BACKGROUND Intraoperative hypotension is commonly defined as MAP <65 mmHg. We evaluated whether cumulative exposure across multiple MAP thresholds provides additional mortality-associated information beyond this single threshold. METHODS We conducted a retrospective cohort study of adults having non-cardiac, non-obstetric surgery using perioperative electronic health record data. Pressure-time burden and proportion of operative time were calculated across MAP thresholds from 50 to 150 mmHg. Decision-tree analysis using recursive partitioning sequentially grouped patients according to MAP exposure patterns associated with 30-day mortality. Discrimination of the multi-threshold blood-pressure-only model was compared with that of a model restricted to exposure below MAP 65 mmHg. Medication associations were exploratory. RESULTS Among 388,407 patients, 30-day mortality was 1.49%. The multi-threshold model had greater validation discrimination than the MAP 65 mmHg model (AUROC, 0.619 vs. 0.591; ΔAUROC, 0.028; 95% CI, 0.025-0.037; p < 0.001), although the improvement was modest. Terminal exposure groups defined by complete combinations of MAP level and cumulative exposure had different observed mortality rates. Medication associations varied across groups. Observed 30-day mortality was generally higher with deeper hypotension and a greater proportion of operative time spent below MAP thresholds, although the relationship was not uniformly monotonic. CONCLUSIONS Multi-threshold MAP exposure captured mortality-associated information not represented by exposure below MAP 65 mmHg alone, complementing this clinical threshold. The multi-threshold analysis identified groups with distinct pressure-time exposure patterns, providing a basis for hemodynamic profiling and investigation of hypotension-related outcomes. External validation is needed to assess the reproducibility and discrimination of these groups in other populations, followed by prospective studies to determine whether management informed by these patterns improves outcomes.
Stellate ganglion block (SGB), an interventional technique that modulates sympathetic activity, has been increasingly investigated beyond traditional pain management in cardiology, neuropsychiatry, and perioperative medicine. This narrative review examines the evolving role of SGB in contemporary anesthesia practice, emphasizing that its effects may extend beyond immediate peripheral sympatholysis to longer-lasting central neural modulation.Technically, ultrasound guidance facilitates precise needle placement and low-volume injection, with improved visualization of relevant anatomy and injectate spread. Dose-finding studies have refined local-anesthetic volume and concentration, whereas continuous blockade may extend sympatholysis in selected refractory conditions. Clinically, SGB has been used in selected pain conditions, including complex regional pain syndrome and herpes zoster–related pain, and has been investigated for non-pain indications such as post-traumatic stress disorder, refractory ventricular arrhythmias, and menopausal vasomotor symptoms. In perioperative settings, SGB has been evaluated for postoperative analgesia, modulation of inflammatory responses, and potential neuroprotective effects.Risk mitigation relies on real-time ultrasound visualization of the needle tip, adjacent vascular structures, and injectate spread, together with predefined management protocols for major complications. Future research should prioritize multicenter prospective studies, standardized procedural parameters, and individualized treatment pathways to support the safe, precise, and evidence-based use of SGB across clinical settings.
