Clinical Trial – Low Dose Spinal Anesthesia in Cesarean Surgery
Anesthesia for cesarean section requires special importance because it may affect both mother
and the baby. To avoid maternal hypotension related to spinal anesthesia must be the primary
objective during anesthesia. Even though many factors influence sensory nerve block for
surgical anesthesia, local anesthetic dose is the main determinant. Another factor that
influence the sensory nerve block is the obesity related to pregnancy. Due to the enlargement
of epidural venous plexus related to pregnancy, the subarachnoid and epidural space reduces,
so the local anesthetic requirement also reduces. Many investigators recommend lower dose of
local anesthetic in obese patients due to reduced requirement There are many studies about
dose regimens for cesarean anesthesia, but ideal dose have not been found. Investigators have
designed this study to see the effects of conventional dose (10 mg bupivacaine) vs. low dose
plus fentanyl (7,5 mg bupivacaine+25 mcg fentanyl) in obese and normal weight pregnant for
cesarean section. The hypothesis was: the low dose regimen provides surgical anesthesia in
obese patients while avoiding maternal hypotension.
Clinical Trial – Minimal Effective Dose of Hyperbaric Spinal Bupivacaine for Saddle Block
The optimal anesthetic technique would provide excellent operating conditions, rapid
recovery, early discharge, no postoperative side effects, and high patient’s satisfaction. In
addition to increasing the quality and decreasing the costs of the anesthetic services (1).
Selective spinal anesthesia (SSA) -spinal block with minimal effective doses for a specific
type of surgery – has become very popular technique) 2(for some orthopedic and gynecological
surgeries [3-9].
Saddle anesthesia is a SSA directs a small bolus of hyperbaric local anesthetic, towards
S4-S5 and coccygeal nerve roots (11), and is commonly utilized for perianal surgeries
(11-14). Hyperbaric bupivacaine has been safely, replaced hyperbaric Lidocaine for saddle
block (11, 12).
Although Saddle blocks at different low doses of hyperbaric bupivacaine (1.5- 4 mg) have been
used previously for mi¬nor perianal surgeries (11, 13, 14), the optimal effective dose has
yet to be determined.
The objective of this study is to determine the minimal effective dose of hyperbaric spinal
bupivacaine required to induce a reliable and satisfactory saddle block for perianal
surgeries (using a modified Dixon’s up-and-down method.