Renal Failure, Acute

Incidence in USA: 1% of all hospital admissions (community-acquired); 5% of all general hospital pts (hospital-acquired); 10–30% of all ICU pts.

Acute tubular necrosis (45%) is most common cause in hospitalized pts.

Population with highest prevalence: Elderly (>65 y).

Two most common definitions:

• RIFLE criteria: Risk, injury, failure, loss, ESRD.

• AKIN criteria: Stage 1, stage 2, stage 3.

Overall mortality of periop ARF: 60–90%

Hyperkalemia (and arrhythmias), metabolic acidosis, acute pulm edema

Aspiration

Bleeding (plt dysfunction)

Metabolic acidosis and hyperkalemia (pH decrease of 0.1 causes K ⁺ increase of 0.5 mEq/L).

Ventricular arrhythmias (may occur without warning).

Encephalopathy (aspiration risk, increased sensitivity to all sedatives and anesthetics).

GI symptoms and aspiration (N/V, bleeding, and encephalopathy).

Coagulopathy (plt dysfunction) and surgical bleeding.

Hemodynamic intolerance of hemodialysis; peritoneal dialysis compromises FRC.

Elective surgery is contraindicated with new-onset ARF; procedures are urgent or emergency.

Consider hemodialysis for severe hyperkalemia prior to nonemergent surgery.

RA Regional anesthesia is relatively contraindicated (plt dysfunction, encephalopathy).

Repetitive hemodynamic insults markedly impair renal recovery.

Dialysis partially controls thrombocytopathy and enteropathy but does not decrease risk of sepsis and poor wound healing.

Dopamine is not renally protective at low doses, and data are mixed about fenoldopam as a protective agent.