[Risk management in spinal anesthesia]

More than one hundred years have passed since Bier first succeeded in spinal anesthesia. Spinal anesthesia now spreads all over the world because it has many advantages. Spinal anesthesia requires both a simple technique and a small volume of drug, produces profound analgesia, and is devoid of systemic pharmacologic side effects. However, several complications after spinal anesthesia have been reported. Although some of them rarely occur, they cause serious consequences once they happen. Those include cardiac arrest, meningitis, intracranial subdural hematoma, spinal epidural hematoma and cauda equina syndrome. Patients should be informed in detail of the incidence, severity, and outcome of these complications, especially when alternative analgesic methods can be chosen. The prediction, early detection and prompt start of the treatment of the complications after spinal anesthesia are important to minimize the risk of adverse outcome.