The nurse is caring for a patient with a chest tube status-post lobectomy. To ensure the chest tube drainage system is functioning correctly, as the patient breathes, the nurse will monitor which chamber of the drainage system for tidaling?

A. Water-seal chamber: Tidaling, the rise and fall of fluid level with respiration, is observed in the water-seal chamber. During inspiration, negative intrathoracic pressure causes the fluid level to rise; during expiration, it falls. This fluctuation indicates patency of the system and that intrapleural pressure changes are being transmitted appropriately. B. Suction control chamber: The suction control chamber regulates the amount of negative pressure applied to the system, either via water column or dry suction mechanism. Continuous bubbling may be seen here when wet suction is used, but tidaling is not assessed in this chamber. C. Collection chamber: The collection chamber simply collects blood, fluid, or air drained from the pleural space. It does not reflect intrathoracic pressure changes and therefore does not demonstrate tidaling with respiration. D. Window chamber: There is no functional “window chamber” used to assess tidaling in standard chest drainage systems. The appropriate chamber for monitoring respiratory fluctuations is specifically the water-seal chamber.