Does spinal anesthesia cause hearing loss in the obstetric population?

Lumbar puncture is believed to cause hypoacousis by causing cerebrospinal fluid leakage in older individuals. We hypothesized that parturients undergoing subarachnoid block (SAB) may experience hearing loss. We evaluated the effects of SAB on hearing in parturients undergoing elective cesarean delivery. We also compared two types of spinal needles: a pencil-point needle (24-gauge Sprotte needle) and a cutting needle (25-gauge Quincke needle). Sixty patients were studied: 20 received lumbar epidural block for labor analgesia (controls), 20 received a SAB with a Sprotte needle, and 20 others received a SAB with a Quincke needle for cesarean delivery. A tone audiometer was used to test for that decibel level at which the patient heard 125-, 250-, 500-, 1000-, 2000-, 4000-, and 8000-Hz frequencies. The hearing test was performed before anesthesia, after delivery, and on the first and second postoperative days. The results were analyzed by using repeated-measures analysis of variance at P < 0.05. No patient from any of the three groups developed a hearing loss either at low or high frequencies. Spinal anesthesia does not lead to significant hearing loss when a pencil- or a cutting-point needle is used in the obstetric population.