Complications of central neural blockade

Abstract

The safety of central nerve block (CNB) has been demonstrated in large case-series of patients. However, major neurological and cardiovascular complications of spinal and epidural anaesthesia have been reported. Hypotension and bradycardia are common complications of CNB and may be profound. Cases of cardiac arrest have also been reported, but the aetiology remains obscure. Although sudden, profound bradycardia or asystole may respond readily to treatment, other cases of cardiac arrest have had a very poor outcome. Minor neurological complications of CNB, including post-dural puncture headache and backache, are common. The association of transient neurological symptoms (TNS) with hyperbaric 5% lignocaine has generated recent concern, but a direct neurotoxic effect of local anaesthetic solutions has not been demonstrated. Cauda equina syndrome has also been associated with the use of hyperbaric 5% lignocaine for spinal anaesthesia. Localized pooling of concentrated local anaesthetic solutions, associated with spinal micro-catheters of small-gauge spinal needles has been suggested as a causative factor. Spinal cord compression owing to haematoma or abscess formation is rare. However, an increased incidence of haematoma has been associated with the introduction of low-molecular-weight heparins for thromboprophylaxis in the USA and guidelines for the use of anticoagulants in patients receiving CNB have recently been published.