A fatal case of cerebral oedema with hyponatraemia and massive polyuria after renal transplantation.

We report the case of a child who died from severe cerebral oedema in the context of hyponatraemia and extreme polyuria immediately after renal transplantation. The patient was treated according to a standard post-transplantation protocol, receiving 0.45% saline solution for urine output replacement. The case highlights the dangers of massive fluid therapy in the context of polyuria and, therefore, the need for intensive monitoring.

Keyhole surgery for isolated pituitary stalk metastatic tumors: a case report and review of the literature.

Solitary metastatic pituitary stalk tumors account for approximately less than 1% of all pituitary gland tumors and present difficulties in clinical diagnosis because most of them are clinically silent and usually too small to cause radiological changes. With the advance of microsurgical techniques, keyhole surgery is indicated to obtain a specimen for pathological diagnosis and possible removal of the tumor. Here, we reported a patient who has a history of advanced breast cancer and who complained of polyuria and polydypsia. Magnetic resonance images revealed a solitary tumor over the pituitary stalk. A right supraorbital craniotomy was performed and the pathological report confirmed the diagnosis of metastatic breast cancer. This is the first case report using keyhole surgery to confirm the pathology and improve the clinical symptoms. The relevant literature is also reviewed.

Improvement of polyuria, bladder sensation and bladder capacity following renal transplantation.

Here, we report a patient with renal failure and bladder dysfunction whose symptoms improved following renal transplantation. A 23-year-old woman underwent renal transplantation for renal failure as a result of dysplastic kidneys. Urodynamic evaluation prior to transplantation showed decreased bladder sensation and increased bladder capacity, probably because of congenital polyuria. One week after surgery, dry mouth disappeared, and urine volume normalized gradually. Urodynamic studies performed 3 and 10 months after transplantation showed improvement of bladder function, and the frequency/volume charts of urination also showed normalization of urine volume. Renal and bladder functions were almost normal 45 months after transplantation. Bladder dysfunction involves numerous factors, but the primary cause was probably congenital polyuria in the present case. This case suggested that blood purification and correction of urine volume by renal transplantation might lead to restoration of normal bladder function.

Persistent post-transplant polyuria managed by bilateral native-kidney laparoscopic nephrectomy.

Polyuria is not considered an absolute indication for pre-transplant nephrectomy; however, it may complicate post-transplantation fluid management. Bilateral native-kidney laparoscopic nephrectomy was performed at our centre in two patients (four kidneys) 1 month after they had received a living related-donor renal transplant. The indication for nephrectomy was severe post-transplant polyuria secondary to the patient's underlying disease: juvenile nephronophthisis. Both patients had a persistent post-transplant daily urine output of 7-8 l/day and continued to have a variable serum creatinine level, dependent on intravenous hydration, more then 3 weeks after transplantation. Bilateral laparoscopic native-kidney nephrectomy in children has previously been reported. However, to the best of our knowledge, laparoscopic nephrectomy has not been described after kidney transplantation and certainly not in the immediate post-transplantation period. The procedure was well tolerated and did not affect renal graft function. In fact, following the procedure, serum creatinine levels stabilized, while daily fluid requirements decreased to 2.5-3.5 l/day in both patients. We concluded that bilateral native-kidney nephrectomy can be safely performed in paediatric renal transplant recipients in the immediate post-transplantation period. This new approach may allow preemptive transplantation and avoid the need for a transition period on dialysis in patients for whom pre-transplant nephrectomy is not absolutely indicated.

Selective decrease in urinary aquaporin 2 and increase in prostaglandin E2 excretion is associated with postobstructive polyuria in human congenital hydronephrosis.

This study was undertaken to determine the role of aquaporin 2 (AQP2) in the impaired urinary concentrating capacity observed in patients who underwent pyeloplasty because of congenital unilateral hydronephrosis as a result of pyeloureteral junction disease. Twelve children (mean age, 8 +/- 2 mo) were examined in the study. From day 1 to day 5 after surgery, the urine was collected separately from pyelostomy draining only from the postobstructed kidney and from the bladder catheter draining mostly from the contralateral kidney used as internal control. After pyeloplasty, the postobstructed kidney was characterized by a reduced urinary excretion of AQP2 (approximately 54%) associated with polyuria that persisted from day 1 to day 5 (433 +/- 58 versus 310 +/- 74 ml/24 h at day 1; 326 +/- 44 versus 227 +/- 26 ml/24 h at day 5). In parallel, urine osmolality from the postobstructed kidney was significantly reduced compared with the contralateral kidney (111 +/- 12 versus 206 +/- 49 at day 1; 136 +/- 24 versus 235 +/- 65 mOsm/kg at day 5). Creatinine clearance from the postobstructed kidney was not significantly different compared with the contralateral kidney throughout the 4 d after surgery. However, on day 5, creatinine clearance from the postobstructed kidney became significantly lower. Prostaglandin E2 in the urine from postobstructed kidneys was found to be twofold higher than in the contralateral samples (26.0 +/- 6.7 versus 13.5 +/- 2.5 at day 5). It is concluded that (1) the selective downregulation of AQP2 in postobstructed kidney may account for the higher excretion of hypotonic urine, and (2) the local increase in prostaglandin E2 synthesis in postobstructed kidney may be involved in AQP2 downregulation and in maintaining a GFR similar to that of the contralateral kidney.

Splenectomy attenuates the inappropriate diuresis associated with tumor necrosis factor administration.

Tumor necrosis factor (TNF) is an important mediator of the systemic response to gram-negative sepsis and endotoxemia. We studied the renal effects of a sublethal TNF infusion in dogs (0.54 = 10(5) international units per kilogram of body weight during a six hour period). The TNF-infused dogs (n = 4) had marked polyuria and natriuresis in comparison with those in the control group (n = 12) (urine output, 35.3 +/- 4.1 versus 3.7 +/- 0.5 millimeters per kilogram per six hours p less than 0.01; sodium excretion, 2.82 +/- 0.27 versus 0.75 +/- 0.19, p less than 0.01). To evaluate the role of the spleen in this response, seven dogs that had splenectomy were infused with TNF. Splenectomy abolished both the polyuria and the natriuresis; this could not be explained by the differences in fluid balance or in hemodynamic or metabolic alterations. Treatment with ibuprofen given intravenously (12.5 milligrams per kilogram 40 minutes before and three hours after the beginning of TNF infusion) in eight dogs that did not undergo splenectomy also abolished these renal effects. Prostaglandin 2 (PGE2) concentrations in selected blood samples from the splenic vein did not increase with TNF infusion, excluding circulating PGE2 as a possible mediator of the renal effects. The results of these studies indicate that, during septic challenge or severe inflammation, the spleen participates in signaling the kidney to increase water and sodium excretion. These renal events are mediated through the cyclo-oxygenase pathway.