**Question:** In upper airway obstruction all of the following changes are seen except

A. Increased respiratory rate
B. Increased heart rate
C. Hypoxia
D. Hypoxia

**Correct Answer:** **D. Hypoxia**

**Core Concept:** Upper airway obstruction is a condition that occurs when the airway is narrowed or blocked, leading to reduced airflow and decreased oxygenation. This can be caused by various factors, such as swelling, inflammation, or the presence of foreign objects. When an individual experiences upper airway obstruction, several physiological responses occur to compensate for the reduced oxygenation.

**Why the Correct Answer is Right:** Hypoxia is a correct response to upper airway obstruction as it is the body's attempt to increase oxygenation by increasing respiratory rate and heart rate. Increased respiratory rate helps to increase the amount of gas exchange in the lungs, while increased heart rate improves cardiac output and oxygen delivery to tissues. However, hypoxia is not a correct response as it indicates low oxygen levels in the blood, which is the opposite of what is desired in the context of upper airway obstruction.

**Why Each Wrong Option is Incorrect:**

A. **Increased respiratory rate:** This response is correct as it helps to increase the amount of gas exchange in the lungs and improve oxygenation.

B. **Increased heart rate:** This response is correct as it improves cardiac output and oxygen delivery to tissues, further aiding in oxygenation.

C. **Hypoxia:** This response is incorrect as it indicates low oxygen levels in the blood, which is counterproductive in the context of upper airway obstruction, where the goal is to increase oxygenation.

**Clinical Pearl:** Understanding the correct physiological responses to upper airway obstruction is crucial for effective management and treatment. In clinical practice, healthcare providers should monitor patients with upper airway obstruction for signs of hypoxia (low oxygen levels) and treat accordingly to improve oxygenation, such as treating the underlying cause and providing appropriate respiratory support.