Pressor Response Index During Blood Return as a Marker for Identifying Intradialytic Hypotension

ABSTRACT Background Intradialytic hypotension (IDH) is a frequent complication of hemodialysis (HD). Although nadir blood pressure–based definitions are prognostically relevant, their use in daily practice is limited because accurate identification requires frequent blood pressure monitoring. Because blood pressure (BP) is routinely measured during HD, the magnitude of the systolic BP rise during blood return may provide a simple and practical marker for identifying IDH. Methods This cross‐sectional study was conducted at a single HD center. Study 1 evaluated factors associated with the pressor response index in 53 HD patients across 159 sessions using analysis of covariance (ANCOVA). Study 2 examined the ability of the index to discriminate HD sessions with and without IDH as defined by McCausland et al. Results The pressor response index was significantly associated with maximum systolic BP drop and hypovolemic symptoms. The index clearly distinguished sessions with and without IDH. The effect size was large (Cohen's d = 1.41), and ROC analysis showed good discrimination (AUC 0.823). The optimal cut‐off value was 10.3% (sensitivity 0.84, specificity 0.65). Conclusion The pressor response index may represent a simple, objective, and practical marker for identifying IDH in routine clinical practice.