Inability to Ventilate Due to a Sudden Intraoperative Tension Hydrothorax.

Intraoperative ventilatory failure is most often attributed to airway or equipment problems, but rare pleural complications can produce abrupt obstructive physiology. We report an 85-year-old woman with severe mitral and aortic stenosis, end-stage renal disease (ESRD) on hemodialysis, and recurrent pleural effusions undergoing video-assisted thoracoscopic surgery (VATS) with bilateral PleurX catheter placement who developed sudden ventilation failure immediately after left-sided catheter placement. Despite prompt airway reassessment and emergent pleural decompression, she progressed to cardiopulmonary arrest with echocardiographic findings consistent with profound hemodynamic compromise. This case highlights tension hydrothorax as a critical diagnostic consideration when unexplained ventilatory failure follows pleural instrumentation, particularly in patients with limited preload reserve.