INTRODUCTION: Pleural effusions can develop with airway obstruction due to atelectasis, postobstructive pneumonia, and/ or malignant pleural studding. Even in the presence of an endobronchial malignancy a significant percentage of these effusions have nonmalignant cytology. This poses a staging dilemma due to the poor sensitivity of thoracentesis. This dilemma leads to lack of confidence in staging, need for further procedures and delays in therapy.Thoracentesis with pleural manometry is used to diagnose trapped lung, safely relieve symptoms, and predict outcome of pleurodesis for malignant effusions.(1,2) The effect of endobronchial intervention on pleural pressures has not been studied. By defining the physiologic character of malignant and paramalignant effusions in this setting we hope to gain information that may solve the dilemma described above. This is the report of our first patient in a prospective series.
CASE PRESENTATION: Our patient is a 52-year-old female with Stage IIIB NSCLC originating in the LUL. Three months after chemotherapy and radiation she complained of worsening dyspnea. Her exam was significant for decreased breath sounds throughout the left side. A CT scan of the chest showed worsening LUL collapse and a moderate effusion. The patient was scheduled for thoracentesis and bronchoscopy with possible intervention. Prior to bronchoscopy, the thoracentesis was performed. Ultrasound guided placement of an 18g angiocath yielded straw colored thin fluid. Pleural pressure at exhalation was found to be -7.5 cm H2O by fluid column and -6 cm H2O by urodynamics monitor (Medtronics, Shoreview, MN) before drainage. The fluid column and monitor had been zeroed together before the procedure. Pleural pressures were reassessed after every 100-200ml removed by syringe pump. After drainage of 200ml the pressure, by both methods, was -9 cm H2O. After 400ml of drainage the pressure was -9 by fluid column and -10 by monitor. After 600ml of drainage the pressure was -16cm H2O by both methods. At this point the drainage slowed and the patient was prepared for bronchoscopy. More than 20ml of fluid remained in the pleural space to ensure accurate readings.On bronchoscopic exam the LUL was occluded, as previously described. The most significant interval change was a new significant stenosis of the lingual. Bronchography was done to further define the anatomy. Then a guidewire was used to feed a 6-7-8mm balloon into the superior subsegment. Flouroscopic images revealed an apple core stricture in the proximal subsegmental bronchus. Dilation to 7mm was successful at opening the bronchus. After bronchoscopy, the transducer, fluid column and catheter were leveled. And the fluid column and the pressure transducer were zeroed A measurement of the pleural pressure revealed a dramatic improvement. Pleural pressure was -5 cm H2O by both methods. Cytology was negative for malignancy in the transudative effusion.
DISCUSSIONS: Endobronchial obstruction and effusions are common complications of lung cancer. In the setting of endobronchial obstruction manometry may prove to be helpful in diagnosis of reversible trapped lung physiology, predicting effusion recurrence or assessing the benefit of an interventional procedure. By directly measuring pleural pressures before and after an intervention we were able to differentiate between a diagnosis of trapped lung and a reversible process. In our patient there was a dramatic change in pleural pressure after intervention by both methods of manometry.
CONCLUSION: Endobronchial obstruction may dramatically effect pleural pressures. We plan to further validate this novel approach to manometry and conduct a series to assess the effects of endobronchial intervention on pleural pressures.
DISCLOSURE: Franklin McGuire, None.