The Value of Thoracic Ultrasonography in a Case of Tension Hydrothorax.

Abstract

CASE We present a 79-year-old female with history of hypertension, stage III chronic kidney disease, and supraventricular tachycardia managed with metoprolol succinate, who presented to the emergency department through ambulance after a fall when standing from a seated position. Triage vital signs were notable for blood pressure 81/49, heart rate 93, oxygen saturation 95% on 3L nasal cannula. Blood pressure did not improve after 3L of intravenous crystalloid. Physical exam revealed a cachectic woman in moderate respiratory distress with absent breath sounds on the right. Electrocardiography revealed sinus tachycardia at a rate of 108, premature atrial contractions, and no atrioventricular blocks. Labs notable for white blood cells of 13.8×103/μL, hemoglobin 10.9 g/dL. Chemistries notable for sodium 134mEq/L, creatinine 1.89mg/dL, blood urea nitrogen 62mg/dL. Troponin was elevated to 0.053 ng/ mL. Lactate was 3.5mmol/L and improved after intravenous fluids. Chest radiography revealed complete opacification of the right hemithorax with tracheal deviation to the left (Fig. 1, panel A) and noncontrasted computed tomography (CT) scan of the chest revealed a large right upper lobe mass and a heterogeneous cystic mass-like lesion occupying the right hemithorax with small pleural effusion (Fig. 1, panel C). Bedside thoracic ultrasonography showed a large heterogenous, loculated pleural effusion with solid structures and an inverted right hemidiaphragm (Fig. 1, Panel E and F). Bedside echocardiography showed a leftward-deviated heart without evidence of pericardial effusion. The inferior vena cava was >2.1 cm in diameter without respiratory variation. A 14 French pigtail chest tube was placed with a forceful gush of fluid on entering the pleural space and immediate drainage of 2000mL serosanguinous fluid. The patient’s blood pressure improved to 122/65 within 3 minutes of chest tube placement. Pleural fluid studies were consistent with a neutrophilic exudate with 79% neutrophils, lactate dehydrogenase 14,892U/L, protein 7.9 g/dL, glucose 23mg/dL, albumin 4.4 g/dL, and hematocrit 7 (Table 1). Cytology was negative for malignant cells. Postprocedure contrasted CT scan demonstrated persistent effusion, multiple masses involving the hilum, persistently collapsed right lung, and improvement in mediastinal shift (Panel D). Positron emission tomography 5 days later revealed a hypermetabolic right upper lobe paramediastinal mass with invasion into the right medial pericardium and the right parietal pleura, likely a primary lung cancer. Because of her advanced disease at presentation and comorbidities, the patient declined biopsy for diagnosis and elected to pursue comfort measures only. She did not want any further procedures so the chest tube remained in place until death. DISCUSSION Tension hydrothorax is a lifethreatening extreme of pleural effusion that threatens cardiopulmonary collapse.1–8 Because of its rarity, the exact physiology is imperfectly described but has been attributed to direct compression of the cardiac chambers, increased intrathoracic pressures leading to impaired venous return, and compression of the great veins.1,2 In dogs, Vaska found that infusing at least 50mL/kg into bilateral pleural spaces could cause symptoms akin to cardiac tamponade. At a pleural pressure of 5mmHg there was evidence of rightventricular systolic collapse on echocardiography, and at a pressure of 15mmHg stroke volume had decreased by nearly 50% and cardiac output by 33%.3 The earliest case report we found of tension hydrothorax from 1966 noted a fluid pressure that “spurted to a height of 10 inches (25.4 cm)” secondary to an undifferentiated carcinoma.2 Causes include empyema,4 nonsmall-cell lung cancer,1,2 small cell lung cancer,5 ventriculoperitoneal shunt,6 diaphragmatic repair,7 disseminated endometriosis,8 and misplaced central line with infusion of intrapleural parenteral nutrition.1 In all cases reported, timely thoracentesis or tube thoracostomy has been associated with improved physiological parameters. Our patient had a neutrophilic exudative pleural effusion, possibly because of complicated parapneumonic effusion. Malignant pleural effusion (MPE) was also a possibility but MPE is usually lymphocytic, thoughmay be neutrophilic in 15% of cases.1 MPE with pleural fluid glucose <60mg/dL can be seen in 15% to 20% of cases, and pleural pH below 7.3 in a third of cases. DOI: 10.1097/LBR.0000000000000856 Disclosure: There is no conflict of interest or other disclosures. LETTERS