Clarus可视管芯引导气管插管的临床运用

背景 Clarus可视管芯(Clarus Video System,CVS)是由美国Clarus公司研发的一种较新的可视光导管芯,其配备高清液晶显示屏及“J”形镜杆融合了可视软镜与光棒的优点,在国外已用于解决气管插管和处理困难气道,并发挥重要作用.目的 明确认识CVS的结构、插管准备工作、操作方法、临床运用及插管可能出现问题及处理对策,有益于提高CVS插管的有效性.内容 介绍CVS的结构、插管准备工作、操作方法、临床运用(包括普通气道和困难气道插管及改良运用)及临床运用可能出现的问题及处理对策.趋向 CVS作为新的可视光导管芯,无论在普通气道还是困难气道插管,单腔管还是双腔管插管,快速诱导或清醒插管,都是有效的工具之一.但在临床中仍应根据具体情况选择合适的操作方法和气管插管设备.     

可视喉罩的临床应用进展

喉罩是气道管理的重要工具,既可以作为声门上通气工具维持通气也可以在处理困难气道时联合可视软镜引导气管插管,并且随着双管喉罩的出现,扩展应用到院前急救,紧急气道处理等许多领域,然而其置入过程依旧盲探,存在移位、声门对位不佳、损伤等诸多风险。可视喉罩在原有喉罩通气基础上增加了可视功能,可观察到喉罩置入,喉罩留置及引导气管插管过程,并且减少了可视软镜等设备的需求,便于术中气道管理,本文从可视喉罩的分类及结构特点,临床应用情况对常用的可视喉罩进行阐述,为临床应用提供参考。     

超声在气道管理中的应用

背景 超声技术在临床麻醉中的应用越来越广泛,近些年关于其在气道管理中的应用也有了一些报道,并认为其安全、方便.目的 分析、总结超声在气道管理各方面应用的文献资料.内容 简要介绍上呼吸道的超声解剖以及获得满意的超声图像的方法和途径,综述超声技术在插管前评估、气管导管位置的确定、双腔气管导管和经皮扩张气管造口术(percu...     

超声检查术在临床气道管理中的应用进展

背景 超声检查术用于气道成像具有几方面的优势:安全、快捷、携带方便、重复性强和应用广泛,并可提供实时动态图像.已经在临床气道管理的许多方面进行了研究. 目的 介绍超声检查术在气道管理方面的应用及其前景. 内容 重点综述超声检查术在临床气道管理方面的应用,包括手术患者困难喉镜显露的预测,影响气道管理技术选择的病理情况评价,餐后状况评价,确定气管导管、支气管导管或气管切开套管的合适直径,气管和环甲膜定位,气道神经阻滞,气管导管位置的确认,经皮扩张气管切开术,鼻胃管位置的确认,气胸的诊断和成功拔管的预测等. 趋向 超声检查术是一项可改善气道管理的有用技术,极具临床价值.     

人工智能在气道管理中的应用

人工智能技术的发展促进了气道管理方法和设备的更新,具有优化、解决气道管理中延迟插管、气道困难和气管导管位置的评估等问题的潜力。本文总结了气道管理领域常用的人工智能模型,从患者气管插管需求的预测、困难气道患者的识别、气管导管定位、气管插管设备的自动化和智能化进行总结阐述,为围术期气道管理工作提供参考。     

困难气道患者的拔管策略

背景 困难气道患者拔管失败率相对较高,易出现严重的并发症.目的 对于困难气道患者,拔管前进行充分的气道评估,制定安全、可控的拔管策略非常重要.内容 重点介绍了困难气道或可疑困难气道患者拔管前的气道评估,以及针对不同的困难气道患者所应该采取的拔管处理策略.趋向 困难气道患者拔管前应该进行全面的气道评估,熟悉困难气道插管、拔管的操作流程、掌握气管导管交换器等困难拔管工具的操作技术以及插管失败后其他的可能选择,以提高困难气道患者围拔管期的安全.     

声门上通气装置引导气管插管的临床应用进展

声门上通气装置（SAD）在院前急救、常规麻醉及困难气道的开放、维持氧合等方面发挥着重要作用,同时也为引导气管插管提供了一个可行方式。在日常麻醉及手术室外治疗或抢救中,保持气道通畅和充分氧合是气道管理的关键。困难插管发生率约4.5%～7.5%,困难气道管理仍是麻醉管理中的重中之重。在困难插管发生时,先可放置SAD,后经SAD盲探或在可视设备辅助下行气管插管,迅速建立气道、提高首次插管成功率、减少插管过程中气道损伤。本文着重介绍不同种类可引导气管插管的SAD的临床应用进展。     

超声在气道管理中的应用进展

超声在气道管理领域的研究不断取得的进展,为临床上将超声应用于气道管理提供了理论依据和新思路,拓宽了超声在气道管理方面的应用范围。超声能够实时显影和测量全气道的几乎所有组织结构,保证气道解剖结构的准确定位及测量,为气道评估提供客观的理论支持。超声可实时成像的特点有助于引导气管插管、确定气管导管及喉罩位置、评估胃内容量等。人工智能提高了超声识别解剖结构的准确率和效率,促进超声在气道管理的拓展应用。本文简述超声在实时引导气管插管、确定气管插管位置、确认喉罩准确对位、预测成功拔管、预测困难气道、定位气道解剖结构、评估胃内容物误吸风险等方面的应用进展,并讨论超声结合人工智能在气道管理领域的应用。     

困难气道患者Cookgas气管插管型喉罩引导气管插管的效果

Cookgas气管插管型喉罩(CILA)是一种新型的气管插管型喉罩,具有管壁柔软、引导气管插管操作简单和喉罩退出容易的优点.本课题组的前期研究表明,在引导气管插管过程中,CILA对咽喉部粘膜的损伤轻,可辅助盲探、纤支镜(FOB)和视可尼喉镜(SOS)进行气管插管.本研究拟对困难气道患者评价CILA引导气管插管的效果,为临床提供参考.     

经Cookgas气管插管型喉罩视可尼喉镜引导全麻患者气管插管的可行性

经典喉罩管腔较小,只能使用内径小于6.0 mm的气管导管,且插管成功后喉罩退出困难,因而引导气管插管的使用范围有限。经典插管型喉罩虽然管腔较大,但其通气导管为硬质导管,无法使用各种纤维硬镜和各种可视管芯引导气管插管。而Cookgas气管插管型喉罩（CILA）是一种新型插管型喉罩,是用于引导气管插管和困难气管插管的有效工具。视可尼喉镜（SOS）是目前广泛应用于气管插管和困难气管插管的光导纤维硬镜，但能否采用SOS经CILA引导气管插管尚需进一步探讨。本研究拟评价SOS经CILA引导全麻患者气管插管的可行性，为临床应用提供参考。     

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.