Hemothorax: blood in the pleural space
A hemothorax is blood collecting in the pleural space, most often from chest trauma (a broken rib tearing a vessel), sometimes after surgery, anticoagulation, or a ruptured vessel. Because the chest can hold liters, a large hemothorax causes both a collapsed lung and dangerous blood loss — a double hit on breathing and circulation.
It is diagnosed when thoracentesis or imaging reveals frankly bloody fluid (formally, a pleural-fluid hematocrit more than half the blood hematocrit). Treatment is prompt drainage with a chest tube, which both empties the blood and lets you measure ongoing bleeding. A brisk, continuing output signals the need for surgery to find and stop the source.
Empyema: pus that must come out
An empyema is frank pus in the pleural space, usually a complication of pneumonia. It begins as a simple parapneumonic exudate, then bacteria and inflammation thicken it; left alone, the fluid loculates into pockets and the pleura forms a stiff peel that traps the lung. The guiding surgical principle is old but true: pus in a space must be drained.
Fluid analysis guides the decision. A parapneumonic effusion that is frankly purulent, grows bacteria, or has a low pH (below about 7.2) and low glucose needs a chest tube plus antibiotics — not just antibiotics alone. For thick, loculated collections, a clot-busting agent instilled into the chest, or surgery to peel away the trapping rind, may be needed.
The chest tube and its underwater seal
A chest tube is a flexible tube placed through the chest wall into the pleural space to drain air, fluid, blood, or pus. The clever part is the underwater seal: the tube's end sits under a column of water, which lets air and fluid bubble out of the chest but never lets atmospheric air flow back in. It is, in effect, a one-way valve that restores the chest's seal.
- Watch the water seal swing with breathing — that tidal movement shows the tube is patent and in the pleural space.
- Watch for bubbling in the seal chamber: continuous bubbling means an ongoing air leak from the lung; new bubbling can mean a loose connection.
- Keep the drainage system below the chest and never clamp a bubbling tube — trapping a leaking lung's air can recreate a tension pneumothorax.