Neuraxial techniques in patients with pre-existing back impairment or prior spine interventions: a topical review with special reference to obstetrics.

Many anaesthetists consider neurological disorders of all kinds as a contraindication for regional anaesthesia particularly for neuraxial techniques. This hesitation is partly rooted in fears of medicolegal problems but also in the heterogeneous literature. Therefore, the present topical review is an attempt to describe the feasibility and the risks of neuraxial techniques in patients with spinal injury, anatomical compromise, chronic back pain or previous spinal interventions, ranging from 'minor' types like epidural blood patches to major surgery such as Harrington fusions. Most reviews and case reports were describing experiences in obstetrics as these patients are more likely to insist on neuraxial blocks. In the acute phase of new neurologic injury, general anaesthesia may be the technique of choice to prevent further haemodynamic and respiratory deterioration. After the acute phase, current evidence is mostly reassuring with respect to the risks of neuraxial blocks as they may even be recommendable in some conditions. Ultrasound technology may be of additional help to increase the success rate. A careful pre-operative examination remains mandatory, while patients should be sufficiently informed about technical aspects and possible relapses or progression of their disease. When necessary, patients should have additional technical and clinical examinations as close as possible to surgery to establish the actual pre-operative status. Most patients may benefit more from spinal techniques rather than from less reliable epidural ones. High concentrations and volumes of local anaesthetics should be avoided at all times, especially in patients with nerve compression, large disc herniation or spinal stenosis.