Clinical Study Of Influential Factors Of Chemical Pleurodesis In Patients With Malignant Pleural Effusion

Objective:To study the factors which affect the pleural adhesion when the sclerosing agent is injected into the pleural cavity of the patients with malignant pleural effusion, to evaluate the predictable value of the methods in combination for the successful rate of pleurodesis.Methods:The patients with large amount of pleural effusion which was caused by the pleural invasion of the lung cancer were conducted the thin tube drainage in the pleural cavity. The samples of effusion were sent to the labs for routine, biochemistry and gas analysis immediately after the operation. The pressure in the pleural cavity was measured at the beginning and after draining 1000ml of fluid, and the change between them was calculated. The pressure was checked again when the effusion was completely drained and the chest CT was undergone to confirm the degree and range of the involved lungs, visceral and parietal pleura. The patients who met the criteria were evaluated their general conditions such as age, weight, duration of the disease and the KPS score before Cisplatin 60mg with 20ml normal saline was injected into their pleural cavity. The tube was closed for four hours and then opened for continuous drainage.6ml of fluid was sampled before the injection and spined for 10 mins at 3000rpm, then the supernatant was taken and placed in the EP tube and stored at -80℃freezer for further investigation. The amount of PAI-1 and TGF-βin the supernatant were detected by ELISA. The tube was removed when the amount of drainage was less than 20 ml for at least three consecutive days and no effusion or only little amount of fluid was shown on the ultrasound. It was considered as the successful adhesion if there was no relapse after four weeks and it was failure otherwise. The general conditions of patients, the images, the pressure of the pleural cavity, the initial biochemistry and gas analysis of the pleural effusion, the amount of PAI-1 and TGF-βin pleural effusion were studied anticipatorily to analyse the effects on pleurodesis.Results:First, there was no significant statistic link between the successful rate of pleural adhesion and the factors like age, weight, duration of the disease and KPS score etc. Second, there was no statistically difference of the success of pleurodesis between no obvious changes and the significant changes on images, for example, more than one lobe's collapse, the massive mass in the lung or visceral pleura thickening caused by the invasion (p>0.05). Third, the successful rate of pleurodesis was lower in the patients whose negative pressure of the pleural cavity was increased than those without the increased negative pressure (p<0.05). The increased negative pressure meant that the pressure of the pleural cavity was decreased more than 5 cm H2O after 1000ml of fluid was initially drained and the pressure was less than -10 after the effusion was completely drained. Fourth, the increasing tumor consumption standard in the pleural cavity was described as the analysis of effusion match both pH<7.25, PCO₂/PO₂>1.2 and the amount of glucose < 3mmol/L. There was statistically difference of the successful rate between the patients who satisfied the above standard and those did not (p<0.05). Fifth, the successful rate of pleurodesis was significantly lower in the patients with the effusion that contained PAI-K7.40ng/mL and TGF-β<100pg/mL than in those without (p<0.01). Sixth, the successful rate was the lowest when the negative pressure and the tumor consumption in pleural cavity were both increased, and the successful rate was the highest when neither occurred. The predictable value of the combination of measurement of pressure in the pleural cavity with the biochemistry and gas analysis of effusion was equal to the measurement of PAI-1 and TGF-βin the effusion (P >0.05).Conclusion: It is concluded that age, weight, duration of the disease, KPS score and images should not be used as the indication of the successful rate of pleurodesis. The successful rate of chemical pleurodesis is affected by pleural elastance, the initial biochemistry and gas analysis of pleural effusion, the amount of PAI-1 and TGF-βin the effusion. Moreover, the combination of the previous two factors can increase the accuracy of diagnosis, and the predictable value is equal to the latter. Although it is extremely valuable about the amount of PAI-1 and TGF-βin the effusion in predicting the successful rate of pleurodesis, it is difficult to use widely because the cost is high, and it can not be detected at any time. Therefore, it is suggested to conduct the easier approaches that are the combination of measurement of pressure in the pleural cavity with the initial biochemistry and gas analysis of pleural effusion. If the predictable successful rate of pleurodesis is low, the procedure should not be performed to avoid the harmful effect.