50.對於急性過敏反應出現呼吸道阻塞症狀時，下列處置何者最不適當？
(A)立刻停止目前正在給與的藥物
(B)合併發紺（cyanosis）情況時，立即給與抗組織胺治療
(C)聽到喘鳴聲（wheezing）時，可先給與吸入性支氣管擴張劑
(D)如果嚴重的喉痙攣（laryngospasm）無法緩解，可考慮緊急環甲切開術（cricothyrotomy）

For this question, understanding cyanosis and wheezing helps identify why (B) is the wrong management choice.

Cyanosis（發紺、紫紺）

Definition:
A bluish or purplish discoloration of the skin and mucosa caused by inadequate oxygenation of the blood.

Common sites:

• Lips

• Tongue

• Fingertips

• Nail beds

What it means clinically:

• The patient is becoming significantly hypoxic.

• This is an airway and oxygenation emergency.

Example:
A patient having severe anaphylaxis develops swollen airway tissues and cannot get enough oxygen → lips turn blue → cyanosis.

Wheezing（喘鳴聲）

Definition:
A high-pitched whistling sound heard during breathing, usually during expiration.

Cause:
Narrowing of the lower airways (bronchi/bronchioles), such as:

• Asthma

• Anaphylaxis

• Bronchospasm

What it sounds like:
A "whistling" or "musical" sound when the patient breathes out.

Why is (B) the most inappropriate?

In an acute allergic reaction with airway obstruction:

• Cyanosis = severe oxygen deprivation

• Priority is:

  • Airway management

  • Oxygen

  • Epinephrine (adrenaline)

Antihistamines work too slowly to treat life-threatening airway compromise.

Therefore:

❌ (B) "When cyanosis is present, immediately give antihistamines" is the most inappropriate action.

Quick exam table

So the MCQ answer is (B), and:

• Cyanosis = lips/skin turning blue from lack of oxygen

• Wheezing = whistling breath sound from narrowed airways.