Chest tube drainage helps in relieving the symptoms of patient with pneumothorax by maintaining?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2016

Medical & Surgical Nursing

Medium

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2016

Explanation

The primary function of a chest tube in a patient with pneumothorax is to restore the normal physiological state of the pleural cavity.
Normally, the pleural space maintains a negative (sub-atmospheric) pressure, which acts like a suction to keep the lungs expanded against the chest wall.
A pneumothorax occurs when air enters this space, neutralizing or creating positive pressure, which leads to lung collapse.
The chest tube evacuates the air, allowing the negative pressure to be re-established, which in turn allows the collapsed lung to re-inflate.

Option B: Maintaining positive pressure in the pleural cavity is the cause of the problem (pneumothorax), not the solution. Positive pressure would further compress the lung.
Option C: Zero pressure (equal to atmospheric pressure) is what exists in the pleural space when a pneumothorax occurs. This pressure is not negative enough to overcome the lung's natural elastic recoil, so the lung remains collapsed.
Option D: 'Square positive pressure' is not a recognized or valid term in respiratory physiology or medicine. It is a nonsensical option designed to be incorrect.

Clinical Relevance

Nursing practice connection: Use the key finding related to Mechanism of chest tube drainage in pneumothorax and the role of intrapleural pressure to guide bedside assessment, documentation, and the next nursing action.
A nurse's primary role is to monitor the chest drainage system to ensure it is functioning correctly to restore negative pressure. This includes checking for air leaks, tidaling, and drainage.
Patient safety is paramount. Never clamp a chest tube without a specific order and clear rationale, as this can quickly lead to a tension pneumothorax, a medical emergency.
What if? If the water-seal chamber shows continuous, vigorous bubbling, it indicates a large air leak either from the patient's lung or within the drainage system. The nurse must immediately assess the patient's respiratory status and check all connections from the patient to the drainage unit to locate the source of the leak.

How to Approach the Question

First, identify the core concept of the question: the purpose of chest tube drainage for a pneumothorax.
Recall the basic physiology of respiration. Remember that lungs stay expanded because the pleural space has a negative pressure, creating a suction effect.
Understand the pathophysiology of a pneumothorax: air enters the pleural space, which eliminates the negative pressure and causes the lung to collapse.
Logically deduce the goal of treatment: to reverse the problem, you must remove the air and restore the original state of negative pressure.
Evaluate the options based on this deduction. 'Negative pressure' is the only option that aligns with the physiological goal of re-expanding the lung.

Concept Tested & Keywords

Concept Tested: Mechanism of chest tube drainage in pneumothorax and the role of intrapleural pressure.
Stem keywords: Chest tube drainage, pneumothorax, pleural cavity
Lead-in keywords: maintaining
Negative lead-in flag: false

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