加速康复外科理念下的改良延续性护理方案对手外伤病人的护理效果

目的 探讨基于加速康复外科（enhanced recovery after surgery, ERAS）理念下的改良延续性护理方案对手外伤病人的护理效果。方法 选取2016年7月至2018年6月收治的118例单侧手外伤病人,采用随机数字表法分为观察组和对照组,每组59例。观察组采用ERAS理念下的改良延续性护理方案,对照组采用常规护理方案。术后第1天、出院时和术后6个月采用视觉模拟疼痛量表（visual analogue scale, VAS）评价病人疼痛情况;出院时和术后6个月采用国际手外科学会总主动活动度（total active motion, TAM）和国家专业手指功能评定标准评价病人患手功能恢复情况。观察两组病人住院时间、护理服务满意度、康复锻炼依从性,以及出院后并发症发生情况。结果 观察组术后第1天、出院时及术后6个月的VAS评分均明显优于对照组［（2.69±1.59）分 vs. （5.03±1.50）分;（1.42±1.21）分 vs. （2.58±1.23）分;（0.22±0.56）分 vs. （1.02±1.11）分］,差异均有统计学意义（P均＜0.05）。术后6个月,观察组患手TAM、肌力及感觉、灵巧性及协调性分别为74.51°±7.65°、（110.56±7.78）分、（2.51±1.14）分,均明显优于对照组的58.47°±5.03°、（94.37±3.85）分、（4.02±1.14）分,差异均有统计学意义（P均＜0.05）。观察组住院时间较对照组明显缩短［（7.31±2.12） d vs. （12.02±2.33） d］,差异有统计学意义（P＜0.05）。观察组护理服务满意度和康复锻炼依从性优良率分别为98.31%（58/59）和98.31%（58/59）,明显优于对照组的83.05%（49/59）和86.44%（51/59）,差异均有统计学意义（P均＜0.05）。结论 基于ERAS理念下的改良延续性护理方案能有效促进单侧手外伤病人术后手功能的恢复,减少并发症的发生,有助于建立良好的医患关系。     

人工全髋关节置换治疗陈旧性化脓性髋关节炎遗留关节畸形的临床疗效

目的 评价人工全髋关节置换术（total hip arthroplasty,THA）治疗陈旧性化脓性髋关节炎遗留关节畸形的临床效果。方法 回顾性收集2014年8月至2019年7月于新疆维吾尔自治区人民医院行THA治疗陈旧性化脓性髋关节炎的18例病人围手术期及术后随访资料。通过Harris评分评估髋关节功能,依据随访时X线片评估假体情况,记录随访过程中并发症发生情况。结果 18例病人随访（29.6±2.3）个月（24~35个月）。下肢短缩由术前的（4.17±1.24） cm改善至术后的（0.62±0.41） cm,差异有统计学意义（t=11.393,P＜0.001）;Harris评分由术前的（43.38±3.81）分提升至末次随访时的（87.61±4.21）分,差异有统计学意义（t=-30.484,P＜0.001）;其中优秀9例,良好6例,尚可3例,优良率为83%。切口脂肪液化1例,其余均愈合良好。术后脱位1例,进行翻修手术。随访期间未观察到假体周围骨折、假体周围感染、骨溶解、无菌性松动等并发症。结论 THA治疗陈旧性化脓性髋关节炎遗留关节畸形病人疗效满意,可显著改善髋关节功能,纠正下肢长度,提高病人生活质量。     

肱尺关节成形术治疗肘关节强直的临床疗效观察

目的 探讨肱尺关节成形术治疗肘关节强直的临床疗效。方法 回顾性分析2012年10月至2015年10月我院采用肱尺关节成形术治疗创伤性肘关节强直的病人23例,其中男15例,女8例;年龄为29~56岁,平均为41.4岁,骨关节炎按Kellgren-Lawrence分级系统为Ⅱ级6例、Ⅲ级17例。术后镇痛、患肢石膏托外固定3 d后拆除并开始功能锻炼。记录术前、术后肘关节最大屈曲、伸直角度及屈伸活动范围,采用Mayo肘关节功能评分系统及疼痛视觉模拟量表（visual analogue scale, VAS）评估治疗效果。结果 本组病人患侧肘关节的骨性异常均得到有效清除;病人肘关节屈曲角度、伸直角度、屈伸活动范围均得到了明显改善,屈伸活动范围由术前的32.39°±9.75°（14例≤30°、9例为31°~60°）提高至术后的120.87°±11.04°（23例病人的屈伸活动度均＞90°）,差异有统计学意义（t=28.090,P＜0.001）;病人术后的肘关节Mayo功能评分为（85.00±10.22）分,优良率为91.3%,显著优于术前的数值,差异有统计学意义（t=8.930,P＜0.001）;术后随着随访时间的延长,VAS评分值持续下降,术后各时间点的数值与术前评分比较,差异均具有统计学意义（P均＜0.001）。结论 肱尺关节成形术治疗创伤性肘关节强直的临床疗效可靠、安全,肘关节功能恢复良好。     

经皮椎间孔镜下病灶清除治疗腰椎间隙感染的疗效分析

目的 分析经皮椎间孔镜下病灶清除引流术治疗腰椎间隙感染的临床疗效。方法 回顾性分析2016年11月至2019年9月我院经皮椎间孔镜下病灶清除治疗的14例腰椎间隙感染病人的临床资料。统计分析病人术前和术后1周、1个月、3个月疼痛视觉模拟量表（visual analogue scale,VAS）评分、日本骨科协会（Japanese Orthopaedic Association,JOA）评分、Oswestry功能障碍指数（Oswestry disability index,ODI）,采用改良MacNab疗效评定标准对手术疗效进行评估。结果 14例病人均获得随访,随访时间为（13.57±2.56）个月。术后1周,白细胞、中性粒细胞百分比、C-反应蛋白、红细胞沉降率均明显低于术前,差异有统计学意义（P＜0.05）。末次随访时,上述指标均恢复至正常范围。所有病人术后症状均明显减轻,术后1周VAS评分［（3.39±0.53）分］和术后3个月VAS评分［（1.46±0.41）分］均明显低于术前［（6.96±0.69）分］,差异有统计学意义（P＜0.05）。病人术后1周ODI降至（46.79±5.18）%,术后3个月为（15.71±2.58）%,病人术后腰椎功能明显改善,与术前［（69.43±1.89）%］比较,差异有统计学意义（P＜0.05）。病人术后1周JOA评分为（19.21±1.76）分,术后3个月为（27.43±2.94）分,与术前［（8.71±1.68）分］比较,差异有统计学意义（P＜0.05）。根据改良MacNab标准,优9例,良3例,可1例,差1例,优良率为85.71%。术后1个月复查腰椎MRI显示脓肿已清除,神经根及硬膜囊无受压,部分病例达到椎间骨性融合。结论 经皮椎间孔镜下病灶置管引流操作简单、创伤小,术后症状明显改善,对于治疗腰椎间隙感染是一种安全有效的方法。     

关节镜下前交叉韧带袖套状保残重建的疗效研究

目的 探讨关节镜下前交叉韧带（anterior crueiate ligament,ACL）袖套状保残重建术的临床疗效。方法 回顾性分析我科2018年3月至2020年1月行关节镜下ACL袖套状保残重建术治疗的30例病人,其中男17例,女13例;年龄为17~43岁。术前及术后2、6、12个月分别采用Lachman试验和前抽屉试验评估膝关节的稳定性;记录Lysholm评分和Tegner运动功能评分,术后12个月时行患膝MRI检查评估重建的ACL。结果 病人随访（14.53±2.48）个月（12~18个月）。术中未出现神经血管损伤病人,术后未出现伤口感染及固定排异反应。术后门诊随访时,前抽屉试验及Lachman试验均为阴性。术后12个月Lysholm评分为（95.5±6.6）分,显著高于术前的（37.9±7.3）分;Tegner功能评分为（6.4±0.8）分,显著高于术前的（1.9±0.5）分,差异均有统计学意义（t=41.482,P＜0.001;t=25.819,P＜0.001）。术后12个月复查MRI显示ACL显影良好。结论 关节镜下ACL袖套状保残重建术安全、微创、并发症少,术后能早期改善病人膝关节功能,值得临床推广。     

股内侧肌下入路与髌旁内侧入路在老年膝关节置换中应用的初步临床分析

目的 分析比较全膝关节置换术（total knee arthroplasty, TKA）中采用股内侧肌下入路（subvastus approach, SVA）与髌旁内侧入路（medial parapatellar approach, MPA）的早期临床疗效。方法 回顾性分析2015年1月至2016年8月在本院完成初次TKA的69例病人资料（年龄均超过60岁）,根据手术入路的不同分为SVA组和MPA组,记录并比较两组病人的手术切口长度、手术时间、总出血量、术后可直腿抬高时间、膝关节术后活动度（range of motion, ROM）。采用疼痛视觉模拟量表（visual analogue scale, VAS）评价病人疼痛情况,采用美国膝关节协会评分（knee society score, KSS）评价病人的膝关节功能。结果 SVA组病人的手术切口长度为（11.48±1.35） cm,与MPA组的（15.24±1.41） cm相比,差异有统计学意义（t=11.041,P＜0.001）;两组间手术总失血量及手术时间比较,差异均无统计学意义（t=0.209,P=0.835;t=1.003,P=0.320）;SVA组病人的术后直腿抬高时间为（1.52±0.62） d,MPA组为（2.61±0.97） d,两组比较,差异有统计学意义（t=5.462,P＜0.001）。术后第3、7天SVA组静息和活动状态下的VAS评分均优于MPA组,两组间比较,除外术后第7天静息状态下的VAS评分,其他时间及状态下的VAS评分差异均有统计学意义（P均＜0.05）。术后第3、7天,MPA组病人的膝关节ROM（89.09°±5.51°、93.03°±7.06°）均小于SVA组（96.36°±4.55°、96.36°±6.53°）,差异均有统计学意义（t=5.842,P＜0.001;t=1.991,P=0.049）。术后2周,MPA组病人的KSS评分为（72.42±4.35）分,小于SVA组病人的（78.79±3.96）分,差异有统计学意义（t=6.214,P＜0.001）。术后第1、3、6、9个月,两组间KSS评分和膝关节ROM比较,差异均无统计学意义（P均＞0.05）。结论 人工全膝关节置换采用SVA对伸膝装置影响小,可促进置换后关节功能及关节活动度的快速恢复,减少疼痛,提高术后满意度。     

脊柱内窥镜下精准减压治疗有根性症状的高龄脊柱侧凸的临床疗效

目的 评价脊柱内窥镜下精准减压治疗有根性症状的高龄脊柱侧凸病人的临床效果。方法 回顾性分析2018年1月至2018年12月在我院行脊柱内窥镜下精准减压手术治疗的16例有根性症状的高龄脊柱侧凸病人的临床资料,其中男9例,女7例;年龄为（77.13±6.04）岁（71~96岁）;9例行侧方椎间孔入路减压神经根松解术,7例行椎板间单侧入路双侧减压神经根松解术。收集病人的手术时间、术后并发症发生情况,收集并比较病人术前、术后6个月随访时的腰痛及下肢痛疼痛视觉模拟量表（visual analogue scale, VAS）评分和Oswestry功能障碍指数（Oswestry disability index, ODI）。结果 16例病人的手术时间为（138.18±27.16） min,随访时间为（8.31±2.02）个月。术前腰痛、下肢放射痛VAS评分和ODI分别为（6.02±0.77）分、（80.50±5.03）%,术后6个月随访时分别为（2.19±0.98）分、（41.25±7.89）%,手术前后数值比较,差异均有统计学意义（t=12.417,P＜0.001;t=23.453,P＜0.001）。结论 对于有根性症状的高龄脊柱侧凸病人,行脊柱内窥镜下精准减压治疗具有手术效果确切、耐受性好、并发症少等优点,可作为有根性症状的高龄脊柱侧凸病人序贯治疗中一种可选择的方案。     

射频治疗对关节镜下半月板部分切除术早期疗效的影响

目的 探讨半月板部分切除术后使用射频汽化修整残留半月板对病人术后膝关节预后的影响。方法 前瞻性地纳入60例病人,随机分为两组,观察组（26例）病人采用膝关节镜下半月板部分切除+射频修整术,对照组病人（34例）采用膝关节镜下单纯半月板部分切除术。对比两组病人术后48 h伤口引流量及疼痛视觉模拟量表（visual analogue scale, VAS）评分;采用膝关节Lysholm评分标准评估膝关节功能,记录并比较两组病人术前及术后6个月随访时的Lysholm评分。结果 观察组和对照组病人的术后引流量分别为（51.15±22.69） ml、（63.24±23.45） ml,VAS评分分别为（1.45±0.50）分、（1.62±0.55）分,两组间比较,差异均无统计学意义（t=0.264,P=0.610;t=0.259,P=0.613）;所有入组病人术后的Lysholm评分为（91.58±5.78）分,均优于术前的（73.53±4.52）分,差异有统计学意义（t=8.012,P=0.005）;观察组及对照组术后的Lysholm评分分别为（90.00±5.54）分、（92.79±5.75）分,差异无统计学意义（t=0.219,P=0.641）。结论 关节镜下行半月板部分切除术的出血量与使用射频汽化仪无关,无论是否使用射频汽化修整残留半月板,病人术后膝关节的功能都能得到较好的恢复。     

颈椎双侧关节突关节脱位合并呼吸障碍病人的手术治疗

目的 分析颈椎双侧关节突关节脱位（bilateral cervical facet dislocations, BCFDs）合并呼吸障碍病人行手术治疗的临床疗效。方法 回顾性分析2001年1月至2014年1月华中科技大学同济医学院附属协和医院骨科采用围手术期多学科合作的呼吸道管理并行手术治疗的56例BCFDs合并呼吸障碍病人的临床资料,其中全瘫16例,不全瘫40例。行后路复位加植骨融合内固定手术42例,行前后联合入路椎体复位植骨融合内固定术12例,行颈前路复位植骨融合内固定术2例。结果 本组病人随访时间为（68.4±18.6）个月（12~120个月）;病人呼吸功能最终均获得明显改善,15例病人因呼吸障碍术后行气管切开（8例全瘫,7例不全瘫）;植骨融合时间为（7.5±4.5）个月（3~12个月）,融合率为100%。术后2周和末次随访时,40例不全瘫病人的美国脊柱损伤协会（American Spinal Injury Association, ASIA）运动功能评分由术前的（44.36±27.46）分分别改善为（56.04±30.48）分和（61.36±25.12）分,差异均有统计学意义（t=1.801,P＜0.05;t=2.889,P＜0.05）;ASIA感觉评分由术前的（56.24±33.86）分分别改善为（67.64±28.36）分和（68.56±12.72）,差异均有统计学意义（t=1.632,P＜0.05;t=2.154,P＜0.05）;神经功能较术前均获得不同程度的改善。16例全瘫病人术后均无明显神经功能改善,ASIA评分手术前后差异无统计学意义（P＞0.05）。本组病人发生肺炎14例,压力性损伤3例,尿道感染9例,并发症发生率为46.43%（26/56）。结论 对于BCFDs合并呼吸障碍病人选择合适的手术治疗方案,同时采用围手术期多学科合作的呼吸道管理,可提高BCFDs合并呼吸障碍病人的临床救治水平。     

股骨侧弓畸形对全膝关节置换术预后的影响

目的 探讨冠状位股骨侧弓畸形的存在对全膝关节置换术（total knee arthroplasty,TKA）疗效的影响。方法 回顾性分析西安交通大学附属红会医院膝关节外科2015年1月至2017年12月接受TKA手术病人142例,其中男28例,女114例;年龄为（67.3±6.7）岁（52~82岁）。根据标准负重正位X线片测量病人股骨侧弓角（femoral bowing angle,FBA）。将FBA＜177°定义为股骨侧弓畸形,根据是否存在股骨侧弓畸形将病人分别纳入股骨侧弓畸形组和直股骨组。使用美国膝关节协会评分（Knee Society score,KSS）及西安大略和麦克马斯特大学（Western Ontario and McMaster University,WOMAC）骨关节炎指数评估病人功能状态。结果 142例病人平均随访49.4个月（43~55个月）。股骨侧弓畸形组59例,直股骨组83例,且股骨侧弓畸形组女性病人比例明显高于直股骨组,差异有统计学意义（P＜0.05）。所有病人在末次随访时的KSS评分、WOMAC评分及分量表均较术前得到明显的改善（P＜0.05）。进一步分析发现,末次随访时直股骨组与股骨侧弓畸形组病人的KSS膝总分［（78.1±6.2）分 vs. （75.1±7.8）分］、疼痛评分［（48.2±2.4）分 vs. （47.0±4.0）分］、WOMAC B部分（僵硬部分）得分［（0.4±0.7）分 vs. （0.7±1.1）分］相比,差异均有统计学意义（P＜0.05）。结论 股骨侧弓畸形多发生于女性;存在股骨侧弓畸形的骨关节炎病人行TKA术后近中期临床效果不及直股骨病人。     

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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.