Morphine is contraindicated in all of the following except
**Core Concept**
Morphine is a potent opioid analgesic that can cause respiratory depression, among other side effects. Its use is contraindicated in certain conditions where these effects could be detrimental.
**Why the Correct Answer is Right**
Morphine works by binding to opioid receptors in the brain and spinal cord, which can lead to decreased respiratory rate and depth. It is contraindicated in conditions where respiratory depression could be life-threatening, such as in patients with chronic obstructive pulmonary disease (COPD). However, in cases of acute severe asthma, morphine may be used cautiously under medical supervision to help control severe bronchospasm and anxiety.
**Why Each Wrong Option is Incorrect**
**Option A:** **Severe Renal Failure**
Morphine and its metabolites are primarily excreted by the kidneys. However, morphine is not contraindicated in severe renal failure, as its elimination is not significantly affected by renal function.
**Option B:** **Severe Hepatic Failure**
Morphine is metabolized by the liver, but it is not contraindicated in severe hepatic failure. In fact, morphine is often used in patients with liver disease for pain management.
**Option C:** **Pulmonary Edema**
Morphine can cause vasodilation, which may worsen pulmonary edema by increasing the pressure in the pulmonary capillaries.
**Option D:** **Head Injury**
Morphine can increase intracranial pressure (ICP) and is therefore contraindicated in patients with head injuries.
**Clinical Pearl / High-Yield Fact**
Morphine is often used in patients with acute severe asthma to help control severe bronchospasm and anxiety, but its use should be cautious and under close medical supervision.
**Correct Answer: C. Pulmonary Edema**