Low-dose spinal anesthesia in cesarean section: a narrative review

Spinal anesthesia is the technique of choice for cesarean delivery, offering rapid onset and reliable anesthesia, but conventional intrathecal doses of hyperbaric bupivacaine frequently cause significant hypotension and delayed recovery. Low-dose spinal anesthesia (LDSA), generally defined as ≤ 8 mg of hyperbaric bupivacaine, often combined with intrathecal opioids, has been investigated as a strategy to mitigate these effects. Current evidence indicates that LDSA can attenuate hemodynamic fluctuations and reduce intraoperative nausea without compromising neonatal outcomes; however, excessively low doses may increase the risk of incomplete block and conversion to general anesthesia. While LDSA may be advantageous in patients with cardiovascular compromise, routine dose reduction for all parturients is not supported by existing data. Thus, LDSA represents a context-specific alternative within modern obstetric anesthesia practice, with benefits and limitations that must be weighed against established prophylactic strategies for managing spinal-induced hypotension.