ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Current knowledge regarding noninvasive ventilation (NIV) and some technical aspects of the subject are discussed. In patients with chronic obstructive pulmonary disease, NIV can prevent endotracheal intubation and reduce mortality. A trial of NIV could be recommended in the early phases of acute exacerbation of chronic obstructive pulmonary disease, before eventual intubation. Some promising preliminary results propose noninvasive ventilation as a possible first line intervention for acute hypoxemic respiratory failure. However, the use of noninvasive ventilation in patients with acute respiratory failure still remains controversial. Large randomized multicenter studies are still needed before extensive clinical application of NIV is used in patients with acute hypoxemic respiratory failure.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Gut dysfunction resulting in increased gut permeability and subsequent bacterial translocation may play an important role in the development of multiple organ system failure in the critically ill within this concept. Intra-abdominal pressure is an important parameter and prognostic indicator of the patient’s underlying physiologic status. Initially thought to affect primarily trauma and surgical patients, intra-abdominal hypertension and the abdominal compartment syndrome have recently also been identified in about 20% of critically ill medical patients. Even slightly increased intra-abdominal pressure, as low as 10 mm Hg, has deleterious effects on end-organ function, impairing neurologic, cardiac, respiratory, gastrointestinal, hepatic, and renal homeostasis. Rapid restoration of volume status and abdominal decompression is essential to preserve organ function, although massive fluid overload may trigger a vicious cycle which by itself may cause intra-abdominal hypertension. The traditional filling pressures are unreliable indices of preload, necessitating the use of new markers, such as right ventricular end diastolic volume index or intrathoracic blood volume index to assess volume status and resuscitate these patients correctly. New techniques, such as intravesical or intragastric pressure monitoring combined with intramucosal pH, together with an high clinical index of suspicion, help the intensivist make a correct diagnosis, adjust treatment, and decide on early decompressive laparotomy with temporary abdominal closure.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Synchronous patient-ventilator interaction is a critical issue for all patients receiving assisted ventilation. The primary variable that affects synchrony is peak flow availability and variability. Appropriately setting the peak flow does decrease patient effort and work, but high peak inspiratory flows have been shown to increase patient respiratory rate. During pressure ventilation, rise time and inspiratory termination criteria have a marked effect on synchrony. Visual assessment of airway pressure and flow waveforms is critical to the appropriate setting of gas delivery to ensure patient-ventilator synchrony.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Ventilatory objectives in patients with acute lung injury and acute respiratory distress syndrome include effective gas exchange and avoidance of ventilator-induced lung injury. In theory, high frequency ventilation (HFV), applied using an open lung approach, accomplishes these objectives, by maintaining end-expiratory alveolar recruitment while avoiding end-inspiratory alveolar overdistension. In addition, by optimizing alveolar recruitment and thus ventilation perfusion matching, the use of HFV may allow reductions in delivered oxygen to less toxic levels. The types of HFV in current clinical use include high frequency jet ventilation, high frequency oscillatory ventilation, and high frequency percussive ventilation. The vast majority of trials of HFV have been conducted in the neonatal population, with relatively little published information in the adult population. In this review, I will briefly discuss the mechanisms of gas exchange, describe relevant human studies evaluating HFV, and explain why early studies failed to show any benefits, whereas recent studies appear to be more promising.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Tracheostomy in critically ill patients offers a number of practical and theoretical advantages compared with conventional translaryngeal orotracheal or nasotracheal intubation. Recent reports suggest that it might be possible to identify factors that allow physicians to determine which patients will be most likely to benefit from tracheostomy. However, the appropriate timing still remains controversial. A body of evidence exists that indicates that tracheostomy in intensive care patients, regardless of the method chosen, should be performed at the bedside. The technique of percutaneous dilatational tracheostomy has been studied in many patients, demonstrating an at least comparable rate of perioperative and a lower rate of postoperative complications compared with conventional open surgical tracheostomy. Based on these results, and taking into account the fact that the use of percutaneous dilatational tracheostomy in the intensive care setting offers some additional logistic advantages, it is the first line method for critically ill patients.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The goals of mechanical ventilation of acute severely brain-injured patients (both traumatic and spontaneous) are improvement of oxygenation and maintenance of mild hypocapnia, minimizing intrathoracic pressure. These patients are also at high risk of developing acute lung injury due to neurogenic pulmonary edema, aspiration of oropharyngeal contents, pneumonia, and atelectasis. The ventilatory strategy needed to match cerebral hemodynamic requests (high tidal volume and low level of positive end expiratory pressure) can induce or exacerbate acute lung injury. Therefore, based on available data, extended clinical research must still be performed to integrate these two opposite ventilatory requirements to successfully treat acute severely brain-injured patients.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Lung volume reduction surgery (LVRS) is a palliative procedure proposed for a selected minority of patients with severe emphysema. Resection of portions of nonfunctional peripheral lung can increase elastic recoil, thereby enhancing expiratory flows and reducing hyperinflation. The postoperative reduction in hyperinflation decreases the load on the respiratory muscles and increases their strength. Despite a purported decrease in dyspnea and improvements in exercise tolerance and quality of life, a substantial number of patients do not show improvements in expiratory flows or gas exchange after surgery. Moreover, the rate of decline in forced expiratory volume in one second and the mortality rate after surgery do not necessarily compare favorably with those reported in patients who do not undergo surgery. Consequently, LVRS should be considered an investigational procedure in the management of patients with severe emphysema. Large multicenter randomized trials currently underway in the US and Europe should help define appropriate patient selection criteria and may clarify short-term and long-term outcomes associated with LVRS.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Acute respiratory failure in infants is usually a single system lung disease. Despite this, the optimal technique for ventilating the surfactant-deficient premature newborn continues to be the subject of clinical investigations. Studies have yet to demonstrate what the optimal lung recruitment strategy is, both in terms of level of mean airway pressure and the duration of sustained inflations. There is further evidence that the inflammatory nature of chronic lung disease of prematurity can be moderated by systemic steroid therapy, although the optimal dose has yet to be worked out. In older children, in whom lung disease is frequently part of a multisystem disorder, it has proved difficult to show improved outcomes with lung-targeted therapy. Randomized trials of inhaled nitric oxide and surfactant therapy have not shown improved survival despite improvements in physiologic parameters.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Patients with acute respiratory distress syndrome or acute lung injury often have a number of risk factors that increase the lung’s susceptibility to injury by mechanical ventilation and that also decrease the lung’s ability to repair the damage incurred. Mechanical ventilation may worsen lung injury by physical force as a result of regional lung overdistension or regional lung shear forces generated during receptive opening and collapse of lungs. The structural disruption caused by ventilation can lead to release of inflammatory mediators, and ventilationper semay also directly activate effector cells to release mediators, resulting in systemic inflammation. Recent clinical studies suggest that lung-protective ventilatory strategies can reduce the incidence of ventilator-induced lung injury, resulting in a decrease in mortality. Monitoring of dynamic pressure-time curve during constant inflation may help to predict and minimize ventilator-induced lung injury. Pharmacologic interventions blocking the release of mediators from effector cells and inhibiting the activity of mediators have also shown promise in animal studies.

ISSN:1070-5295    

出版商:OVID    

年代:2000

数据来源: OVID