[Negative-pressure pulmonary edema associated with transurethral resection syndrome]

We described a patient who had developed negative-pressure pulmonary edema associated with severe transurethral resection syndrome. A relatively healthy, 67-yr-old man (171 cm and 77 kg) with hypertrophic prostate was scheduled for transurethral resection of the prostate under spinal anesthesia. The patient was sedated with continuous propofol infusion because of his anxiety and wish of being asleep. Fifty minutes after starting the operation, electrolyte analysis revealed a decrease in serum Na+ concentration (116 mEq.l-1), and 10 mg of furosemide and hypertonic saline were administered. Thirty minutes later, the arterial oxygen saturation dropped suddenly and arterial blood gas analysis suggested marked pulmonary insufficiency (PaO2: 64 mmHg and PaCO2: 59.4 mmHg). The patient's trachea was intubated and endotracheal release of pinkish foamy sputum was observed. Chest X-ray showed severe lung edema. Massive absorption of the irrigation fluid might have decreased the electrolyte concentration (Na+: 101.0 mEq.l-1) and colloid oncotic pressure. No evidence of cardiac failure was observed immediately after the incidence of pulmonary edema with pulmonary catheter monitoring. The patient's airway was almost intact under spontaneous breathing, but augmented negative-pressure derived from intermittent snoring was considered to be sufficient to break hydrostatic balance of pulmonary capillary vessels and lead to severe pulmonary edema.