困难气道患者的麻醉处理

目的对407例困难气道患者麻醉处理进行总结。方法在麻醉中出现困难通气和（或）困难插管,根据病情采用方法各异。结果困难通气要调整舌体位置,可使用口咽通气道或鼻咽通气道,喉痉孪、支气管痉孪并哮喘要寻找原因正确处理。对困难气道患者的插管,至少有12种经喉插管的方法（如清醒、经鼻、纤支镜）;环甲膜穿刺或气管切开可作为保护呼吸道的紧急措施。结论困难气道包括困难通气和（或）困难插管,对预计困难气道的患者,应充分评估与准备。     

重视围术期气道管理

气道管理（airway management）与麻醉安全和质量密切相关，美国有文献报道，麻醉相关并发症首要原因与气道管理不当有关，而欧洲健康与医学研究院资料显示，50％以上严重麻醉相关并发症，包括死亡、不可逆昏迷是由气道管理不当引起的，而英国困难气道协会发现，每年死亡患者20％以上死于麻醉和ICU气道管理失当。我国尚缺乏相关统     

七氟醚对发育期哮喘患儿气道作用的研究进展

哮喘是一种患儿发育期常见的气道慢性炎症性疾病,严重影响患儿的生活质量和生命健康。在麻醉药物和手术刺激等多种因素的影响下,哮喘在围术期易被诱发及加重。七氟醚是目前小儿麻醉中最常用的吸入麻醉药,不同浓度的七氟醚可对哮喘患儿气道产生不同的效应。本文综述不同浓度七氟醚对哮喘患儿气道力学、气道炎症以及气道重塑作用的相关研究进展,为哮喘患儿的围术期用药及治疗方案提供参考。     

年龄对喉罩置入丙泊酚麻醉EC50和AAI的影响

喉罩(LMA)常用于短小手术患者的气道维持,其操作较气管导管方便、易行,但LMA的放置需一定的条件,麻醉方法或麻醉深度不当可出现张口困难、呕吐、呛咳甚至气管痉挛等症状。阿片类药物复合丙泊酚麻醉诱导可为LMA的置入创造一个良好的条件[1,2]。年龄是影响丙泊酚药效学的重要因素,达到同等效应时,老年人对丙泊酚的需要量明显减少[3,4]。LMA置入时年龄对丙泊酚麻醉诱导半数有效效应室浓度(EC50)、听觉诱发电位指数(AAI)的影响报道不多。本观察测定不同年龄患者LMA置入时丙泊酚麻醉诱导的EC50,并探讨年龄与EC50、AAI的相关性,为临床…     

气管插管后静脉注射利多卡因可以减轻哮喘患者的支气管收缩

背景尽管预防性静脉注射利多卡因可以减轻气道对多种吸入刺激的反应性，但是其对哮喘患者插管后气道阻力的影响尚不清楚。本文旨在检验哮喘患者静脉注射利多卡因是否可以减轻插管诱发的支气管收缩。方法30例哮喘患者[年龄49．1±15．9岁（均数±标准差）]在常规麻醉诱导（依托咪酯0．3mg／kg，芬太尼5μg/kg，罗库溴铵0．6mg／kg，50％氧化亚氮）后行气管插管。分别在插管后即刻、5、10和15分钟测定气道阻力。插管后5分钟，静脉注射利多卡因（利多卡因2mg／kg在5分钟内静脉推注，并以3mg·kg^-1·h^-1的速度持续输注10分钟）或生理盐水。结果插管后即刻的气道平均阻力为23±12cmH2O·s·L^-1。注射盐水后气道阻力进一步增加38％，但是注射利多卡因后气道阻力较注射前下降（26％，P〈0．004）。结论气管插管后静脉注射利多卡因可以减轻哮喘患者的支气管收缩。     

PTEN基因在哮喘患者中的表达及地塞米松对其调节作用的研究

目的探讨支气管哮喘患者气道黏膜组织PTEN基因的表达情况及地塞米松对其调节作用。方法 选择5例支气管哮喘患者及6例非哮喘患者作为对照,气道黏膜组织取自支气管纤维镜黏膜活检。人气道上皮细胞A549用来研究地塞米松对PTEN的调节作用。采用荧光定量PCR检测PTEN基因的表达变化。结果 PTEN基因在哮喘患者中的表达低于非哮喘患者（下降3.784倍）,两组比较差异有统计学意义（P〈0.05）。细胞实验证明地塞米松能上调人气道上皮细胞A549中PTEN的表达,呈时间和剂量依赖性（P〈0.01）。结论 PTEN参与人哮喘的发病机制,地塞米松对PTEN的上调作用可能是地塞米松治疗哮喘的新途径。     

静脉注射利多卡因对哮喘患者气道张力和肺功能的影响

背景为防止哮喘患者发生反射性支气管痉挛，通常以局部麻醉药喷雾或静脉注射作为辅助用药。利多卡因可减轻气道对可增加气道张力的神经性刺激的反应性，但仍缺乏有关利多卡因对气道基础张力影响的相关报道。因此，本研究检验了静脉注射利多卡因对哮喘患者气道基础张力的影响。方法用计算机X线断层扫描技术对15例哮喘志愿者基础状态下和输注利多卡因时的小气道（2～5mm）、中气道（5—8mm）和大气道（〉8mm）进行扫描，以分析在基础状态和输注利多卡因时气道管腔直径和气道壁厚度的变化，以及利多卡因引起的肺功能的改变。结果利多卡因显著降低1秒钟用力呼气量（forced expiratory volume in 1s，FEV1）（7±2％，P=0．006）。与基础状态相比，输注利多卡因期间气道管腔直径缩小并具有统计学意义（-3±0．5％，P〈0．001）。而且，FEV1的变化与气道管腔直径变化之间呈明显相关（r^2=0．47，P=0．01）。结论尽管利多卡因能减低气道对刺激感觉神经致气道痉挛药物的反应性，却并不降低基础气道张力。相反，即便是静注利多卡因亦会导致气道张力增高和气道狭窄。因此，当使用利多卡因预防气管插管所致支气管痉挛时，应用听诊法保持对气道的监测，即使是静注利多卡因期间亦应如此。     

病例报道：静脉注射利多卡因引起支气管痉挛

静脉注射利多卡因（1．5mg/kg）实施气管内插管引起一例17个月女婴短暂支气管痉挛,该女婴患有轻度间歇性哮喘。静脉注射利多卡因后即刻,患儿双肺出现弥漫性呼气性哮鸣音,且气道峰压急剧增高。大约5分钟后,患儿症状缓解,后续麻醉过程平稳。该病例与最近的临床研究相符,即静脉注射利多卡因可引起哮喘患者的气道收缩。麻醉医师应当高度警惕这种潜在的并发症。     

异丙酚和硫喷妥钠对气道压力影响的比较

异丙酚与硫喷妥钠相比具有扩张支气管,降低气道阻力的作用。但对于它们在气道敏感性正常病人的作用如何,研究尚少。本试验,旨在比较异丙酚与硫喷妥钠对气道敏感性正常病人的各项呼吸力学参数的影响。资料和方法2０例４５岁以下术前无心肺疾患、无过敏史、施行腹腔手术的成年男女病人,随机分为两组,每组１０例。其中异丙酚组（Ｐ组）男２例,女８例,平均年龄3５．５岁,平均体重５８．７ｋｇ;硫喷妥钠组（Ｔ组）男１例,女９例,平均年龄３９．４岁,平均体重６０．３ｋｇ。病人均不用麻醉前用药。Ｐ组诱导用药为异内酚 ２ｍｇ·ｋｇ…     

气道狭窄支架置入术的麻醉管理

气管 支气管内支架置入技术为治疗气道狭窄提供了有效的治疗手段。该治疗技术的麻醉管理是麻醉医师面临的具有挑战性的临床工作之一。现就气道狭窄病人的支架置入术及麻醉管理等进展作一综述。     

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.     

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.     

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.