The results support our hypothesis and may lead to a technique for assessing the competence of cerebral autoregulation.

No abstract

No abstract

A 76-year-old woman sustained inadvertent perforation of her posterior bladder wall during transurethral resection of a bladder tumour. In the immediate postoperative period, she developed life-threatening respiratory failure following the formation of a large, unilateral pleural effusion. After therapeutic drainage, biochemical analysis of the effusion revealed that it had a high concentration of glycine. The¯uid used for intra-and postoperative bladder irrigation had leaked from the perforated bladder and collected in the pleural cavity. This type of hydrothorax complicating endoscopic urological surgery has not been described previously.Keywords Complications; respiratory failure, glycinothorax. Surgery; urolological. Surgery to the bladder is usually performed using endoscopic techniques. It is usual for the bladder to be ®lled and irrigated with¯uid to optimise operating conditions and a 1.5% glycine solution has been found to be suitable for use with diathermy. We present a patient who suffered life-threatening respiratory failure following transurethral resection of a bladder tumour and this was associated with the peri-operative formation of a large pleural effusion. The diagnosis and pathophysiology of this complication is discussed. Case historyA 76-year-old woman was admitted for elective transurethral resection of a bladder tumour. She had a history of mild emphysema requiring no treatment. A pre-operative chest X-ray was reported as normal. Routine blood results were unremarkable with a serum creatinine of 96 mmol.l À1 and sodium of 134 mmol.l À1 . The patient opted for surgery to be performed under general anaesthesia, which was induced with propofol 2 mg.kg À1 , fentanyl 1 mg.kg À1 and vecuronium 0.1 mg.kg À1 . The trachea was intubated and the lungs ventilated with 66% nitrous oxide in oxygen with iso¯urane titrated to clinical need. The patient remained stable throughout the 1 h procedure with an oxyhaemoglobin saturation [S p O 2 ] of 97±100% and an endtidal carbon dioxide tension of 33±36 mmHg. During resection of the extensive in®ltrating tumour the posterior wall of the bladder was perforated and it was decided to stop further surgery. At the end of the procedure neuromuscular relaxation was reversed and the patient was extubated when she objected to her tracheal tube. She was breathing comfortably and had an S p O 2 of 100% on 5 l.min À1 of oxygen via a face mask. She was taken to the recovery ward to regain full consciousness, for routine monitoring and oxygen therapy.Initially the patient's observations were stable, and she opened her eyes to command and made some incomprehensible sounds. However, over the following 20 min the patient's condition deteriorated. Her conscious level changed and she rapidly became unrousable. Her S p O 2 decreased below 90% despite increasing the oxygen therapy to 15 l.min À1 via a face mask with a reservoir bag. Her respiratory pattern also changed from appropriate-sized breaths at a rate of 12 breath.min À1 to very shallow, rapid ones at a rate of 40 breath...