A patient develops type 2 respiratory failure. Which is a probable cause of this?

NORCET -4 , 2023

Medical & Surgical Nursing

Medium

Appeared in: NORCET -4 , 2023

Explanation

Type 2 respiratory failure, or hypercapnic failure, is defined by inadequate alveolar ventilation, leading to elevated arterial carbon dioxide levels (PaCO₂ greater than 50 mmHg).
Flail chest results from multiple fractures of adjacent ribs, creating an unstable segment of the chest wall.
This unstable segment moves paradoxically (inward on inspiration, outward on expiration), which disrupts the normal mechanics of breathing.
The paradoxical motion leads to alveolar hypoventilation, meaning the patient cannot move enough air to effectively eliminate carbon dioxide, causing hypercapnia.

Option A: Interstitial lung disease causes scarring and thickening of the lung tissue, which impairs oxygen diffusion. This leads to hypoxemia with a normal or low PaCO₂, characteristic of Type 1 respiratory failure.
Option C: Pulmonary oedema involves fluid filling the alveoli, which creates a barrier to oxygen transfer (a shunt effect). This results in hypoxemia, which is the primary feature of Type 1 respiratory failure.
Option D: Acute Respiratory Distress Syndrome (ARDS) is characterized by widespread inflammation and fluid leakage into the alveoli, causing severe oxygenation failure (hypoxemia). It is a classic example of Type 1 respiratory failure.

Visual 1: Diagram - Illustration of paradoxical chest wall movement in a patient with flail chest during inspiration and expiration. This helps visualize the mechanical failure.
Visual 2: Table - A comparison chart detailing the key differences in pathophysiology, blood gas findings, and common causes between Type 1 and Type 2 respiratory failure.

Clinical Relevance

Nursing practice connection: Use the key finding related to Pathophysiology and causes of Type 2 (Hypercapnic) Respiratory Failure to guide bedside assessment, documentation, and the next nursing action.
Recognizing the underlying cause of respiratory failure is critical for nurses as it dictates the management. Type 2 failure often requires mechanical ventilation to support the work of breathing and ensure adequate CO₂ removal.
A nurse caring for a patient with chest trauma must be vigilant for signs of flail chest, such as paradoxical chest movement, and respiratory distress, indicating impending ventilatory failure.
What if? If the patient had a drug overdose depressing the respiratory center instead of flail chest, it would also cause Type 2 respiratory failure. However, the intervention would be different, focusing on reversing the drug's effects (e.g., with naloxone for opioids) and supporting ventilation, rather than stabilizing a chest wall injury.

How to Approach the Question

First, identify the core concept in the question: 'Type 2 respiratory failure'.
Recall the key feature of Type 2 failure: it is a problem of ventilation (the 'pump'), leading to high carbon dioxide (hypercapnia).
Evaluate each option based on whether it primarily affects ventilation (moving air) or oxygenation (gas exchange in the alveoli).
Interstitial lung disease, pulmonary oedema, and ARDS all primarily damage the lung tissue itself, impairing oxygenation. This makes them causes of Type 1 failure.
Flail chest is a mechanical defect of the chest wall (the 'pump'), which directly impairs the ability to ventilate. This correctly identifies it as a cause of Type 2 failure.

Concept Tested & Keywords

Concept Tested: Pathophysiology and causes of Type 2 (Hypercapnic) Respiratory Failure.
Stem keywords: type 2 respiratory failure, probable cause
Lead-in keywords: Which is
Negative lead-in flag: false

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