Low-Dose Subarachnoid Anesthesia Combined with PENG and FLCN Blocks Reduces Hypotensive Episodes Without Compromising Anesthetic Depth and Duration in Hip Fracture Surgery: A Retrospective Observational Study

<i>Background and Objectives</i>: In the context of hip fracture surgeries, episodes of hypotension are common, and have been associated in various studies with increased complications and mortality. The latest clinical guidelines recommend close hemodynamic management. Our research team hypothesized that the use of peripheral nerve blocks in this surgery could help adjust the doses of subarachnoid anesthesia for these procedures, thereby limiting the hypotensive episodes, without compromising an adequate depth and duration of intraoperative anesthesia. <i>Materials and Methods</i>: A retrospective study of 184 elderly patients undergoing hip fracture surgery is proposed. In total, 76 patients were operated under subarachnoid anesthesia using 9.5 mg of hyperbaric bupivacaine 0.5% and 10 mcg of fentanyl (Group S), while 108 received a reduced dose of 5 mg hyperbaric bupivacaine 0.5% and 10 mcg of fentanyl, supplemented by preoperative PENG and FLCN blocks (Group B). The main outcome of this study is to compare the number and duration of hypotensive episodes, and its secondary outcome is to compare the use of vasoactive drugs between the groups. <i>Results</i>: The number of hypotensive episodes and their duration were lower in Group B: -12.94 min (-8.57 to -18.03, <i>p</i> = 0.000). The consumption of vasoactive drugs did not reach statistical significance. None of the patients in Group B required supplementary intraoperative anesthesia. <i>Conclusions</i>: Reducing the dose in subarachnoid anesthesia is associated with better hemodynamic control in hip fracture surgeries, and PENG + NFCL blocks are proposed as an appropriate adjunct to ensure adequate anesthetic depth and duration despite a substantial subarachnoid anesthesia dose adjustment.