Okay, let's tackle this question. The patient is a child with peripheral circulatory failure and the given blood gas values. The pH is 7.0, which is really low—severe acidosis. The pCO2 is 15 mmHg, which is decreased, indicating respiratory alkalosis. Wait, but pH is acidotic. So this is a mixed disorder? Maybe metabolic acidosis with respiratory compensation?

The question asks for immediate therapy. Peripheral circulatory failure suggests shock. In shock, especially septic or hypovolemic, there's lactic acidosis. The low pCO2 is the body's attempt to blow off CO2 to compensate for the metabolic acidosis. The immediate therapy would be to address the shock. So the first step is fluid resuscitation, probably with normal saline or another isotonic solution.

Looking at the options, if one of them is fluid administration, that's the correct answer. The other options might include things like insulin (for DKA?), bicarbonate (but in acute severe acidosis, bicarbonate isn't always the first step), or inotropes. Bicarbonate is used in hyperkalemia or certain acidosis types, but immediate therapy for shock is fluids. Inotropes might come later if fluids don't help.

So the correct answer should be fluid resuscitation. The other options are incorrect because they don't address the immediate cause of peripheral circulatory failure. The clinical pearl here is that in shock with metabolic acidosis, the priority is restoring perfusion, not correcting the acidosis itself right away.

**Core Concept**
This question tests recognition of **metabolic acidosis with respiratory compensation** and **immediate management of shock**. Peripheral circulatory failure (e.g., shock) leads to lactic acidosis, while the body compensates by hyperventilating (low pCO2). Immediate therapy focuses on restoring perfusion.

**Why the Correct Answer is Right**
The low pH (7.0) and low pCO2 (15 mmHg) indicate **severe metabolic acidosis** with respiratory compensation. Peripheral circulatory failure suggests **hypovolemic or septic shock**, where tissue hypoxia causes lactic acid accumulation. Immediate therapy requires **fluid resuscitation** (e.g., normal saline) to improve cardiac output and oxygen delivery. This addresses the root cause (poor perfusion) rather than correcting the acidosis directly.

**Why Each Wrong Option is Incorrect**
**Option A:** *Insulin administration* is for diabetic ketoacidosis, not shock-related acidosis.
**Option B:** *Bicarbonate therapy* is reserved for life-threatening acidemia (pH <7.0) with specific indications (e.g., hyperkalemia) but not as first-line in shock. **Option C:** *Inotropes* (e.g., dopamine) are used after fluid resuscitation if hypotension persists. **Clinical Pearl / High-Yield Fact** In **shock-induced metabolic acidosis**, prioritize **fluid resuscitation** over acid-base correction. Bicarbonate is not first-line; it may worsen outcomes if administered without addressing perfusion. Remember: "Shock is a cause of acidosis, not a result." **Correct Answer: C. Intravenous normal saline infusion**

✓ Correct Answer: B. A bolus of Ringers lactate