Severe re-expansion pulmonary oedema after medical thoracoscopy

Dear Sir, This case report discusses a severe instance of re-expansion pulmonary oedema (RPO) following medical thoracoscopy (MT) in a 71-year-old man with a history of shortness of breath (SOB) for 3 months, right pleural effusion and multiple lung nodules on chest X-ray Figure 1a. Computed tomography revealed a suspicious large right renal mass, possibly renal cell carcinoma (RCC). Outpatient ultrasound-guided thoracentesis removed 400 mL of bloody fluid, providing relief from SOB. As the pleural fluid analysis did not yield any malignant cells, outpatient MT was done. Tumour growth was observed on the pleural and diaphragmatic surfaces Figure 2a, and 1.5 L of fluid was drained, during which rapid re-expansion of the lung was seen Figure 2b–d. Multiple parietal pleura biopsy samples were collected, and an indwelling pleural catheter (IPC) was inserted for passive drainage.Figure 1: Chest X-rays show (a) right pleural effusion and multiple pulmonary nodules, (b) full lung re-expansion at 2 h postprocedure, (c) new increased opacity seen on the right lung postintubation, and (d) improvement of right lung opacity at postextubation.Figure 2: Thoracoscopy images show (a) pleural effusion and diaphragmatic nodules, (b) re-expansion of the lung and pleural nodules, (c) lung re-expansion as trocar is withdrawn, and (d) pulmonary nodule visualised as the lung re-expands.Shortly after the procedure, the patient appeared stable initially but developed coughing. A follow-up chest X-ray 2 h later showed full lung re-expansion, but with a new right-sided opacity, IPC in place and subcutaneous emphysema Figure 1b. Three hours postprocedure, the patient experienced acute SOB and severe desaturation from initial peripheral oxygen saturation of 95% on room air to 85% on non-rebreathing mask oxygen. He was transferred to the intensive care unit (ICU), where he was intubated and mechanically ventilated. There was no evidence of bleeding, pneumothorax or myocardial infarction. He was, therefore, treated for RPO with supportive mechanical ventilation. Within less than 24 h, his condition improved. He was weaned off inotropes, extubated to nasal prongs and his postextubation chest X-ray showed improvement in the right-sided lung opacity Figure 1c & d. He was transferred out of the ICU 2 days after the procedure and discharged from the hospital 3 days later. Subsequent histological examination confirmed a diagnosis of metastatic RCC. Outpatient MT with1 or without2 IPC insertion is generally considered feasible and safe, with less than 1% of cases requiring admission when patients are carefully selected. Although our patient had a good performance status and no chronic oxygen supplementation, he unexpectedly developed RPO, necessitating intubation and mechanical ventilation. Re-expansion pulmonary oedema is a rare complication of large-volume thoracentesis, with reported incidence rates ranging from 0.1% to 0.4% and a mortality rate of up to 20%.3,4 While most cases exhibit mild symptoms, severe RPO requiring ICU care has been documented.5 Common risk factors for RPO include rapid lung re-expansion due to the removal of more than 1 L of fluid and the absence of septations.5 As a safety precaution, it is recommended that patients who undergo outpatient MT be observed for at least a few hours before discharge to prevent acute deterioration outside the hospital. Financial support and sponsorship Nil. Conflicts of interest See KC is a member of the SMJ Editorial Board and was thus not involved in the peer review and publication decisions of this article.