(P<0.05或0.01)。0.3、0.6、1.2g/kg盐酸精氨酸、醋酸精氨酸组家兔死亡率明显低于烧伤对照组(P<0.05或0.01),而2.4g/kg醋酸精氨酸、盐酸精氨酸组死亡率高于烧伤对照组及其他剂量组(P<0.05)。结论家兔严重烧伤后免疫功能下降,盐酸精氨酸和醋酸精氨酸都能有效提高机体免疫功能,疗效相当,醋酸精氨酸的安全性明显优于盐酸精氨酸;两种精氨酸的剂量都不宜过大,否则会致死亡率上升。     

增加精氨酸摄入量对烧伤患者血浆氨基酸谱的影响

目的观察摄入大剂量精氨酸对烧伤患者血浆氨基酸谱的影响。方法10例烧伤患者随机分为烧伤试验组和烧伤对照组(各5例),前者给予占总热量2%的盐酸精氨酸静脉注射液,后者给予占总热量2%的14复合氨基酸静脉注射液。两组患者其他营养成分的摄入量均相同。营养方案自伤后第3天起执行,给予总量的1/4;伤后4、5d给予总量的1/2;伤后6~21d给予全量。在两组患者伤后3d(方案实施前)及7、14、21、28d清晨取其静脉血标本,检测血浆氨基酸谱水平。以10名健康志愿献血者的血浆氨基酸谱水平作为正常参考值。结果伤后3d,两组患者血浆瓜氨酸水平显著低于正常参考值(P<0.05),而鸟氨酸和精氨酸水平与正常参考值比较差异无统计学意义(P>0.05)。烧伤对照组伤后3d后精氨酸、瓜氨酸和鸟氨酸水平呈现下降趋势。而烧伤试验组伤后14、21、28d血浆精氨酸水平分别为(280±121)、(223±106)、(110±44)μmol/L,与同期烧伤对照组(124±21)、(59±15)、(50±26)μmol/L相比明显偏高;伤后21d瓜氨酸和鸟氨酸水平分别为(30±5)、(162±44)μmol/L,明显高于同期烧伤对照组(8±7)、(66±4)μmol/L(P<0.05或0.01)。两组患者伤后血浆其他氨基酸水平差异均无统计学意义(P>0.05)。结论机体烧伤后血浆瓜氨酸转化为精氨酸的过程加速。增加外源性精氨酸摄入量可显著提高血浆精氨酸、鸟氨酸、瓜氨酸水平,但对其他氨基酸水平无明显影响,这一药理作用可能是通过加速鸟氨酸循环实现的。     

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.