Hypothyroidism and non-cardiogenic pulmonary edema: are we missing something here?

Summary

We report the case of a 42-year-old female with a history of hypothyroidism and asthma presenting with progressive dyspnea and orthopnea after 2 days of an upper respiratory tract infection (URTI). Based on the clinical and radiological findings, the patient was admitted as a case of cardiogenic pulmonary edema secondary to possible viral myocarditis. However, a normal brain natriuretic peptide (BNP) level with a normal ejection fraction (EF) on echocardiogram changed our working diagnosis from cardiogenic to non-cardiogenic pulmonary edema. Further questioning revealed a history of nocturnal snoring, frequent awakening, and daytime fatigue, suggesting a possible sleep apnea syndrome (SAS). In conclusion, we believe that SAS was the missing link between our patient's hypothyroidism and non-cardiogenic pulmonary edema.

Learning points

• Always keep an open mind and look for a pathology that would explain the whole clinical scenario.

• The involvement of the respiratory system in hypothyroidism can range from SAS, pulmonary hypertension, hypoventilation, and severe respiratory failure.

• Hypothyroidism and SAS should be considered in the differential diagnosis of non-cardiogenic pulmonary edema.

• Patients should be instructed to take levothyroxine on an empty stomach 30–60 min before food to avoid erratic absorption of the hormone.