BACKGROUND AND OBJECTIVES: One of the most important factors affecting the level of analgesia after intrathecal administration of local anesthetics is their density relative to CSF density. This study evaluated the onset time, duration and cephalad spread of spinal anesthesia with 2% lidocaine in patients submitted to short orthopedic surgeries. METHODS: 250 patients aged 15 to 78 years, physical status ASA I and II scheduled for different orthopedic surgeries were submitted to spinal anesthesia, in the lateral position, with 60 mg (3 ml) of plain 2% lidocaine. The following parameters were monitored: onset time for analgesia, degree of motor block, duration of effects, cephalad spread of analgesia and cardiovascular changes. RESULTS: The mean analgesia onset time was 1.47 ± 0.75 min. No correlation between age and analgesia onset time was detected but the latency time until total motor block was shorter in the older patients. Total motor block was observed in 93% of patients. Blockade failed in 1.75% of patients. Sensory block duration was of 102.32 ± 15.45 min and motor block duration was of 106.48 ± 16.48 min. Hypotension and bradycardia were observed, respectively, in 5.6% and 1.2% of the patients. Transient neurological symptoms were observed in three patients (1.2%) submitted to video arthroscopy. CONCLUSIONS: Isobaric lidocaine, in a fixed dose of 60 mg produced effective spinal anesthesia, with good cardio circulatory stability, low TNS incidence but a wide variation in the upper level of sensory block. Plain 2% isobaric lidocaine seems to be an option for spinal anesthesia for surgeries lasting up to one hour especially for ambulatory patients.
ANESTHETICS, Local; ANESTHETIC TECHNIQUES, Regional
