An unusual diagnosis of increasing respiratory failure after lung resection

Abstract

A 77-year-old non-smoker female with an unremarkable medical history was admitted to the Thoracic Surgery Unit for a solitary pulmonary nodule (SPN) of the right lower lobe. At diagnostic workup, a brain CT scan showed multiple ischemic chronic lesions. Despite these findings, which could be suggestive of an asymptomatic chronic paradoxical embolism scenario, a transthoracic echocardiography (TTE) did not reveal cardiac defects or shunts. After clinical staging, the patient underwent sublobar resection for diagnostic purposes for suspicion of primary lung cancer. The frozen section analysis was indicative of a bronchial carcinoid tumor, and, accordingly, a right lower lobectomy was performed during the same surgical attempt. The postoperative course was uneventful, and the patient was discharged on the 7th post-op day. The final diagnosis was indicative of an atypical bronchial carcinoid. Two weeks later, the patient returned to the Emergency Department due to the occurrence of increasing dyspnoea; a hypoxic and hypocapnic respiratory failure was detected at blood gas analysis. Due to the clinical suspicion of a pulmonary thromboembolic event, a CT scan was performed, followed by lung scintigraphy: neither confirmed the diagnosis. At clinical examination, we noted that both the dyspnoea and the gas exchanges worsened (decreased to 20 % of the baseline SaO2 values,) when changing from the supine to the standing position.This condition, generally called platypnea orthodeoxia syndrome, was deemed to be related to a cardiopulmonary right-to-left shunt (RLS) [1].A retrospective re-evaluation of the lung scintigraphy, showed a tracer uptake in both kidneys and in the brain [2], and a transcranial color-coded duplex sonography (TCCS) with saline contrast medium injection showed multiple high-intensity transient signals (HITS) even during normal breathing [3], confirming the clinical presence of a RLS.A transesophageal contrast echocardiography (TEE,) showed a severe tricuspid insufficiency and fibrotic endocardial plaques (Fig. 1), suggesting long-standing rightsided carcinoid heart disease [4,5]. Moreover, a patent

Platypnea–orthodeoxia syndrome after right lower lobectomy for lung cancer

“…Pneumonectomy, (in particular right sided) has previously been implicated as a cause of POS in both the presence and absence of elevated right heart pressures [3]. Of note, there are only five published cases of POS after right lower lobectomy [4–7].…”