SPINAL INSTRUMENTATION FOR DUCHENNES MUSCULAR-DYSTROPHY - EXPERIENCE OF HYPOTENSIVE ANESTHESIA TO MINIMIZE BLOOD-LOSS

Nineteen patients with Duchenne's muscular dystrophy underwent segment al spinal instrumentation and posterior fusion between 1989 and 1994. The indication for surgery was loss of the ability to walk and develop ment of scoliosis with sitting discomfort, Preoperative assessment inc luded evaluation of pulmonary function. Average age at operation was 1 2.5 years. Instrumentation and fusion extended from upper thoracic lev els to L-5 or the sacrum. A Hartshill rectangle was used in all cases, with banked allograft bone. Severe intraoperative blood loss was avoi ded by use of hypotensive anaesthesia. Peroperatively, systolic blood pressure was maintained between 75 and 85 mm Hg. Average blood loss wa s 1,236 ml (range, 400-3,100) or 30% of estimated total blood volume. Average transfusion requirements were 3 units of packed cells. Postope rative analgesia was provided by infusion via an epidural catheter, Th ere were no postoperative wound or chest infections. Three patients re quired catheterisation for urinary retention. Postoperatively patients were fitted with a Neofract jacket to allow early mobilisation and di scharge. Mean postoperative length of stay was 16 days. Posterior spin al fusion by using the Hartshill rectangle provided good correction an d fixation. Hypotensive anaesthesia permitted surgery to be performed rapidly in a relatively dry field and avoided the complications of sev ere intraoperative blood loss and massive transfusion.