Is a ebl of 1780 normal for lamectomy?

Yes: A laminectomy is a surgical incision into the backbone to get access to the structures associated with the spinal cord. The commonest reasons for a laminectomy are a prolapsed or herniated intervertebral disc, or a narrowing of the spinal canal. Ebl or estimated blood loss for lumbar fusion surgery averages between 1, 000 - 1, 500 ml.

Seems excessive: This seems like an excess amount of bleeding for a simple laminectomy, even at multiple levels. Even if you had a concurrent fusion, this seems to be a lot. Blood loss for a simple laminectomy without a fusion in my patients ranges about 10-50 cc in general. It is possible that you actually had much more done than just a laminectomy. 2 liters might be ok with complex scoliosis surgery.