How do you know that intercostal drainage tube is functioning?

JIPMER Nursing Officer-2017

Medical & Surgical Nursing

Easy

Appeared in: JIPMER Nursing Officer-2017

Explanation

The key sign of a functioning intercostal drainage tube is the oscillation of the water column in the water-seal chamber, a phenomenon known as 'tidaling'.
This fluctuation directly reflects the changes in intrapleural pressure that occur with breathing, confirming that the tube is patent (not blocked) and properly positioned within the pleural space.
In a patient who is breathing spontaneously, the water level rises during inspiration and falls during expiration.
The absence of tidaling suggests either that the lung has fully re-expanded or that the tube is obstructed.

Option A: Continuous bubbling in the water-seal chamber is not a sign of normal function; it indicates a persistent air leak either from the patient's lung or within the drainage system.
Option B: This refers to the suction control chamber, not the water-seal chamber. Bubbling here only indicates that the wall suction is turned on and set to the prescribed level.
Option D: The complete absence of bubbling and tidaling is an ambiguous finding. It is not a definitive sign of a functioning tube.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Assessment of intercostal drainage (chest tube) system function as background academic context rather than a clinical decision trigger.
Regularly assessing for tidaling is a critical nursing responsibility to ensure the chest tube is working effectively and to detect potential complications early.
The drainage system must always be kept below the level of the patient's chest to prevent backflow of fluid into the pleural space.
What if? - If tidaling, which was previously present, suddenly stops, the nurse must act quickly. First, check the tubing for any kinks or dependent loops. If none are found, assess the patient's respiratory status. The cessation could mean the lung has re-expanded (a positive sign) or the tube is blocked by a clot (a negative sign requiring intervention).

How to Approach the Question

First, identify the core concept of the question, which is how to assess the normal function of an intercostal drainage system.
Recall the different components of a chest drainage unit (collection chamber, water-seal chamber, suction control chamber) and the purpose of each.
Differentiate between normal and abnormal findings. 'Tidaling' or 'oscillation' is the classic sign of a patent tube connected to the pleural space.
Analyze the distractors: Continuous bubbling in the water-seal chamber indicates an air leak. Bubbling in the suction chamber relates to the suction source, not tube patency. Absence of any activity is ambiguous.
Select the option that describes the expected dynamic movement of fluid that confirms a connection to the patient's respiratory cycle.

Concept Tested & Keywords

Concept Tested: Assessment of intercostal drainage (chest tube) system function.
Stem keywords: intercostal drainage tube, functioning
Lead-in keywords: How do you know

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E6 Nursing Fundamentals Potter Perry 12e Part 5 pp. 36-38, 2-4, 35-37