Unilateral pulmonary edema: a case report and review of the literature

Unilateral pulmonary edema is an uncommon condition and is a rare clinical entity that is often misdiagnosed at the initial stages. In a majority of patients it occurs in the upper lobe of the right lung. There are many causes of unilateral pulmonary edema, but the commonest is the presence of a grade 3 mitral regurgitation. Due to its rare presentation, a high index of suspicion is required, and correct management is necessary to reduce the morbidity and mortality.

We present a case of right-sided unilateral pulmonary edema in an 86-year-old Sinhalese Sri Lankan woman who presented with acute onset dyspnea with cardiogenic shock due to acute non-ST elevation myocardial infarction, complicated with grade 3 mitral regurgitation. She had clinical features of heart failure and pulmonary edema, but a chest X-ray showed unilateral infiltrates only on the right side. Distinguishing pneumonia from pulmonary edema according to chest X-ray findings was a challenge initially, and she was therefore initially treated for both conditions. She had remarkable clinical and radiological improvement after 12 hours of intravenously administered furosemide and glyceryl trinitrate therapy. Her brain natriuretic peptide level was elevated and further supported and confirmed the diagnosis retrospectively.

Unilateral pulmonary edema is a completely reversible condition with good patient outcome if it is suspected early and treated early. Even in the absence of readily available echocardiogram skills, a clinical examination is of paramount importance in making a clinical decision in low-resource settings to reduce mortality.