Key Concepts
Introduction
Chest drainage systems operate on the principle of restoring negative intrapleural pressure by providing a one-way evacuation path for air and fluid. Modern disposable units integrate three chambers: the collection chamber measures output, the water-seal chamber prevents atmospheric air re-entry (acting as a one-way valve), and the suction control chamber (wet or dry) regulates applied negative pressure. Water-seal tidaling reflects respiratory pressure changes transmitted through the pleural space and confirms system patency. Air leak assessment is performed systematically by evaluating bubbling in the water-seal chamber: continuous bubbling indicates a persistent bronchopleural fistula or system breach. The nurse manages the entire chest drainage system, troubleshoots complications, interprets assessment findings, titrates suction, and determines readiness for tube removal. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and end organs, neuro baseline, likely infection sources, and devices that can fail quietly. When...