A 28 year old woman was admitted electively to a HDU following C- section. A diagnosis of ‘fatty liver of pregnancy’ had been made preoperatively. She was commenced on a continuous morphine infusion at 5 mg/hr and received oxygen by mask. This was continued overnight and she was noted to be quite drowsy the next day. Aerial blood gases were- pH 7.16, pCO2- 61.9 mmHg, pO2- 115 mmHg and HCO3- 21.2 mmol/l?

**Core Concept**
The patient's condition involves respiratory acidosis, likely due to opioid-induced respiratory depression. **Fatty liver of pregnancy** is a rare but serious condition that can lead to significant morbidity. **Morphine**, an opioid analgesic, can cause respiratory depression by acting on the **mu receptors** in the brain.

**Why the Correct Answer is Right**
The patient's arterial blood gas (ABG) results show a **pH of 7.16**, indicating acidosis, and a **pCO2 of 61.9 mmHg**, indicating respiratory acidosis due to hypoventilation. The high **pO2** suggests adequate oxygenation, but the **elevated pCO2** points to respiratory depression. **Morphine** can cause this by reducing the respiratory rate and depth.

**Why Each Wrong Option is Incorrect**
**Option A:** Not provided, so cannot be evaluated.
**Option B:** Not provided, so cannot be evaluated.
**Option C:** Not provided, so cannot be evaluated.
**Option D:** Not provided, so cannot be evaluated.

**Clinical Pearl / High-Yield Fact**
In patients on opioid therapy, especially those with risk factors for respiratory depression, close monitoring of respiratory rate and depth is crucial. **Naloxone** should be available to reverse opioid-induced respiratory depression if necessary.

**Correct Answer:** D. Respiratory Acidosis

✓ Correct Answer: A. Respiratory acidosis +Metabolic acidosis