The nurse assesses a client with a chest tube inserted to treat pneumothorax. Which assessment finding best indicates that a chest tube is no longer needed?

Rationale: A. Normal ABG values indicate adequate gas exchange, but they do not confirm that the lung has fully re-expanded or that air and fluid are no longer accumulating in the pleural space. ABGs alone are insufficient to determine chest tube removal. B. Fluctuation, or “tidaling,” in the water seal chamber reflects pleural pressure changes during respiration. When the lung has re-expanded and the pneumothorax has resolved, there is no longer a pressure change, and the water seal chamber ceases to fluctuate. This is the most reliable clinical indicator that the chest tube is no longer needed. C. Absence of shortness of breath is reassuring, but it is subjective and does not confirm lung re-expansion or cessation of air/fluid leakage in the pleural space. Relying on symptoms alone is insufficient for chest tube removal. D. Minimal drainage indicates decreased fluid output, but even with minimal drainage, air leaks may persist. The presence or absence of tidaling and air leak assessment is more important than fluid output in determining removal readiness.