Optimizing spinal anesthesia for ambulatory surgery.

Background and objectives: Spinal anesthesia is used for ambulatory surgical procedures. We provide an overview of the use of local anesthetics, use of continuous techniques, and use of adjuncts for optimization of spinal anesthesia for ambulatory surgery.

Methods: Review of current literature and critical analysis of selected manuscripts.

Results: Small doses of lidocaine (approximately 40 mg) and bupivacaine (approximately 7.5 mg) are appropriate for ambulatory surgery. Increasing concentration of local anesthetic solution may result in increased duration of anesthesia and recovery. While use of hyperbaric solutions consistently produce more cephalad sensory block, use of isobaric solutions provide adequate sensory and motor block for lower extremity surgical procedures. The use of continuous techniques may provide valuable anesthetic titration, as small doses of spinal anesthetics may produce highly variable results. Epinephrine is not recommended as an adjunct due to prolongation of recovery time. In contrast, intrathecal fentanyl may prolong surgical anesthesia without prolonging recovery.

Conclusions: Ambulatory spinal anesthesia may be optimized by selection of dose, concentration, and baricity of local anesthetic. Use of a continuous technique or an intrathecal adjunct may also be valuable means to optimize spinal anesthesia for ambulatory surgery.