6.1 Pre-operative
Patients may be exposed to contrast agents from clinical procedures
prior to having their cardiac surgery. These are known to be nephrotoxic
and would, therefore, involve a certain risk of developing
contrast-induced AKI (CI-AKI). Newer iso-osmolar contrast agents that
are less toxic can be used as an alternative for these procedures.
Likewise, factors that alter renal perfusion should be identified and
corrected. Nephrotoxic medications should be discontinued. If necessary,
perioperative hydration and inotropic agents to improve cardiac output
may be used. While intravenous isotonic crystalloid solution could lower
CI-AKI risk, excess fluids may potentially cause harm and increase
CI-AKI incidence. Whenever possible, renal recovery should be
encouraged, and surgery should be delayed to prevent CS-AKI
risk.42 Likewise, pre-operative anaemia is reported to
be independently associated with postoperative AKI and should thereby be
avoided and managed appropriately before surgery.27