国人寰椎定量解剖研究及螺钉置入的安全性探讨

目的:观察和测量国人寰椎以获取形态学参数,为临床治疗提供科学证据,减少相关手术并发症。方法:用电子游标卡尺和量角器测量48套正常成年人寰椎新鲜标本的相关参数,包括寰椎前弓宽度(AW)、寰椎前弓与侧块相连处厚度(AD)、后弓椎动脉沟最窄处骨内的高度(ITG)、后弓椎动脉沟最窄处外缘的高度(OTG)、侧块中点高度(MHL)和侧块宽度(LW)、寰椎侧块外倾角(α),并进行统计学分析。结果:AW平均为(20.45±1.53)mm;AD男性左侧平均为(3.91±1.32)mm,右侧平均为(4.11±1.42)mm,女性左侧平均为(3.72±1.61)mm,右侧平均为(3.82±1.53)mm;ITG男性左侧平均为(2.46±1.57)mm,右侧平均为(2.41±1.65)mm,女性左侧平均为(2.36±1.57)mm,右侧平均为(2.32±1.65)mm;OTG男性左侧平均为(4.76±2.26)mm,右侧平均为(4.64±1.70)mm,女性左侧平均为(4.55±2.26)mm,右侧平均为(4.53±1.30)mm;MHL平均为13.68mm;LW平均为12.98mm;α平均为25°。结论:手术时必须考虑到个体、性别、左右差异。术中禁忌盲目操作以免造成椎动脉、神经根及脊髓损伤。由于寰椎椎弓根螺钉和寰椎侧块螺钉进钉点不同,使得寰椎椎弓根螺钉的长度较寰椎侧块螺钉要长。     

寰椎椎弓根显露置钉技术的影像学测量研究

目的 :利用CT三维重建对椎动脉沟后弓高度4 mm的寰椎进行置钉通道相关参数测量,探讨椎弓根显露置钉技术的意义。方法:回顾性分析2015年4月至2015年6月行颈椎CT三维重建检查且排除上颈椎畸形、手术的患者90例,其中单侧或双侧椎动脉沟后弓高度4 mm的51例,共84侧。利用其图像数据行寰椎三维数字化重建,并分别测量置钉通道相关数据。结果:51例患者中,椎动脉沟处后弓最低高度为(3.28±0.51)mm,侧块高度、宽度、与后弓移行处高度均可容纳3.5 mm直径螺钉置入。0°~15°(0°、5°、10°、15°)理想椎弓根螺钉钉道长度依次为(27.36±1.81)、(27.01±1.68)、(27.07±1.75)、(27.48±1.72)mm,椎弓根显露置钉技术钉道长度依次为(23.44±1.79)、(23.87±1.84)、(24.58±1.89)、(25.56±2.01)mm,侧块螺钉钉道长度为(20.78±2.05)mm。螺钉通道5个截面的CT值均值分别为椎弓根螺钉(701.89±141.48)HU、侧块螺钉(599.11±137.33)HU。0°~15°理想椎弓根螺钉通道长度之间差异无统计学意义(P0.05),0°~15°椎弓根显露置钉法钉道长度随内倾角增加而增长(P0.05),且均比侧块螺钉钉道长(P0.05),椎弓根螺钉通道穿过骨质CT值均值高于侧块螺钉通道(P0.01)。结论:利用椎弓根显露置钉技术可完成椎动脉沟处后弓高度4 mm的寰椎置钉,且钉道长度损失不多,穿行骨量较大,预期把持力良好。     

数字化三维重建模拟后路枕骨髁螺钉置钉

目的:利用数字化三维重建技术测量枕骨髁螺钉的最佳置钉参数,探讨后路枕骨髁螺钉置入的安全性及各置钉参数间的相关性。方法:选取50例枕颈部形态正常者的上颈椎螺旋CT扫描图像,男25例,女25例,年龄25~60岁(38.5±7.6岁)。排除骨折脱位、感染、肿瘤、畸形及退行性变,将数据导入Mimics软件,对枕骨及寰椎进行三维CT重建,模拟置入直径3.5mm的枕骨髁螺钉,测量枕骨髁长、宽、高、进钉点至枕骨内侧缘和颅底部的距离,并通过3-matic软件测量枕骨髁螺钉进钉长度、头倾角、内倾角及与枕骨切线间的切线角,比较枕骨髁解剖学参数与螺钉置钉参数间的差异。结果:共模拟置入100枚枕骨髁螺钉,三维模型大体观察均无舌下神经管、寰枕关节面和枕骨髁内外侧壁的损伤。男、女枕骨髁解剖学参数及螺钉进钉点参数、置钉后枕骨髁螺钉置钉参数左右两侧比较均无统计学差异(P0.05)。男性枕骨髁解剖学长、宽、高、进钉点距枕髁内侧缘水平距离及距颅底垂直距离分别为22.00±1.67mm、11.27±1.21mm、10.72±1.13mm、5.37±0.10mm及2.95±0.47mm,女性分别为21.07±1.43mm、10.64±0.81mm、9.62±0.95mm、5.05±0.10mm及3.04±0.48mm,女性枕骨髁长、宽、高及进钉点距枕髁内侧缘水平距离均显著性小于男性(P0.05),进钉点距颅底垂直距离与男性无统计学差异(P0.05);置钉后男性头倾角、颅底切线角、内倾角及进钉长度分别为3.90°±2.01°、12.45°±4.73°、28.15°±4.53°、22.47±1.48mm,女性分别4.19°±2.01°、11.25°±4.61°、30.00°±4.70°、21.59±1.62mm,女性进钉长度较男性短(P0.05),头倾角、颅底切线角及内倾角男女性无统计学差异(P0.05)。头倾角与切线角间存在正相关性(r=0.519,P0.05),与其余置钉参数间无相关性(P0.05)。结论 :国人女性枕骨髁解剖学参数与男性存在差异,枕骨髁三维重建下模拟螺钉置入显示男女性枕骨髁均可安全容纳螺钉置入固定,理论上切线角可结合进钉点及内倾角指导枕骨髁螺钉的安全置入。     

枢椎椎弓根骨折半螺纹螺钉固定长度的影像学研究

 目的影像学测量枢椎椎弓根不同部位骨折后路半螺纹螺钉的固定长度。方法收集2007年6月至2013年6月收治非Hangman骨折致寰枢椎损伤汉族患者的影像学资料,枢椎椎体及关节突间部（椎弓根）骨折者均以排除,共160例患者资料纳入研究,男120例,女40例;年龄18~72岁,平均41.4岁。在ADW 4.4工作站行CT三维重建,选取枢椎椎弓根钉道设计图像,以Ebraheim法确定枢椎进钉点,测量自进钉点经枢椎椎弓根最狭窄部位中点至枢椎体前方皮质骨后缘的距离（半螺纹螺钉长度）;模拟临床常见的三种枢椎椎弓根骨折（经椎体后壁骨折、经峡部骨折、经椎板前缘骨折）的骨折线,分别测量自进钉点至骨折线的距离（螺杆长度)和自骨折线至枢椎椎体前方皮质骨后缘的距离（螺纹长度）。观察身高、性别、不同部位骨折半螺纹螺钉长度、螺杆长度及螺纹长度的规律。结果男性身高162~177 cm,平均（167±7.9） cm;女性身高151~167 cm,平均（156±6.6） cm。枢椎椎弓根骨折后所需半螺纹螺钉长度男性平均（28.8±3.2）mm;女性（24.7±2.6） mm,男性半螺纹螺钉较女性长（t=6.50,P< 0.05）。患者身高与半螺纹螺钉长度呈正相关（r=0.667,P<0.01）。骨折线越靠近枢椎体后壁半螺纹螺钉的螺杆越长、螺纹越短,经椎体后壁骨折组螺杆长度男性平均17 mm、女性15 mm,螺纹长度男性平均12 mm、女性10 mm;经峡部骨折组螺杆长度男性平均14 mm、女性13 mm,螺纹长度男性平均15 mm、女性12 mm;经椎板前缘骨折组螺杆长度男性平均10 mm、女性9 mm,螺纹长度男性平均18 mm、女性15 mm。结论枢椎椎弓根骨折后路手术中使用的半螺纹螺钉长度与身高、性别有关。椎弓根骨折部位不同,所需半螺纹螺钉的螺杆、螺纹长度也不相同。     

经皮穿刺内固定治疗上颈椎骨折与不稳

目的:探讨经皮穿刺内固定治疗上颈椎骨折与不稳的方法与效果。方法:对40例20～45岁正常人C1、C2行CT扫描,测量C1、C2侧块的标准角、安全角、椎动脉内壁至标准角距离、齿状突基底冠状径、矢状径、齿状突长度、枢椎总高度及齿状突轴心线与C3椎体前缘夹角等相关数据。采用自行设计的器械行经皮穿刺内固定治疗上颈椎骨折与不稳47例。其中齿状突骨折21例,Jefferson骨折7例,C1前弓骨折4例,寰枢椎脱位及本脱位15例,分析其治疗结果。结果:C1、C2侧块在正位投照上的标准角右侧为(24.0±3.7)°,左侧为(23.8±1.8)°。安全角右侧为15.2°～30.3°,左侧为14.8°～32.1°。椎动脉内壁至寰椎侧块上下缘中点连线的距离右侧为(5.6±2.2)mm,左侧为(5.8±1.9)mm。侧位投照像上,标准角为(24.1±18)°,安全角为12.6°～26.8°。齿状突基底冠状径为(8.8±1.2)mm,矢状径为(10.9±1.0)mm,齿状突长度为(14.2±1.2)mm,枢椎总高度为(38.2±1.8)mm,齿状突轴心线与C3椎体前缘夹角为(23.1±1.4)°。全组病例平均随访18个月,未发现脱钉、弯钉及断钉。齿状突螺钉固定17例,除2例齿状突骨折未愈合外。余均获骨性愈合。C1、C2侧块螺钉固定治疗者中26例颈椎旋转活动比正常减少40°,伸屈正常。4例颈部强直感,未恢复原有工作。结论:经皮穿刺颈     

经骶1-2侧块螺钉固定的解剖学研究

目的:研究经骶1-2侧块螺钉固定的解剖学特征,探讨该技术的可行性。方法:对27例(男14例,女13例)骶尾椎CT资料进行三维重建,利用Advantage Workstation 4.2后处理工作站软件测量以第2骶后孔上缘上方5mm为进钉点的经骶1-2侧块螺钉(the sacral 1-2 translateral mass screw,STMS)固定的相关解剖学数据,包括:外倾角(从进钉点到骶骨翼最前上角的连线在水平面上与骶骨正中线的夹角)、上倾角(从进钉点到骶骨翼最前上角的连线与S1椎体上终板在矢状位上的夹角)及钉道长度(从进钉点到骶骨翼最前上角的距离)。对不同性别间及左右侧别间进行统计学分析。在三维图形上观察钉道轨迹,并根据上述测量数据在15例骶骨标本上置入STMS,观察螺钉与椎管、骶前后孔及耳状面关系。结果:平均外倾角男性为30.39°±5.01°,女性为35.81°±4.45°,男性左侧为31.14°±5.25°,右侧为29.64°±4.86°;女性左侧为36.46°±4.94°,右侧为35.15°±4.00°,性别间的差异有显著性意义(P<0.05),男性及女性的左右侧比较,差异无显著性意义(P>0.05)。平均上倾角男性为26.71°±16.50°,女性为19.48°±9.09°;左侧为23.67°±14.81°,右侧为22.22°±12.89°;平均钉道长度男性为54.48±3.01mm,女性为53.02±2.89mm;左侧为53.99±2.78mm,右侧为53.56±3.28mm。上倾角及钉道长度在性别及侧别间均无显著性差异(P>0.05)。在三维重建图形上观察钉道位于侧块内,置钉实验中STMS均未穿透至椎管、骶前后孔及耳状面。结论:在S1椎弓根螺钉不能提供有效固定的情况下,术前行CT三维测量以获得进钉参数,经骶1-2侧块螺钉固定技术可以安全的应用于骶骨固定。     

寰椎后弓-横突髓腔钉道的影像解剖学参数及其临床意义

目的通过影像归档和通信系统(PACS)测量成人寰椎后弓-横突髓腔钉道的解剖学参数,并结合临床病例探讨其临床意义。方法选择2016年1月—2017年6月本院PACS中18~70岁患者的颈椎三维CT数据,共200例,男女各100例,年龄(54.95±11.93)岁。选取寰椎后弓-横突髓腔最长轴切面为测量截面,利用PACS测量软件手工测量该截面入钉点与后结节距离、入钉角度与矢状面夹角、入钉角度与横截面夹角、钉道长度、椎动脉沟狭窄处髓腔高度和入钉点髓腔最大高度等解剖学参数,所得数据纳入统计学分析。结合临床病例探讨其可行性。结果入钉点与后结节距离为(7.45±1.75)mm,入钉角度与矢状面夹角为54.26°±6.06°,入钉角度与横截面夹角为9.15°±3.40°、钉道长度为(18.55±3.75)mm,椎动脉沟狭窄处髓腔高度为(2.09±0.81)mm,入钉点髓腔最大高度为(4.93±0.37)mm。男性寰椎后弓-横突髓腔钉道在入钉点与后结节距离、钉道长度、椎动脉沟狭窄处髓腔高度和入钉点髓腔最大高度均大于女性,差异有统计学意义(P0.05),不同性别之间入钉角度与矢状面夹角和入钉角度与横截面夹角差异无统计学意义(P0.05)。经有限病例初步证实该置钉方式具有可行性。结论寰椎后弓-横突髓腔的解剖学特点能够满足置钉要求,在常规寰椎椎弓根螺钉进钉点狭小无法置钉或钉道破裂置钉失败时,可以当做替代置钉钉道方案。     

与国人舟骨形态学相关的舟骨螺钉内固定应用

目的 探讨与国人舟骨形态学相关的舟骨螺钉内固定应用.方法 测量27例成人舟骨标本的舟骨长轴长度(沿舟骨长轴线从近极到远极关节面的距离)、舟骨腰部宽度、远极宽度和近极宽度(垂直于舟骨长轴的方向,分别测量舟骨腰部最窄部位的宽度、距离远极关节面2 mm处的远极宽度和距离近极顶端2 mm处的近极宽度),男17例,女10例.比较男性和女性标本的测量数据,并分别同国内可供选择的舟骨内固定螺钉的各项指标进行比较分析.结果 舟骨长轴长度:男性标本(29.3±1.3)mm,女性标本(25.4±1.1)mm,两者比较差异有统计学意义.舟骨腰部宽度、近极宽度和远极宽度男性标本分别为(10.3±0.8)mm、(4.5±0.6)mm和(6.0±0.5)mm,女性标本分别为(9.0±0.8)mm、(4.0±0.4)mm和(5.6±0.4)mm,男性标本的测量值均显著大于女性标本.所有舟骨标本的平均近极宽度均小于远极宽度.国内部分可供选择的舟骨螺钉产品(3.0空心螺钉垫圈系统和部分Acutrak标准型螺钉)的尾端直径大于舟骨近极平均宽度.结论 根据舟骨形态学相关测量结果,治疗舟骨骨折螺钉的适宜平均长度男、女性分别为25 mm和21 mm.因国人舟骨近极宽度相对较窄小,选择背侧入路从近极置入螺钉时,应选择尾端直径适宜的螺钉产品,以减少并发症的发生率.     

数字化三维重建模拟前路枕骨髁螺钉置钉

目的 :使用数字化三维重建技术测量前路枕骨髁螺钉的相关置钉参数,探讨前路枕骨髁螺钉置入的可行性和安全性。方法:选取宁波市第六医院共50例枕颈部形态正常者的上颈椎螺旋CT扫描图像,男30例,女20例,年龄42.2±8.6岁(23～68岁)。排除感染、肿瘤、解剖畸形、骨折脱位、退行性变及严重骨质疏松,将CT数据导入Mimics软件,对枕骨及寰椎进行三维CT重建后,模拟前路置入直径3.5mm的枕骨髁螺钉,测量进钉点至枕骨髁内侧缘及寰枕关节面的距离、螺钉与舌下神经管的最短垂直距离、进入枕骨髁骨质内的钉道长度,再用3-matic软件测量螺钉的头倾角及外倾角,将螺钉各置钉参数进行统计学分析。结果:共模拟成功置入100枚前路枕骨髁螺钉,三维模型观察均无枕骨髁内外侧壁、寰枕关节面及舌下神经管的损伤。前路枕骨髁螺钉各置钉参数左右两侧比较均无统计学差异(P0.05)。进钉点距枕骨髁内侧缘水平距离及寰枕关节面垂直距离分别为3.28±0.54mm、2.84±0.45mm,螺钉头倾角、外倾角、距离舌下神经管最短垂直距离及钉道长度分别为4.07°±2.40°、33.09°±4.37°、4.76±0.74mm、21.54±2.01mm。结论:通过数字化三维重建模拟前路枕骨髁螺钉置钉,显示正常成人枕骨髁有足够的体积空间容纳直径3.5mm的前路枕骨髁螺钉置入,前路枕骨髁螺钉技术是治疗枕颈不稳时颅侧固定的一种安全可行的方法。     

骶骨后路钉板固定的解剖学研究

目的 探讨骶骨横行或斜行骨折时钉板固定的安全性.方法 30具新鲜成人尸体标本,男15具,女15具;年龄38～82岁,平均65岁.在骶骨上做标记:O点为骶骨螺钉进钉点(O_1点位于关节突关节的外下缘,O_2和O_3点位于经相邻骶后孔连线中点的水平线与骶外侧嵴的交点,O_4点位于S_3、S_4骶后孔连线的中点至骶外侧嵴水平线的中点),D_1为骶骨内侧置钉钉道长度,D_2为骶骨垂直置钉钉道长度,D_3为骶骨外侧置钉钉道长度,α为骶骨横截面上内侧置钉最大偏移角度,β为骶骨横截面上外侧置钉最大偏移角度.结果 S_1的D_1、D_2、D_3、α,β值分别为(38.73±5.29)mm、(31.15±4.68)mm、(41.47±6.18)mm、31.88°±4.32°、34.31°±5.12°;S_2的D_1、D_2、D_3、α,β值分别为(28.53±2.19)mm、(23.95±2.59)min、(34.69±5.13)mm、14.70°±3.54°、20.48°±5.35°;S_3的D_1、D_2、D_3、α,β值分别为(30.62±3.15)mm、(17.18±3.51)mm、(24.66±5.13)mm、52.00°±7.55°、39.00°±5.50°;S_4的D_1、D_2、D_3、α,β值分别为(23.21±4.14)mm、(9.07±2.20)mm、(14.52±3.51)mm、18.47°±4.42°、10.23°±2.69°.结论 S_1螺钉在O_1点进钉,平行于L_5棘突是理想的置钉路径.S_2-S_4理想的置钉路径:S_2螺钉在O_2点进钉,横截面上偏向外侧小于20.48°±5.35°;S_3螺钉在O_3点进钉,横截面上偏向内侧小于52.00°±7.55°;S_4螺钉在O_4点进钉,横截面上偏向内侧小于18.47°±4.42°.     

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.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

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.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

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.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

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.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.