Oliguric renal failure of surgical origin

Deciphering the mechanisms of the Na+/H+ exchanger-3 regulation in organ dysfunction

The Na+/H+ exchanger-3 (NHE3) belongs to the mammalian NHE protein family and catalyzes the electro-neutral exchange of extracellular sodium for intracellular proton across cellular membranes. Its transport function is of essential importance for the maintenance of the body's salt and water homeostasis as well as acid-base balance. Indeed, NHE3 activity is finely regulated by a variety of stimuli, both acutely and chronically, and its transport function is fundamental for a multiplicity of severe and world-wide infection-pathological conditions. This review aims to provide a concise overview of NHE3 physiology and discusses the role of NHE3 in clinical conditions of prominent importance, specifically in hypertension, diabetic nephropathy, heart failure, acute kidney injury, and diarrhea. Study of NHE3 function in models of these diseases has contributed to the deciphering of mechanisms that control the delicate ion balance disrupted in these disorders. The majority of the findings indicate that NHE3 transport function is activated before the onset of hypertension and inhibited thereafter; NHE3 transport function is also upregulated in diabetic nephropathy and heart failure, while it is reported to be downregulated in acute kidney injury and in diarrhea. The molecular mechanisms activated during these pathological conditions to regulate NHE3 transport function are examined with the aim of linking NHE3 dysfunction to the analyzed clinical disorders.

Renal impairment after thoracotomy: incidence, risk factors, and significance

One hundred thirty patients undergoing major thoracotomy between June 1991 and June 1992 at The Royal Brompton Hospital, London, were analyzed; renal impairment developed in 31 patients (24%). The mortality and morbidity was significantly greater for the renal impairment group. Six patients (19%) with renal impairment died after operation, in contrast to 0 of the 99 patients in whom renal impairment did not develop. The average length of hospital stay for the patients with renal impairment was 12 days compared with 8 days for the normal renal function group (p << 0.001). Five factors were highly significantly associated with renal impairment: a past history of renal impairment or diuretic intake, undergoing pneumonectomy, postoperative infection, and blood loss (p < 0.001). The most important of these appears to be postoperative infection or blood loss, as they also were associated with death (p = 0.01). Other factors less significantly associated with renal impairment included a past history of hypertension, ischemic heart disease, intraoperative gentamicin, and epidural analgesia (p < 0.01). This study emphasizes that thoracotomy must be considered carefully in patients with these predisposing factors, particularly if pneumonectomy is likely. Care must be taken in the use of aminoglycosides and epidural analgesia. Maintenance of renal blood flow by careful control of hemodynamic indices appears to be the most important intervention.