Clotting parameters and thromboelastography in children with neuromuscular and idiopathic scoliosis undergoing posterior spinal fusion

Study Design. An unblinded comparison of laboratory values between patients with idiopathic and neuromuscular scoliosis. Objectives. To compare standard tests of coagulation and thromboelastography (TEG) parameters between two groups of patients undergoing posterior spinal fusion (PSF). Summary of Background Data. Children with neuromuscular scoliosis such as cerebral palsy have more intraoperative blood loss than children with idiopathic scoliosis during PSF. Various reasons suggested for this include nutritional deficiencies, altered tissue integrity, hepatic dysfunction, and use of antiepileptic medications that can cause poor hemostasis and altered coagulation. We have observed alterations in coagulation factor levels in patients with cerebral palsy due to spastic quadriplegia with moderate blood volume loss (25% estimated blood volume). Methods. In a prospective analysis, we compared standard tests of coagulation ( prothrombin time [ PT], partial thromboplastin time [PTT], platelet count, fibrinogen levels) and TEG at baseline and at a blood loss of 15% estimated blood volume in patients with idiopathic scoliosis and cerebral palsy undergoing PSF. Results. There were no differences between the groups in terms of gender distribution and age. There was a significant difference between the baseline PT and PTT values, although both groups were within laboratory norms. After 15% blood volume loss, there were differences seen in the PT, PTT, maximum amplitude on the TEG, ionized calcium, and serum magnesium levels ( P < 0.05). Conclusions. Children with cerebral palsy undergoing PSF have increased bleeding that starts earlier in the procedure than it does for patients with idiopathic scoliosis undergoing PSF. We found that, even though children with spastic quadriplegia had baseline PT and PTT values within normal limits, they were significantly different when compared with normal patients.