控制性低中心静脉压对腹腔镜肝癌切除术患者中心静脉血氧饱和度和乳酸的影响

目的 探讨腹腔镜肝癌切除术中硝酸甘油控制性低中心静脉压（CLCVP）对患者术中中心静脉血氧饱和度（ScvO₂）和动脉血乳酸（Lac）的影响。
方法 选择择期行腹腔镜肝癌切除术患者50例,男27例,女23例,年龄36～64岁,BMI 18~25 kg/m²,ASA Ⅰ或Ⅱ级,采用随机数字表将患者随机分为两组：CLCVP组（L组）和对照组（C组）,每组25例。L组在切肝前5 min通过静脉泵注硝酸甘油0.2～0.5 μg·kg^-1·min^-1,维持CVP≤5 cmH₂O;C组常规输液并维持CVP 6～12 cmH₂O。记录术中出血量、输液量和苏醒时间,记录切肝前15 min、切肝中10、40 min、切肝后30 min的ScvO₂、Lac、HR和MAP。记录术后不良反应的发生情况。
结果 与C组比较,L组术中出血量和输液量明显降低（P＜0.05）。与切肝前15 min比较,切肝中10、40 min,L组ScvO₂和MAP明显降低（P＜0.05）;切肝中10 min,L组HR明显增快（P＜0.05）。与C组比较,切肝中10、40 min,L组ScvO₂和MAP明显降低（P＜0.05）。两组苏醒时间、术后不良反应发生率差异无统计学意义。
结论 腹腔镜肝切除术中硝酸甘油CLCVP可有效减少术中出血,使ScvO₂下降,对Lac值无明显影响,且不增加不良反应。     

脑氧饱和度监测下控制性降压对老年高血压患者术后谵妄的影响

目的 探讨脑氧饱和度(rSO₂)监测下控制性降压对老年高血压患者术后谵妄（POD）的影响。方法 择期全麻下行鼻泪道手术的老年高血压患者110例,男53例,女57例,年龄65~85岁,ASA Ⅱ或Ⅲ级,高血压Ⅰ或Ⅱ级,采用随机数字表法分为两组：rSO₂监测组（S组）和对照组（C组）,每组55例。两组均采用乌拉地尔联合艾司洛尔控制性降压,维持MAP≥基础值的70%,且MAP≥55 mmHg;当S组rSO₂<基础值的80%或rSO₂最低值<基础值的50%,并且持续时间大于10 s,则逐步提升血压直至rSO₂恢复至≥基础值的80%或绝对值＞50%。C组rSO₂监护仪施行遮盖处理。记录入室后吸氧5 min（T0）、控制性降压15 min（T1）、30 min（T2）、控制性降压结束后5 min（T3）、拔管后10 min（T4）的HR、MAP、rSO₂;记录rSO₂基础值、术中最低值及较基础值下降的最大百分比;术后1、2、3 d采用谵妄评定方法 中文修订版（CAM-CR量表）对患者进行POD评估。结果 与T0时比较,T1—T2时两组MAP明显下降（P<0.05）,C组rSO₂明显下降（P<0.05）,T3—T4时逐渐回升至术前水平。T1—T2时S组rSO₂明显高于C组（P<0.05）,术中rSO₂最低值明显高于C组（P<0.05）,rSO₂较基础值下降的最大百分比明显低于C组（P<0.05）。术后1 d S组POD发生率明显低于C组（P<0.05）。结论 rSO₂监测下控制性降压能减少老年高血压患者鼻泪道手术后谵妄的发生,提高围术期安全性。     

心肺转流期间老年患者局部脑氧饱和度与术后认知功能障碍的相关性

目的 探究老年患者心肺转流（CPB）期间局部脑氧饱和度（rSO₂）与术后认知功能障碍（POCD）的相关性。
方法 选择择期行CPB下心脏手术的老年患者84例,男46例,女38例,年龄≥65岁,BMI 18～29 kg/m²,ASA Ⅱ—Ⅳ级。术中应用近红外光谱技术,持续监测rSO₂。采用神经心理学测试方法评估患者术前1 d和术后第7天的认知功能,采用Z值计分法判定POCD。根据术后第7天是否发生POCD将患者分为两组：非POCD组和POCD组。CPB前期包括入室吸氧前至主动脉插管（期间包括麻醉后、手术开始、劈胸骨、悬吊心包）,CPB中期包括CPB开始至CPB结束（期间包括CPB低温恒温期及搭桥或换瓣）,CPB后期包括主动脉拔管和术毕。记录CPB前期、中期、后期rSO2平均值（rSO_2mean）,术中rSO₂最低值（rSO_2min）。采用Logistic回归和拟合曲线分析患者术中rSO₂与POCD的相关性。
结果 有36例（42.9%）患者发生POCD。多因素Logistic回归分析显示,CPB前期rSO_2mean（OR=1.12,95%CI 1.02～1.24,P=0.02）、CPB中期rSO_2mean（OR=1.55,95%CI 1.24～1.95,P<0.05）、CPB后期rSO_2mean（OR=1.32,95%CI 1.15～1.60,P<0.05）和rSO_2min（OR=1.33,95%CI 1.16～1.52,P<0.05）是发生POCD的独立危险因素。拟合曲线显示,CPB中期rSO_2mean（r=-0.60）和rSO_2min（r=-0.57）均与POCD呈线性负相关(P<0.05)。
结论 术中rSO₂降低与患者CPB术后发生POCD具有相关性。术中rSO₂降低可能是POCD的独立危险因素。     

食管癌根治术中肾脏氧饱和度与术后肾功能异常的相关性

目的 探讨食管癌根治术中肾脏区域组织氧饱和度（rSO₂）与术后肾功能异常的相关性。
方法 选择拟行食管癌根治术的患者116例,男93例,女23例,年龄18～64岁,BMI＜24 kg/m²,ASA Ⅱ或Ⅲ级。术中连续监测左侧肾脏rSO₂。设定麻醉诱导后肾脏rSO₂为基础值,当术中肾脏rSO₂绝对值≤50%或低于基础值的75%时,定义为肾脏rSO₂异常下降。记录术前及术后24 h尿素氮（BUN）、血清肌酐（SCr）,术后肾功能异常定义为术后24 h血浆SCr＞130 μmol/L或BUN＞7.5 mmol/L。根据术后是否出现肾功能异常将患者分为两组：肾功能正常组和肾功能异常组。采用列联系数分析术中肾脏rSO₂异常下降与术后肾功能异常的相关性。
结果 有40例（34.5%）患者术中出现肾脏rSO₂异常下降,有45例（38.8%）患者术后出现肾功能异常。二元Logistic回归分析显示男性是术后肾功能异常的危险因素（OR=5.490,95%CI 1.526～19.754,P=0.009）。食管癌根治术中肾脏rSO₂的异常下降与术后肾脏功能异常呈正相关（rs=0.587,P=0.009)。
结论 食管癌根治术中肾脏rSO₂异常下降与术后肾功能异常呈正相关。     

不同通气模式对腹腔镜肝切除术患者出血量和术后肝功能的影响

目的 探讨不同通气模式对腹腔镜肝切除术患者出血量和术后肝功能的影响。
方法 选择择期全麻下行腹腔镜肝切除术患者60例，男35例，女25例，年龄18～64岁，BMI 18.5～24.0 kg/m²，ASA Ⅱ或Ⅲ级。采用随机数字表法将患者分为两组：压力控制通气（PCV）组和容量控制通气（VCV）组，每组30例。PCV组通过调整气道峰压，使术中VT达到理想体重×8 ml，同时调整RR维持P_ETCO₂ 35～45 mmHg；V组VT设定为理想体重×8 ml，同时调整RR维持P_ETCO₂ 35～45 mmHg。记录麻醉诱导后10 min（T₀）、气腹后10 min（T₁）、切肝前10 min（T₂）、切肝后10 min（T₃）、气腹结束后10 min（T₄）吸气峰压（Ppeak）、气道平均压（Pmean）、CVP、PaCO₂和氧合指数（PaO₂/FiO₂）。记录术中胶体液用量和出血量，术后24、48和72 h丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）以及腹腔引流量。
结果 与T₀时比较，T₁—T₃时两组Ppeak均明显升高（P＜0.05）；T₁—T₄时VCV组、T₃和T₄时PCV组CVP均明显升高（P＜0.05）。与VCV组比较，PCV组T₁、T₂时CVP明显降低（P＜0.05），术中胶体液用量和出血量明显减少（P＜0.05）。两组术后24、48和72 h的ALT、AST和腹腔引流量差异无统计学意义。
结论 压力控制通气模式下腹腔镜肝切除术中患者出血量明显减少，可能与术中较低的气道峰压有关，但两种不同通气模式下患者术后肝功能损伤无明显差异。     

低每搏量变异度指导的液体治疗对老年患者肺叶切除术后恢复质量的影响

目的 探究低每搏量变异度（SVV）指导的液体治疗对老年患者肺叶切除术后恢复的影响。

方法 选择2022年2月至2023年1月择期胸腔镜下肺叶切除术的老年患者100例,男50例,女50例,年龄65～75岁,BMI 18～24 kg/m²,ASA Ⅱ或Ⅲ级。采用随机数表法将患者分为两组：低SVV阈值目标导向液体治疗（GDFT）组（G组）和对照组（C组）,每组50例。G组8%＜SVV≤10%,C组10%＜SVV≤13%。记录麻醉时间、手术时间、单肺通气（OLV）时间,记录入手术室即刻（T₀）、插管即刻（T₁）、OLV开始即刻（T₂）、手术开始即刻（T₃）、OLV结束即刻（T₄）和术毕（T₅）时的HR和MAP。记录术中液体出入量以及各种血管活性药使用情况。记录术前24 h和术后24、48 h血浆胃动素（MTL）、胃泌素（GAS）、肠型脂肪酸结合蛋白（IFABP）浓度。记录术后2、6、12、24、48 h静息时VAS疼痛评分以及术后48 h内PCIA有效按压次数、PCIA总按压次数以及补救镇痛例数。记录术后首次肛门排气时间、首次排便时间、首次下床活动时间、术后住院时间、胃肠道并发症（恶心呕吐、腹胀）发生情况。

结果 与C组比较,G组T₁—T₅时MAP、术后24、48 h血浆MTL和GAS浓度均明显升高（P<0.05）,术后24、48 h血浆IFABP浓度、术中胶体输注量和总液输注量均明显降低（P<0.05）,术后首次肛门排气时间、首次排便时间、首次下床活动时间和术后住院时间均明显缩短（P<0.05）。两组尿量、出血量、术后2、6、12、24、48 h静息时VAS疼痛评分、术后48 h内PCIA有效按压次数、PCIA总按压次数、补救镇痛率差异均无统计学意义。

结论 低SVV阈值（8%＜SVV≤10%）GDFT能很好地促进胃液分泌和肠黏膜屏障功能恢复,对老年患者肺叶切除术后胃肠功能的恢复有积极作用。     

间歇呼吸暂停联合低水平PEEP通气策略在输尿管软镜手术中的应用

目的 探讨间歇呼吸暂停联合低水平呼气末正压(PEEP)通气策略对输尿管软镜手术患者的影响。方法 选择接受输尿管软镜钬激光碎石术的患者73例,男59例,女14例,年龄25~60岁,BMI 18~28 kg/m²,ASA Ⅰ或Ⅱ级,随机分为三组：呼吸暂停联合低水平PEEP组（P组,n=25）、呼吸暂停组（A组,n=28）和对照组(C组,n=20)。P组术中采用呼吸暂停联合低水平PEEP (5 cmH₂O)通气模式,A组术中采用传统呼吸暂停通气模式,C组术中采用常规通气模式。P组和A组于麻醉诱导前（T0）、插管后10 min（T1）、第1次呼吸暂停前（T2）、最后1次呼吸暂停结束后即刻（T3）和拔管后30 min（T4）时,C组于T0—T1、术者第1次要求呼吸暂停前（T2）、碎石结束后即刻（T3）、T4时记录基本生命体征并抽取桡动脉及颈内静脉血进行血气分析,术后24 h（T5）时抽取颈内静脉血。记录T0—T4时PaCO₂、pH、氧合指数（OI）、脑氧饱和度（rSO₂）、脑氧摄取率（CERO₂）、动脉和颈内静脉血氧分压差（Pa-jvO2）、动脉和颈内静脉血氧饱和度差（Sa-jvO2）;T0、T4—T5时血清肺Clara细胞分泌蛋白(CC16)、静脉血清S100β蛋白含量、静脉血清肌钙蛋白（cTnT和cTnI）、肌红蛋白（Mb）和肌酸激酶同工酶（CK-MB）。记录激光碎石时间和术者满意程度评分。结果 与C组比较,T3时A组PaCO₂明显升高、pH、OI明显降低（P<0.05）。与A组比较,T3时P组PaCO₂明显降低、pH、OI明显升高（P<0.05）。三组不同时点rSO₂、CERO₂、Pa-jvO2、Sa-jvO2、CC16、S100β蛋白、cTnT、cTnI、Mb、CK-MB差异均无统计学意义。与C组比较,P组和A组激光碎石时间明显缩短（P<0.05）,术者满意程度评分明显升高（P<0.05）。结论 间歇呼吸暂停联合低水平PEEP(5 cmH₂O)通气策略可安全地用于输尿管软镜手术,既保留了传统呼吸暂停通气策略的优势,同时减少了其带来的不利影响,是一种更优化的通气策略。     

驱动压导向呼气末正压通气对原位肝移植患者术中氧合和术后并发症的影响

目的： 评价驱动压导向呼气末正压（PEEP）通气对原位肝移植术（OLT）患者术中氧合和术后并发症的影响。
方法： 选择2020年1月至2023年9月行OLT患者118例,男89例,女29例,年龄18～70岁,BMI＜28 kg/m² ,ASA Ⅲ或Ⅳ级。采用随机数字表法将患者分为两组：驱动压组（D组）和固定PEEP组（P组）,每组59例。两组全麻期间均采用容量控制通气,I∶E 1∶2,V_T 6 ml/kg（理想体重）,RR 10～15次/分。D组在机械通气5 min后开始PEEP滴定试验,将PEEP从2 cmH₂O逐渐递增到10 cmH₂O,选择能产生最低驱动压的PEEP,维持该PEEP直至手术结束。P组术中维持PEEP 5 cmH₂O。记录术中出入量、血管活性药物使用情况。记录插管后5 min（T₁）、无肝期（T₂）、新肝期（T₃）、手术结束即刻（T₄）的HR、SBP、DBP、气道峰压（Ppeak）、气道平台压（Pplat）、PEEP、血气分析结果,并计算驱动压、动态肺顺应性（Cdyn）、氧合指数（OI）、死腔率（V_D/ V_T）。记录术后7 d内术后肺部并发症（PPCs）的发生情况。
结果： 与P组比较,D组晶体液输注量明显增加,去甲肾上腺素、去氧肾上腺素及肾上腺素使用率明显升高（P<0.05）。与T₂时比较,两组T₁、T₃、T₄时HR明显减慢,SBP、DBP明显升高（P<0.05）。与T₁时比较,两组T₂—T₄时Ppeak、Pplat、驱动压、OI明显升高,T₃、T₄时Cdyn明显降低（P<0.05）。与P组比较,D组术后7 d内PPCs发生率明显降低（P<0.05）。两组其余指标差异无统计学意义。
结论： 驱动压导向PEEP通气可改善原位肝移植患者术中氧合,降低PPCs发生率,但术中血管活性药物的使用率升高。     

局部脑氧饱和度监测对老年高血压脊柱内固定手术围术期循环和炎症因子的影响

目的 探讨局部脑氧饱和度（rSO₂）监测在高血压老年病人脊柱内固定手术中对围术期循环、炎症因子水平以及病人术后认知功能的影响。方法 选取我院2020年1月至2021年1月老年高血压骨科全麻手术病人106例,随机抽签分为观察组与对照组,观察组术中持续监测rSO₂,对照组仅行常规管理。观察两组麻醉前（T0）、手术开始时（T1）、手术开始30 min（T2）、手术开始90 min（T3）及术后（T4）的rSO₂、平均动脉血压（MAP）及心率变化,比较两组手术前、术后3 d神经生长因子（NGF）、前列腺素E2（PGE₂）、神经肽Y（NPY）、白介素6（IL-6）、C反应蛋白（CRP）、肿瘤坏死因子-α（TNF-α）水平、术后神经认知功能障碍（PND）及躁动发生率。结果 观察组手术时间、出血量、术后引流量明显低于对照组（P＜0.05）。T1、T2、T3时观察组rSO₂明显高于对照组（P＜0.05）;T2、T3时观察组MAP明显高于对照组（P＜0.05）。与术前比较,两组术后3 d NGF、PGE₂、NPY、IL-6、CRP、TNF-α水平均明显升高（P＜0.05）,但术后3 d观察组IL-6、CRP、TNF-α水平明显低于对照组（P＜0.05）。两组PND及躁动发生率比较,差异无统计学意义（P＞0.05）。结论 rSO2监测指导高血压老年病人脊柱内固定手术的血压管理效果可靠,可减少术中出血量并降低术后炎性因子水平。     

急性超容血液稀释对老年脊柱手术患者S-100β蛋白、NSE水平及POCD的影响

目的：探讨急性超容血液稀释（AHH）对老年脊柱手术患者S-100β蛋白、神经元特异性烯醇化酶（NSE）水平及术后认知功能障碍（POCD）的影响。方法：选择择期骨科脊柱手术患者80例,ASA分级Ⅰ-Ⅱ级。按照随机数字表将患者分为AHH组和C组,每组40例。AHH组麻醉诱导后应用6%羟乙基淀粉130/0.4以20 ml/min速度行AHH,输注量为全身血容量的20%。C组不实施血液稀释,麻醉和手术方法与AHH组相同。记录两组术中出血量、异体输血量及尿量;于术前1 d、手术开始后1 h、术毕、术后12 h记录平均动脉压（MAP）、心率（HR）、中心静脉压（CVP）;于术前1 d、手术开始后15 min、手术开始后45 min、术毕检测动脉血氧含量（CaO₂）、静脉血氧含量（CjvO₂）、动静脉血氧含量差（Da-jvO₂）及脑氧摄取率（CERO₂）;于术前1 d,术后1、3、7 d行简易智能精神状态检查量表（MMSE）评分和S-100β蛋白、NSE水平测定。记录两组POCD发生率。结果：（1）AHH组术中出血量、输异体血量少于C组（P<0.05）,尿量多于C组（P<0.05）。（2）与术前1 d及C组同时间点比较,AHH组术毕时MAP［（75.6±4.1）mmHg］降低（P<0.05）;与术前1 d及C组同时间点比较,AHH组手术开始后1 h时CVP［（6.9±0.6）cmH₂O］升高（P<0.05）,但均在正常范围内。（3）与术前1 d及C组同时间点比较,AHH组手术开始后15 min、45 min、术毕时Da-jvO₂、CERO₂水平下降（P<0.05）。（4）与术前1 d比较,两组术后1 d的MMSE评分下降（P<0.05）,S-100β蛋白和NSE水平升高（P<0.05）,术后3、7 d有所恢复。两组间术后1 d的MMSE评分、S-100β蛋白和NSE水平差异有统计学意义（P<0.05）。（5）两组POCD发生率差异无统计学意义（P>0.05）。结论：AHH可明显减少老年脊柱手术患者的术中失血量和异体血输注量,降低S-100β蛋白和NSE水平,不增加POCD的发生风险。     

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.     

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.     

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.