Background: Studies have reported lower pain threshold, spinal anesthesia duration, and level of sensory
block in addicts compared to non-addict patients undergoing spinal anesthesia for surgery. Moreover, blood
gas and cerebrospinal fluid (CSF) were likely to be affected as well. The aim in the present study is to evaluate
CSF and spinal parameters in addict versus non-addict patients during lower limb surgery.
Methods: In this case-control study, 22 opium addicts and 22 sex- and age- matched non-addicts undergoing
lower limb surgery under spinal anesthesia were included. The CSF parameters, venous blood gas (VBG), and
sensory and motor block findings were compared between the groups.
Findings: The addict and non-addict patients were similar regarding CSF and blood gas parameters except
higher pH in VBG (7.39 ± 0.06 vs. 7.33 ± 0.11, P = 0.030) and CSF (7.39 ± 0.06 vs. 7.33 ± 0.11, P = 0.030) for
addict patients. The addict patients had significantly later onset of sensory block (5.72 ± 1.57 vs. 3.16 ± 0.93
minutes, P < 0.001) and shorter motor block duration (137.72 ± 11.51 vs. 149.09 ± 14.44 minutes, P = 0.006),
with no significant difference in the sensory block duration and motor block onset.
Conclusion: Addict patients have delayed onset of sensory block with shorter duration of motor block and lower
sensory block level. Among the blood gas and CSF markers, only pH was significantly higher in addict patients,
needing further evaluations; however, it seems that addiction has no significant effect on these parameters.