With the rapid expansion of the lung after the collapse of various durations caused by pleural effusion or pneumothorax, unilateral pulmonary edema develops [60J. It is accompanied by varying degrees of hypoxia and hypotension, which in some cases may require intubation and fur nical ventilation, and in rare cases can cause le tal end .
Pathophysiological characteristics
The mechanism of development of pulmonary edema during its smoothing is not precisely known. In animal experiments this kind of swelling went who only develop if the light were not for how many days in a state of collapse, and its unfolding prois passed around by the establishment in the pleural cavity negative -negative pressure. Miller and colleagues studied monkeys with pneumonia motoraksom lasting from 1 hour to 3 days. It was found that at the expansion lung edema developed only in those cases where the pneumothorax was observed in Techa of 3 days, and the expansion of the lung occurred during the creation of intrapleural pressure — 10 mm Hg. Art. Edema developed not smiling if smoothing occurred over 3 days after the development of a pneumothorax, but using underwater drainage, pneumothorax or duration of one hour, regardless of whether the lung smoothing uses carried Vanianegative pressure or underwater drainage.
In a study on rabbits Pavlin and Cheney showed that ,. if the duration of the collapse of the lung was 7 days, then the resulting pulmonary edema was more significant than with the 3-day duration of the collapse . The expansion of the lung at a negative pressure of -20 mm Hg. v., did not cause the formation of larger swelling than with positive -negative pressure, but at a pressure of -40 mmHg. Art. or —100 mm Hg. Art. the size of the edema was increasing. In some of these experimental animals, edema of the contralateral lung simultaneously developed, but it was less pronounced [60]. However, there are reports that people have pulmonary edema WHO Nick even at the expansion of light without creating a negative -negative intrapleural pressure . In almost all cases of edema, the duration of the existence of pleural effusion or pneumothorax was at least 3 days.
The development of pulmonary edema during its smoothing is probably caused by an increase in the vascular permeability of the lung. At times orator edema as humans , as well as in rabbits nakapli vayuschayasya pleural fluid has a high with protein contents, Pavlin and colleagues have put forward the hypothesis that the use of mechanical Sgiach means of ventilation causes damage to the capillaries, leading to the development of pulmonary edema. Data about increasing pro permeability of capillaries to light it is not unfolding IME etsya .
Clinical picture
The development of pulmonary edema during its expansion is characterized by the appearance of a severe attack of cough or a feeling of heaviness in the chest during or immediately after thoracocentesis or the introduction of drainage. Over the next 24-48 hours, symptoms Zabolev Nia is increasing, and the X-ray can be seen in all the swelling of the ipsilateral lung. Edema can also be observed in the contra-lateral lung . If during the first 48 hours the patient does not die, then usually comes full recovery. About ser eznosti this complication show reports SLU teas deaths in young healthy people . The frequency of pulmonary edema is not known when its expanded, but Bernstein revealed that he develops in 10% of patients who produce lightweight smoothing after spontaneous pnevmoto Rax .
Prevention
The possibility of developing lung edema by its expanded follows must bear in mind in patients who produce torakostomiyu with drainage or thoracentesis over extensive pneumothorax or pleural effusion is present in a few days. In animal experiments, Miller and colleagues and Pavlin and Cheney showed that patients with spontaneous pneumothorax when draining method torakostomii drainage tube must be connected to the appa Rath underwater drainage and not to negatively system of pressure. If in 24—48 Underwater drainage, the lung has not expanded, then a negative pressure should be created in the pleural cavity.
If thoracentesis is carried out without control of intrapleural pressure, then the volume of output pleural fluid should not exceed 1000 ml. In a study conducted by our Research Institute have shown that in some patients during therapeutic thoracentesis , a sharp drop in intrapleural pressure to -50 cm of water. Art . or even a well . Often at the time of the fall of intrapleural pressure in patients there are no symptoms, so the doctor can not notice this. We believe in wasps Nove of pulmonary edema may lie create a high negative pressure exerted by the action mechanical Wie in lung. Therefore, if the volume of pleural fluid output exceeds 1000 ml, we produce thoracentesis controlled intrapleural pressure and continuing the thoraco tsentez only if the pressure does not drop below -20 cm water . We have shown that while maintaining the pressure at a level above —20 cm of water. Art. thoracentesis can be continued without the risk of developing pulmonary edema . In some patients with constant monitoring of intrapleural pressure, we were able to withdraw more than 5000 ml of pleural fluid. One to if the patient during thoracentesis there is heaviness in the chest or acute cough, no doubt, this manipulation should be discontinued.