呼吸机在治疗创伤性颈髓损伤呼吸衰竭中的应用

总结创伤性颈髓损伤合并呼吸衰竭患者使用呼吸机的适应证，比较了CMV及SIMV、正常吸呼比及反比呼吸的血气值、认为在早期宜采用CMV模式及反比呼吸，脱机时应采用间断脱机法，C4及以下水平损伤者脱机前可改用PS法。使用呼吸机的合并症主要有肺部感染、酸碱及水电解质平衡紊乱、气道阻塞等。     

Field 5. Safety practices procedures for mechanical ventilation. French-speaking Society of Intensive Care. French Society of Anesthesia and Resuscitation

Invasive or endotracheal mechanical ventilation can lead to numerous complications likely to burden morbidity and mortality of patients in the intensive care unit. Various safety practices for mechanical ventilation may involve intubation, the mechanical ventilation period, weaning and extubation, the use of tracheostomy as well as non-invasive ventilation. The main objective of safety practices described in this chapter is to prevent or avoid the main risks due to invasive mechanical ventilation.     

Ventilatory support in the intensive care unit

This article focuses on a classification of modes of mechanical ventilation, the indications for and complications of invasive and non-invasive mechanical ventilation and adjuncts to mechanical ventilation.     

危重患者术后机械通气的应用

目的探讨机械通气在ICU危重患者术后的应用。方法对20例外科危重患者在出现呼吸危象的情况下，建立人工气道，应用呼吸机辅助呼吸。结果20例中，脱离呼吸机15例；痊愈14例，死亡5例，植物状态1例，最长通气时间152天。结论对外科危重病患者及早行机械通气是治疗呼吸衰竭最有效和迅速的方法。小潮气量通气、把握呼吸机撤离的时机、控制感染是减少并发症、提高抢救成功率的关键。     

Ventilatory support in the intensive care unit

This article focuses on a classification of modes of mechanical ventilation, the indications for and complications of invasive and non-invasive mechanical ventilation and the recent evidence on adjuncts to mechanical ventilation.     

早期机械通气对颅脑损伤合并呼吸衰竭的应用价值

目的探讨早期机械通气对颅脑损伤合并呼吸衰竭的应用价值。方法选取笔者所在医院2007年6月～2011年9月收治的106例颅脑损伤合并呼吸衰竭患者,将其分为对照组、常规机械通气组、早期机械通气组。比较三组通气前后PaO2、PaCO2、SaO2等血气指标及GCS评分、LIS评分、ALI指数变化。结果三组抢救成功率分别为59.34%、64.26%和70.67%,其中早期机械通气组的抢救成功率明显高于对照组、常规机械通气组,差异有统计学意义（P〈0.05）;三组患者治疗后各项指标均有显著改善,但早期机械通气组治疗前后比较具有统计学意义（P〈0.01）;早期机械通气组与对照组、常规机械通气组治疗后各项指标比较,差异有统计学意义（P〈0.05）。结论颅脑损伤合并呼吸衰竭患者早期机械通气可改善低氧血症,减轻脑水肿和颅内高压,对改善疾病预后有重要临床意义。     

Protektive Beatmungstherapie

General anesthesia and mechanical ventilation affect gas exchange, ventilation and pulmonary perfusion and there is an increasing body of evidence that mechanical ventilation itself promotes lung injury. Lung protective mechanical ventilation in patients suffering from acute lung injury or acute respiratory distress syndrome by means of reduced tidal volumes and limited plateau pressures has been shown to result in reduction of systemic inflammatory mediators, increased ventilator-free days and reduction in mortality. Experimental studies suggest that mechanical ventilation of uninjured lungs may also induce lung damage; however, the clinical relevance remains unknown. Human prospective studies comparing mechanical ventilation strategies during general anesthesia have shown inconsistent results with respect to inflammatory mediators. There is a lack of clinical evidence that lung protective ventilation strategies as used in patients with lung injury may improve clinical outcome of patients with uninjured lungs. The question of which ventilatory strategy will best protect normal human lungs remains unanswered.     

Survival following mechanical ventilation of recipients of bone marrow transplants and peripheral blood stem cell transplants

Survival of bone marrow transplant recipients requiring mechanical ventilation is poor but improving. This study reports a retrospective audit of all haematopoietic stem cell transplant (HSCT) recipients requiring mechanical ventilation at an Australian institution over a period spanning 11 years from 1988 to 1998. Recipients of autologous transplants are significantly less likely to require mechanical ventilation than recipients of allogeneic transplants. Of 50 patients requiring mechanical ventilation, 28% survived to discharge from the intensive care unit, 20% to 30 days post-ventilation, 18% to discharge from hospital and 12% to six months post-ventilation. Risk factors for mortality in the HSCT recipient requiring mechanical ventilation include renal, hepatic and cardiovascular insufficiency and greater severity of illness. Mechanical ventilation of HSCT recipients should not be regarded as futile therapy.     

机械通气治疗腹部外科术后急性呼吸衰竭的临床研究

目的探讨腹部外科术后发生急性呼吸衰竭的诱因及影响机械通气疗效的因素。方法回顾性分析91例患者腹部外科术后发生急性呼吸衰竭的基础疾病、诱因及机械通气治疗的效果。结果诱因包括术后发生肺部感染53例，严重腹腔感染或急性重症胰腺炎导致的急性呼吸窘迫综合征(ARDS) 38例。其中合并慢性阻塞性肺病(COPD)38例，重度营养不良32例，低钾血症14例。呼吸衰竭发生在术后(4.08±2.45)d，机械通气维持时间(21.66±21.42)d。死亡33例（36.3%），撤机成功58例（63.7%）。结论腹部外科术后发生急性呼吸衰竭时，应合理实施机械通气并调整撤机策略，避免机械通气依赖。及时处理原发病，有效控制腹腔感染，积极进行对症与支持治疗是影响机械通气成败的因素。     

纤维支气管镜联合机械通气序贯治疗老年COPD严重呼吸衰竭的临床研究

目的：探讨纤维支气管镜联合机械通气序贯治疗老年COPD严重呼吸衰竭的临床效果。方法选择我科收治的116例老年COPD严重呼吸衰竭患者,随机分为纤维支气管镜联合机械通气序贯治疗组（简称观察组）以及单纯机械通气序贯治疗组（简称对照组）,每组各58例。观察两组患者的临床疗效,机械通气治疗后的相关指标以及切换时间窗时的血气分析指标。结果观察组患者有效率84.48%,优于对照组有效率70.69%,差异具有统计学意义（P＜0.05）。与对照组比较,观察组的有创机械通气时间、总机械通气时间、呼吸衰竭纠正时间、感染控制窗出现时间、住院时间以及PaCO2均降低明显,PaO2和pH值则升高明显,差异具有统计学意义（P＜0.05）。结论纤维支气管镜联合机械通气序贯治疗老年COPD严重呼吸衰竭,可有效改善患者临床症状,缩短机械通气时间,提高疗效,具有临床推广价值。     

„Neurally adjusted ventilatory assist“ (NAVA)

The aim of mechanical ventilation is to assure gas exchange while efficiently unloading the respiratory muscles and mechanical ventilation is an integral part of the care of patients with acute respiratory failure. Modern lung protective strategies of mechanical ventilation include low-tidal-volume ventilation and the continuation of spontaneous breathing which has been shown to be beneficial in reducing atelectasis and improving oxygenation. Poor patient-ventilator interaction is a major issue during conventional assisted ventilation. Neurally adjusted ventilator assist (NAVA) is a new mode of mechanical ventilation that uses the electrical activity of the diaphragm (EAdi) to control the ventilator. First experimental studies showed an improved patient-ventilator synchrony and an efficient unloading of the respiratory muscles. Future clinical studies will have to show that NAVA is of clinical advantage when compared to conventional modes of assisted mechanical ventilation. This review characterizes NAVA according to current publications on this topic.     

Flail chest syndrome and pulmonary contusion.

Controlled mechanical ventilation has been the mainstay of treatment in the flail chest syndrome for more than 20 years, retrospective studies have recently suggested that the technique is unnecessary, and they infer that spontaneous ventilation or intermittent mandatory ventilation are equally effective. The common theme of these investigations is that mechanical ventilation is required only to relieve hypoxemia associated with the underlying contusion. In two cases of flail chest, spontaneous respiratory efforts resulted in complete disruption of the fracture sites and thus prolonged the duration of mechanical ventilation that was required. In severe cases of flail chest syndrome, there is still a need for controlled mechanical ventilation to splint the rib fractures in a position which facilitates union of the fragments.     

Tracheostomy timing in traumatic spinal cord injury

The study conducted is the retrospective study and the main objective is to evaluate the benefits and safety of early versus late tracheostomy in traumatic spinal cord injury (SCI) patients requiring mechanical ventilation. Tracheostomy offers many advantages in critical patients who require prolonged mechanical ventilation. Despite the large amount of patients treated, there is still an open debate about advantages of early versus late tracheostomy. Early tracheostomy following the short orotracheal intubation is probably beneficial in appropriately selected patients. It is a retrospective clinical study and we evaluated clinical records of 152 consecutive trauma patients who required mechanical ventilation and who received tracheostomy. The results show that the early placement (before day 7 of mechanical ventilation) offers clear advantages for shortening of mechanical ventilation, reducing ICU stay and lowering rates of severe orotracheal intubation complication, such as tracheal granulomas and concentric tracheal stenosis. On the other hand, we could not demonstrate that early tracheostomy avoids neither risk of ventilator-associated pneumonia nor the mortality rate. In SCI patients, the early tracheostomy was associated with shorter duration of mechanical ventilation, shorter length of ICU stay and decreased laryngotracheal complications. We conclude by suggesting early tracheostomy in traumatic SCI patients who are likely to require prolonged mechanical ventilation.     

Clinical efficacy of high frequency jet ventilation during extracorporeal shock wave lithotripsy of renal and ureteral calculi: a comparison with conventional mechanical ventilation

The use of high frequency jet ventilation compared to conventional mechanical ventilation during general anesthesia for extracorporeal shock wave lithotripsy of renal or ureteral calculi can reduce stone movement. This decrease in stone movement theoretically lessens the total shock and energy requirements for stone fragmentation and perirenal tissue damage. To assess these theoretical advantages of high frequency jet ventilation, we studied patients undergoing extracorporeal shock wave lithotripsy to determine differences in stone movement during high frequency jet and conventional mechanical ventilation (30 patients), and in total shock requirements (1,174 patients). Mean stone movement in the 30 patients was 34.3 +/- 4.3 mm. during conventional mechanical ventilation compared to 4.1 +/- 1.9 mm. during high frequency jet ventilation (p less than 0.001). Mean total shocks were 1,542 +/- 212 (452 patients) during conventional mechanical ventilation compared to 1,217 +/- 165 (722 patients) during high frequency jet ventilation (p less than 0.001). Only 1 patient in the study had clinically significant perirenal tissue damage. We conclude that high frequency jet ventilation when compared to conventional mechanical ventilation results in clinically and economically beneficial decreases in total shocks for extracorporeal shock wave lithotripsy fragmentation of renal or ureteral calculi.     

Markedly improved pulmonary function after open heart surgery in infancy utilizing surface cooling, profound hypothermia, and circulatory arrest.

The use of surface-induced profound hypothermia with limited cardiopulmonary bypass and circulatory arrest markedly diminished the need for mechanical ventilation for patients undergoing cardiac surgery. Eleven of twenty-two patients were extubated in the operating room and five more patients within 70 minutes postoperatively. Five patients required mechanical ventilation. Four of the five were extubated within 24 hours (mean, 19.05 hours); only one patient required mechanical ventilation greater than 24 hours. This experience would indicate that as the age of surgery is decreased, in conjunction with improved technics of cardiac surgery and anesthesia, the need for mechanical ventilation should be diminished.     

心理支持疗法对机械通气患者应激反应的影响

目的 观察心理支持疗法(PST)对ICU患者机械通气应激反应的影响。方法 将34例连续机械通气时间在20h的清醒患者，随机分为采用标准的PST方法进行治疗的观察组和对照组，观察焦虑抑郁程度和应激反应改变情况。结果 对照组患者的焦虑抑郁程度明显高于观察组，部分应激反应激素水平升高幅度也明显大于观察组。结论 PST可通过缓解机械通气患者的焦虑抑郁等不良情绪状态减轻机械通气带来的各种心身应激反应，有利于提高机械通气治疗的有效性和安全性。     

Artificial respiration and kidney function disorder--a vicious circle?

Acute lung disease is commonly associated with interstitial pulmonary edema and a tendency towards partial or total alveolar collapse. To counteract this tendency mechanical ventilation is successfully used in most cases. Mechanical ventilation, however, leads to a harmful retention of water and salt, which may worsen interstitial pulmonary edema and further impair gas exchange. This problem seems to be less known. A survey of the effects of currently used modes of mechanical ventilation on excretory function and hemodynamics of the kidneys is given together with a short review of the possible afferent and efferent mechanisms which mediate the renal response to mechanical ventilation. Some clinical suggestions are made to break through the vicious cycle between mechanical ventilation and kidney function.     

Non-invasive mechanical ventilation in acute respiratory failure due to chronic obstructive pulmonary disease: correlates for success.

BACKGROUND--Non-invasive mechanical ventilation is increasingly used in the treatment of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to identify simple parameters to predict the success of this technique. METHODS--Fifty nine episodes of acute respiratory failure in 47 patients with COPD treated with non-invasive mechanical ventilation were analysed, considering each one as successful (78%) or unsuccessful (22%) according to survival and to the need for endotracheal intubation. RESULTS--Pneumonia was the cause of acute respiratory failure in 38% of the unsuccessful episodes but only in 9% of the successful ones. Success with non-invasive mechanical ventilation was associated with less severely abnormal baseline clinical and functional parameters, and with less severe levels of acidosis assessed during an initial trial of non-invasive mechanical ventilation. CONCLUSIONS--The severity of the episode of acute respiratory failure as assessed by clinical and functional compromise, and the level of acidosis and hypercapnia during an initial trial of non-invasive mechanical ventilation, have an influence on the likelihood for success with non-invasive mechanical ventilation and may prove to be useful in deciding whether to continue with this treatment.     

Effects of sequential changes from conventional ventilation to high-frequency oscillatory ventilation at increasing mean airway pressures in an ovine model of combined lung and head injury

BACKGROUND: The objective of this study was to determine the intracranial, cardiovascular and respiratory changes induced by conversion to high-frequency oscillator ventilation from conventional mechanical ventilation at increasing airway pressures. METHODS: In this study, 11 anaesthetized sheep had invasive cardiovascular and intracranial monitors placed. Lung injury was induced by saline lavage and head injury was induced by inflation of an intracranial balloon catheter. All animals were sequentially converted from conventional mechanical ventilation to high-frequency oscillator ventilation at target mean airway pressures of 16, 22, 28, 34 and 40 cm H(2)O. The mean airway pressure was achieved by adjusting positive end expiratory pressure while on conventional mechanical ventilation, and continuous distending pressures while on high-frequency oscillator ventilation. Cerebral lactate production, oxygen consumption and venous oximetry were measured and analysed in relation to changes in transcranial Doppler flow velocity. Transcranial Doppler profiles together with other physiological parameters were measured at each airway pressure. RESULTS: Cerebral perfusion pressure was significantly lower during high-frequency oscillator ventilation than during conventional mechanical ventilation (CMV: 45, 34, 22, 6, 9 mmHg vs. HFOV: 33, 20, 19, 5, 5 mmHg at airway pressures mentioned above, P = 0.02). Intracranial pressure and cerebrovascular resistance increased with increasing intrathoracic pressures (P = 0.001). Cerebral metabolic indices demonstrated an initial increase in anaerobic metabolism followed by a decrease in cerebral oxygen consumption progressing to cerebral infarction as intrathoracic pressures were further increased in a stepwise fashion. Arterial PaCO(2) increased significantly after converting from conventional mechanical ventilation to high-frequency oscillator ventilation (P = 0.001). However, no difference was observed between conventional mechanical ventilation and high-frequency oscillator ventilation when intracranial pressure, metabolic and transcranial Doppler indices were compared at equivalent mean airway pressures. CONCLUSIONS: The use of high positive end expiratory pressure with conventional mechanical ventilation or high continuous distending pressure with high-frequency oscillator ventilation increased intracranial pressure and adversely affected cerebral metabolic indices in this ovine model. Transcranial Doppler is a useful adjunct to intracranial pressure and intracranial venous saturation monitoring when major changes in ventilation strategy are adopted.     

Effect of ventilator-induced lung injury on the development of reperfusion injury in a rat lung transplant model

OBJECTIVE: Although mechanical ventilation can potentially worsen preexisting lung injury, its importance in the setting of lung transplantation has not been explored. This study was undertaken to examine the effect of 2 ventilatory strategies on the development of ischemia-reperfusion injury after lung transplantation. METHODS: In a rat lung transplant model animals were randomized into 2 groups defined by the ventilatory strategy during the early reperfusion period. In conventional mechanical ventilation the transplanted lung was ventilated with a tidal volume equal to 50% of the inspiratory capacity of the left lung and a low positive end-expiratory pressure. In minimal mechanical stress ventilation the transplanted lung was ventilated with a tidal volume equal to 20% of the inspiratory capacity of the left lung, and positive end-expiratory pressure was adjusted according to the shape of the pressure-time curve to minimize pulmonary stress. RESULTS: After 3 hours of reperfusion, oxygenation from the transplanted lung was significantly higher with minimal mechanical stress ventilation than with conventional ventilation. In addition, elastance, cytokine levels, and morphologic signs of injury were significantly lower in the group with minimal mechanical stress ventilation. CONCLUSIONS: This study demonstrates that the mode of mechanical ventilation used in the early phase of reperfusion of the transplanted lung can influence ischemia-reperfusion injury, and a protective ventilatory strategy on the basis of minimizing pulmonary mechanical stress can lead to improved lung function after lung transplantation.