Contributions to nephrology
-
Acute kidney injury (AKI) is a common and serious postoperative complication following exposure to cardiopulmonary bypass (CPB). Several mechanisms have been proposed by which the kidney can be damaged and interventional studies addressing known targets of renal injury have been undertaken in an attempt to prevent or attenuate CPB-associated AKI. However, no definitive strategy appears to protect a broad heterogeneous population of cardiac surgery patients from CPB-associated AKI. ⋯ Sodium bicarbonate is safe, simple to administer and inexpensive. If part of AKI after CPB is truly secondary to hemoglobin-induced pigment nephropathy, prophylactic sodium bicarbonate infusion might help attenuate it. A trial of such treatment might be a reasonable future investigation in higher risk patients receiving CPB.
-
Traditionally the epidemiology of acute renal failure was assessed in patients requiring renal replacement therapy. Recent data emphasized the importance of less severe impairment of kidney function, hence the terminology acute kidney injury (AKI) was introduced. ⋯ Small changes in kidney function have an impact on outcomes and this knowledge has led to the introduction of the terminology AKI, encompassing both discrete and severe impairment of kidney function. The RIFLE classification describes the whole range of AKI and has been validated in multiple cohorts. As a consequence of increasing comorbidity, the incidence of AKI is increasing. The incidence of acute renal failure requiring renal replacement therapy even compares to that of acute lung injury, and up to two thirds of general ICU patients meet RIFLE criteria for AKI.
-
Sustained low-efficiency dialysis (SLED) is an increasingly popular form of renal replacement therapy for patients with renal failure in the intensive care unit. Advantages of SLED are efficient clearance of small solutes, good hemodynamic tolerability, flexible treatment schedules, and reduced costs. Studies comparing outcomes of SLED with those of other dialysis modalities are being performed.
-
The practice of renal replacement therapy (RRT) has reached an optimal standard of care worldwide. Nevertheless, some aspects of acute renal failure treatment and support still present wide variability between different centers. This is especially true for the mode and dose of RRT. This review describes the epidemiology of dialysis prescription and delivery around the world based on recent observational studies and international surveys. ⋯ A trend to continuous therapies and increased RRT dosage over the last 10 years is shown by the surveys presented, even if scientific evidence is now very necessary as far as definitive RRT indications and prescriptions are concerned.
-
Continuous renal replacement therapies (CRRTs) are increasingly used in order to maintain normal or near-normal acid-base balance in intensive care unit (ICU) patients. Acid-base balance is greatly influenced by the type of dialysis employed and by the administration route of replacement fluids. In continuous veno-venous hemofiltration, buffer balance depends on losses with ultrafiltrate and gain with replacement fluid, while in techniques such as continuous veno-venous hemodiafiltration, clinicians should balance the role of the dialysate. ⋯ However, the dialysate buffer or electrolyte concentration need always to be balanced with that of the replacement fluids employed. Both fluids should contain electrolytes in concentrations aiming for a physiologic level and taking into account preexisting deficits or excess and all input and losses. Clinicians should be aware that in CRRTs the quality control for sterility, physical properties, individualized prescription and balance control are vitally important.