A 5-year-old girl is admitted to your Paeds ward. The parents give the history that the child has had recurrent, intermittent episodes of fever and respiratory distress over the past 1.5 years, including cough, wheezing, and dyspnea lasting for 3-4 days. With every episode, hemoptysis is present. Now she is diagnosed with Right lower lobe pneumonia which improves upon treatment. On physical examination, the patient is pale, icteric with digital clubbing. Which of the following is the most appropriate next Investigation?

**Core Concept**
The patient's presentation of recurrent episodes of fever, respiratory distress, hemoptysis, and digital clubbing in a child suggests a possible diagnosis of a congenital heart disease with pulmonary hypertension, leading to chronic hypoxia and subsequent right-to-left shunting. This clinical scenario necessitates further investigation to identify the underlying cause.

**Why the Correct Answer is Right**
The presence of icterus in this patient suggests liver dysfunction or congestion, which is often seen in conditions like pulmonary hypertension. The correct investigation would be a **Chest X-ray with a right-to-left shunt (Eisenmenger's) sign**. However, the most specific and appropriate next investigation would be an **echocardiogram** to evaluate the cardiac structure and function, including the presence of any cardiac defects, septal defects, or pulmonary hypertension.

**Why Each Wrong Option is Incorrect**
**Option A:** Chest X-ray is a good initial investigation but not specific enough to diagnose the underlying cause.
**Option B:** Pulmonary function tests may provide some information on lung function but are not the best next step in this scenario.
**Option D:** ECG may show nonspecific changes in this patient but is not a direct investigation for the suspected cardiac defects or pulmonary hypertension.

**Clinical Pearl / High-Yield Fact**
In children with recurrent episodes of respiratory distress, fever, and hemoptysis, always consider the possibility of a congenital heart disease with pulmonary hypertension. A high index of suspicion and prompt investigation can lead to early diagnosis and management.

**Correct Answer:** D. Echocardiogram

✓ Correct Answer: B. Bronchoalveolar lavage