| 1 | Efficacy of prone position in acute respiratory distress syndrome patients: A pathophysiology-based review显示文摘Acute respiratory distress syndrome(ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the 'sponge lung'- and the 'shape matching'-model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients' response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort. | Vasilios Koulouras Georgios Papathanakos Athanasios Papathanasiou Georgios Nakos | 2016 | World Journal of Critical Care Medicine2016，5，2： | 39 |
| 2 | Why there is a need to discuss pulmonary hypertension other than pulmonary arterial hypertension?显示文摘Pulmonary hypertension(PH) is a condition characterized by the elevation of the mean pulmonary artery pressure above 25 mm Hg and the pulmonary vascular resistance above 3 wood units. Pulmonary arterial hypertension(PAH) is an uncommon conditionwith severe morbidity and mortality, needing early recognition and appropriate and specific treatment. PH is frequently associated with hypoxemia, mainly chronic obstructive pulmonary disease and DPLD and/or left heart diseases(LHD), mainly heart failure with reduced or preserved ejection fraction. Although in the majority of patients with PH the cause is not PAH, a significant number of published studies are still in regard to group Ⅰ PH, leading to a logical assumption that PH due to other causes is not such an important issue. So, is there a reason to discuss PH other than PAH? Chronic lung diseases, mainly chronic obstructive lung disease and DPLD, are associated with a high incidence of PH which is linked to exercise limitations and a worse prognosis. Although pathophysiological studies suggest that specific PAH therapy may benefit such patients, the results presented from small studies in regard to the safety and effectiveness of the specific PAH therapy are discouraging. PH is a common complication of left heart disease and is related to disease severity, especially in patients with reduced ejection fraction. There are two types of PH related to LHD based on diastolic pressure difference(DPD, defined as diastolic pulmonary artery pressure- mean PAWP): Isolated post-capillary PH, defined as PAWP > 15 mm Hg and DPD < 7 mm Hg, and combined post-capillary PH and pre-capillary PH, defined as PAWP > 15 mm Hg and DPD ≥ 7 mm Hg. The potential use of PAH therapies in patients with PH related to left heart disease is based on a logical pathobiological rationale. In patients with heart failure, endothelial dysfunction has been proposed as a cause of PH and hence as a target for treatment, supported by the presence of increased endothelin-1 activity and impaired nitric oxide-dependent vasodilation. Unfortunately, so far, there is no evidence supporting the use of specific PAH therapies in patients with PH related to left heart disease. In conclusion, the presence of PH in patients with conditions other than PAH contributes to the severity of the disease, affecting the outcome and quality of life. The disappointing results regarding the effectiveness of specific PAH therapies in patients withchronic lung diseases and LHD underline the need for seeking new underlying mechanisms and thus novel therapies targeting PH due to left heart disease and/or lung diseases. | Athanasios Papathanasiou George Nakos | 2015 | World Journal of Critical Care Medicine2015，4，4： | 1 |
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