Bain环路对单肺通气时血气值及肺分流量的影响

目的与方法：选择２２例订前肺功能正常和轻度损害肺地切除术的病人，观察单肺通气（ＯＬＶ）期间术侧肺加用Ｂａｉｎ环路行持续气道正压通气ＣＰＡＰ）对Ｑｓ／Ｑｔ和氧合的影响。结果与结论：不用Ｂａｉｎ环路的１组病人，术侧肺完全萎缩，ＰａＯ２、ＰｖＯ２均明显降低，分别为双肺通气（ＴＬＶ）时的６３％和７４％，Ａ－ａＤＯ２和Ｑｓ／Ｑｔ升高，说明低氧血症与ＯＬＶ时严重肺内分流有关，而在术侧肺加明Ｂａｉｎ环路者上述变     

单肺麻醉期间非通气侧肺吹入氧化亚氮对肺内分流的影响

目的 探讨单肺麻醉期间对非通气侧肺吹入氧化亚氮（Ｎ２Ｏ）对减少肺内分流、预防低氧血症的作用。方法 择其开胸手术病人２２例，随机分两组：观察组、对照组各１１例。在单肺麻醉期间非通气侧肺吹入Ｎ２Ｏ，并在单肺通气后３０及６０分，分别采动脉血作血气分析，计算分流率（Ｑｓ／Ｑｔ）。在单肺麻醉期间非通气侧肺的支气管导管开口于大气中，并在单肺通气３０及６０分分别采动脉血作血气分析并计算Ｑｓ／Ｑｔ。结果 在单肺麻     

异丙酚对单肺通气时肺内分流的影响

目的：探讨异丙酚对单肺通气（ＯＬＶ）时缺氧性肺血管收缩（ＨＰＶ）、肺内分流的影响。方法：观察组用异丙酚６－１２ｍｇ．ｋｇ＾－１．ｈ＾－１静注，对照组用不抑制ＨＰＶ、对Ｑｓ／Ｑｔ无影响的普鲁卡因４０－６０ｍｇ．ｋｇ＾－１．ｈ＾－１静滴。观察两组ＯＬＶ不同时期Ｑｓ／Ｑｔ、ＰａＯ２、ＰｖＯ２、ＰａＣｏ２和ＰＨ变化。结果：ＯＬＶ时两组病人Ｑｓ／Ｑｔ和ＰａＯ２组内不同时值或组间同时值比较均无显著差异。结论：     

单肺通气期间提高PETCO2反映PaCO2准确性的研究

目的：探讨单肺通气期间影响ＰＥＴＣＯ的因素及如何提高ＰＥＴＣＯ２反映ＰａＣＯ２的准确性。方法：对２７例患者进行了临床研究。结果：（１）肺内分流（Ｑｓ／Ｑｔ）量显著影响ＰＥＴＣＯ２；（２）机械通气参数中，ＶＴ对其影响最大，其他依次为ＲＲ、ＦＩＯ２和Ｉ／Ｅ。结论：单肺通气较合理的参数为ＶＴ１０ｍｌ／ｋｇ，ＲＲ１２次／分，ＦＩＯ２０．８及Ｉ／Ｅ１２。     

单肺麻醉期间氟烷和氯胺酮对肺内分流的不同影响

单肺通气时缺氧性肺血管收缩（ＨＰＶ）使非通气侧肺内分流减少５０％。吸入麻醉药可抑制ＨＰＶ反应，使Ｑｓ／Ｑｔ增加，ＰａＯ２下降。就氟烷和氯胺酮对ＨＰＶ和 Ｑｓ／Ｑｔ的影响，在２２例开胸行非肺部手术的成年患者中进行对比观察。结果：两组在ＯＬＶ２分钟时Ｑｓ／Ｑｔ明显上升，１０分钟时呈下降趋势，但氟烷组Ｑｓ／Ｑｔ明显高于氯胺酮组，表明氟烷时ＨＰＶ有抑制作用。ＰａＯ２、ＰａＣＯ２、ＰｖＯ２、ｐＨ等观察指标有相应变化，但尚在正常范围。     

三种药物对心脏瓣膜置换术后早期肺高压治疗的对比观察

目的 观察吸入一氧化氮（ＮＯ），静注前列腺素Ｅ１及米力农对心脏瓣膜置换术患者体外循环后早期肺高压的治疗作用，并比较它们对血液动力学和肺内分流率（Ｑｓ／Ｑｔ）的影响。方法 选择瓣膜病合并肺高压瓣膜置换术患者３１例，主动脉插管拔除后５分开始用药治疗，随机分为三组：吸入ＮＯ（Ｎ组，９例）静注前列腺素Ｅ１（Ｐ组，１０例）静注米力农（Ｍ组，１２例），采用Ｓｗａｎ－Ｇａｎｚ导管技术测定血浆液动力学参数，取构动     

坐位全身麻醉对肺血液动力及肺内分流的影响

目的 观测神经外科手术中坐位全身麻醉对肺血液动力及肺内分流（Ｑｓ／Ｑｔ）的影响。方法 ２８例后颅窝及后颈髓手术病人，采用静脉复合诱导、吸入七氟醚或安氟醚及伍用芬太尼维持麻醉，以Ｓｗａｎ－Ｇａｎｚ导管和动脉、混合静脉缺血气检测方法监测血液动力学和肺内分流状况，参数包括ＣＩ、ＲＡＰ、ＭＰＡＰ、ＰＣＷＰ、ＰＶＲＩ、ｐＨａ、ＰａＣＯ２、ＰａＯ２、ＰａＯ２／ＦｉＯ２及Ｑｓ／Ｑｔ。分别在麻醉前、坐位前、坐位后     

异丙酚和安氟醚对单肺通气时肺内分流的影响

异丙酚是一种新型静脉麻醉药，本文报告异丙酚静脉麻醉和安氟醚吸入麻醉时单肺通气（ＯＬＶ）条件下对肺内分流（Ｑｓ／Ｑｔ）的影响。资料与方法病例选择及分组　选择需行ＯＬＶ的肺、食管手术患者４０例，随机分为两组，异丙酚组（Ⅰ组）和安氟醚组（Ⅱ组）各２０例。Ⅰ组男１３，女７例，年龄（５４．１４±６．９５）岁，体重（５６．８６±７．８）ｋｇ；Ⅱ组男１２，女８例，年龄（５３．１６±７．３２）岁，体重（５４．４０±８．５）ｋｇ。两组手术均为肺叶切除和食管癌根治术，肺与食管手术各１０例。术前病人无明显心、肺、肝、…     

地氟醚与异氟醚吸入对单肺通气肺内分流影响的比较

缺氧性肺血管收缩（ＨＰＶ）是肺血流重要的自身调节机制之一［１］。吸入麻醉药对ＨＰＶ均有不同程度的抑制作用,使单肺通气（ＯＬＶ）时Ｑ_ｓ／Ｑ_ｔ增加,Ｐ_ａＯ_２下降［２］。有文献报道,与氟烷及安氟醚相比,异氟醚抑制最轻［５］。本文以开胸手术需单肺通气的病人进行观察,比较地氟醚和异氟醚相同剂量吸入对单肺通气肺内分流（ＱＳ／Ｑｔ）的影响及动脉氧分压（ＰａＯ_２）降低的程度。探讨两药对单肺通气时ＨＰＶ的影响。资料与方法无心血管疾病,肺功能基本正常的择期需开胸单肺通气病人２０例,ＡＳＡ为Ⅰ～Ⅱ级,随机分为地…     

相同MAC浓度的安氟醚和异氟醚对脑电图功率谱的影响

２４例 ２０～５０岁、ＡＳＡⅠ级、行择期外科手术的患者，随机分成两组：安氟醚组和异氟醚组。不用术前药，麻醉诱导以静脉硫喷妥钠５ｍｇ／ｋｇ、阿曲库胺０．６～０．７ｍｇ／ｋｇ。单纯吸入安氟醚或异氟醚维持全麻。气管插管后控制呼吸，维持呼气末二氧化碳分压（ＰＥＴＣＯ２）４．２７。４．９３ｈｐａ。以ＴＯＦ监测肌松，间断给予阿曲库胺 １０～１５ｍｇ，维持Ｔ４／Ｔ１＜２５％。采用 ＦＰ１－Ａ１、ＦＰ２－Ａ２双导联监护脑电，验证呼气末麻醉药浓度在 ０． ５、０．８、１． ０、１． ３和 １．５ ＭＡＣ时的脑电功率谱、９５％边缘频率（ＳＥＦ）和中心频率（ＭＰＦ）改变。结果发现，随ＭＡＣ增加脑电功率谱表现出波增加，α和β波减少，而ＳＥＦ、ＭＰＦ值随ＭＡＣ增加而减少的改变呈负性线性关系，ｒ＝－０．９５。提示脑电功率谱、ＳＥＦ和ＭＰＦ在评价全麻深度上有一定意义。     

Prevention of atelectasis formation during the induction of general anesthesia in morbidly obese patients

Atelectasis caused by general anesthesia is increased in morbidly obese patients. We have shown that application of positive end-expiratory pressure (PEEP) during the induction of anesthesia prevents atelectasis formation in nonobese patients. We therefore studied the efficacy of PEEP in morbidly obese patients to prevent atelectasis. Twenty-three adult morbidly obese patients (body mass index >35 kg/m(2)) were randomly assigned to one of two groups. In the PEEP group, patients breathed 100% oxygen (5 min) with a continuous positive airway pressure of 10 cm H(2)O and, after the induction, mechanical ventilation via a face mask with a PEEP of 10 cm H(2)O. In the control group, the same induction was applied but without continuous positive airway pressure or PEEP. Atelectasis, determined by computed tomography, and blood gas analysis were measured twice: before the induction and directly after intubation. After endotracheal intubation, patients of the control group showed an increase in the amount of atelectasis, which was much larger than in the PEEP group (10.4% +/- 4.8% in control group versus 1.7% +/- 1.3% in PEEP group; P < 0.001). After intubation with a fraction of inspired oxygen of 1.0, PaO(2) was significantly higher in the PEEP group compared with the control group (457 +/- 130 mm Hg versus 315 +/- 100 mm Hg, respectively; P = 0.035) We conclude that in morbidly obese patients, atelectasis formation is largely prevented by PEEP applied during the anesthetic induction and is associated with a better oxygenation. IMPLICATIONS: Application of positive end-expiratory pressure during induction of general anesthesia in morbidly obese patients prevents atelectasis formation and improves oxygenation. Therefore, this technique should be considered for anesthesia induction in morbidly obese patients.     

Prevention of atelectasis formation during induction of general anesthesia

General anesthesia promotes atelectasis formation, which is augmented by administration of large oxygen concentrations. We studied the efficacy of positive end-expiratory pressure (PEEP) application during the induction of general anesthesia (fraction of inspired oxygen [FIO(2)] 1.0) to prevent atelectasis. Sixteen adult patients were randomly assigned to one of two groups. Both groups breathed 100% O(2) for 5 min and, after a general anesthesia induction, mechanical ventilation via a face mask with a FIO(2) of 1.0 for another 5 min before endotracheal intubation. Patients in the first group (PEEP group) had continuous positive airway pressure (CPAP) (6 cm H(2)O) and mechanical ventilation via a face mask with a PEEP of 6 cm H(2)O. No CPAP or PEEP was applied in the control group. Atelectasis, determined by computed radiograph tomography, and analysis of blood gases were measured twice: before the beginning of anesthesia and directly after the intubation. There was no difference between groups before the anesthesia induction. After endotracheal intubation, patients in the control group showed an increase of the mean area of atelectasis from 0.8% +/- 0.9% to 4.1% +/- 2.0% (P = 0.0002), whereas the patients of the PEEP group showed no change (0.5% +/- 0.6% versus 0.4% +/- 0.7%). After the intubation with a FIO(2) of 1.0, PaO(2) was significantly higher in the PEEP group than in the control (591 +/- 54 mm Hg versus 457 +/- 99 mm Hg; P = 0.005). Atelectasis formation is prevented by application of PEEP during the anesthesia induction despite the use of large oxygen concentrations, resulting in improved oxygenation. IMPLICATIONS: Application of positive end-expiratory pressure during the induction of general anesthesia prevents atelectasis formation. Furthermore, it improves oxygenation and probably increases the margin of safety before intubation. Therefore, this technique should be considered for all anesthesia induction, at least in patients at risk of difficult airway management during the anesthesia induction.     

Electrogastrographic changes in children who undergo day-surgery anesthesia.

BACKGROUND/PURPOSE: Postoperative nausea and vomiting is common after general anesthesia. The timing of resuming oral input is arbitrary. This study aims to estimate the duration of emetic effects of general anesthesia after day surgery in children with electrogastrography (EGG). METHODS: Children between the age of 3 and 12 years undergoing elective nonabdominal surgery were recruited. The standard anesthesia protocol of thiopentone (5 mg/kg), O2 (30%), N2O (70%), and isoflurane (1.5%) was adopted. Caudal block was applied to the patients. A laryngeal mask was used. A mobile electrogastrogram (EGG) machine (Synectic; International Medtronic Synectics, Stockholm, Sweden) was attached to the epigastrium of the patient at least 1 hour before the operation and the recording continued through the operation and for a further 2 hours after the operation. The first half hour of preoperative recording was taken as normal control period. The results were analyzed using paired t test. RESULTS: Twenty patients who underwent circumcision under general anesthesia were studied. The mean age was 6.6 years. The mean anesthetic duration was 33.2 min. The tachygastria component (associated with nausea and vomiting) became prominent immediately after induction and returned to normal 1 half hour after cessation of general anesthesia. The dominant frequency instability coefficient of EGG (DFIC) and the dominant power instability coefficient (DPIC) peaked during the first half hour period postoperatively and returned to baseline 1 hour postoperatively (DPIC, P>.05). Bradygastria became prominent during the periods 1 half-hour before and 1 half-hour after the general anesthesia and returned to baseline 1 hour postoperatively (P<.05). CONCLUSIONS: Significant EGG changes occur during day-surgery general anesthesia for children undergoing nonabdominal surgery. These changes return to baseline 1 hour after reversal of anesthesia. It is probably safe to restart feeding 1 hour later after day-surgery general anesthesia without causing nausea and vomiting.     

Effect of respiratory care on pulmonary function in patients after cardiopulmonary bypass

BACKGROUND: Respiratory failure after cardiopulmonary bypass (CPB) remains one of the major complications after cardiac surgery. This study was designed to evaluate effects of respiratory care after CPB on pulmonary function. METHODS: Eighteen patients scheduled for cardiac surgery were investigated. Preoperative respiratory functions (%VC, FEV1.0%, V25/Ht, FRC-CC, deltaN2) were measured in all the patients. Both induction and maintenance of anesthesia were performed using propofol, midazolam, fentanyl, and vecuronium bromide. All the patients were ventilated using volume controlled ventilation by setting FIO2 at 0.5, the respiratory frequency at 15 x min(-1), the tidal volume at 6-10 ml x kg(-1) adjusted to maintain PaCO2 between 30 to 40 mmHg, and the peak airway pressures below 40 cmH2O, PEEP of 0 cmH2O. From 1 hour after the operation, the patients were randomly divided into 2 groups: group A, ventilated artificially with PEEP of 5 cmH2O and group B, ventilated with PEEP adjusted to the patient's lower inflection point (LIP) obtained by the pressure-volume curve. PaO2, Qs/Qt and FRC were measured after induction of anesthesia, just after surgery, 1 hour after surgery and 1 hour after artificial ventilation with PEEP. The values of the LIP were obtained from the P-V curves with the constant-flow methods before and after surgery. RESULTS: PaO2 and FRC decreased and Qs/Qt increased significantly after the surgery in all the patients. One hour after artificial ventilation with PEEP, PaO2 increased and Qs/Qt decreased significantly compared with the values after operation. However, there was no significant difference in the magnitude of these changes among the different groups. The changes in PaO2 and Qs/Qt were not correlated with the changes in FRC and preoperative respiratory functions. The LIP tended to increase after surgery in 2 groups. CONCLUSIONS: Although pulmonary function deteriorated after CPB. PEEP could improve oxygenation in all the patients. There were no significant differences in the degree of these improvements between patients receiving PEEP of 5 cmH2O and patients with PEEP adjusted to their LIP. There was no significant relationship between preoperative pulmonary function and changes in oxygenation after CPB.     

Positive end-expiratory pressure during induction of general anesthesia increases duration of nonhypoxic apnea in morbidly obese patients

Positive end-expiratory pressure (PEEP) applied during induction of anesthesia prevents atelectasis formation and increases the duration of nonhypoxic apnea in nonobese patients. PEEP also prevents atelectasis formation in morbidly obese patients. Because morbidly obese patients have difficult airway management more often and because arterial desaturation develops rapidly, we studied the clinical benefit of PEEP applied during anesthesia induction. Thirty morbidly obese patients were randomly allocated to one of two groups. In the PEEP group, patients breathed 100% O(2) through a continuous positive airway pressure device (10 cm H(2)O) for 5 min. After induction of anesthesia, they were mechanically ventilated with PEEP (10 cm H(2)O) for another 5 min until tracheal intubation. In the control group, the sequence was the same but without any continuous positive airway pressure or PEEP. We measured apnea duration until Spo(2) reached 90% and we performed arterial blood gases analyses just before apnea and at 92% Spo(2). Nonhypoxic apnea duration was longer in the PEEP group compared with the control group (188 +/- 46 versus 127 +/- 43 s; P = 0.002). Pao(2) was higher before apnea in the PEEP group (P = 0.038). Application of positive airway pressure during induction of general anesthesia in morbidly obese patients increases nonhypoxic apnea duration by 50%.     

Intraoperative phenylephrine infusion decreases the magnitude of redistribution hypothermia.

Core hypothermia during the first hour after induction of general anesthesia results largely from an internal core-to-peripheral redistribution of body heat. This redistribution results from both central inhibition of tonic thermoregulatory vasoconstriction in the arteriovenous shunt and anesthetic-induced vasodilation. We therefore tested the hypothesis that acute administration of phenylephrine, a pure alpha-adrenergic agonist, reduces the magnitude of anesthetic-induced core-to-peripheral redistribution of body heat. Patients undergoing minor oral surgery were randomly assigned to an infusion of 0.5 microgram.kg-1.min-1 phenylephrine i.v. or no treatment (control). The phenylephrine infusion was started immediately before anesthesia was induced with 2.5 mg/kg propofol i.v. Subsequently, anesthesia was maintained with sevoflurane and 60% nitrous oxide in oxygen. Calf minus toe, skin-temperature gradients < 0 degree C were considered indicative of significant arteriovenous shunt vasodilation. Ambient temperature and end-tidal concentrations of maintenance sevoflurane were comparable in each group. Although there were no significant differences in skin-temperature gradients, core temperatures in the untreated patients decreased significantly more (1.2 +/- 0.4 degrees C) than in those given phenylephrine (0.5 +/- 0.2 degree C, P < 0.001). These data suggest that maintaining precapillary vasoconstriction of blood vessels, not in the arteriovenous shunt reduces the magnitude of redistribution hypothermia. Implications: Core hypothermia immediately after induction of general anesthesia results largely from core-to-peripheral redistribution of body heat. Core temperature reduction during the first hour of anesthesia decreased less in patients given phenylephrine than in untreated controls. These data suggest that maintaining precapillary vasoconstriction possibly reduces the magnitude of redistribution hypothermia.     

Ventilation-perfusion relationships and atelectasis formation in the supine and lateral positions during conventional mechanical and differential ventilation

Patients without respiratory symptoms were studied awake and during general anesthesia with mechanical ventilation prior to elective surgery. Ventilation-perfusion (VA/Q) relationships, gas exchange and atelectasis formation were studied during five different conditions: 1) supine, awake; 2) supine during anesthesia with conventional mechanical ventilation (CV); 3) in the left lateral position during CV; 4) as 3) but with 10 cm of positive end-expiratory pressure (PEEP) and 5) as 3) but using differential ventilation with selective PEEP (DV + SPEEP) to the dependent lung. Atelectatic areas and increases of shunt blood flow and blood flow to regions with low VA/Q ratios appeared after induction of anesthesia and CV. With the patients in the lateral position, further VA/Q mismatch with a fall in PaO2 and increased dead space ventilation was observed. Atelectatic lung areas were still present, although the total atelectatic area was slightly decreased. Some of the effects caused by the lateral position could be counteracted by adding PEEP. Perfusion of regions with low VA/Q ratios and venous admixture were then diminished, while PaO2 was slightly increased; shunt blood flow and dead space ventilation were essentially unchanged. During CV + PEEP, there was a decrease in cardiac output, compared to CV in the lateral position. DV + SPEEP was more effective than CV + PEEP in decreasing shunt flow and increasing PaO2 in the lateral position; in addition to this, cardiac output was not affected.     

不同水平呼气末正压通气对肥胖患者围术期呼吸功能的影响

目的 评价不同水平呼气末正压(PEEP)通气对肥胖患者胃减容手术围术期呼吸功能的影响.方法 选择2018年3月至2019年12月于我院行择期腹腔镜下胃减容手术肥胖患者70例,男43例,女27例,年龄28～52岁,BMI 34～43 kg/m2,ASAⅡ或Ⅲ级.采用随机数字表法将患者分为两组:PEEP 10 cmH2 O...     

麻醉诱导期开始采用肺保护性通气策略对妇科腔镜手术患者氧合及预后的影响

目的探讨从麻醉诱导期开始采用肺保护性通气策略对妇科腔镜手术患者氧合及预后的影响。方法选择在本院接受妇科腹腔镜手术的患者60例,随机分为三组,每组20例。采用间歇正压通气(IPPV)模式,氧浓度为100%,氧气流量2 L/min,吸呼比为1∶2。A组:从诱导期(即自主呼吸消失后,予面罩机械通气5 min)开始全程通气模式:VT6 ml/kg,RR 16次/分,PEEP为5cm H2O,每30分钟给予一次手法肺复张(手控通气,气道压力维持40 cm H2O,持续30 s);B组:诱导期通气模式:VT10 ml/kg,RR 10次/分,插管后通气模式:VT6 ml/kg,RR 16次/分,PEEP 5cm H2O,每30分钟给予一次手法肺复张;C组:全程通气模式均为VT10 ml/kg,RR 10次/分。记录插管前(T0)、气腹后(T1)、手术开始30 min(T2)、60 min(T3)、放气腹(T4)时的气道峰压(Ppeak)、平均气道压(Pmean)、计算肺顺应性(CL),并在T0、T1、T3、清醒拔管后吸空气5 min(T5)时抽取动脉血进行血气分析,计算氧合指数(OI)及肺内分流率(Qs/Qt)。记录患者术后并发症发生情况与住院天数。结果与T0时比较,T1~T4时三组Ppeak和Pmean均明显升高,C组Ppeak明显高于A组和B组(P0.05),T2时C组Pmean明显高于A组和B组(P0.05);三组CL在气腹后明显降低(P0.05),T3和T4时C组明显低于A组和B组(P0.05);三组PETCO2在气腹后明显升高,T2~T4时C组明显低于A组与B组(P0.05),A组与B组差异无统计学意义;三组OI随着时间延长变化差异无统计学意义,拔管后三组均明显降低(P0.05);三组Qs/Qt随着手术进行呈上升趋势,与T0时比较,三组在T3时明显上升(P0.05),C组明显大于A组和B组(P0.05);T5时均明显下降(P0.05)。术后仅C组有1例发生肺部感染。结论与常规通气相比,对接受妇科腔镜手术患者采用保护性肺通气策略能够明显改善患者的肺顺应性和氧合功能,有利于肺保护。     

The effect of sedation with propofol and fentanyl during epidural catheter insertion on intraoperative temperatures

General anesthesia inhibits thermoregulation by suppressing tonic vasoconstriction and facilitates a core-to-peripheral redistribution of body heat, which is the major cause of core hypothermia during the first hour of anesthesia. We randomly assigned 16 patients to two groups; 1) patients who received fentanyl (1 microgram.kg-1, i.v.) and propofol (1.5 mg.kg-1.h-1) during insertion of epidural catheters (P group), and 2) no drug (control) group (C group). We measured tympanic (Ttym) and skin temperatures at the time of admission to operating rooms, after dural catheter insertion, before induction of anesthesia, just after induction of anesthesia, and one hour after induction. After dural catheter insertion, forearm-finger tip skin temperature gradient of P group was significantly smaller than C group. One hour after induction of anesthesia, Ttym of P group was significantly higher than C group. We can conclude that a sedative dose of propofol and fentanyl before induction of general anesthesia inhibits redistribution hypothermia during general anesthesia.