单肺通气期间七氟醚对肺内分流的影响

目的：了解七氟醚对缺氧性肺血管收缩（ＨＰＶ）的抑制程度。方法：选择３４例开胸行非肺部手术病人随机分为七氟醚组（１２例）、氟烷组（１４例）、氯胺酮组（８例）。在双肺通气３０分钟、单肺通气２分钟、１０分钟、３０分钟及６０分钟同时采集动脉血和混合静脉血行血气分析，计算分流率。结果：双肺通气３０分钟时三组分流率无明显差别。七氟醚、氟完与氯胺酮相比能明显增加单肺通气期间肺分流率，抑制ＨＰＶ，ＰａＯ２、Ｐａｃ     

单肺通气氧合效果的临床观察

单肺通气氧合效果的临床观察李骐昂胸内手术实行单侧肺通气，手术野平静，便于手术操作，并且适合于气管、支气管手术。但是单肺通气引起肺内分流，导致静脉血掺杂，动脉血氧分压（ＰａＯ２）下降。为了升高ＰａＯ２临床上往往采取一些措施。本文采取吸入高浓度氧并观察单...     

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     

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     

吲哚美辛预治疗对单肺通气下血浆前列环素的影响

探讨吲哚美辛预处理对单肺通气时血浆６－ｋｅｔｏ－ＰＧＦ１α的影响。方法 双肺通气１５分钟，单肺通气１５分钟，４５分钟，７５分钟，双肺通气３０分钟５个时相分别测动脉血氧分压，用放免法检测血浆６－ｋｅｔｏ－ＰＧＦ１α含量。结果 Ｉ组ＰａＯ２随单肺通气时间的延长而下降，而血浆ＰＧＦ１α明显升高。     

单肺通气时PETCO2与PaCO2的关系

对２６例ＡＳＡＩ～Ⅱ级开胸肺手术的患者，分为Ａ、Ｂ两组，分别以双肺通气（ＴＬＶ）为对照行单肺通气（ＯＴＶ）或ＯＴＶ ＋术侧肺用Ｂａｉｎ回路行ＣＰＡＰ，测量ＴＬＶ３０分，ＯＬＶ３０分、６０分和Ｒ－ＴＬＶ３０分的ＰＥＴＣＯ２和ＰａＣＯ２值，观察两者的关系。结果表明，两组中ＯＬＶ时的ＰＥＴＣＯ２和ＰａＣＯ２均正常，但较ＴＬＶ时有升高的趋势（Ｐ＜０．０５），Ｒ－ＴＬＶ后又复原（Ｐ＞０．０５）；两组间ＯＬＶ时的测量值无差异（Ｐ＞０．０５），而ＰＥＴＣＯ２与Ｐ。ＣＯ２有密切的相关性（Ｐ＜０．０５）；Ｐ（ａ－ＥＴ）ＣＯ２和ＰＥＴＣＯ２的计算值在不同通气时无显著性差异，说明ＰＥＴＣＯ２可作为一种无创监测手段指导ＯＬＶ时的通气效果。     

单肺通气时改变呼吸频率对潮气量和每分钟通气量的影响

观察１７例肺叶切除术的病人，探讨双肺通气，单肺等容通气和单肺等压通气时不同呼吸频率对潮气，每分钟通气量及血气值的影响，结果提示，改变ｆ对气道压力无影响，ｆ与Ｖｔ呈负相关ｒ＝－０．９９．而ｆ与ＶＥ呈相关ｒ＝－０．９９．ＰＬＶ时ＴＬＶ时明显减少，ＶＥ也相应减少，若提高ｆ，若提高ｆ，可使ＯＬＶ－等容时ＶＥ的不足得以缓解。ＯＬＶ－等压则不然。ＯＬＶ时的血气值有所改变ＰａＯ２较ＴＬＶ降低５０％，而ＰａＣＯ３     

门脉阻断对家兔血液气体的影响

通过对２５只家兔门脉阻断（ＰＶＯ）及开放（ＰＶＲ）的血气分析，发现动脉血氧分压（ＰａＯ２）、二氧化碳分压（ＰａＣＯ２）、血氧饱和度（０２ＳＴ）、ｐＨ值、碱剩余（ＢＥ）、混合静脉血氧分压（ＰＯ２）及肺分流率（Ｓｈｕｎｔ）在ＰＶＯ及ＰＶＲ后均有不同程度的改变。提示门脉阻断对家兔血液气体有较大的影响。     

两种不同血气监测的标准与呼吸机撤离后复发的关系

文章对１３９例肺性脑病（简称肺脑）病人行机械通气治疗，应用两种不同的血气监测三项指标（ｐＨ、ＰａＣＯ２、ＰａＯ２）的标准，来判断撤离呼吸机的时间和条件。结果：撤机后短期内复发人数：甲组３例、乙组４２例。两组复发率有显著差异（Ｐ〈０．００１）。作者认为血气监测标准与呼吸机撤离后复发有着密切关系。     

肺高压小儿围术期低氧血症及处理

目的：为了提高先心病肺高压小儿围术期存活率，减少死亡率，探讨围术期低氧血症的原因及纠治低氧血症原则。方法：应用血气及肺动脉压力测定技术对４０例先天性心脏病室间隔缺损（ＶＳＤ）小儿（肺高压组２０例，肺动脉压正常组２０例）体外循环（ＣＰＢ）转流前、后血气及肺动脉压力变化进行了研究。结果：转流前，肺高压组ＰａＯ２明显低于对照组，Ａ－ａＤＯ２明显大于对照组。转流后，随着肺动脉压力降低，ＰａＯ２并无明显改善，肺高压组ＰａＯ２比对照组降低更为明显，Ａ－ａＤＯ２进一步加大。结论：上述结果可能与下列因素有关：（１）术前肺损伤较重；（２）ＣＰＢ加重肺损伤；（３）转后心功能降低。故加强围术期呼吸、循环管理至关重要。     

Facilitation of alternative one-lung and two-lung ventilation by use of an endotracheal tube exchanger for pediatric empyema during video-assisted thoracoscopy

Background Video-assisted thoracoscopic surgery (VATS) has emerged as an innovative and popular procedure for the management of postpneumonic empyema in children refractory to medical response. Alternative uses of two- and one-lung ventilations have been required during VATS. This study evaluated the efficacy of alternating one- and two-lung ventilation through intraoperatively through the same single-lumen endobronchial tube using a tube exchanger during a thoracoscopic procedure for pediatric empyema.Methods Between May 1995 and August 2001, 62 consecutive pediatric patients undergoing VATS for evacuation of the loculated empyema cavity were studied. The same single-lumen endobronchial tube was used, with an indwelling endotracheal tube exchanger in place for readjustment of the tube position to provide alternation of one- and two-lung ventilations in a thoracosopic procedure. Duration of operation, heart rate, mean arterial pressure, peak airway pressure, an partial pressure of oxygen (PaO₂) and carbon dioxide (PaCO₂) changes during one- and two-lung ventilations were recorded. The quality of lung deflation and inflation was rated by the surgeon using direct visualization as excellent, fair or poor.Results The mean operating time was 90 min (range, 50–120 min). No differences were found in heart rate, mean arterial pressure, or PaO₂ during one- and two-lung ventilations. Peak airway pressure and PaCO₂ during two-lung ventilation were significantly higher than during one-lung ventilation. The quality of lung deflation and inflation was judged excellent for all the patients.Conclusions The VATS procedure can be performed safely and effectively in children using proper anesthetic technique. Retention of a tube exchanger within a single-lumen endobronchial tube an easily provide alternative one- and two-lung ventilations without inducing any significant airway flow obstruction during the operation.     

支气管封堵器单肺通气在新生儿电视胸腔镜手术中的应用

目的探讨支气管封堵器（bronchial blocker,BB）行单肺通气（one lung ventilation,OLV）在新生儿电视胸腔镜手术（video-assisted thoracoscopicsugery,VATS）中应用的有效性和安全性。方法择期行VATS的患儿60例,按OLV方法完全随机平均分为支气管插管组（A组）和BB组（B组）,每组30例。比较两组患儿术前双肺通气时（T0）、OLV 10min（T1）、肺萎陷即刻（T2）、肺萎陷后30min（T3）、肺萎陷后60min（T4）、恢复双肺通气后10min（T5）和术毕6h（T6）、术毕12h（T7）的SpO2、动脉血氧分压（arterial blood partial pressure of oxygen, PaO2）、PET CO2、动脉血二氧化碳分压（arterial blood partial pressure of carbondioxide, PaCO2）、乳酸水平及气道压变化情况,比较两组患儿OLV情况和围术期情况。结果两组息儿气道压从T1开始升高,T4达到最高,T4时A组（34．8±4．9）cmH2O（1cmH2O=0．098kPa）较B组（30．0±4．3）cmH2O更为显著（P〈0．05）;T4时两组患儿SpO2和PaO2下降至最低,两组间比较差异无统计学意义（p〉0．05）;T4时两组患儿PETCO2和PaCO2升至最高,A组较B组更为显著（P〈0．05）;两组患儿乳酸水平呈升高趋势,但各时点差异无统计学意义（P〉0．05）。B组肺萎陷效果、术中出血量、手术时间、拔管时间、监护室时间和气管黏膜损伤情况均显著优于A组（P〈0．05）。结论BB行OLV可为新生儿VATS提供充分的通气和良好的肺萎陷。     

Comparative study of the non-dependent continuous positive pressure ventilation and high-frequency positive-pressure ventilation during one-lung ventilation for video-assisted thoracoscopic surgery

The application of volume controlled high-frequency positive-pressure ventilation (HFPPV) to the non-dependent lung (NL) may have comparable effects to continuous positive-airway pressure (CPAP) on the surgical conditions during one-lung ventilation (OLV) for video-assisted thoracoscopic surgery (VATS). After local Ethics Committee approval and informed consent, we randomly allocated 30 patients scheduled for elective VATS after the first 15?min of OLV to ventilate the NL with CPAP of 2?cm H(2)O (NL-CPAP(2)) and HFPPV using tidal volume 2?ml/kg, inspiratory to expiratory ratio <0.3 and respiratory rate 60/min (NL-HFPPV) for 30?min, each in a randomized crossover order. Intraoperative adequacy of surgical conditions was evaluated using a visual analog scale and the changes in hemodynamic and arterial oxygen were recorded. The application of NL-CPAP(2) and NL-HFPPV resulted in more improved arterial oxygenation than during OLV for VATS (P<0.001). The operative field was much better during the application of NL-CPAP(2) than during NL-HFPPV (P<0.001). We concluded that the application of CPAP to the NL during OLV offers good quality of operative field and improved arterial oxygenation for VATS.     

Techniques de ventilation artificielle sur un seul poumon en cours de thoracotomie

Different means of limiting the fall in arterial Po₂ produced by single lung artificial ventilation were studied in 60 patients during thoracotomy. Changing from ventilating both lungs to the one healthy lung in the lateral recumbent position, without modifying tidal volume and frequency, brought about a fall in arterial Po₂ from 180±56 to 67±40 mmHg. The alveolar to arterial oxygen gradient increased to 110±45 mmHg (the alveolar oxygen pressure being calculated). Reducing the tidal volume so as to keep the inflation pressure at its initial level did not improve the arterial Po₂ but slightly increased the arterial Pco₂ (2.3 mmHg). The use of 6 to 8 cm H₂O positive end-expiratory pressure did not significantly modify the arterial Po₂ or Pco₂. Increasing the inspired oxygen fraction from 0.5 to 0.7 increased the arterial Po₂ from 100±89 mmHg to 165±59 mmHg, whilst the alveolar to arterial oxygen gradient increased to 118±60 mmHg. Clamping the pulmonary artery increased the arterial Po₂ and dual lung ventilation restored it to its initial value. Therefore, the only effective means of increasing oxygenation was to increase the inspired oxygen fraction. Unilateral continuous positive airway pressure was not used so as not to impair surgery. Dual lung ventilation may be necessary if the arterial Po₂ remains low.     

Unilateral high-frequency jet ventilation during one-lung ventilation for thoracotomy

One-lung ventilation is indicated during thoracic operations for bronchopleural fistula, pulmonary abscess, and pulmonary hemorrhage in spite of the possibility of the development of severe hypoxemia. To evaluate methods for improving oxygen transport during one-lung ventilation, we applied high-frequency jet ventilation (HFJV) and continuous positive airway pressure (CPAP) to the nondependent lung following deflation to atmospheric pressure in each procedure, and measured the effects on cardiac output and arterial oxygenation. In each case, the dependent lung was ventilated with conventional intermittent positive pressure ventilation (IPPV).

Eight patients were studied during posterolateral thoracotomy using double-lumen endobronchial tubes. HFJV or CPAP to the nondependent lung improved arterial oxygenation significantly during both closed and open stages of the surgical procedures (p < 0.008). When the chest was open, HFJV maintained satisfactory cardiac output, whereas CPAP usually decreased cardiac output (p < 0.008). There were no significant differences in mean partial pressure of arterial carbon dioxide between HFJV, CPAP, and deflation to atmospheric pressure.

In conclusion, HFJV to the nondependent lung provides not only satisfactory oxygenation but also good cardiac output, thereby maintaining better oxygen transport than CPAP or deflation to atmospheric pressure, while the dependent lung is ventilated with IPPV during one-lung ventilation for thoracotomy.     

Unilateral high-frequency jet ventilation during one-lung ventilation for thoracotomy

One-lung ventilation is indicated during thoracic operations for bronchopleural fistula, pulmonary abscess, and pulmonary hemorrhage in spite of the possibility of the development of severe hypoxemia. To evaluate methods for improving oxygen transport during one-lung ventilation, we applied high-frequency jet ventilation (HFJV) and continuous positive airway pressure (CPAP) to the nondependent lung following deflation to atmospheric pressure in each procedure, and measured the effects on cardiac output and arterial oxygenation. In each case, the dependent lung was ventilated with conventional intermittent positive pressure ventilation (IPPV). Eight patients were studied during posterolateral thoracotomy using double-lumen endobronchial tubes. HFJV or CPAP to the nondependent lung improved arterial oxygenation significantly during both closed and open stages of the surgical procedures (p less than 0.008). When the chest was open, HFJV maintained satisfactory cardiac output, whereas CPAP usually decreased cardiac output (p less than 0.008). There were no significant differences in mean partial pressure of arterial carbon dioxide between HFJV, CPAP, and deflation to atmospheric pressure. In conclusion, HFJV to the nondependent lung provides not only satisfactory oxygenation but also good cardiac output, thereby maintaining better oxygen transport than CPAP or deflation to atmospheric pressure, while the dependent lung is ventilated with IPPV during one-lung ventilation for thoracotomy.     

Augmented spontaneous breathing and pulmonary gas exchange during pneumoperitoneum

BACKGROUND AND OBJECTIVE: Ventilation of the lungs with positive end-expiratory pressure during pneumoperitoneum has been shown to improve the arterial partial pressure of oxygen. The implications of spontaneous breathing on pulmonary gas exchange remain unknown in this setting. We therefore sought to examine the influence of pressure-support ventilation with spontaneous breathing on gas exchange during simulated laparoscopy. METHODS: Ten pigs were subjected to pneumoperitoneum at a pressure of 15 cmH2O. Animals received, in a random order, pressure-support and pressure-controlled ventilation for 60 min per mode. Inert gas and haemodynamic measurements were performed before changing to a subsequent mode. RESULTS: Pressure-support ventilation was more efficient than pressure-controlled ventilation regarding perfusion of normal V(A)/Q lung areas (78 +/- 4% vs. 72 +/- 5%) (P < 0.05), alveolar-arterial partial pressure of oxygen difference (9.73 +/- 1.3 vs. 11.2 +/- 1.2 kPa) and arterial partial pressure of oxygen (14.93 +/- 1.6 vs. 13.7 +/- 2.0 kPa) (P < 0.05). CONCLUSIONS: Pressure-support ventilation resulted in significantly better gas exchange than pressure-controlled ventilation in this model of simulated laparoscopy.     

Selective PEEP in Acute Bilateral Lung Disease. Effect on Patients in the Lateral Posture

Seven patients with acute respiratory failure due to diffuse and fairly uniform lung disease were studied during mechanical ventilation in the lateral decubital position with: (a) zero end-expiratory pressure (ZEEP) through a double-lumen oro-bronchial tube to permit a recording of the ventilation to each lung; (b) bilateral positive end-expiratory pressure (PEEP) of 1.2 kPa, with maintenance of ventilation distribution between lungs as observed during ZEEP; (c) selective PEEP of 1.2 kPa, applied to the dependent lung only, with ventilation as during ZEEP; and (d) conventional PEEP of 1.2 kPa applied to both lungs through a single-lumen tube, with free distribution of ventilation between the lungs. During ZEEP, 69% of ventilation was distributed to the non-dependent and 31% to the dependent lung; cardiac output was 6.51 X min-1, venous admixture (QS/QT) 40% and arterial oxygen tension (PaO2) 8.3 kPa. With bilateral PEEP, functional residual capacity (FRC) increased by 0.331, cardiac output was reduced to 5.11 X min-1 and venous admixture to 32%. PaO2 increased to 10.1 kPa. With selective PEEP the dependent lung FRC increased by 0.211 and the FRC of the non-dependent lung decreased by 0.081. Cardiac output increased to 6.11 X min-1, which was no longer significantly different from that during ZEEP. Venous admixture remained at the same level as with bilateral PEEP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Unilateral donor lung dysfunction does not preclude successful contralateral single lung transplantation.

Single lung transplantation remains limited by a severe shortage of suitable donor lungs. Potential lung donors are often deemed unsuitable because accepted criteria (both lungs clear on the chest roentgenogram, arterial oxygen tension greater than 300 mm Hg with an inspired oxygen fraction of 1.0, a positive end-expiratory pressure of 5 cm H2O, and no purulent secretions) do not distinguish between unilateral and bilateral pulmonary disease. Many adequate single lung grafts may be discarded as a result of contralateral aspiration or pulmonary trauma. We have recently used intraoperative unilateral ventilation and perfusion to assess single lung function in potential donors with contralateral lung disease. In the 11-month period ending October 1, 1990, we performed 18 single lung transplants. In four of these cases (22%), the donor chest roentgenogram or bronchoscopic examination demonstrated significant unilateral lung injury. Donor arterial oxygen tension, (inspired oxygen fraction 1.0; positive end-expiratory pressure 5 cm H2O) was below the accepted level in each case (246 +/- 47 mm Hg, mean +/- standard deviation). Through the sternotomy used for multiple organ harvest, the pulmonary artery to the injured lung was clamped. A double-lumen endotracheal tube or endobronchial balloon occlusion catheter was used to permit ventilation of the uninjured lung alone. A second measurement of arterial oxygen tension (inspired oxygen fraction 1.0; positive end-expiratory pressure 5 cm H2O) revealed excellent unilateral lung function in all four cases (499.5 +/- 43 mm Hg; p less than 0.0004). These single lung grafts (three right, one left) were transplanted uneventfully into four recipients (three with pulmonary fibrosis and one with primary pulmonary hypertension). Lung function early after transplantation was adequate in all patients. Two patients were extubated within 24 hours. There were two late deaths, one caused by rejection and Aspergillus infection and the other caused by cytomegalovirus 6 months after transplantation. Two patients are alive and doing well. We conclude that assessment of unilateral lung function in potential lung donors is indicated in selected cases, may be quickly and easily performed, and may significantly increase the availability of single lung grafts.     

Single-lung ventilation with carbon dioxide hemipneumothorax: hemodynamic and respiratory effects in piglets

Objectives: Video‐assisted thoracoscopic surgery (VATS) has become a standard procedure in pediatric surgery. To facilitate surgical access, the dependent lung has to collapse using intrathoracic carbon dioxide insufflation and/or single‐lung ventilation. These procedures can induce hemodynamic deteriorations in adults. The potential impacts of single‐lung ventilation in combination with capnothorax on hemodynamics in infants have never been studied before. Aim: We conducted a randomized experimental study focusing on hemodynamic and respiratory changes during single‐lung ventilation with or without capnothorax in a pediatric animal model. Methods: Twelve piglets were randomly assigned to receive single‐lung ventilation with (SLV‐CO₂) or without (SLV) capnothorax with an insufflation pressure of 5 mmHg for a period of two hours. Before, during, and after single‐lung ventilation, hemodynamic and respiratory parameters were measured. Results: Although mean arterial pressure remained stable during the course of the study and no critical incidents were monitored, cardiac index (CI) decreased significantly with SLV‐CO₂ (baseline 3.6 ± 1.6 l·min^?1·m^?2 vs 2.9 ± 1.1 l·min^?1·m^?2 at 120 min, P < 0.05). Furthermore, global end‐diastolic volume and intrathoracic blood volume (ITBV) decreased as well significantly with SLV‐CO₂, causing a significant between‐group difference in ITBV (P < 0.05). Conclusions: Despite a decrease in CI and preload parameters, the combination of single‐lung ventilation and low‐pressure capnothorax was well tolerated in piglets and could justify further clinical studies to be performed in infants and children focusing on hemodynamic and respiratory changes during VATS.