Hearing loss after continuous or single-shot spinal anesthesia.

Background and objectives: Hearing loss after spinal anesthesia is probably caused by cerebrospinal fluid (CSF) leakage. Spinal catheters may mechanically plug the hole in the dura and cause inflammatory swelling which should prevent cerebrospinal fluid leakage and hearing loss. An audiometric evaluation was therefore performed in patients who had spinal anesthesia by single-shot or catheter.

Methods: Twenty-one patients received single-shot spinal anesthesia and 19 patients continuous spinal anesthesia for orthopedic surgery of the lower limbs. Spinal catheters were removed 24 hours after the start of anesthesia. Audiometry was performed on the day before the operation and on the first, second, and third postoperative day and repeated on the fifth postoperative day, if necessary.

Results: The frequency of hearing impairment (threshold change > 10 dB) was 43% in the single-shot and 37% in the continuous spinal group. The deterioration lasted longer in the continuous spinal group (3 days vs. 1.4 days; P < .01).

Conclusion: Although inflammatory swelling of the dura mater around the spinal catheter had been observed, use of such a catheter for 24 hours did not prevent hearing loss after its removal.