Does smoking affect the onset time of sensory blocks or the duration of motor blocks in parturient women? A randomized controlled trial

Background: In general, smoking or exposure to secondhand smoke is still common worldwide, and the rate of smoking in women of childbearing age is gradually increasing. Cesarean section rates have been increasing in recent years, and anesthesia guidelines recommend regional anesthesia for cesarean sections. Since nicotine and local anesthetics have different effects on ligand-gated ion channels, smoking may affect spinal anesthesia in pregnant women. Aim: The aim of this study was to investigate the effects of smoking on spinal anesthesia, which is applied for cesarean sections in pregnant women. Patients and Methods: After approval from the institution's ethics committee, 100 pregnant women were divided into two groups: current smokers (Group S, smoker) (n = 50) and lifelong nonsmokers (Group NS, nonsmoker) (n = 50). The dose of local anesthetic was adjusted according to the height of each patient. After free cerebrospinal fluid flow was observed, all patients were given 20 μμg of fentanyl in 0.05 mg/cm hyperbaric 0.5% bupivacaine within 10 seconds. The onset of sensory and motor block, the duration of sensory and motor block, and the visual analogue scale (VAS) score were monitored. Results: Data from 100 parturient women were investigated. Even though the median time required for the onset of sensory block to occur was significantly higher in Group S (P = 0.019), the duration of motor block was found to be shorter (P = 0.003); however, the duration of sensory block was similar in both groups (P = 0.771). VAS scores were significantly higher in Group S (P = 0.001). Conclusions: In conclusion, the pregnant women who smoked had longer motor block onset times, shorter motor block durations, higher VAS scores, and lower patient satisfaction levels.