No renal protection from volatile-anesthetic preconditioning in open heart surgery

Acute kidney injury (AKI) is a common complication of open heart surgery (OHS). Preconditioning with volatile anesthetics is well proven to provide myocardial protection. Renal protection provided by volatile-anesthetic preconditioning has also been investigated; however, it is still controversial at the clinical level. This study aimed to investigate whether preconditioning with volatile anesthetics could mediate renal protection in OHS.

A retrospective analytic study was designed. Medical records of patients (age ≥20 years) who had undergone OHS were reviewed. Types of anesthesia were classified as 'opioid-based anesthesia' (O group) and 'volatile-anesthetic-based anesthesia' (V group) according to the definitions given in the main text. Some medical records that had incomplete or ambiguous data were excluded. Renal protection was considered to be present if there was no clinical renal dysfunction as defined by the criteria given in the main text. AKI was considered to be present when there was a decrease of the postoperative estimated glomerular filtration rate (eGFR) that was >25 % of the preoperative eGFR. Also, postoperative 24-h oliguria (post-oliguria) and the provision of postoperative 48-h dialysis (post-dialysis) were considered. Differences between the O and V groups were tested by the appropriate statistics. A p value of <0.05 indicated significance.

A total of 1,122 patients (702 males) were included in this study. The O and V groups included 704 and 418 patients, respectively. AKI was present in 9.52 and 8.37 % of the patients in the O and V groups, respectively (p = 0.532). Post-oliguria was found in 36.08 and 37.79 % of the patients in the O and V groups; and post-dialysis was provided in 3.98 and 4.31 %, respectively, of these patients; these two parameters showed no significant differences between the groups.

This study could not demonstrate volatile-anesthetic-mediated renal protection in OHS. Therefore, in practice, pharmacological preconditioning with volatile anesthetics did not seem to be beneficial.