Iohexol injection triggers acute non-cardiogenic pulmonary oedema in a comorbid patient

Acute respiratory distress syndrome (ARDS) is a severe lung injury marked by inflammation and increased vascular permeability. While iodinated contrast agents like iohexol are widely used in imaging, they can rarely trigger adverse reactions. Among these, acute non-cardiogenic pulmonary oedema is a life-threatening but often reversible complication, distinct from cardiac issues. This case highlights the critical need for awareness regarding this rare, severe reaction to ensure prompt recognition and intervention, preventing potentially fatal outcomes.

This is a case report detailing a single female patient with multiple comorbidities who developed acute respiratory distress minutes after intravenous iohexol administration for abdominal imaging. The diagnostic process involved clinical assessment for severe hypoxaemia, bilateral pulmonary crackles, and diffuse opacities on chest imaging. Bedside echocardiography and brain natriuretic peptide (BNP) levels were used to specifically exclude cardiogenic pulmonary oedema, confirming a non-cardiogenic origin.

The patient experienced acute respiratory distress within minutes of intravenous iohexol injection, presenting with severe hypoxaemia, bilateral pulmonary crackles, and diffuse opacities on chest imaging. Crucially, bedside echocardiography and brain natriuretic peptide levels confirmed the absence of cardiac dysfunction, definitively ruling out cardiogenic pulmonary oedema.

A diagnosis of contrast-induced non-cardiogenic pulmonary oedema was made, highlighting a rare, life-threatening reaction. She required non-invasive ventilation and supportive therapy, demonstrating the severity of the reaction. Fortunately, the patient achieved complete resolution of symptoms and imaging abnormalities over 1 week, underscoring the reversible nature of this severe adverse event with timely intervention.