Spinal instrumentation for Duchenne's muscular dystrophy: experience of hypotensive anaesthesia to minimise blood loss.

Nineteen patients with Duchenne's muscular dystrophy underwent segmental spinal instrumentation and posterior fusion between 1989 and 1994. The indication for surgery was loss of the ability to walk and development of scoliosis with sitting discomfort. Preoperative assessment included evaluation of pulmonary function. Average age at operation was 12.5 years. Instrumentation and fusion extended from upper thoracic levels to L-5 or the sacrum. A Hartshill rectangle was used in all cases, with banked allograft bone. Severe intraoperative blood loss was avoided by use of hypotensive anaesthesia. Peroperatively, systolic blood pressure was maintained between 75 and 85 mm Hg. Average blood loss was 1,246 ml (range, 400-3,100) or 30% of estimated total blood volume. Average transfusion requirements were 3 units of packed cells. Postoperative analgesia was provided by infusion via an epidural catheter. There were no postoperative wound or chest infections. Three patients required catheterisation for urinary retention. Postoperatively patients were fitted with a Neofract jacket to allow early mobilisation and discharge. Mean postoperative length of stay was 16 days. Posterior spinal fusion by using the Hartshill rectangle provided good correction and fixation. Hypotensive anaesthesia permitted surgery to be performed rapidly in a relatively dry field and avoided the complications of severe intraoperative blood loss and massive transfusion.