Renal Failure: CPB surgery
Clinical - Cardiovascular
After coronary revascularization, patients who develop ARF experience significant increases in both short- and long-term mortality. Mortality is far lower in patients with normal renal function (0.9 %) then in patients with accute renal failure (up to 60%).
Nonpulsatile flow and hypotension lead to renal vasoconstriction and decreased RBF. Norepinephrine and renin increase. High renin correlates c renal failure. Thromboxane from platelets also cause vasoconstriction. 2% of CPB patients will have ARF, if ARF occurs mortality is 60-80% . In normal kidney patients pulsatile vs non-pulsatile flow does not change ARF incidence . Pulsatile flow may be better for patients c CRI. ARF after CPB is more related to cardiac function after surgery than with mean pressures (even <50) while on CPB.
Risk factors for ARF following CPB include starting Cr 1.9 or higher , and combined/complex surgery .
Dopamine does not improve renal outcome post CPB, and it may be harmful by increasing arrhythmias post-op. A metaanalysis of 13 RCTs including 1,059 patients suggested that fenoldopam (a D1 agonist) may reduce the risk of in-hospital death (OR 0.46, p = 0.002) and renal replacement therapy (OR 0.36, p < 0.001) as well as reducing ICU LOS by 0.93 days (p = 0.002).
Summary of Renal Dysfunction in CPB
- 2% incidence (60-80% mortality when it occurs)
- Risk factors include starting Cr 1.9 or higher, combined/complex surgery
- Consider pulsatile flow for patients who already have CRI
- Fenoldopam (but not dopamine) may reduce death, renal replacement therapy, and ICU stay.