Management of acute renal failure following surgical operation and head injury

Management of acute kidney injury in neurotrauma

Fortunately, the incidence of acute kidney injury (AKI) in neurotrauma is low and decreasing. Whereas the majority of AKI occurs in older patients with pre-existing chronic kidney disease, neurotrauma typically occurs in children and young adults with normal renal function. The development of outreach trauma teams has improved initial resuscitation, reducing both volume responsive and volume unresponsive cases of AKI. Most cases occur in the setting of multiple organ trauma with muscle injury, or patients who subsequently develop multiple organ failure. Once AKI has developed and renal replacement therapy is required, continuous modalities of renal replacement therapy offer an advantage to the patient with compromised cerebral perfusion and intracranial hypertension, by reducing the rate of change in serum urea, compared with standard intermittent therapies of hemodialysis and hemofiltration, thus minimizing abrupt changes in serum osmolality. Continuous hemodialysis and hemofiltration are better suited to maintain a normal or high serum sodium and thermal losses through the extracorporeal circuit, than peritoneal dialysis. Dialyzers should preferably be minimally bioincompatible and of a small surface area. In patients at risk of intracranial hemorrhage and those with invasive intracranial monitoring, systemic anticoagulants should either be avoided or regional anticoagulants should be used.

Nonoliguric acute renal failure

Oliguria has been considered a cardinal feature of acute renal failure. However, many recent reports indicate that acute renal failure usually occurs in the setting of well-maintained urine output. Moreover, the nonoliguric state may accompany acute renal failure due to pre- and post-renal azotemia and a variety of renal parenchymal disorders, as well as acute tubular necrosis. Most studies indicate that nonoliguric forms of acute renal failure are associated with less morbidity and mortality than oliguric acute renal failure. Uncontrolled studies also suggest that volume expansion, potent diuretic agents, and renal vasodilators can convert oliguric to nonoliguric acute tubular necrosis if administered early in the course of acute renal failure. However, prospective studies of early intervention in oliguric patients are needed.

The management of acute reversible intrinsic renal failure

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