Question

The assignment is to write a page on the pathophysiology of Acute respiratory distress, hypoxia, congestive heart failure and shortness of breath. Can someone please help with the pathophysiology for each diagnosis in complete sentences thanks. It would be helpful if it is typed or written in print so I can understand writing. Thanks again

Answer 1

PATHOPHYSIOLOGY

1. ACUTE RESPIRATORY DISTRESS SYNDROME

Inflamation due to neutrophil activity is the key in pathogenesis of ARDS. Increased capillary permeability is the hallmark.There is damage of capillary endothelium and alveolar epithelium leading to fluid accumulation in alveoli. This fluid rich in protein causes damage to alveoli by releasing pro-inflammatory cytokines such as tumor necrosis factor. This brings neutrophils to the lungs which becomes active and releases toxic mediators. Excessive free radical production causes oxidative stress and cell damage leading to ARDS.

2. HYPOXIA

Hypoxia is a condition in which tissue oxygen levels are decreased. Hypoxemia is decreased oxygen level in the blood. The pathophysiologic changes that can cause hypoxemia and hypoxia are ventilation-perfusion mismatch, right to left shunt, diffusion impairment, hypoventilation and low inspired oxygen. Oxygen is mostly bound to hemoglobin and is carried to the tissues. The above causes, decreased oxygen and low hemoglobin etc., leads to hypoxemia leading to hypoxia

3. Congestive cardiac failure:

CHF can be caused as a result of abnormality in cardiac structure, function, rhythm or conduction. Decreased stroke volume leads to sodium and water retention in the body leading to increased preload and increased pulmonary congestion.This causes pheripheral edema.

Increased sympathetic tone increases the heart rate and causes vasoconstriction. Venous vasoconstriction increases the preload and arterial vasoconstriction increases the afterload. The afterload increases the cardiac workload decreasing the stroke volume leading to decreased tissue perfusion.

4. Dyspnea

The pathophysiology of shortness of breath can be due to fluid retention and decreased tissue perfusion. These can lead to activation of several pathways leading to increased breathing, stimulation of receptors in airways and excessive stimulation of respiratory center.