<prompt> A 72 years old patient with BPH underwent transurethral resection of prostate under spinal anaesthesia. After one hour, he developed vomiting and altered sensorium. The most probable cause is:HyperkalemiaWater intoxicationRupture of bladderOver dosage of spinal anesthetic agent  <response>: - If surgery prolonged or when the size of prostate 75gm it leads to dilutional hyponatremia or water intoxication known as TUR syndrome. TUR syndrome Dilutional Hyponatremia or water intoxication Results from a hypervolemic, hyponatremic state due to absorption of the hypotonic irrigating solution. Clinical features: Nausea, vomiting, confusion, hypeension, bradycardia, visual disturbances The risk increases with resection time 90 minutes or gland size 75 gm Rx- Diuresis furosemide and in severe cases, hypeonic saline 3 administration. 