Respiratory complications are common in patients with Myasthenia Gravis because of?

SCTIMST Staff Nurse - 2015 (Set-B)

Medical & Surgical Nursing

Medium

Appeared in: SCTIMST Staff Nurse - 2015 (Set-B)

Explanation

Myasthenia Gravis (MG) is a neuromuscular disorder characterized by weakness of skeletal muscles, including those essential for respiration.
This weakness affects the diaphragm, intercostal muscles, and bulbar (throat) muscles, diminishing the force of the cough reflex.
An ineffective cough prevents the clearance of airway secretions, leading to pooling in the lungs.
Retained secretions are a primary cause of complications such as atelectasis, aspiration pneumonia, and ultimately, respiratory failure.

Option A: Airway narrowing is a feature of obstructive pulmonary diseases like asthma or COPD, caused by bronchospasm or inflammation, not the neuromuscular weakness seen in MG.
Option B: MG is an autoimmune disorder (overactive immune system), not an immunodeficiency (weak immune system). The increased infection risk is a consequence of poor secretion clearance, not a failure of the immune system to fight pathogens.
Option D: The primary issue in MG is the lack of muscular strength to expel normal secretions. The secretions themselves are not inherently more viscous or thicker than normal.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of respiratory complications in Myasthenia Gravis as background academic context rather than a clinical decision trigger.
Nurses must prioritize airway management in patients with MG. This includes frequent respiratory assessments, monitoring oxygen saturation, and assessing cough strength and swallowing ability.
Key nursing interventions include positioning the patient upright to maximize lung expansion, teaching assisted coughing techniques (e.g., huff coughing), and having suction equipment readily available at the bedside.
It is crucial to schedule medications (like pyridostigmine) so that their peak effect coincides with mealtimes to improve swallowing and reduce aspiration risk.

How to Approach the Question

First, identify the core pathology of the disease mentioned in the stem. Myasthenia Gravis is fundamentally a disease of muscle weakness.
Next, analyze how this core pathology would affect the respiratory system. Muscle weakness would directly impact the physical act of breathing and coughing.
Evaluate each option in light of this understanding. 'Ineffective coughing' is a direct mechanical result of respiratory muscle weakness.
Rule out the other options by considering their own underlying causes. 'Narrowed airways' relates to obstructive diseases, 'impaired immunity' to immunodeficiency, and 'viscosity of secretions' to conditions like cystic fibrosis. None of these are the primary mechanism in MG.

Concept Tested & Keywords

Concept Tested: Pathophysiology of respiratory complications in Myasthenia Gravis.
Stem keywords: Myasthenia Gravis, Respiratory complications
Lead-in keywords: because of