Transient neurologic syndrome in one thousand forty-five patients after 3% lidocaine spinal anesthesia

Recent reports have discussed the potential risk of transient radicular irritation (TRI) after spinal anesthesia with lidocaine. Because we have not encountered such neurologic sequelae with the high incidence reported, we prospectively examined the incidence of TRI after spinal anesthesia with lidocaine. One thousand forty-five adult patients (aged 47 ± 15 yr) receiving spinal anesthesia with 3% hyperbaric lidocaine (1.0-1.5 mL) for anorectal surgery were consecutively studied. After the induction of spinal anesthesia, all patients were placed in the prone position for surgery. Patients were evaluated for neurologic symptoms in the buttocks, thighs, or lower extremities using a checklist to standardize data collection. Although there was no complaint of neurologic symptoms on Postoperative Day (POD) 1, four patients (0.4%) reported aching, hypesthesia, numbness, or dull pain of both lower extremities and buttocks by the morning of POD 3. In three patients, the symptoms resolved without any treatment by POD 5, whereas in one patient, numbness of the lower extremities lasted until POD 7. We conclude that a combination of lidocaine with surgical position or leg manipulation during surgery might be a major contributing factor in the development of transient neurologic syndrome. Implications: Recent studies have reported the potential risk of transient neurologic syndrome after lidocaine spinal anesthesia. The current study reports a low incidence of such sequelae in 1045 patients undergoing anorectal surgery during the prone position. Other factors, such as surgical position, may be important in the development of this syndrome.