Spinal anesthesia can be used effectively and efficiently for a variety of cases in both the inpatient and the
ambulatory surgery setting. Choice of agent, dose, distribution, use of adjuncts, and occasionally the use of continuous
spinal anesthesia can tailor the spinal
anesthetic to a specific type and duration of surgery. Although
spinal anesthesia is extremely safe, adherence of new guidelines for patients receiving
anticoagulant drugs,
LMWH in particular, may minimize the risk of neurologic injury from spinal
bleeding. At present, intrathecal adjuncts, such as
neostigmine and
clonidine used with
local anesthetics, have shown limited usefulness, whereas lipophilic
opioids, such as
fentanyl, appear to increase duration and quality of spinal block without increasing the time to recovery. In the future, shorter-acting
local anesthetics, possibly in conjunction with continuous
catheter technologies, may reduce recovery times after
spinal anesthesia without increasing risk. Spinal agents with long-acting
analgesic properties that do not produce sensorimotor deficits may go beyond the immediate
perioperative period and relieve
postoperative pain. Currently there is controversy surrounding the use of spinal
lidocaine and the occurrence of
TNS, especially in the outpatient setting. The prudent use of small-dose
bupivacaine and possibly
procaine may reduce this risk, further supporting the use of
spinal anesthesia for ambulatory as well as inpatient
surgical procedures.