Dural sac cross-sectional area is a highly effective parameter for spinal anesthesia in geriatric patients undergoing transurethral resection of the prostate: a prospective, double blinded, randomized study

Abstract

Background Spinal anesthesia is optimal choice for transurethral resection of the prostate (TURP), but the sensory block should not cross the T10 level. With advancing age, the sensory blockade level increases after spinal injection in some patients with spinal canal stenosis. We optimize the dose of spinal anesthesia according to the decreased ratio of the dural sac cross-sectional area (DSCSA), the purpose of this study is to hypothesis that if DSCSA is an effective parameter to modify the dosage of spinal anesthetics to achieve a T10 blockade in geriatric patients undergoing TURP. Methods Sixty geriatric patients schedule for TURP surgery were enrolled in this study. All subjects were randomized divided into two groups, the ultrasound (group U) and the control (group C) groups, patient receive either a dose of 2 ml of 0.5% isobaric bupivacaine in group C, or a modified dose of 0.5% isobaric bupivacaine in group U. We measured the sagittal anteroposterior diameter (D) of the dural sac at the L3–4 level with ultrasound, and calculated the approximate DSCSA (A) according to the following formula: A = π(D/2)2, ( π = 3.14). The modified dosage of bupivacaine was adjusted according to the decreased ratio of the DSCSA. Results The cephalad spread of the sensory blockade level was significantly lower (P < 0.001) in group U (T10, range T7–T12) compared with group C (T3, range T2–T9). The dosage of bupivacaine was significantly decreased in group U compared with group C (P < 0.001). The regression times of the two segments were delay in group U compared with group C (P < 0.001). The maximal decrease in MAP was significantly higher in the group C than in group U after spinal injection (P < 0.001), without any modifications HR in either group. Eight patients in group C and two patients in group U required ephedrine (P = 0.038). Conclusions The DSCSA is a highly effective parameter for spinal anesthesia in geriatric patients undergoing TURP, a modified dose of local anesthetic is a critical factor for controlling the sensory level. Trial registration This study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR1800015566).on 8, April, 2018.

A Second Prone Dose Algorithm for Patients Undergoing Spinal Anesthesia During Thoracolumbar Surgeries

“…A case study by Spiegel et al 19 presented a patient whose exceptionally large intrathecal volume, as measured by MRI, was the likely cause of a failed spinal anesthesia attempt. Another study by Wang et al 20 used the cross-sectional area of the dural sac acquired using ultrasound to effectively dose spinal anesthesia for patients undergoing transurethral prostate resection. These studies show that size of the dural sac may have serious implications in the effectiveness of spinal anesthesia and is likely a major causative factor of first dose failure in our manuscript.…”

Comparison of clinical efficacy of hyperbaric ropivacaine with hyperbaric bupivacaine in spinal anesthesia for transurethral resection of prostate: A randomized and double-blind study

“…6,7 For the TURP procedure, it is essential to achieve a sensory blockade at the T10 dermatome, and the procedure typically takes 60-75 min to complete. 8 The efficacy and time of the anesthetic block crucially hinge on the choice of the LA, considering its type and concentration. Lipophilic opioids such as fentanyl are increasingly administered intrathecally as an adjunct to LAs.…”

The Relationship of Spinal Anesthesia Dosing Based on Thecal Sac Area to Anesthetic Failure in Lumbar Surgery

“…13,14 Instead, the literature suggests that cross-sectional area of the thecal sac may better account for variability in a patients' thecal sac volume. 15,16 Patients undergoing lumbar surgery under SA offer a unique opportunity to individualize their anesthesia dose based on anatomic variables given the availability of lumbar cross-sectional imaging.…”