Impact of residual kidney function on hemodynamic changes during induction of general anesthesia in hemodialysis...

This study aimed to investigate whether residual kidney function (RKF) influences perioperative hemodynamic stability in hemodialysis patients. Although anesthesiologists have had the clinical impression that RKF contributes to more stable blood pressure during induction of general anesthesia, this association has not been demonstrated. We hypothesized that RKF was associated with less hypotension at induction.

We conducted a single-center retrospective study of hemodialysis patients undergoing elective surgery under general anesthesia. RKF was defined as urine output ≥ 100 mL/day. The primary outcome was the lowest systolic blood pressure (SBP) during induction. Propensity score matching was performed. Independent predictors of hypotension were identified using multivariable logistic regression.

Of 1,086 patients screened, 882 were analyzed (RKF + 335; RKF- 527). After matching, 160 patients were included in each group. In the matched cohort, the lowest SBP was higher in the RKF + group (111 ± 32 vs. 105 ± 30 mmHg; p = 0.044). In the full cohort, both the lowest SBP (112 ± 30 vs. 103 ± 29 mmHg; p < 0.001) and the decrease (28 ± 33 vs. 37 ± 31 mmHg; p < 0.001) were more favorable in the RKF + group, with lower phenylephrine use (0.09 ± 0.19 vs. 0.16 ± 0.35 mg; p = 0.001). Logistic regression confirmed RKF, surgery type, and preoperative SBP as independent predictors.

RKF was associated with higher SBP at induction of general anesthesia, independent of anesthetic and vasopressor doses. Preoperative assessment of RKF may help identify dialysis patients at risk of induction-related hypotension.